feat: refactor modules to use format strings (#1374)

Cargo.lock

@@ -867,6 +867,15 @@ version = "1.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a1d01941d82fa2ab50be1e79e6714289dd7cde78eba4c074bc5a4374f650dfe0"
 
+[[package]]
+name = "quick-xml"
+version = "0.18.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3cc440ee4802a86e357165021e3e255a9143724da31db1e2ea540214c96a0f82"
+dependencies = [
+ "memchr",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.7"
@@ -1151,6 +1160,7 @@ dependencies = [
  "pest",
  "pest_derive",
  "pretty_env_logger",
+ "quick-xml",
  "rayon",
  "regex",
  "remove_dir_all",

Cargo.toml

@@ -59,6 +59,7 @@ open = "1.4.0"
 unicode-width = "0.1.8"
 textwrap = "0.12.1"
 term_size = "0.3.2"
+quick-xml = "0.18.1"
 
 # Optional/http:
 attohttpc = { version = "0.15.0", optional = true, default-features = false, features = ["tls", "form"] }

src/config.rs

@@ -235,37 +235,84 @@ impl StarshipConfig {
 
     /// Get the subset of the table for a module by its name
     pub fn get_module_config(&self, module_name: &str) -> Option<&Value> {
-        let module_config = self.config.as_ref()?.as_table()?.get(module_name);
+        let module_config = self.get_config(&[module_name]);
         if module_config.is_some() {
             log::debug!(
                 "Config found for \"{}\": \n{:?}",
                 &module_name,
                 &module_config
             );
-        } else {
-            log::trace!("No config found for \"{}\"", &module_name);
         }
         module_config
     }
 
+    /// Get the value of the config in a specific path
+    pub fn get_config(&self, path: &[&str]) -> Option<&Value> {
+        let mut prev_table = self.config.as_ref()?.as_table()?;
+
+        assert_ne!(
+            path.len(),
+            0,
+            "Starship::get_config called with an empty path"
+        );
+
+        let (table_options, _) = path.split_at(path.len() - 1);
+
+        // Assumes all keys except the last in path has a table
+        for option in table_options {
+            match prev_table.get(*option) {
+                Some(value) => match value.as_table() {
+                    Some(value) => {
+                        prev_table = value;
+                    }
+                    None => {
+                        log::trace!(
+                            "No config found for \"{}\": \"{}\" is not a table",
+                            path.join("."),
+                            &option
+                        );
+                        return None;
+                    }
+                },
+                None => {
+                    log::trace!(
+                        "No config found for \"{}\": Option \"{}\" not found",
+                        path.join("."),
+                        &option
+                    );
+                    return None;
+                }
+            }
+        }
+
+        let last_option = path.last().unwrap();
+        let value = prev_table.get(*last_option);
+        if value.is_none() {
+            log::trace!(
+                "No config found for \"{}\": Option \"{}\" not found",
+                path.join("."),
+                &last_option
+            );
+        };
+        value
+    }
+
     /// Get the subset of the table for a custom module by its name
     pub fn get_custom_module_config(&self, module_name: &str) -> Option<&Value> {
-        let module_config = self.get_custom_modules()?.get(module_name);
+        let module_config = self.get_config(&["custom", module_name]);
         if module_config.is_some() {
             log::debug!(
                 "Custom config found for \"{}\": \n{:?}",
                 &module_name,
                 &module_config
             );
-        } else {
-            log::trace!("No custom config found for \"{}\"", &module_name);
         }
         module_config
     }
 
     /// Get the table of all the registered custom modules, if any
     pub fn get_custom_modules(&self) -> Option<&toml::value::Table> {
-        self.config.as_ref()?.as_table()?.get("custom")?.as_table()
+        self.get_config(&["custom"])?.as_table()
     }
 
     pub fn get_root_config(&self) -> StarshipRootConfig {
@@ -277,75 +324,6 @@ impl StarshipConfig {
     }
 }
 
-#[derive(Clone)]
-pub struct SegmentConfig<'a> {
-    pub value: &'a str,
-    pub style: Option<Style>,
-}
-
-impl<'a> ModuleConfig<'a> for SegmentConfig<'a> {
-    fn from_config(config: &'a Value) -> Option<Self> {
-        match config {
-            Value::String(ref config_str) => Some(Self {
-                value: config_str,
-                style: None,
-            }),
-            Value::Table(ref config_table) => Some(Self {
-                value: config_table.get("value")?.as_str()?,
-                style: config_table.get("style").and_then(<Style>::from_config),
-            }),
-            _ => None,
-        }
-    }
-
-    fn load_config(&self, config: &'a Value) -> Self {
-        let mut new_config = self.clone();
-        match config {
-            Value::String(ref config_str) => {
-                new_config.value = config_str;
-            }
-            Value::Table(ref config_table) => {
-                if let Some(Value::String(value)) = config_table.get("value") {
-                    new_config.value = value;
-                };
-                if let Some(style) = config_table.get("style") {
-                    new_config.style = <Style>::from_config(style);
-                };
-            }
-            _ => {}
-        };
-        new_config
-    }
-}
-
-impl<'a> SegmentConfig<'a> {
-    pub fn new(value: &'a str) -> Self {
-        Self { value, style: None }
-    }
-
-    /// Immutably set value
-    pub fn with_value(&self, value: &'a str) -> Self {
-        Self {
-            value,
-            style: self.style,
-        }
-    }
-
-    /// Immutably set style
-    pub fn with_style(&self, style: Option<Style>) -> Self {
-        Self {
-            value: self.value,
-            style,
-        }
-    }
-}
-
-impl Default for SegmentConfig<'static> {
-    fn default() -> Self {
-        Self::new("")
-    }
-}
-
 /** Parse a style string which represents an ansi style. Valid tokens in the style
  string include the following:
  - 'fg:<color>'    (specifies that the color read should be a foreground color)

src/configs/aws.rs

@@ -1,48 +1,24 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
-use std::collections::HashMap;
-
-use ansi_term::{Color, Style};
+use crate::config::{ModuleConfig, RootModuleConfig};
 use starship_module_config_derive::ModuleConfig;
-
-#[derive(Clone, PartialEq)]
-pub enum AwsItems {
-    All,
-    Region,
-    Profile,
-}
+use std::collections::HashMap;
 
 #[derive(Clone, ModuleConfig)]
 pub struct AwsConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub profile: SegmentConfig<'a>,
-    pub region: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
-    pub displayed_items: AwsItems,
     pub region_aliases: HashMap<String, &'a str>,
 }
 
 impl<'a> RootModuleConfig<'a> for AwsConfig<'a> {
     fn new() -> Self {
         AwsConfig {
-            symbol: SegmentConfig::new("☁️  "),
-            profile: SegmentConfig::default(),
-            region: SegmentConfig::default(),
-            style: Color::Yellow.bold(),
+            format: "on [$symbol$profile(\\($region\\))]($style) ",
+            symbol: "☁️  ",
+            style: "bold yellow",
             disabled: false,
-            displayed_items: AwsItems::All,
             region_aliases: HashMap::new(),
         }
     }
 }
-
-impl<'a> ModuleConfig<'a> for AwsItems {
-    fn from_config(config: &toml::Value) -> Option<Self> {
-        match config.as_str()? {
-            "all" => Some(AwsItems::All),
-            "region" => Some(AwsItems::Region),
-            "profile" => Some(AwsItems::Profile),
-            _ => None,
-        }
-    }
-}

src/configs/battery.rs

@@ -1,40 +1,39 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct BatteryConfig<'a> {
-    pub full_symbol: SegmentConfig<'a>,
-    pub charging_symbol: SegmentConfig<'a>,
-    pub discharging_symbol: SegmentConfig<'a>,
-    pub unknown_symbol: Option<SegmentConfig<'a>>,
-    pub empty_symbol: Option<SegmentConfig<'a>>,
-    pub display: Vec<BatteryDisplayConfig>,
+    pub full_symbol: &'a str,
+    pub charging_symbol: &'a str,
+    pub discharging_symbol: &'a str,
+    pub unknown_symbol: Option<&'a str>,
+    pub empty_symbol: Option<&'a str>,
+    pub display: Vec<BatteryDisplayConfig<'a>>,
     pub disabled: bool,
-    pub percentage: SegmentConfig<'a>,
+    pub format: &'a str,
 }
 
 impl<'a> RootModuleConfig<'a> for BatteryConfig<'a> {
     fn new() -> Self {
         BatteryConfig {
-            full_symbol: SegmentConfig::new("•"),
-            charging_symbol: SegmentConfig::new("↑"),
-            discharging_symbol: SegmentConfig::new("↓"),
+            full_symbol: "•",
+            charging_symbol: "↑",
+            discharging_symbol: "↓",
             unknown_symbol: None,
             empty_symbol: None,
+            format: "[$symbol$percentage]($style) ",
             display: vec![BatteryDisplayConfig {
                 threshold: 10,
-                style: Color::Red.bold(),
+                style: "red bold",
             }],
             disabled: false,
-            percentage: SegmentConfig::default(),
         }
     }
 }
 
 #[derive(Clone, ModuleConfig)]
-pub struct BatteryDisplayConfig {
+pub struct BatteryDisplayConfig<'a> {
     pub threshold: i64,
-    pub style: Style,
+    pub style: &'a str,
 }

src/configs/character.rs

@@ -1,28 +1,23 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct CharacterConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub error_symbol: SegmentConfig<'a>,
-    pub vicmd_symbol: SegmentConfig<'a>,
-    pub use_symbol_for_status: bool,
-    pub style_success: Style,
-    pub style_failure: Style,
+    pub format: &'a str,
+    pub success_symbol: &'a str,
+    pub error_symbol: &'a str,
+    pub vicmd_symbol: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for CharacterConfig<'a> {
     fn new() -> Self {
         CharacterConfig {
-            symbol: SegmentConfig::new("❯"),
-            error_symbol: SegmentConfig::new("✖"),
-            vicmd_symbol: SegmentConfig::new("❮"),
-            use_symbol_for_status: false,
-            style_success: Color::Green.bold(),
-            style_failure: Color::Red.bold(),
+            format: "$symbol ",
+            success_symbol: "[❯](bold green)",
+            error_symbol: "[❯](bold red)",
+            vicmd_symbol: "[❮](bold green)",
             disabled: false,
         }
     }

src/configs/cmd_duration.rs

@@ -1,13 +1,12 @@
 use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct CmdDurationConfig<'a> {
     pub min_time: i64,
-    pub prefix: &'a str,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
     pub show_milliseconds: bool,
     pub disabled: bool,
 }
@@ -16,9 +15,9 @@ impl<'a> RootModuleConfig<'a> for CmdDurationConfig<'a> {
     fn new() -> Self {
         CmdDurationConfig {
             min_time: 2_000,
-            prefix: "took ",
+            format: "took [$duration]($style) ",
             show_milliseconds: false,
-            style: Color::Yellow.bold(),
+            style: "yellow bold",
             disabled: false,
         }
     }

src/configs/conda.rs

@@ -1,14 +1,13 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct CondaConfig<'a> {
     pub truncation_length: usize,
-    pub symbol: SegmentConfig<'a>,
-    pub environment: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
@@ -16,15 +15,9 @@ impl<'a> RootModuleConfig<'a> for CondaConfig<'a> {
     fn new() -> Self {
         CondaConfig {
             truncation_length: 1,
-            symbol: SegmentConfig {
-                value: "C ",
-                style: None,
-            },
-            environment: SegmentConfig {
-                value: "",
-                style: None,
-            },
-            style: Color::Green.bold(),
+            format: "via [$symbol$environment]($style) ",
+            symbol: "🅒 ",
+            style: "green bold",
             disabled: false,
         }
     }

src/configs/crystal.rs

@@ -1,20 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct CrystalConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for CrystalConfig<'a> {
     fn new() -> Self {
         CrystalConfig {
-            symbol: SegmentConfig::new("🔮 "),
-            style: Color::Red.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "🔮 ",
+            style: "bold red",
             disabled: false,
         }
     }

src/configs/custom.rs

@@ -1,6 +1,5 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig, VecOr};
+use crate::config::{ModuleConfig, RootModuleConfig, VecOr};
 
-use ansi_term::Style;
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, Default, PartialEq)]
@@ -14,15 +13,14 @@ pub struct Directories<'a>(pub Vec<&'a str>);
 
 #[derive(Clone, ModuleConfig)]
 pub struct CustomConfig<'a> {
-    pub symbol: Option<SegmentConfig<'a>>,
+    pub format: &'a str,
+    pub symbol: &'a str,
     pub command: &'a str,
     pub when: Option<&'a str>,
     pub shell: VecOr<&'a str>,
     pub description: &'a str,
-    pub style: Option<Style>,
+    pub style: &'a str,
     pub disabled: bool,
-    pub prefix: Option<&'a str>,
-    pub suffix: Option<&'a str>,
     pub files: Files<'a>,
     pub extensions: Extensions<'a>,
     pub directories: Directories<'a>,
@@ -31,15 +29,14 @@ pub struct CustomConfig<'a> {
 impl<'a> RootModuleConfig<'a> for CustomConfig<'a> {
     fn new() -> Self {
         CustomConfig {
-            symbol: None,
+            format: "[$symbol$output]($style) ",
+            symbol: "",
             command: "",
             when: None,
             shell: VecOr::default(),
             description: "<custom config>",
-            style: None,
+            style: "green bold",
             disabled: false,
-            prefix: None,
-            suffix: None,
             files: Files::default(),
             extensions: Extensions::default(),
             directories: Directories::default(),

src/configs/directory.rs

@@ -1,7 +1,6 @@
 use crate::config::{ModuleConfig, RootModuleConfig};
 use std::collections::HashMap;
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
@@ -11,8 +10,8 @@ pub struct DirectoryConfig<'a> {
     pub substitutions: HashMap<String, &'a str>,
     pub fish_style_pwd_dir_length: i64,
     pub use_logical_path: bool,
-    pub prefix: &'a str,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
@@ -24,8 +23,8 @@ impl<'a> RootModuleConfig<'a> for DirectoryConfig<'a> {
             fish_style_pwd_dir_length: 0,
             substitutions: HashMap::new(),
             use_logical_path: true,
-            prefix: "in ",
-            style: Color::Cyan.bold(),
+            format: "[$path]($style) ",
+            style: "cyan bold",
             disabled: false,
         }
     }

src/configs/docker_context.rs

@@ -1,13 +1,12 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct DockerContextConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub context: SegmentConfig<'a>,
-    pub style: Style,
+    pub symbol: &'a str,
+    pub style: &'a str,
+    pub format: &'a str,
     pub only_with_files: bool,
     pub disabled: bool,
 }
@@ -15,9 +14,9 @@ pub struct DockerContextConfig<'a> {
 impl<'a> RootModuleConfig<'a> for DockerContextConfig<'a> {
     fn new() -> Self {
         DockerContextConfig {
-            symbol: SegmentConfig::new("🐳 "),
-            context: SegmentConfig::default(),
-            style: Color::Blue.bold(),
+            symbol: "🐳 ",
+            style: "blue bold",
+            format: "via [$symbol$context]($style) ",
             only_with_files: true,
             disabled: false,
         }

src/configs/dotnet.rs

@@ -1,25 +1,24 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
-
-use ansi_term::{Color, Style};
-use starship_module_config_derive::ModuleConfig;
-
-#[derive(Clone, ModuleConfig)]
-pub struct DotnetConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
-    pub heuristic: bool,
-    pub disabled: bool,
-}
-
-impl<'a> RootModuleConfig<'a> for DotnetConfig<'a> {
-    fn new() -> Self {
-        DotnetConfig {
-            symbol: SegmentConfig::new("•NET "),
-            version: SegmentConfig::default(),
-            style: Color::Blue.bold(),
-            heuristic: true,
-            disabled: false,
-        }
-    }
-}
+use crate::config::{ModuleConfig, RootModuleConfig};
+
+use starship_module_config_derive::ModuleConfig;
+
+#[derive(Clone, ModuleConfig)]
+pub struct DotnetConfig<'a> {
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
+    pub heuristic: bool,
+    pub disabled: bool,
+}
+
+impl<'a> RootModuleConfig<'a> for DotnetConfig<'a> {
+    fn new() -> Self {
+        DotnetConfig {
+            format: "[$symbol$version( 🎯 $tfm)]($style) ",
+            symbol: "•NET ",
+            style: "blue bold",
+            heuristic: true,
+            disabled: false,
+        }
+    }
+}

src/configs/elixir.rs

@@ -1,24 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct ElixirConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub otp_version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for ElixirConfig<'a> {
     fn new() -> Self {
         ElixirConfig {
-            symbol: SegmentConfig::new("💧 "),
-            version: SegmentConfig::default(),
-            otp_version: SegmentConfig::default(),
-            style: Color::Purple.bold(),
+            format: "via [$symbol$version \\(OTP $otp_version\\)]($style) ",
+            symbol: "💧 ",
+            style: "bold purple",
             disabled: false,
         }
     }

src/configs/elm.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct ElmConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for ElmConfig<'a> {
     fn new() -> Self {
         ElmConfig {
-            symbol: SegmentConfig::new("🌳 "),
-            version: SegmentConfig::default(),
-            style: Color::Cyan.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "🌳 ",
+            style: "cyan bold",
             disabled: false,
         }
     }

src/configs/env_var.rs

@@ -1,28 +1,25 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct EnvVarConfig<'a> {
-    pub symbol: Option<SegmentConfig<'a>>,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub variable: Option<&'a str>,
     pub default: Option<&'a str>,
-    pub prefix: &'a str,
-    pub suffix: &'a str,
-    pub style: Style,
+    pub format: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for EnvVarConfig<'a> {
     fn new() -> Self {
         EnvVarConfig {
-            symbol: None,
+            symbol: "",
+            style: "black bold dimmed",
             variable: None,
             default: None,
-            prefix: "",
-            suffix: "",
-            style: Color::Black.bold().dimmed(),
+            format: "with [$env_value]($style) ",
             disabled: false,
         }
     }

src/configs/erlang.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct ErlangConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for ErlangConfig<'a> {
     fn new() -> Self {
         ErlangConfig {
-            symbol: SegmentConfig::new("🖧 "),
-            version: SegmentConfig::default(),
-            style: Color::Red.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "🖧 ",
+            style: "bold red",
             disabled: false,
         }
     }

src/configs/git_branch.rs

@@ -1,26 +1,25 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct GitBranchConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub truncation_length: i64,
     pub truncation_symbol: &'a str,
-    pub branch_name: SegmentConfig<'a>,
-    pub style: Style,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for GitBranchConfig<'a> {
     fn new() -> Self {
         GitBranchConfig {
-            symbol: SegmentConfig::new(" "),
+            format: "on [$symbol$branch]($style) ",
+            symbol: " ",
+            style: "bold purple",
             truncation_length: std::i64::MAX,
             truncation_symbol: "…",
-            branch_name: SegmentConfig::default(),
-            style: Color::Purple.bold(),
             disabled: false,
         }
     }

src/configs/git_commit.rs

@@ -1,15 +1,12 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct GitCommitConfig<'a> {
     pub commit_hash_length: usize,
-    pub hash: SegmentConfig<'a>,
-    pub prefix: &'a str,
-    pub suffix: &'a str,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
     pub only_detached: bool,
     pub disabled: bool,
 }
@@ -19,10 +16,8 @@ impl<'a> RootModuleConfig<'a> for GitCommitConfig<'a> {
         GitCommitConfig {
             // be consistent with git by default, which has DEFAULT_ABBREV set to 7
             commit_hash_length: 7,
-            hash: SegmentConfig::default(),
-            prefix: "(",
-            suffix: ") ",
-            style: Color::Green.bold(),
+            format: "[\\($hash\\)]($style) ",
+            style: "green bold",
             only_detached: true,
             disabled: false,
         }

src/configs/git_state.rs

@@ -1,34 +1,33 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct GitStateConfig<'a> {
-    pub rebase: SegmentConfig<'a>,
-    pub merge: SegmentConfig<'a>,
-    pub revert: SegmentConfig<'a>,
-    pub cherry_pick: SegmentConfig<'a>,
-    pub bisect: SegmentConfig<'a>,
-    pub am: SegmentConfig<'a>,
-    pub am_or_rebase: SegmentConfig<'a>,
-    pub progress_divider: SegmentConfig<'a>,
-    pub style: Style,
+    pub rebase: &'a str,
+    pub merge: &'a str,
+    pub revert: &'a str,
+    pub cherry_pick: &'a str,
+    pub bisect: &'a str,
+    pub am: &'a str,
+    pub am_or_rebase: &'a str,
+    pub style: &'a str,
+    pub format: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for GitStateConfig<'a> {
     fn new() -> Self {
         GitStateConfig {
-            rebase: SegmentConfig::new("REBASING"),
-            merge: SegmentConfig::new("MERGING"),
-            revert: SegmentConfig::new("REVERTING"),
-            cherry_pick: SegmentConfig::new("CHERRY-PICKING"),
-            bisect: SegmentConfig::new("BISECTING"),
-            am: SegmentConfig::new("AM"),
-            am_or_rebase: SegmentConfig::new("AM/REBASE"),
-            progress_divider: SegmentConfig::new("/"),
-            style: Color::Yellow.bold(),
+            rebase: "REBASING",
+            merge: "MERGING",
+            revert: "REVERTING",
+            cherry_pick: "CHERRY-PICKING",
+            bisect: "BISECTING",
+            am: "AM",
+            am_or_rebase: "AM/REBASE",
+            style: "bold yellow",
+            format: "[\\($state( $progress_current/$progress_total)\\)]($style) ",
             disabled: false,
         }
     }

src/configs/git_status.rs

@@ -1,65 +1,40 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct GitStatusConfig<'a> {
-    pub stashed: SegmentConfig<'a>,
-    pub stashed_count: CountConfig,
-    pub ahead: SegmentConfig<'a>,
-    pub behind: SegmentConfig<'a>,
-    pub diverged: SegmentConfig<'a>,
-    pub show_sync_count: bool,
-    pub conflicted: SegmentConfig<'a>,
-    pub conflicted_count: CountConfig,
-    pub deleted: SegmentConfig<'a>,
-    pub deleted_count: CountConfig,
-    pub renamed: SegmentConfig<'a>,
-    pub renamed_count: CountConfig,
-    pub modified: SegmentConfig<'a>,
-    pub modified_count: CountConfig,
-    pub staged: SegmentConfig<'a>,
-    pub staged_count: CountConfig,
-    pub untracked: SegmentConfig<'a>,
-    pub untracked_count: CountConfig,
-    pub prefix: &'a str,
-    pub suffix: &'a str,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
+    pub stashed: &'a str,
+    pub ahead: &'a str,
+    pub behind: &'a str,
+    pub diverged: &'a str,
+    pub conflicted: &'a str,
+    pub deleted: &'a str,
+    pub renamed: &'a str,
+    pub modified: &'a str,
+    pub staged: &'a str,
+    pub untracked: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for GitStatusConfig<'a> {
     fn new() -> Self {
         GitStatusConfig {
-            stashed: SegmentConfig::new("$"),
-            stashed_count: CountConfig::default(),
-            ahead: SegmentConfig::new("⇡"),
-            behind: SegmentConfig::new("⇣"),
-            diverged: SegmentConfig::new("⇕"),
-            conflicted: SegmentConfig::new("="),
-            show_sync_count: false,
-            conflicted_count: CountConfig::default(),
-            deleted: SegmentConfig::new("✘"),
-            deleted_count: CountConfig::default(),
-            renamed: SegmentConfig::new("»"),
-            renamed_count: CountConfig::default(),
-            modified: SegmentConfig::new("!"),
-            modified_count: CountConfig::default(),
-            staged: SegmentConfig::new("+"),
-            staged_count: CountConfig::default(),
-            untracked: SegmentConfig::new("?"),
-            untracked_count: CountConfig::default(),
-            prefix: "[",
-            suffix: "] ",
-            style: Color::Red.bold(),
+            format: "([\\[$all_status$ahead_behind\\]]($style) )",
+            style: "red bold",
+            stashed: "\\$",
+            ahead: "⇡",
+            behind: "⇣",
+            diverged: "⇕",
+            conflicted: "=",
+            deleted: "✘",
+            renamed: "»",
+            modified: "!",
+            staged: "+",
+            untracked: "?",
             disabled: false,
         }
     }
 }
-
-#[derive(Clone, Copy, ModuleConfig, Default)]
-pub struct CountConfig {
-    pub enabled: bool,
-    pub style: Option<Style>,
-}

src/configs/go.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct GoConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for GoConfig<'a> {
     fn new() -> Self {
         GoConfig {
-            symbol: SegmentConfig::new("🐹 "),
-            version: SegmentConfig::default(),
-            style: Color::Cyan.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "🐹 ",
+            style: "bold cyan",
             disabled: false,
         }
     }

src/configs/hg_branch.rs

@@ -1,26 +1,25 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct HgBranchConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
+    pub symbol: &'a str,
+    pub style: &'a str,
+    pub format: &'a str,
     pub truncation_length: i64,
     pub truncation_symbol: &'a str,
-    pub branch_name: SegmentConfig<'a>,
-    pub style: Style,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for HgBranchConfig<'a> {
     fn new() -> Self {
         HgBranchConfig {
-            symbol: SegmentConfig::new(" "),
+            symbol: " ",
+            style: "bold purple",
+            format: "on [$symbol$branch]($style) ",
             truncation_length: std::i64::MAX,
             truncation_symbol: "…",
-            branch_name: SegmentConfig::default(),
-            style: Color::Purple.bold(),
             disabled: true,
         }
     }

src/configs/hostname.rs

@@ -1,15 +1,13 @@
 use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct HostnameConfig<'a> {
     pub ssh_only: bool,
-    pub prefix: &'a str,
-    pub suffix: &'a str,
     pub trim_at: &'a str,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
@@ -17,10 +15,9 @@ impl<'a> RootModuleConfig<'a> for HostnameConfig<'a> {
     fn new() -> Self {
         HostnameConfig {
             ssh_only: true,
-            prefix: "",
-            suffix: "",
             trim_at: ".",
-            style: Color::Green.bold().dimmed(),
+            format: "on [$hostname]($style) ",
+            style: "green dimmed bold",
             disabled: false,
         }
     }

src/configs/java.rs

@@ -1,21 +1,22 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct JavaConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub style: Style,
     pub disabled: bool,
+    pub format: &'a str,
+    pub style: &'a str,
+    pub symbol: &'a str,
 }
 
 impl<'a> RootModuleConfig<'a> for JavaConfig<'a> {
     fn new() -> Self {
         JavaConfig {
-            symbol: SegmentConfig::new("☕ "),
-            style: Color::Red.dimmed(),
+            format: "via [$symbol$version]($style) ",
             disabled: false,
+            style: "red dimmed",
+            symbol: "☕ ",
         }
     }
 }

src/configs/jobs.rs

@@ -1,22 +1,23 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct JobsConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
     pub threshold: i64,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for JobsConfig<'a> {
     fn new() -> Self {
         JobsConfig {
-            symbol: SegmentConfig::new("✦"),
             threshold: 1,
-            style: Color::Blue.bold(),
+            format: "[$symbol$number]($style) ",
+            symbol: "✦",
+            style: "bold blue",
             disabled: false,
         }
     }

src/configs/julia.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct JuliaConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for JuliaConfig<'a> {
     fn new() -> Self {
         JuliaConfig {
-            symbol: SegmentConfig::new("ஃ "),
-            version: SegmentConfig::default(),
-            style: Color::Purple.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "ஃ ",
+            style: "bold purple",
             disabled: false,
         }
     }

src/configs/kubernetes.rs

@@ -1,15 +1,13 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 use std::collections::HashMap;
 
 #[derive(Clone, ModuleConfig)]
 pub struct KubernetesConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub context: SegmentConfig<'a>,
-    pub namespace: SegmentConfig<'a>,
-    pub style: Style,
+    pub symbol: &'a str,
+    pub format: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
     pub context_aliases: HashMap<String, &'a str>,
 }
@@ -17,10 +15,9 @@ pub struct KubernetesConfig<'a> {
 impl<'a> RootModuleConfig<'a> for KubernetesConfig<'a> {
     fn new() -> Self {
         KubernetesConfig {
-            symbol: SegmentConfig::new("☸ "),
-            context: SegmentConfig::default(),
-            namespace: SegmentConfig::default(),
-            style: Color::Cyan.bold(),
+            symbol: "☸ ",
+            format: "on [$symbol$context( \\($namespace\\))]($style) ",
+            style: "cyan bold",
             disabled: true,
             context_aliases: HashMap::new(),
         }

src/configs/memory_usage.rs

@@ -1,32 +1,23 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct MemoryConfig<'a> {
-    pub show_percentage: bool,
-    pub show_swap: bool,
     pub threshold: i64,
-    pub symbol: SegmentConfig<'a>,
-    pub separator: SegmentConfig<'a>,
-    pub ram: SegmentConfig<'a>,
-    pub swap: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
+    pub symbol: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for MemoryConfig<'a> {
     fn new() -> Self {
         MemoryConfig {
-            show_percentage: false,
-            show_swap: true,
             threshold: 75,
-            symbol: SegmentConfig::new("🐏 "),
-            separator: SegmentConfig::new(" | "),
-            ram: SegmentConfig::default(),
-            swap: SegmentConfig::default(),
-            style: Color::White.bold().dimmed(),
+            format: "via $symbol[$ram( | $swap)]($style) ",
+            style: "white bold dimmed",
+            symbol: "🐏 ",
             disabled: true,
         }
     }

src/configs/nim.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct NimConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for NimConfig<'a> {
     fn new() -> Self {
         NimConfig {
-            symbol: SegmentConfig::new("👑 "),
-            version: SegmentConfig::default(),
-            style: Color::Yellow.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "👑 ",
+            style: "yellow bold",
             disabled: false,
         }
     }

src/configs/nix_shell.rs

@@ -1,26 +1,25 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct NixShellConfig<'a> {
-    pub use_name: bool,
-    pub impure_msg: SegmentConfig<'a>,
-    pub pure_msg: SegmentConfig<'a>,
-    pub style: Style,
-    pub symbol: SegmentConfig<'a>,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
+    pub impure_msg: &'a str,
+    pub pure_msg: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for NixShellConfig<'a> {
     fn new() -> Self {
         NixShellConfig {
-            use_name: false,
-            impure_msg: SegmentConfig::new("impure"),
-            pure_msg: SegmentConfig::new("pure"),
-            style: Color::Blue.bold(),
-            symbol: SegmentConfig::new("❄️  "),
+            format: "via [$symbol$state( \\($name\\))]($style) ",
+            symbol: "❄️  ",
+            style: "bold blue",
+            impure_msg: "impure",
+            pure_msg: "pure",
             disabled: false,
         }
     }

src/configs/nodejs.rs

@@ -1,20 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct NodejsConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for NodejsConfig<'a> {
     fn new() -> Self {
         NodejsConfig {
-            symbol: SegmentConfig::new("⬢ "),
-            style: Color::Green.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "⬢ ",
+            style: "bold green",
             disabled: false,
         }
     }

src/configs/ocaml.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct OCamlConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for OCamlConfig<'a> {
     fn new() -> Self {
         OCamlConfig {
-            symbol: SegmentConfig::new("🐫 "),
-            version: SegmentConfig::default(),
-            style: Color::Yellow.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "🐫 ",
+            style: "bold yellow",
             disabled: false,
         }
     }

src/configs/package.rs

@@ -1,12 +1,12 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct PackageConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub display_private: bool,
     pub disabled: bool,
 }
@@ -14,8 +14,9 @@ pub struct PackageConfig<'a> {
 impl<'a> RootModuleConfig<'a> for PackageConfig<'a> {
     fn new() -> Self {
         PackageConfig {
-            symbol: SegmentConfig::new("📦 "),
-            style: Color::Fixed(208).bold(),
+            format: "is [$symbol$version]($style) ",
+            symbol: "📦 ",
+            style: "208 bold",
             display_private: false,
             disabled: false,
         }

src/configs/php.rs

@@ -1,20 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct PhpConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub style: Style,
+    pub symbol: &'a str,
+    pub style: &'a str,
+    pub format: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for PhpConfig<'a> {
     fn new() -> Self {
         PhpConfig {
-            symbol: SegmentConfig::new("🐘 "),
-            style: Color::Fixed(147).bold(),
+            symbol: "🐘 ",
+            style: "147 bold",
+            format: "via [$symbol$version]($style) ",
             disabled: false,
         }
     }

src/configs/purescript.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct PureScriptConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for PureScriptConfig<'a> {
     fn new() -> Self {
         PureScriptConfig {
-            symbol: SegmentConfig::new("<=> "),
-            version: SegmentConfig::default(),
-            style: Color::White.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "<=> ",
+            style: "bold white",
             disabled: false,
         }
     }

src/configs/python.rs

@@ -1,30 +1,27 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct PythonConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub pyenv_prefix: SegmentConfig<'a>,
     pub pyenv_version_name: bool,
     pub python_binary: &'a str,
     pub scan_for_pyfiles: bool,
-    pub style: Style,
+    pub format: &'a str,
+    pub style: &'a str,
+    pub symbol: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for PythonConfig<'a> {
     fn new() -> Self {
         PythonConfig {
-            symbol: SegmentConfig::new("🐍 "),
-            version: SegmentConfig::default(),
-            pyenv_prefix: SegmentConfig::new("pyenv "),
             pyenv_version_name: false,
             python_binary: "python",
             scan_for_pyfiles: true,
-            style: Color::Yellow.bold(),
+            format: "via [$symbol$version( \\($virtualenv\\))]($style) ",
+            style: "yellow bold",
+            symbol: "🐍 ",
             disabled: false,
         }
     }

src/configs/ruby.rs

@@ -1,20 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct RubyConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for RubyConfig<'a> {
     fn new() -> Self {
         RubyConfig {
-            symbol: SegmentConfig::new("💎 "),
-            style: Color::Red.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "💎 ",
+            style: "bold red",
             disabled: false,
         }
     }

src/configs/rust.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct RustConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for RustConfig<'a> {
     fn new() -> Self {
         RustConfig {
-            symbol: SegmentConfig::new("🦀 "),
-            version: SegmentConfig::default(),
-            style: Color::Red.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "🦀 ",
+            style: "bold red",
             disabled: false,
         }
     }

src/configs/singularity.rs

@@ -1,26 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct SingularityConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub label: &'a str,
-    pub prefix: &'a str,
-    pub suffix: &'a str,
-    pub style: Style,
+    pub symbol: &'a str,
+    pub format: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for SingularityConfig<'a> {
     fn new() -> Self {
         SingularityConfig {
-            symbol: SegmentConfig::default(),
-            label: "",
-            prefix: "[",
-            suffix: "]",
-            style: Color::Blue.bold().dimmed(),
+            format: "[$symbol\\[$env\\]]($style) ",
+            symbol: "",
+            style: "blue bold dimmed",
             disabled: false,
         }
     }

src/configs/starship_root.rs

@@ -4,66 +4,66 @@ use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct StarshipRootConfig<'a> {
-    pub add_newline: bool,
-    pub prompt_order: Vec<&'a str>,
+    pub format: &'a str,
     pub scan_timeout: u64,
 }
 
+// List of default prompt order
+// NOTE: If this const value is changed then Default prompt order subheading inside
+// prompt heading of config docs needs to be updated according to changes made here.
+pub const PROMPT_ORDER: [&str; 42] = [
+    "username",
+    "hostname",
+    "singularity",
+    "kubernetes",
+    "directory",
+    "git_branch",
+    "git_commit",
+    "git_state",
+    "git_status",
+    "hg_branch",
+    "docker_context",
+    "package",
+    // ↓ Toolchain version modules ↓
+    // (Let's keep these sorted alphabetically)
+    "dotnet",
+    "elixir",
+    "elm",
+    "erlang",
+    "golang",
+    "java",
+    "julia",
+    "nim",
+    "nodejs",
+    "ocaml",
+    "php",
+    "purescript",
+    "python",
+    "ruby",
+    "rust",
+    "terraform",
+    "zig",
+    // ↑ Toolchain version modules ↑
+    "nix_shell",
+    "conda",
+    "memory_usage",
+    "aws",
+    "env_var",
+    "crystal",
+    "cmd_duration",
+    "custom",
+    "line_break",
+    "jobs",
+    #[cfg(feature = "battery")]
+    "battery",
+    "time",
+    "character",
+];
+
 impl<'a> RootModuleConfig<'a> for StarshipRootConfig<'a> {
     fn new() -> Self {
         StarshipRootConfig {
-            add_newline: true,
-            // List of default prompt order
-            // NOTE: If this const value is changed then Default prompt order subheading inside
-            // prompt heading of config docs needs to be updated according to changes made here.
-            prompt_order: vec![
-                "username",
-                "hostname",
-                "singularity",
-                "kubernetes",
-                "directory",
-                "git_branch",
-                "git_commit",
-                "git_state",
-                "git_status",
-                "hg_branch",
-                "docker_context",
-                "package",
-                // ↓ Toolchain version modules ↓
-                // (Let's keep these sorted alphabetically)
-                "dotnet",
-                "elixir",
-                "elm",
-                "erlang",
-                "golang",
-                "java",
-                "julia",
-                "nim",
-                "nodejs",
-                "ocaml",
-                "php",
-                "purescript",
-                "python",
-                "ruby",
-                "rust",
-                "terraform",
-                "zig",
-                // ↑ Toolchain version modules ↑
-                "nix_shell",
-                "conda",
-                "memory_usage",
-                "aws",
-                "env_var",
-                "crystal",
-                "cmd_duration",
-                "custom",
-                "line_break",
-                "jobs",
-                #[cfg(feature = "battery")]
-                "battery",
-                "time",
-                "character",
-            ],
+            format: "\n$all",
             scan_timeout: 30,
         }
     }

src/configs/terraform.rs

@@ -1,26 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct TerraformConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub workspace: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub show_version: bool,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for TerraformConfig<'a> {
     fn new() -> Self {
         TerraformConfig {
-            symbol: SegmentConfig::new("💠 "),
-            workspace: SegmentConfig::default(),
-            version: SegmentConfig::default(),
-            show_version: false,
-            style: Color::Fixed(105).bold(),
+            format: "via [$symbol$workspace]($style) ",
+            symbol: "💠 ",
+            style: "bold 105",
             disabled: false,
         }
     }

src/configs/time.rs

@@ -1,13 +1,13 @@
 use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct TimeConfig<'a> {
+    pub format: &'a str,
+    pub style: &'a str,
     pub use_12hr: bool,
-    pub format: Option<&'a str>,
-    pub style: Style,
+    pub time_format: Option<&'a str>,
     pub disabled: bool,
     pub utc_time_offset: &'a str,
     pub time_range: &'a str,
@@ -16,9 +16,10 @@ pub struct TimeConfig<'a> {
 impl<'a> RootModuleConfig<'a> for TimeConfig<'a> {
     fn new() -> Self {
         TimeConfig {
+            format: "at [$time]($style) ",
+            style: "bold yellow",
             use_12hr: false,
-            format: None,
-            style: Color::Yellow.bold(),
+            time_format: None,
             disabled: true,
             utc_time_offset: "local",
             time_range: "-",

src/configs/username.rs

@@ -1,21 +1,22 @@
 use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
-pub struct UsernameConfig {
-    pub style_root: Style,
-    pub style_user: Style,
+pub struct UsernameConfig<'a> {
+    pub format: &'a str,
+    pub style_root: &'a str,
+    pub style_user: &'a str,
     pub show_always: bool,
     pub disabled: bool,
 }
 
-impl<'a> RootModuleConfig<'a> for UsernameConfig {
+impl<'a> RootModuleConfig<'a> for UsernameConfig<'a> {
     fn new() -> Self {
         UsernameConfig {
-            style_root: Color::Red.bold(),
-            style_user: Color::Yellow.bold(),
+            format: "via [$user]($style) ",
+            style_root: "red bold",
+            style_user: "yellow bold",
             show_always: false,
             disabled: false,
         }

src/configs/zig.rs

@@ -1,22 +1,21 @@
-use crate::config::{ModuleConfig, RootModuleConfig, SegmentConfig};
+use crate::config::{ModuleConfig, RootModuleConfig};
 
-use ansi_term::{Color, Style};
 use starship_module_config_derive::ModuleConfig;
 
 #[derive(Clone, ModuleConfig)]
 pub struct ZigConfig<'a> {
-    pub symbol: SegmentConfig<'a>,
-    pub version: SegmentConfig<'a>,
-    pub style: Style,
+    pub format: &'a str,
+    pub symbol: &'a str,
+    pub style: &'a str,
     pub disabled: bool,
 }
 
 impl<'a> RootModuleConfig<'a> for ZigConfig<'a> {
     fn new() -> Self {
         ZigConfig {
-            symbol: SegmentConfig::new("↯ "),
-            version: SegmentConfig::default(),
-            style: Color::Yellow.bold(),
+            format: "via [$symbol$version]($style) ",
+            symbol: "↯ ",
+            style: "bold yellow",
             disabled: false,
         }
     }

src/formatter/mod.rs

@@ -2,4 +2,5 @@ pub mod model;
 mod parser;
 pub mod string_formatter;
 
+pub use model::{StyleVariableHolder, VariableHolder};
 pub use string_formatter::StringFormatter;

src/formatter/model.rs

@@ -1,17 +1,103 @@
 use std::borrow::Cow;
+use std::collections::BTreeSet;
 
+/// Type that holds a number of variables of type `T`
+pub trait VariableHolder<T> {
+    fn get_variables(&self) -> BTreeSet<T>;
+}
+
+/// Type that holds a number of style variables of type `T`
+pub trait StyleVariableHolder<T> {
+    fn get_style_variables(&self) -> BTreeSet<T>;
+}
+
+#[derive(Clone)]
 pub struct TextGroup<'a> {
     pub format: Vec<FormatElement<'a>>,
     pub style: Vec<StyleElement<'a>>,
 }
 
+#[derive(Clone)]
 pub enum FormatElement<'a> {
     Text(Cow<'a, str>),
     Variable(Cow<'a, str>),
     TextGroup(TextGroup<'a>),
+    Conditional(Vec<FormatElement<'a>>),
 }
 
+#[derive(Clone)]
 pub enum StyleElement<'a> {
     Text(Cow<'a, str>),
     Variable(Cow<'a, str>),
 }
+
+impl<'a> VariableHolder<Cow<'a, str>> for FormatElement<'a> {
+    fn get_variables(&self) -> BTreeSet<Cow<'a, str>> {
+        match self {
+            FormatElement::Variable(var) => {
+                let mut variables = BTreeSet::new();
+                variables.insert(var.clone());
+                variables
+            }
+            FormatElement::TextGroup(textgroup) => textgroup.format.get_variables(),
+            FormatElement::Conditional(format) => format.get_variables(),
+            _ => Default::default(),
+        }
+    }
+}
+
+impl<'a> VariableHolder<Cow<'a, str>> for Vec<FormatElement<'a>> {
+    fn get_variables(&self) -> BTreeSet<Cow<'a, str>> {
+        self.iter().fold(BTreeSet::new(), |mut acc, el| {
+            acc.extend(el.get_variables());
+            acc
+        })
+    }
+}
+
+impl<'a> VariableHolder<Cow<'a, str>> for &[FormatElement<'a>] {
+    fn get_variables(&self) -> BTreeSet<Cow<'a, str>> {
+        self.iter().fold(BTreeSet::new(), |mut acc, el| {
+            acc.extend(el.get_variables());
+            acc
+        })
+    }
+}
+
+impl<'a> StyleVariableHolder<Cow<'a, str>> for StyleElement<'a> {
+    fn get_style_variables(&self) -> BTreeSet<Cow<'a, str>> {
+        match self {
+            StyleElement::Variable(var) => {
+                let mut variables = BTreeSet::new();
+                variables.insert(var.clone());
+                variables
+            }
+            _ => Default::default(),
+        }
+    }
+}
+
+impl<'a> StyleVariableHolder<Cow<'a, str>> for Vec<StyleElement<'a>> {
+    fn get_style_variables(&self) -> BTreeSet<Cow<'a, str>> {
+        self.iter().fold(BTreeSet::new(), |mut acc, el| {
+            acc.extend(el.get_style_variables());
+            acc
+        })
+    }
+}
+
+impl<'a> StyleVariableHolder<Cow<'a, str>> for Vec<FormatElement<'a>> {
+    fn get_style_variables(&self) -> BTreeSet<Cow<'a, str>> {
+        self.iter().fold(BTreeSet::new(), |mut acc, el| match el {
+            FormatElement::TextGroup(textgroup) => {
+                acc.extend(textgroup.style.get_style_variables());
+                acc
+            }
+            FormatElement::Conditional(format) => {
+                acc.extend(format.get_style_variables());
+                acc
+            }
+            _ => acc,
+        })
+    }
+}

src/formatter/parser.rs

@@ -6,6 +6,18 @@ use super::model::*;
 #[grammar = "formatter/spec.pest"]
 struct IdentParser;
 
+fn _parse_value(value: Pair<Rule>) -> FormatElement {
+    match value.as_rule() {
+        Rule::text => FormatElement::Text(_parse_text(value).into()),
+        Rule::variable => FormatElement::Variable(_parse_variable(value).into()),
+        Rule::textgroup => FormatElement::TextGroup(_parse_textgroup(value)),
+        Rule::conditional => {
+            FormatElement::Conditional(_parse_format(value.into_inner().next().unwrap()))
+        }
+        _ => unreachable!(),
+    }
+}
+
 fn _parse_textgroup(textgroup: Pair<Rule>) -> TextGroup {
     let mut inner_rules = textgroup.into_inner();
     let format = inner_rules.next().unwrap();
@@ -22,55 +34,32 @@ fn _parse_variable(variable: Pair<Rule>) -> &str {
 }
 
 fn _parse_text(text: Pair<Rule>) -> String {
-    let mut result = String::new();
-    for pair in text.into_inner() {
-        result.push_str(pair.as_str());
-    }
-    result
+    text.into_inner()
+        .map(|pair| pair.as_str().chars())
+        .flatten()
+        .collect()
 }
 
 fn _parse_format(format: Pair<Rule>) -> Vec<FormatElement> {
-    let mut result: Vec<FormatElement> = Vec::new();
-
-    for pair in format.into_inner() {
-        match pair.as_rule() {
-            Rule::text => result.push(FormatElement::Text(_parse_text(pair).into())),
-            Rule::variable => result.push(FormatElement::Variable(_parse_variable(pair).into())),
-            Rule::textgroup => result.push(FormatElement::TextGroup(_parse_textgroup(pair))),
-            _ => unreachable!(),
-        }
-    }
-
-    result
+    format.into_inner().map(_parse_value).collect()
 }
 
 fn _parse_style(style: Pair<Rule>) -> Vec<StyleElement> {
-    let mut result: Vec<StyleElement> = Vec::new();
-
-    for pair in style.into_inner() {
-        match pair.as_rule() {
-            Rule::text => result.push(StyleElement::Text(_parse_text(pair).into())),
-            Rule::variable => result.push(StyleElement::Variable(_parse_variable(pair).into())),
+    style
+        .into_inner()
+        .map(|pair| match pair.as_rule() {
+            Rule::string => StyleElement::Text(pair.as_str().into()),
+            Rule::variable => StyleElement::Variable(_parse_variable(pair).into()),
             _ => unreachable!(),
-        }
-    }
-
-    result
+        })
+        .collect()
 }
 
 pub fn parse(format: &str) -> Result<Vec<FormatElement>, Error<Rule>> {
-    let pairs = IdentParser::parse(Rule::expression, format)?;
-    let mut result: Vec<FormatElement> = Vec::new();
-
-    // Lifetime of Segment is the same as result
-    for pair in pairs.take_while(|pair| pair.as_rule() != Rule::EOI) {
-        match pair.as_rule() {
-            Rule::text => result.push(FormatElement::Text(_parse_text(pair).into())),
-            Rule::variable => result.push(FormatElement::Variable(_parse_variable(pair).into())),
-            Rule::textgroup => result.push(FormatElement::TextGroup(_parse_textgroup(pair))),
-            _ => unreachable!(),
-        }
-    }
-
-    Ok(result)
+    IdentParser::parse(Rule::expression, format).map(|pairs| {
+        pairs
+            .take_while(|pair| pair.as_rule() != Rule::EOI)
+            .map(_parse_value)
+            .collect()
+    })
 }

src/formatter/spec.pest

@@ -1,16 +1,51 @@
+// Expression
+//
+// The expression of the format string.
+//
+// Should be started with SOI and ended with EOI, with a format string in it.
 expression = _{ SOI ~ value* ~ EOI }
-value = _{ text | variable | textgroup }
+value = _{ text | variable | textgroup | conditional }
 
-variable = { "$" ~ variable_name }
-variable_name = @{ char+ }
+// Variable
+//
+// A variable is defined as one of the following:
+//
+// - A valid variable name followed by a `$` character (`$[a-zA-Z_][a-zA-Z0-9_]*`),
+//   e.g. `$variable`.
+//
+// - Some texts wrapped in a curly bracket (`${[^\(\)\[\]\\\${}]+}`),
+//   e.g. `${env:HOST}`.
+variable = { "$" ~ (variable_name | variable_scope) }
+variable_name = @{ ('a'..'z' | 'A'..'Z' | "_") ~ char* }
 char = _{ 'a'..'z' | 'A'..'Z' | '0'..'9' | "_" }
 
-text = { text_inner+ }
-text_inner = _{ text_inner_char | escape }
-text_inner_char = { !("[" | "]" | "(" | ")" | "$" | "\\") ~ ANY }
+variable_scope = _{ "{" ~ variable_scoped_name ~ "}" }
+variable_scoped_name = { scoped_char+ }
+scoped_char = _{ !(escaped_char | "{" | "}") ~ ANY }
+
+// Text
+//
+// Texts can be one of `string` or `escaped_char`, where string is one or more of
+// unescapable chars.
+//
+// This is implemented so as to ensure all functional characters are escaped.
+text = { (string | escape)+ }
+string = @{ text_inner_char+ }
+text_inner_char = { !escaped_char ~ ANY }
 escape = _{ "\\" ~ escaped_char }
 escaped_char = { "[" | "]" | "(" | ")" | "\\" | "$" }
 
+// TextGroup
+//
+// A textgroup is a pair of `format` and `style` (`[format](style)`)
+//
+// - `format`: A format string, can contain any number of variables, texts or textgroups.
+// - `style`: A style string, can contain any number of variables or texts.
 textgroup = { "[" ~ format ~ "]" ~ "(" ~ style ~ ")" }
-format = { (variable | text | textgroup)* }
-style = { (variable | text)* }
+format = { value* }
+style = { (variable | string)* }
+
+// Conditional
+//
+// A conditional format string that won't render if all the containing variables are empty.
+conditional = { "(" ~ format ~ ")" }

src/formatter/string_formatter.rs

@@ -1,7 +1,11 @@
 use ansi_term::Style;
-use pest::error::Error;
+use pest::error::Error as PestError;
 use rayon::prelude::*;
-use std::collections::BTreeMap;
+use std::borrow::Cow;
+use std::collections::{BTreeMap, BTreeSet};
+use std::error::Error;
+use std::fmt;
+use std::iter::FromIterator;
 
 use crate::config::parse_style_string;
 use crate::segment::Segment;
@@ -10,109 +14,263 @@ use super::model::*;
 use super::parser::{parse, Rule};
 
 #[derive(Clone)]
-enum VariableValue {
-    Plain(String),
+enum VariableValue<'a> {
+    Plain(Cow<'a, str>),
     Styled(Vec<Segment>),
+    Meta(Vec<FormatElement<'a>>),
 }
 
-impl Default for VariableValue {
+impl<'a> Default for VariableValue<'a> {
     fn default() -> Self {
-        VariableValue::Plain(String::new())
+        VariableValue::Plain(Cow::Borrowed(""))
     }
 }
 
-type VariableMapType = BTreeMap<String, Option<VariableValue>>;
+type VariableMapType<'a> =
+    BTreeMap<String, Option<Result<VariableValue<'a>, StringFormatterError>>>;
+type StyleVariableMapType<'a> =
+    BTreeMap<String, Option<Result<Cow<'a, str>, StringFormatterError>>>;
+
+#[derive(Debug, Clone)]
+pub enum StringFormatterError {
+    Custom(String),
+    Parse(PestError<Rule>),
+}
+
+impl fmt::Display for StringFormatterError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::Custom(error) => write!(f, "{}", error),
+            Self::Parse(error) => write!(f, "{}", error),
+        }
+    }
+}
+
+impl Error for StringFormatterError {}
+
+impl From<String> for StringFormatterError {
+    fn from(error: String) -> Self {
+        StringFormatterError::Custom(error)
+    }
+}
 
 pub struct StringFormatter<'a> {
     format: Vec<FormatElement<'a>>,
-    variables: VariableMapType,
+    variables: VariableMapType<'a>,
+    style_variables: StyleVariableMapType<'a>,
 }
 
 impl<'a> StringFormatter<'a> {
     /// Creates an instance of StringFormatter from a format string
-    pub fn new(format: &'a str) -> Result<Self, Error<Rule>> {
+    ///
+    /// This method will throw an Error when the given format string fails to parse.
+    pub fn new(format: &'a str) -> Result<Self, StringFormatterError> {
         parse(format)
             .map(|format| {
-                let variables = _get_variables(&format);
-                (format, variables)
+                // Cache all variables
+                let variables = VariableMapType::from_iter(
+                    format
+                        .get_variables()
+                        .into_iter()
+                        .map(|key| (key.to_string(), None))
+                        .collect::<Vec<(String, Option<_>)>>(),
+                );
+                let style_variables = StyleVariableMapType::from_iter(
+                    format
+                        .get_style_variables()
+                        .into_iter()
+                        .map(|key| (key.to_string(), None))
+                        .collect::<Vec<(String, Option<_>)>>(),
+                );
+                (format, variables, style_variables)
             })
-            .map(|(format, variables)| Self { format, variables })
+            .map(|(format, variables, style_variables)| Self {
+                format,
+                variables,
+                style_variables,
+            })
+            .map_err(StringFormatterError::Parse)
     }
 
     /// Maps variable name to its value
-    pub fn map(mut self, mapper: impl Fn(&str) -> Option<String> + Sync) -> Self {
-        self.variables.par_iter_mut().for_each(|(key, value)| {
-            *value = mapper(key).map(VariableValue::Plain);
-        });
+    ///
+    /// You should provide a function or closure that accepts the variable name `name: &str` as a
+    /// parameter and returns the one of the following values:
+    ///
+    /// - `None`: This variable will be reserved for further mappers. If it is `None` when
+    /// `self.parse()` is called, it will be dropped.
+    ///
+    /// - `Some(Err(StringFormatterError))`: This variable will throws `StringFormatterError` when
+    /// `self.parse()` is called. Return this if some fatal error occurred and the format string
+    /// should not be rendered.
+    ///
+    /// - `Some(Ok(_))`: The value of this variable will be displayed in the format string.
+    ///
+    pub fn map<T, M>(mut self, mapper: M) -> Self
+    where
+        T: Into<Cow<'a, str>>,
+        M: Fn(&str) -> Option<Result<T, StringFormatterError>> + Sync,
+    {
+        self.variables
+            .par_iter_mut()
+            .filter(|(_, value)| value.is_none())
+            .for_each(|(key, value)| {
+                *value = mapper(key).map(|var| var.map(|var| VariableValue::Plain(var.into())));
+            });
+        self
+    }
+
+    /// Maps a meta-variable to a format string containing other variables.
+    ///
+    /// This function should be called **before** other map methods so that variables found in
+    /// the format strings of meta-variables can be cached properly.
+    ///
+    /// See `StringFormatter::map` for description on the parameters.
+    pub fn map_meta<M>(mut self, mapper: M) -> Self
+    where
+        M: Fn(&str, &BTreeSet<String>) -> Option<&'a str> + Sync,
+    {
+        let variables = self.get_variables();
+        let (variables, style_variables) = self
+            .variables
+            .iter_mut()
+            .filter(|(_, value)| value.is_none())
+            .fold(
+                (VariableMapType::new(), StyleVariableMapType::new()),
+                |(mut v, mut sv), (key, value)| {
+                    *value = mapper(key, &variables).map(|format| {
+                        StringFormatter::new(format).map(|formatter| {
+                            let StringFormatter {
+                                format,
+                                mut variables,
+                                mut style_variables,
+                            } = formatter;
+
+                            // Add variables in meta variables to self
+                            v.append(&mut variables);
+                            sv.append(&mut style_variables);
+
+                            VariableValue::Meta(format)
+                        })
+                    });
+
+                    (v, sv)
+                },
+            );
+
+        self.variables.extend(variables);
+        self.style_variables.extend(style_variables);
+
         self
     }
 
     /// Maps variable name to an array of segments
-    pub fn map_variables_to_segments(
-        mut self,
-        mapper: impl Fn(&str) -> Option<Vec<Segment>> + Sync,
-    ) -> Self {
-        self.variables.par_iter_mut().for_each(|(key, value)| {
-            *value = mapper(key).map(VariableValue::Styled);
-        });
+    ///
+    /// See `StringFormatter::map` for description on the parameters.
+    pub fn map_variables_to_segments<M>(mut self, mapper: M) -> Self
+    where
+        M: Fn(&str) -> Option<Result<Vec<Segment>, StringFormatterError>> + Sync,
+    {
+        self.variables
+            .par_iter_mut()
+            .filter(|(_, value)| value.is_none())
+            .for_each(|(key, value)| {
+                *value = mapper(key).map(|var| var.map(VariableValue::Styled));
+            });
+        self
+    }
+
+    /// Maps variable name in a style string to its value
+    ///
+    /// See `StringFormatter::map` for description on the parameters.
+    pub fn map_style<T, M>(mut self, mapper: M) -> Self
+    where
+        T: Into<Cow<'a, str>>,
+        M: Fn(&str) -> Option<Result<T, StringFormatterError>> + Sync,
+    {
+        self.style_variables
+            .par_iter_mut()
+            .filter(|(_, value)| value.is_none())
+            .for_each(|(key, value)| {
+                *value = mapper(key).map(|var| var.map(|var| var.into()));
+            });
         self
     }
 
     /// Parse the format string and consume self.
-    pub fn parse(self, default_style: Option<Style>) -> Vec<Segment> {
+    ///
+    /// This method will throw an Error in the following conditions:
+    ///
+    /// - Format string in meta variables fails to parse
+    /// - Variable mapper returns an error.
+    pub fn parse(self, default_style: Option<Style>) -> Result<Vec<Segment>, StringFormatterError> {
         fn _parse_textgroup<'a>(
             textgroup: TextGroup<'a>,
-            variables: &'a VariableMapType,
-        ) -> Vec<Segment> {
-            let style = _parse_style(textgroup.style);
-            _parse_format(textgroup.format, style, &variables)
+            variables: &'a VariableMapType<'a>,
+            style_variables: &'a StyleVariableMapType<'a>,
+        ) -> Result<Vec<Segment>, StringFormatterError> {
+            let style = _parse_style(textgroup.style, style_variables);
+            _parse_format(
+                textgroup.format,
+                style.transpose()?,
+                &variables,
+                &style_variables,
+            )
         }
 
-        fn _parse_style(style: Vec<StyleElement>) -> Option<Style> {
-            let style_string = style
-                .iter()
-                .flat_map(|style| match style {
-                    StyleElement::Text(text) => text.as_ref().chars(),
-                    StyleElement::Variable(variable) => {
-                        log::warn!(
-                            "Variable `{}` monitored in style string, which is not allowed",
-                            &variable
-                        );
-                        "".chars()
+        fn _parse_style<'a>(
+            style: Vec<StyleElement>,
+            variables: &'a StyleVariableMapType<'a>,
+        ) -> Option<Result<Style, StringFormatterError>> {
+            let style_strings = style
+                .into_iter()
+                .map(|style| match style {
+                    StyleElement::Text(text) => Ok(text),
+                    StyleElement::Variable(name) => {
+                        let variable = variables.get(name.as_ref()).unwrap_or(&None);
+                        match variable {
+                            Some(style_string) => style_string.clone().map(|string| string),
+                            None => Ok("".into()),
+                        }
                     }
                 })
-                .collect::<String>();
-            parse_style_string(&style_string)
+                .collect::<Result<Vec<Cow<str>>, StringFormatterError>>();
+            style_strings
+                .map(|style_strings| {
+                    let style_string: String =
+                        style_strings.iter().flat_map(|s| s.chars()).collect();
+                    parse_style_string(&style_string)
+                })
+                .transpose()
         }
 
         fn _parse_format<'a>(
-            mut format: Vec<FormatElement<'a>>,
+            format: Vec<FormatElement<'a>>,
             style: Option<Style>,
-            variables: &'a VariableMapType,
-        ) -> Vec<Segment> {
-            let mut result: Vec<Segment> = Vec::new();
-
-            format.reverse();
-            while let Some(el) = format.pop() {
-                let mut segments = match el {
-                    FormatElement::Text(text) => {
-                        vec![_new_segment("_text".into(), text.into_owned(), style)]
-                    }
-                    FormatElement::TextGroup(textgroup) => {
-                        let textgroup = TextGroup {
-                            format: textgroup.format,
-                            style: textgroup.style,
-                        };
-                        _parse_textgroup(textgroup, &variables)
-                    }
-                    FormatElement::Variable(name) => variables
-                        .get(name.as_ref())
-                        .map(|segments| {
-                            let value = segments.clone().unwrap_or_default();
-                            match value {
-                                VariableValue::Styled(segments) => segments
+            variables: &'a VariableMapType<'a>,
+            style_variables: &'a StyleVariableMapType<'a>,
+        ) -> Result<Vec<Segment>, StringFormatterError> {
+            let results: Result<Vec<Vec<Segment>>, StringFormatterError> = format
+                .into_iter()
+                .map(|el| {
+                    match el {
+                        FormatElement::Text(text) => Ok(vec![_new_segment("_text", text, style)]),
+                        FormatElement::TextGroup(textgroup) => {
+                            let textgroup = TextGroup {
+                                format: textgroup.format,
+                                style: textgroup.style,
+                            };
+                            _parse_textgroup(textgroup, &variables, &style_variables)
+                        }
+                        FormatElement::Variable(name) => variables
+                            .get(name.as_ref())
+                            .expect("Uncached variable found")
+                            .as_ref()
+                            .map(|segments| match segments.clone()? {
+                                VariableValue::Styled(segments) => Ok(segments
                                     .into_iter()
                                     .map(|mut segment| {
+                                        // Derive upper style if the style of segments are none.
                                         if !segment.has_style() {
                                             if let Some(style) = style {
                                                 segment.set_style(style);
@@ -120,80 +278,124 @@ impl<'a> StringFormatter<'a> {
                                         }
                                         segment
                                     })
-                                    .collect(),
+                                    .collect()),
                                 VariableValue::Plain(text) => {
-                                    vec![_new_segment(name.to_string(), text, style)]
+                                    Ok(vec![_new_segment(name, text, style)])
                                 }
+                                VariableValue::Meta(format) => {
+                                    let formatter = StringFormatter {
+                                        format,
+                                        variables: _clone_without_meta(variables),
+                                        style_variables: style_variables.clone(),
+                                    };
+                                    formatter.parse(style)
+                                }
+                            })
+                            .unwrap_or_else(|| Ok(Vec::new())),
+                        FormatElement::Conditional(format) => {
+                            // Show the conditional format string if all the variables inside are not
+                            // none.
+                            fn _should_show_elements<'a>(
+                                format_elements: &[FormatElement],
+                                variables: &'a VariableMapType<'a>,
+                            ) -> bool {
+                                format_elements.get_variables().iter().any(|var| {
+                                    variables
+                                        .get(var.as_ref())
+                                        .map(|map_result| {
+                                            let map_result = map_result.as_ref();
+                                            map_result
+                                                .and_then(|result| result.as_ref().ok())
+                                                .map(|result| match result {
+                                                    // If the variable is a meta variable, also
+                                                    // check the format string inside it.
+                                                    VariableValue::Meta(meta_elements) => {
+                                                        let meta_variables =
+                                                            _clone_without_meta(variables);
+                                                        _should_show_elements(
+                                                            &meta_elements,
+                                                            &meta_variables,
+                                                        )
+                                                    }
+                                                    _ => true,
+                                                })
+                                                // The variable is None or Err, or a meta variable
+                                                // that shouldn't show
+                                                .unwrap_or(false)
+                                        })
+                                        // Can't find the variable in format string
+                                        .unwrap_or(false)
+                                })
                             }
-                        })
-                        .unwrap_or_default(),
-                };
-                result.append(&mut segments);
-            }
 
-            result
+                            let should_show: bool = _should_show_elements(&format, variables);
+
+                            if should_show {
+                                _parse_format(format, style, variables, style_variables)
+                            } else {
+                                Ok(Vec::new())
+                            }
+                        }
+                    }
+                })
+                .collect();
+            Ok(results?.into_iter().flatten().collect())
         }
 
-        _parse_format(self.format, default_style, &self.variables)
+        _parse_format(
+            self.format,
+            default_style,
+            &self.variables,
+            &self.style_variables,
+        )
     }
 }
 
-/// Extract variable names from an array of `FormatElement` into a `BTreeMap`
-fn _get_variables<'a>(format: &[FormatElement<'a>]) -> VariableMapType {
-    let mut variables: VariableMapType = Default::default();
-
-    fn _push_variables_from_textgroup<'a>(
-        variables: &mut VariableMapType,
-        textgroup: &'a TextGroup<'a>,
-    ) {
-        for el in &textgroup.format {
-            match el {
-                FormatElement::Variable(name) => _push_variable(variables, name.as_ref()),
-                FormatElement::TextGroup(textgroup) => {
-                    _push_variables_from_textgroup(variables, &textgroup)
-                }
-                _ => {}
-            }
-        }
-        for el in &textgroup.style {
-            if let StyleElement::Variable(name) = el {
-                _push_variable(variables, name.as_ref())
-            }
-        }
+impl<'a> VariableHolder<String> for StringFormatter<'a> {
+    fn get_variables(&self) -> BTreeSet<String> {
+        BTreeSet::from_iter(self.variables.keys().cloned())
     }
+}
 
-    fn _push_variable<'a>(variables: &mut VariableMapType, name: &'a str) {
-        variables.insert(name.to_owned(), None);
+impl<'a> StyleVariableHolder<String> for StringFormatter<'a> {
+    fn get_style_variables(&self) -> BTreeSet<String> {
+        BTreeSet::from_iter(self.style_variables.keys().cloned())
     }
-
-    for el in format {
-        match el {
-            FormatElement::Variable(name) => _push_variable(&mut variables, name.as_ref()),
-            FormatElement::TextGroup(textgroup) => {
-                _push_variables_from_textgroup(&mut variables, &textgroup)
-            }
-            _ => {}
-        }
-    }
-
-    variables
 }
 
 /// Helper function to create a new segment
-fn _new_segment(name: String, value: String, style: Option<Style>) -> Segment {
+fn _new_segment(
+    name: impl Into<String>,
+    value: impl Into<String>,
+    style: Option<Style>,
+) -> Segment {
     Segment {
-        _name: name,
-        value,
+        _name: name.into(),
+        value: value.into(),
         style,
     }
 }
 
+fn _clone_without_meta<'a>(variables: &VariableMapType<'a>) -> VariableMapType<'a> {
+    VariableMapType::from_iter(variables.iter().map(|(key, value)| {
+        let value = match value {
+            Some(Ok(value)) => match value {
+                VariableValue::Meta(_) => None,
+                other => Some(Ok(other.clone())),
+            },
+            Some(Err(e)) => Some(Err(e.clone())),
+            None => None,
+        };
+        (key.clone(), value)
+    }))
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
     use ansi_term::Color;
 
-    // match_next(result: Iter<Segment>, value, style)
+    // match_next(result: IterMut<Segment>, value, style)
     macro_rules! match_next {
         ($iter:ident, $value:literal, $($style:tt)+) => {
             let _next = $iter.next().unwrap();
@@ -202,7 +404,7 @@ mod tests {
         }
     }
 
-    fn empty_mapper(_: &str) -> Option<String> {
+    fn empty_mapper(_: &str) -> Option<Result<String, StringFormatterError>> {
         None
     }
 
@@ -212,7 +414,7 @@ mod tests {
         let style = Some(Color::Red.bold());
 
         let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
-        let result = formatter.parse(style);
+        let result = formatter.parse(style).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, "text", style);
     }
@@ -221,7 +423,7 @@ mod tests {
     fn test_textgroup_text_only() {
         const FORMAT_STR: &str = "[text](red bold)";
         let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
-        let result = formatter.parse(None);
+        let result = formatter.parse(None).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, "text", Some(Color::Red.bold()));
     }
@@ -233,20 +435,48 @@ mod tests {
         let formatter = StringFormatter::new(FORMAT_STR)
             .unwrap()
             .map(|variable| match variable {
-                "var1" => Some("text1".to_owned()),
+                "var1" => Some(Ok("text1".to_owned())),
                 _ => None,
             });
-        let result = formatter.parse(None);
+        let result = formatter.parse(None).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, "text1", None);
     }
 
+    #[test]
+    fn test_variable_in_style() {
+        const FORMAT_STR: &str = "[root]($style)";
+        let root_style = Some(Color::Red.bold());
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map_style(|variable| match variable {
+                "style" => Some(Ok("red bold".to_owned())),
+                _ => None,
+            });
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, "root", root_style);
+    }
+
+    #[test]
+    fn test_scoped_variable() {
+        const FORMAT_STR: &str = "${env:PWD}";
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map(|variable| Some(Ok(format!("${{{}}}", variable))));
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, "${env:PWD}", None);
+    }
+
     #[test]
     fn test_escaped_chars() {
         const FORMAT_STR: &str = r#"\\\[\$text\]\(red bold\)"#;
 
         let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
-        let result = formatter.parse(None);
+        let result = formatter.parse(None).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, r#"\[$text](red bold)"#, None);
     }
@@ -259,7 +489,7 @@ mod tests {
         let inner_style = Some(Color::Blue.normal());
 
         let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
-        let result = formatter.parse(outer_style);
+        let result = formatter.parse(outer_style).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, "outer ", outer_style);
         match_next!(result_iter, "middle ", middle_style);
@@ -274,10 +504,10 @@ mod tests {
         let formatter = StringFormatter::new(FORMAT_STR)
             .unwrap()
             .map(|variable| match variable {
-                "var" => Some("text".to_owned()),
+                "var" => Some(Ok("text".to_owned())),
                 _ => None,
             });
-        let result = formatter.parse(None);
+        let result = formatter.parse(None).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, "text", var_style);
     }
@@ -292,7 +522,7 @@ mod tests {
         let formatter = StringFormatter::new(FORMAT_STR)
             .unwrap()
             .map_variables_to_segments(|variable| match variable {
-                "var" => Some(vec![
+                "var" => Some(Ok(vec![
                     _new_segment("_1".to_owned(), "styless".to_owned(), None),
                     _new_segment("_2".to_owned(), "styled".to_owned(), styled_style),
                     _new_segment(
@@ -300,16 +530,133 @@ mod tests {
                         "styled_no_modifier".to_owned(),
                         styled_no_modifier_style,
                     ),
-                ]),
+                ])),
                 _ => None,
             });
-        let result = formatter.parse(None);
+        let result = formatter.parse(None).unwrap();
         let mut result_iter = result.iter();
         match_next!(result_iter, "styless", var_style);
         match_next!(result_iter, "styled", styled_style);
         match_next!(result_iter, "styled_no_modifier", styled_no_modifier_style);
     }
 
+    #[test]
+    fn test_meta_variable() {
+        const FORMAT_STR: &str = "$all";
+        const FORMAT_STR__ALL: &str = "$a$b";
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map_meta(|var, _| match var {
+                "all" => Some(FORMAT_STR__ALL),
+                _ => None,
+            })
+            .map(|var| match var {
+                "a" => Some(Ok("$a")),
+                "b" => Some(Ok("$b")),
+                _ => None,
+            });
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, "$a", None);
+        match_next!(result_iter, "$b", None);
+    }
+
+    #[test]
+    fn test_multiple_mapper() {
+        const FORMAT_STR: &str = "$a$b$c";
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map(|var| match var {
+                "a" => Some(Ok("$a")),
+                "b" => Some(Ok("$b")),
+                _ => None,
+            })
+            .map(|var| match var {
+                "b" => Some(Ok("$B")),
+                "c" => Some(Ok("$c")),
+                _ => None,
+            });
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, "$a", None);
+        match_next!(result_iter, "$b", None);
+        match_next!(result_iter, "$c", None);
+    }
+
+    #[test]
+    fn test_conditional() {
+        const FORMAT_STR: &str = "($some) should render but ($none) shouldn't";
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map(|var| match var {
+                "some" => Some(Ok("$some")),
+                _ => None,
+            });
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, "$some", None);
+        match_next!(result_iter, " should render but ", None);
+        match_next!(result_iter, " shouldn't", None);
+    }
+
+    #[test]
+    fn test_nested_conditional() {
+        const FORMAT_STR: &str = "($some ($none)) and ($none ($some))";
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map(|var| match var {
+                "some" => Some(Ok("$some")),
+                _ => None,
+            });
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, "$some", None);
+        match_next!(result_iter, " ", None);
+        match_next!(result_iter, " and ", None);
+        match_next!(result_iter, " ", None);
+        match_next!(result_iter, "$some", None);
+    }
+
+    #[test]
+    fn test_conditional_meta_variable() {
+        const FORMAT_STR: &str = r"(\[$all\]) ";
+
+        let formatter = StringFormatter::new(FORMAT_STR)
+            .unwrap()
+            .map_meta(|var, _| match var {
+                "all" => Some("$some"),
+                _ => None,
+            });
+        let result = formatter.parse(None).unwrap();
+        let mut result_iter = result.iter();
+        match_next!(result_iter, " ", None);
+    }
+
+    #[test]
+    fn test_variable_holder() {
+        const FORMAT_STR: &str = "($a [($b) $c](none $s)) $d [t]($t)";
+        let expected_variables =
+            BTreeSet::from_iter(vec!["a", "b", "c", "d"].into_iter().map(String::from));
+
+        let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
+        let variables = formatter.get_variables();
+        assert_eq!(variables, expected_variables);
+    }
+
+    #[test]
+    fn test_style_variable_holder() {
+        const FORMAT_STR: &str = "($a [($b) $c](none $s)) $d [t]($t)";
+        let expected_variables = BTreeSet::from_iter(vec!["s", "t"].into_iter().map(String::from));
+
+        let formatter = StringFormatter::new(FORMAT_STR).unwrap().map(empty_mapper);
+        let variables = formatter.get_style_variables();
+        assert_eq!(variables, expected_variables);
+    }
+
     #[test]
     fn test_parse_error() {
         // brackets without escape
@@ -323,4 +670,21 @@ mod tests {
             assert!(StringFormatter::new(FORMAT_STR).is_err());
         }
     }
+
+    #[test]
+    fn test_variable_error() {
+        const FORMAT_STR: &str = "$never$some";
+        let never_error = StringFormatterError::Custom("NEVER".to_owned());
+
+        let segments = StringFormatter::new(FORMAT_STR).and_then(|formatter| {
+            formatter
+                .map(|var| match var {
+                    "some" => Some(Ok("some")),
+                    "never" => Some(Err(never_error.clone())),
+                    _ => None,
+                })
+                .parse(None)
+        });
+        assert!(segments.is_err());
+    }
 }

src/module.rs

@@ -1,8 +1,6 @@
-use crate::config::SegmentConfig;
 use crate::context::Shell;
 use crate::segment::Segment;
 use crate::utils::wrap_colorseq_for_shell;
-use ansi_term::Style;
 use ansi_term::{ANSIString, ANSIStrings};
 use std::fmt;
 
@@ -66,17 +64,8 @@ pub struct Module<'a> {
     /// The module's description
     description: String,
 
-    /// The styling to be inherited by all segments contained within this module.
-    style: Style,
-
-    /// The prefix used to separate the current module from the previous one.
-    prefix: Affix,
-
     /// The collection of segments that compose this module.
-    segments: Vec<Segment>,
-
-    /// The suffix used to separate the current module from the next one.
-    suffix: Affix,
+    pub segments: Vec<Segment>,
 }
 
 impl<'a> Module<'a> {
@@ -86,23 +75,10 @@ impl<'a> Module<'a> {
             config,
             _name: name.to_string(),
             description: desc.to_string(),
-            style: Style::default(),
-            prefix: Affix::default_prefix(name),
             segments: Vec::new(),
-            suffix: Affix::default_suffix(name),
         }
     }
 
-    /// Get a reference to a newly created segment in the module
-    pub fn create_segment(&mut self, name: &str, segment_config: &SegmentConfig) -> &mut Segment {
-        let mut segment = Segment::new(name);
-        segment.set_style(segment_config.style.unwrap_or(self.style));
-        segment.set_value(segment_config.value);
-        self.segments.push(segment);
-
-        self.segments.last_mut().unwrap()
-    }
-
     /// Set segments in module
     pub fn set_segments(&mut self, segments: Vec<Segment>) {
         self.segments = segments;
@@ -123,31 +99,11 @@ impl<'a> Module<'a> {
         self.segments.iter().all(|segment| segment.is_empty())
     }
 
+    /// Get values of the module's segments
     pub fn get_segments(&self) -> Vec<&str> {
         self.segments.iter().map(Segment::get_value).collect()
     }
 
-    /// Get the module's prefix
-    pub fn get_prefix(&mut self) -> &mut Affix {
-        &mut self.prefix
-    }
-
-    /// Get the module's suffix
-    pub fn get_suffix(&mut self) -> &mut Affix {
-        &mut self.suffix
-    }
-
-    /// Sets the style of the segment.
-    ///
-    /// Accepts either `Color` or `Style`.
-    pub fn set_style<T>(&mut self, style: T) -> &mut Module<'a>
-    where
-        T: Into<Style>,
-    {
-        self.style = style.into();
-        self
-    }
-
     /// Returns a vector of colored ANSIString elements to be later used with
     /// `ANSIStrings()` to optimize ANSI codes
     pub fn ansi_strings(&self) -> Vec<ANSIString> {
@@ -155,26 +111,17 @@ impl<'a> Module<'a> {
     }
 
     pub fn ansi_strings_for_shell(&self, shell: Shell) -> Vec<ANSIString> {
-        let mut ansi_strings = self
+        let ansi_strings = self
             .segments
             .iter()
             .map(Segment::ansi_string)
             .collect::<Vec<ANSIString>>();
 
-        ansi_strings.insert(0, self.prefix.ansi_string());
-        ansi_strings.push(self.suffix.ansi_string());
-
-        ansi_strings = match shell {
+        match shell {
             Shell::Bash => ansi_strings_modified(ansi_strings, shell),
             Shell::Zsh => ansi_strings_modified(ansi_strings, shell),
             _ => ansi_strings,
-        };
-
-        ansi_strings
-    }
-
-    pub fn to_string_without_prefix(&self, shell: Shell) -> String {
-        ANSIStrings(&self.ansi_strings_for_shell(shell)[1..]).to_string()
+        }
     }
 }
 
@@ -195,67 +142,6 @@ fn ansi_strings_modified(ansi_strings: Vec<ANSIString>, shell: Shell) -> Vec<ANS
         .collect::<Vec<ANSIString>>()
 }
 
-/// Module affixes are to be used for the prefix or suffix of a module.
-pub struct Affix {
-    /// The affix's name, to be used in configuration and logging.
-    _name: String,
-
-    /// The affix's style.
-    style: Style,
-
-    /// The string value of the affix.
-    value: String,
-}
-
-impl Affix {
-    pub fn default_prefix(name: &str) -> Self {
-        Self {
-            _name: format!("{}_prefix", name),
-            style: Style::default(),
-            value: "via ".to_string(),
-        }
-    }
-
-    pub fn default_suffix(name: &str) -> Self {
-        Self {
-            _name: format!("{}_suffix", name),
-            style: Style::default(),
-            value: " ".to_string(),
-        }
-    }
-
-    /// Sets the style of the module.
-    ///
-    /// Accepts either `Color` or `Style`.
-    pub fn set_style<T>(&mut self, style: T) -> &mut Self
-    where
-        T: Into<Style>,
-    {
-        self.style = style.into();
-        self
-    }
-
-    /// Sets the value of the module.
-    pub fn set_value<T>(&mut self, value: T) -> &mut Self
-    where
-        T: Into<String>,
-    {
-        self.value = value.into();
-        self
-    }
-
-    /// Generates the colored ANSIString output.
-    pub fn ansi_string(&self) -> ANSIString {
-        self.style.paint(&self.value)
-    }
-}
-
-impl fmt::Display for Affix {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        write!(f, "{}", self.ansi_string())
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -268,10 +154,7 @@ mod tests {
             config: None,
             _name: name.to_string(),
             description: desc.to_string(),
-            style: Style::default(),
-            prefix: Affix::default_prefix(name),
             segments: Vec::new(),
-            suffix: Affix::default_suffix(name),
         };
 
         assert!(module.is_empty());
@@ -285,10 +168,7 @@ mod tests {
             config: None,
             _name: name.to_string(),
             description: desc.to_string(),
-            style: Style::default(),
-            prefix: Affix::default_prefix(name),
             segments: vec![Segment::new("test_segment")],
-            suffix: Affix::default_suffix(name),
         };
 
         assert!(module.is_empty());

src/modules/aws.rs

@@ -7,7 +7,8 @@ use std::str::FromStr;
 
 use super::{Context, Module, RootModuleConfig};
 
-use crate::configs::aws::{AwsConfig, AwsItems};
+use crate::configs::aws::AwsConfig;
+use crate::formatter::StringFormatter;
 
 type Profile = String;
 type Region = String;
@@ -51,73 +52,64 @@ fn get_aws_profile_and_region() -> (Option<Profile>, Option<Region>) {
         env::var("AWS_VAULT")
             .or_else(|_| env::var("AWS_PROFILE"))
             .ok(),
-        env::var("AWS_REGION").ok(),
-        env::var("AWS_DEFAULT_REGION").ok(),
+        env::var("AWS_DEFAULT_REGION")
+            .or_else(|_| env::var("AWS_REGION"))
+            .ok(),
     ) {
-        (Some(p), Some(_), Some(dr)) => (Some(p), Some(dr)),
-        (Some(p), Some(r), None) => (Some(p), Some(r)),
-        (None, Some(r), None) => (None, Some(r)),
-        (Some(p), None, Some(dr)) => (Some(p), Some(dr)),
-        (Some(ref p), None, None) => (Some(p.to_owned()), get_aws_region_from_config(Some(p))),
-        (None, None, Some(dr)) => (None, Some(dr)),
-        (None, Some(_), Some(dr)) => (None, Some(dr)),
-        (None, None, None) => (None, get_aws_region_from_config(None)),
+        (Some(p), Some(r)) => (Some(p), Some(r)),
+        (None, Some(r)) => (None, Some(r)),
+        (Some(ref p), None) => (Some(p.to_owned()), get_aws_region_from_config(Some(p))),
+        (None, None) => (None, get_aws_region_from_config(None)),
     }
 }
 
-fn get_aws_region() -> Option<Region> {
-    match (
-        env::var("AWS_REGION").ok(),
-        env::var("AWS_DEFAULT_REGION").ok(),
-    ) {
-        (Some(r), None) => Some(r),
-        (None, Some(dr)) => Some(dr),
-        (Some(_), Some(dr)) => Some(dr),
-        (None, None) => get_aws_region_from_config(None),
-    }
-}
-
-fn alias_region(region: &str, aliases: &HashMap<String, &str>) -> String {
-    match aliases.get(region) {
-        None => region.to_string(),
+fn alias_region(region: String, aliases: &HashMap<String, &str>) -> String {
+    match aliases.get(&region) {
+        None => region,
         Some(alias) => (*alias).to_string(),
     }
 }
 
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
-    const AWS_PREFIX: &str = "on ";
-
     let mut module = context.new_module("aws");
     let config: AwsConfig = AwsConfig::try_load(module.config);
 
-    module.set_style(config.style);
+    let (aws_profile, aws_region) = get_aws_profile_and_region();
+    if aws_profile.is_none() && aws_region.is_none() {
+        return None;
+    }
 
-    module.get_prefix().set_value(AWS_PREFIX);
-
-    module.create_segment("symbol", &config.symbol);
-    match config.displayed_items {
-        AwsItems::All => {
-            let (aws_profile, aws_region) = get_aws_profile_and_region();
-
-            let aws_segment = match (&aws_profile, &aws_region) {
-                (None, None) => return None,
-                (Some(p), Some(r)) => format!("{}({})", p, alias_region(r, &config.region_aliases)),
-                (Some(p), None) => p.to_string(),
-                (None, Some(r)) => alias_region(r, &config.region_aliases),
-            };
-            module.create_segment("all", &config.region.with_value(&aws_segment));
-        }
-        AwsItems::Profile => {
-            let aws_profile = env::var("AWS_PROFILE").ok()?;
-
-            module.create_segment("profile", &config.profile.with_value(&aws_profile));
-        }
-        AwsItems::Region => {
-            let aws_region = alias_region(&get_aws_region()?, &config.region_aliases);
-
-            module.create_segment("region", &config.region.with_value(&aws_region));
-        }
+    let mapped_region = if let Some(aws_region) = aws_region {
+        Some(alias_region(aws_region, &config.region_aliases))
+    } else {
+        None
     };
 
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "profile" => aws_profile.as_ref().map(Ok),
+                "region" => mapped_region.as_ref().map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::error!("Error in module `aws`: \n{}", error);
+            return None;
+        }
+    });
+
     Some(module)
 }

src/modules/battery.rs

@@ -1,6 +1,8 @@
 use super::{Context, Module, RootModuleConfig, Shell};
 use crate::configs::battery::BatteryConfig;
 
+use crate::formatter::StringFormatter;
+
 /// Creates a module for the battery percentage and charging state
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     // TODO: Update when v1.0 printing refactor is implemented to only
@@ -14,60 +16,58 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let BatteryStatus { state, percentage } = battery_status;
 
     let mut module = context.new_module("battery");
-    let battery_config: BatteryConfig = BatteryConfig::try_load(module.config);
+    let config: BatteryConfig = BatteryConfig::try_load(module.config);
 
-    // Parse config under `display`
-    let display_styles = &battery_config.display;
-    let display_style = display_styles
+    // Parse config under `display`.
+    // Select the first style that match the threshold,
+    // if all thresholds are lower do not display battery module.
+    let display_style = config
+        .display
         .iter()
-        .find(|display_style| percentage <= display_style.threshold as f32);
+        .find(|display_style| percentage <= display_style.threshold as f32)?;
 
-    if let Some(display_style) = display_style {
-        // Set style based on percentage
-        module.set_style(display_style.style);
-        module.get_prefix().set_value("");
+    // Parse the format string and build the module
+    match StringFormatter::new(config.format) {
+        Ok(formatter) => {
+            let formatter = formatter
+                .map_meta(|variable, _| match variable {
+                    "symbol" => match state {
+                        battery::State::Full => Some(config.full_symbol),
+                        battery::State::Charging => Some(config.charging_symbol),
+                        battery::State::Discharging => Some(config.discharging_symbol),
+                        battery::State::Unknown => config.unknown_symbol,
+                        battery::State::Empty => config.empty_symbol,
+                        _ => {
+                            log::debug!("Unhandled battery state `{}`", state);
+                            None
+                        }
+                    },
+                    _ => None,
+                })
+                .map_style(|style| match style {
+                    "style" => Some(Ok(display_style.style)),
+                    _ => None,
+                })
+                .map(|variable| match variable {
+                    "percentage" => Some(Ok(format!("{}{}", percentage.round(), percentage_char))),
+                    _ => None,
+                });
 
-        match state {
-            battery::State::Full => {
-                module.create_segment("full_symbol", &battery_config.full_symbol);
-            }
-            battery::State::Charging => {
-                module.create_segment("charging_symbol", &battery_config.charging_symbol);
-            }
-            battery::State::Discharging => {
-                module.create_segment("discharging_symbol", &battery_config.discharging_symbol);
-            }
-            battery::State::Unknown => {
-                log::debug!("Unknown detected");
-                if let Some(unknown_symbol) = battery_config.unknown_symbol {
-                    module.create_segment("unknown_symbol", &unknown_symbol);
+            match formatter.parse(None) {
+                Ok(format_string) => {
+                    module.set_segments(format_string);
+                    Some(module)
                 }
-            }
-            battery::State::Empty => {
-                if let Some(empty_symbol) = battery_config.empty_symbol {
-                    module.create_segment("empty_symbol", &empty_symbol);
+                Err(e) => {
+                    log::warn!("Cannot parse `battery.format`: {}", e);
+                    None
                 }
             }
-            _ => {
-                log::debug!("Unhandled battery state `{}`", state);
-                return None;
-            }
         }
-
-        let mut percent_string = Vec::<String>::with_capacity(2);
-        // Round the percentage to a whole number
-        percent_string.push(percentage.round().to_string());
-        percent_string.push(percentage_char.to_string());
-        module.create_segment(
-            "percentage",
-            &battery_config
-                .percentage
-                .with_value(percent_string.join("").as_ref()),
-        );
-
-        Some(module)
-    } else {
-        None
+        Err(e) => {
+            log::warn!("Cannot load `battery.format`: {}", e);
+            None
+        }
     }
 }
 

src/modules/character.rs

@@ -1,14 +1,15 @@
 use super::{Context, Module, RootModuleConfig, Shell};
 use crate::configs::character::CharacterConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module for the prompt character
 ///
-/// The character segment prints an arrow character in a color dependant on the exit-
-/// code of the last executed command:
-/// - If the exit-code was "0", the arrow will be formatted with `style_success`
-/// (green by default)
-/// - If the exit-code was anything else, the arrow will be formatted with
-/// `style_failure` (red by default)
+/// The character segment prints an arrow character in a color dependant on the
+/// exit-code of the last executed command:
+/// - If the exit-code was "0", it will be formatted with `success_symbol`
+///   (green arrow by default)
+/// - If the exit-code was anything else, it will be formatted with
+///   `error_symbol` (red arrow by default)
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     enum ShellEditMode {
         Normal,
@@ -19,12 +20,11 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     let mut module = context.new_module("character");
     let config: CharacterConfig = CharacterConfig::try_load(module.config);
-    module.get_prefix().set_value("");
 
     let props = &context.properties;
-    let exit_code_default = std::string::String::from("0");
+    let exit_code_default = String::from("0");
     let exit_code = props.get("status_code").unwrap_or(&exit_code_default);
-    let keymap_default = std::string::String::from("viins");
+    let keymap_default = String::from("viins");
     let keymap = props.get("keymap").unwrap_or(&keymap_default);
     let exit_success = exit_code == "0";
 
@@ -38,22 +38,33 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         _ => ASSUMED_MODE,
     };
 
-    if exit_success {
-        module.set_style(config.style_success);
-    } else {
-        module.set_style(config.style_failure);
-    };
-
-    /* If an error symbol is set in the config, use symbols to indicate
-    success/failure, in addition to color */
-    if config.use_symbol_for_status && !exit_success {
-        module.create_segment("error_symbol", &config.error_symbol)
-    } else {
-        match mode {
-            ShellEditMode::Normal => module.create_segment("vicmd_symbol", &config.vicmd_symbol),
-            ShellEditMode::Insert => module.create_segment("symbol", &config.symbol),
+    let symbol = match mode {
+        ShellEditMode::Normal => config.vicmd_symbol,
+        ShellEditMode::Insert => {
+            if exit_success {
+                config.success_symbol
+            } else {
+                config.error_symbol
+            }
         }
     };
 
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(symbol),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `character`:\n{}", error);
+            return None;
+        }
+    });
+
     Some(module)
 }

src/modules/cmd_duration.rs

@@ -1,7 +1,7 @@
-use super::{Context, Module, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
-use crate::config::RootModuleConfig;
 use crate::configs::cmd_duration::CmdDurationConfig;
+use crate::formatter::StringFormatter;
 
 /// Outputs the time it took the last command to execute
 ///
@@ -28,19 +28,30 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    let config_min = config.min_time as u128;
+    if elapsed < config.min_time as u128 {
+        return None;
+    }
 
-    let module_color = match elapsed {
-        time if time < config_min => return None,
-        _ => config.style,
-    };
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "duration" => Some(Ok(render_time(elapsed, config.show_milliseconds))),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.set_style(module_color);
-    module.create_segment(
-        "cmd_duration",
-        &SegmentConfig::new(&render_time(elapsed, config.show_milliseconds)),
-    );
-    module.get_prefix().set_value(config.prefix);
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `cmd_duration`: \n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/conda.rs

@@ -1,10 +1,10 @@
 use std::env;
 
-use super::{Context, Module};
+use super::{Context, Module, RootModuleConfig};
 
 use super::utils::directory::truncate;
-use crate::config::RootModuleConfig;
 use crate::configs::conda::CondaConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the current Conda environment
 ///
@@ -17,14 +17,34 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let mut module = context.new_module("conda");
-    let config = CondaConfig::try_load(module.config);
+    let config: CondaConfig = CondaConfig::try_load(module.config);
 
     let conda_env = truncate(conda_env, config.truncation_length);
 
-    module.set_style(config.style);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "environment" => Some(Ok(conda_env.as_str())),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("environment", &config.environment.with_value(&conda_env));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `conda`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/crystal.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::crystal::CrystalConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Crystal version
@@ -20,14 +21,34 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let crystal_version = utils::exec_cmd("crystal", &["--version"])?.stdout;
-    let formatted_version = format_crystal_version(&crystal_version)?;
 
     let mut module = context.new_module("crystal");
     let config: CrystalConfig = CrystalConfig::try_load(module.config);
-    module.set_style(config.style);
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => format_crystal_version(&crystal_version).map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `crystal`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/custom.rs

@@ -1,10 +1,9 @@
-use ansi_term::Color;
 use std::io::Write;
 use std::process::{Command, Output, Stdio};
 
 use super::{Context, Module, RootModuleConfig};
 
-use crate::{config::SegmentConfig, configs::custom::CustomConfig};
+use crate::{configs::custom::CustomConfig, formatter::StringFormatter};
 
 /// Creates a custom module with some configuration
 ///
@@ -13,7 +12,7 @@ use crate::{config::SegmentConfig, configs::custom::CustomConfig};
 /// command can be run -- if its result is 0, the module will be shown.
 ///
 /// Finally, the content of the module itself is also set by a command.
-pub fn module<'a>(name: &'a str, context: &'a Context) -> Option<Module<'a>> {
+pub fn module<'a>(name: &str, context: &'a Context) -> Option<Module<'a>> {
     let toml_config = context.config.get_custom_module_config(name).expect(
         "modules::custom::module should only be called after ensuring that the module exists",
     );
@@ -44,35 +43,42 @@ pub fn module<'a>(name: &'a str, context: &'a Context) -> Option<Module<'a>> {
     }
 
     let mut module = Module::new(name, config.description, Some(toml_config));
-    let style = config.style.unwrap_or_else(|| Color::Green.bold());
 
-    if let Some(prefix) = config.prefix {
-        module.get_prefix().set_value(prefix);
-    }
-    if let Some(suffix) = config.suffix {
-        module.get_suffix().set_value(suffix);
+    let output = exec_command(config.command, &config.shell.0)?;
+
+    let trimmed = output.trim();
+    if trimmed.is_empty() {
+        return None;
     }
 
-    if let Some(symbol) = config.symbol {
-        module.create_segment("symbol", &symbol);
-    }
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                // This may result in multiple calls to `get_module_version` when a user have
+                // multiple `$version` variables defined in `format`.
+                "output" => Some(Ok(trimmed)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    if let Some(output) = exec_command(config.command, &config.shell.0) {
-        let trimmed = output.trim();
-
-        if trimmed.is_empty() {
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `custom.{}`:\n{}", name, error);
             return None;
         }
+    });
 
-        module.create_segment(
-            "output",
-            &SegmentConfig::new(&trimmed).with_style(Some(style)),
-        );
-
-        Some(module)
-    } else {
-        None
-    }
+    Some(module)
 }
 
 /// Return the invoking shell, using `shell` and fallbacking in order to STARSHIP_SHELL and "sh"

src/modules/directory.rs

@@ -7,8 +7,9 @@ use unicode_segmentation::UnicodeSegmentation;
 use super::{Context, Module};
 
 use super::utils::directory::truncate;
-use crate::config::{RootModuleConfig, SegmentConfig};
+use crate::config::RootModuleConfig;
 use crate::configs::directory::DirectoryConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the current directory
 ///
@@ -29,8 +30,6 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("directory");
     let config: DirectoryConfig = DirectoryConfig::try_load(module.config);
 
-    module.set_style(config.style);
-
     // Using environment PWD is the standard approach for determining logical path
     // If this is None for any reason, we fall back to reading the os-provided path
     let physical_current_dir = if config.use_logical_path {
@@ -80,33 +79,39 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     // Substitutions could have changed the prefix, so don't allow them and
     // fish-style path contraction together
-    if config.fish_style_pwd_dir_length > 0 && config.substitutions.is_empty() {
+    let fish_prefix = if config.fish_style_pwd_dir_length > 0 && config.substitutions.is_empty() {
         // If user is using fish style path, we need to add the segment first
         let contracted_home_dir = contract_path(&current_dir, &home_dir, HOME_SYMBOL);
-        let fish_style_dir = to_fish_style(
+        to_fish_style(
             config.fish_style_pwd_dir_length as usize,
             contracted_home_dir,
             &truncated_dir_string,
-        );
+        )
+    } else {
+        String::from("")
+    };
+    let final_dir_string = format!("{}{}", fish_prefix, truncated_dir_string);
 
-        module.create_segment(
-            "path",
-            &SegmentConfig {
-                value: &fish_style_dir,
-                style: None,
-            },
-        );
-    }
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "path" => Some(Ok(&final_dir_string)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.create_segment(
-        "path",
-        &SegmentConfig {
-            value: &truncated_dir_string,
-            style: None,
-        },
-    );
-
-    module.get_prefix().set_value(config.prefix);
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `directory`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/docker_context.rs

@@ -1,14 +1,17 @@
+use std::env;
+use std::path::PathBuf;
+
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::docker_context::DockerContextConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
-const DOCKER_CONFIG_FILE: &str = ".docker/config.json";
-
 /// Creates a module with the currently active Docker context
 ///
 /// Will display the Docker context if the following criteria are met:
 ///     - There is a file named `$HOME/.docker/config.json`
+///     - Or a file named `$DOCKER_CONFIG/config.json`
 ///     - The file is JSON and contains a field named `currentContext`
 ///     - The value of `currentContext` is not `default`
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
@@ -23,9 +26,17 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     {
         return None;
     }
+    let docker_config = PathBuf::from(
+        &env::var_os("DOCKER_CONFIG")
+            .unwrap_or(dirs_next::home_dir()?.join(".docker").into_os_string()),
+    )
+    .join("config.json");
 
-    let config_path = dirs_next::home_dir()?.join(DOCKER_CONFIG_FILE);
-    let json = utils::read_file(config_path).ok()?;
+    if !docker_config.exists() {
+        return None;
+    }
+
+    let json = utils::read_file(docker_config).ok()?;
     let parsed_json = serde_json::from_str(&json).ok()?;
 
     match parsed_json {
@@ -33,9 +44,31 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
             let current_context = root.get("currentContext")?;
             match current_context {
                 serde_json::Value::String(ctx) => {
-                    module.set_style(config.style);
-                    module.create_segment("symbol", &config.symbol);
-                    module.create_segment("context", &config.context.with_value(&ctx));
+                    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+                        formatter
+                            .map_meta(|variable, _| match variable {
+                                "symbol" => Some(config.symbol),
+                                _ => None,
+                            })
+                            .map_style(|variable| match variable {
+                                "style" => Some(Ok(config.style)),
+                                _ => None,
+                            })
+                            .map(|variable| match variable {
+                                "context" => Some(Ok(ctx)),
+                                _ => None,
+                            })
+                            .parse(None)
+                    });
+
+                    module.set_segments(match parsed {
+                        Ok(segments) => segments,
+                        Err(error) => {
+                            log::warn!("Error in module `docker_context`:\n{}", error);
+                            return None;
+                        }
+                    });
+
                     Some(module)
                 }
                 _ => None,

src/modules/dotnet.rs

@@ -1,3 +1,5 @@
+use quick_xml::events::Event;
+use quick_xml::Reader;
 use std::ffi::OsStr;
 use std::iter::Iterator;
 use std::ops::Deref;
@@ -6,6 +8,7 @@ use std::str;
 
 use super::{Context, Module, RootModuleConfig};
 use crate::configs::dotnet::DotnetConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 type JValue = serde_json::Value;
@@ -48,20 +51,90 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     // Internally, this module uses its own mechanism for version detection.
     // Typically it is twice as fast as running `dotnet --version`.
     let enable_heuristic = config.heuristic;
-    let version = if enable_heuristic {
-        let repo_root = context.get_repo().ok().and_then(|r| r.root.as_deref());
-        estimate_dotnet_version(&dotnet_files, &context.current_dir, repo_root)?
-    } else {
-        get_version_from_cli()?
-    };
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &config.version.with_value(&version.0));
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "symbol" => Some(Ok(config.symbol)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => {
+                    let version = if enable_heuristic {
+                        let repo_root = context.get_repo().ok().and_then(|r| r.root.as_deref());
+                        estimate_dotnet_version(&dotnet_files, &context.current_dir, repo_root)
+                    } else {
+                        get_version_from_cli()
+                    };
+                    version.map(|v| Ok(v.0))
+                }
+                "tfm" => find_current_tfm(&dotnet_files).map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `dotnet`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }
 
+fn find_current_tfm<'a>(files: &[DotNetFile<'a>]) -> Option<String> {
+    let get_file_of_type = |t: FileType| files.iter().find(|f| f.file_type == t);
+
+    let relevant_file = get_file_of_type(FileType::ProjectFile)?;
+
+    get_tfm_from_project_file(relevant_file.path)
+}
+
+fn get_tfm_from_project_file(path: &Path) -> Option<String> {
+    let project_file = utils::read_file(path).ok()?;
+    let mut reader = Reader::from_str(&project_file);
+    reader.trim_text(true);
+
+    let mut in_tfm = false;
+    let mut buf = Vec::new();
+
+    loop {
+        match reader.read_event(&mut buf) {
+            // for triggering namespaced events, use this instead:
+            // match reader.read_namespaced_event(&mut buf) {
+            Ok(Event::Start(ref e)) => {
+                // for namespaced:
+                // Ok((ref namespace_value, Event::Start(ref e)))
+                match e.name() {
+                    b"TargetFrameworks" => in_tfm = true,
+                    b"TargetFramework" => in_tfm = true,
+                    _ => in_tfm = false,
+                }
+            }
+            // unescape and decode the text event using the reader encoding
+            Ok(Event::Text(e)) => {
+                if in_tfm {
+                    return e.unescape_and_decode(&reader).ok();
+                }
+            }
+            Ok(Event::Eof) => break, // exits the loop when reaching end of file
+            Err(e) => panic!("Error at position {}: {:?}", reader.buffer_position(), e),
+            _ => (), // There are several other `Event`s we do not consider here
+        }
+
+        // if we don't keep a borrow elsewhere, we can clear the buffer to keep memory usage low
+        buf.clear();
+    }
+    None
+}
+
 fn estimate_dotnet_version<'a>(
     files: &[DotNetFile<'a>],
     current_dir: &Path,

src/modules/elixir.rs

@@ -1,9 +1,10 @@
-use regex::Regex;
-
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::elixir::ElixirConfig;
+use crate::formatter::StringFormatter;
+use crate::utils;
 
+use regex::Regex;
 const ELIXIR_VERSION_PATTERN: &str = "\
 Erlang/OTP (?P<otp>\\d+)[^\\n]+
 
@@ -11,7 +12,7 @@ Elixir (?P<elixir>\\d[.\\d]+).*";
 
 /// Create a module with the current Elixir version
 ///
-/// Will display the Rust version if any of the following criteria are met:
+/// Will display the Elixir version if any of the following criteria are met:
 ///     - Current directory contains a `mix.exs` file
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let is_elixir_project = context.try_begin_scan()?.set_files(&["mix.exs"]).is_match();
@@ -24,23 +25,36 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     let mut module = context.new_module("elixir");
     let config = ElixirConfig::try_load(module.config);
-    module.set_style(config.style);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(&elixir_version)),
+                "otp_version" => Some(Ok(&otp_version)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &config.version.with_value(&elixir_version));
-    module.create_segment(
-        "otp_version",
-        &config
-            .otp_version
-            .with_value(&format!(" (OTP {})", otp_version)),
-    );
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `elixir`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }
 
 fn get_elixir_version() -> Option<(String, String)> {
-    use crate::utils;
-
     let output = utils::exec_cmd("elixir", &["--version"])?.stdout;
 
     parse_elixir_version(&output)

src/modules/elm.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::elm::ElmConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Elm version
@@ -24,14 +25,35 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let elm_version = utils::exec_cmd("elm", &["--version"])?.stdout;
-    let formatted_version = Some(format!("v{}", elm_version.trim()))?;
+    let module_version = Some(format!("v{}", elm_version.trim()))?;
 
     let mut module = context.new_module("elm");
     let config: ElmConfig = ElmConfig::try_load(module.config);
-    module.set_style(config.style);
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(&module_version)),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `elm`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/env_var.rs

@@ -1,9 +1,10 @@
 use std::env;
 
-use super::{Context, Module, SegmentConfig};
+use super::{Context, Module};
 
 use crate::config::RootModuleConfig;
 use crate::configs::env_var::EnvVarConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the value of the chosen environment variable
 ///
@@ -16,17 +17,30 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let config: EnvVarConfig = EnvVarConfig::try_load(module.config);
 
     let env_value = get_env_value(config.variable?, config.default)?;
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "env_value" => Some(Ok(&env_value)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.set_style(config.style);
-    module.get_prefix().set_value("with ");
-
-    if let Some(symbol) = config.symbol {
-        module.create_segment("symbol", &symbol);
-    }
-
-    // TODO: Use native prefix and suffix instead of stacking custom ones together with env_value.
-    let env_var_stacked = format!("{}{}{}", config.prefix, env_value, config.suffix);
-    module.create_segment("env_var", &SegmentConfig::new(&env_var_stacked));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `env_var`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/erlang.rs

@@ -1,6 +1,7 @@
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::erlang::ErlangConfig;
+use crate::formatter::StringFormatter;
 
 /// Create a module with the current Erlang version
 ///
@@ -17,14 +18,33 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    let erlang_version = get_erlang_version()?;
-
     let mut module = context.new_module("erlang");
     let config = ErlangConfig::try_load(module.config);
-    module.set_style(config.style);
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &config.version.with_value(&erlang_version));
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => get_erlang_version().map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `erlang`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/git_branch.rs

@@ -3,6 +3,7 @@ use unicode_segmentation::UnicodeSegmentation;
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::git_branch::GitBranchConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the Git branch in the current directory
 ///
@@ -10,15 +11,11 @@ use crate::configs::git_branch::GitBranchConfig;
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("git_branch");
     let config = GitBranchConfig::try_load(module.config);
-    module.set_style(config.style);
 
-    module.get_prefix().set_value("on ");
-
-    let truncation_symbol = get_graphemes(config.truncation_symbol, 1);
-    module.create_segment("symbol", &config.symbol);
+    let truncation_symbol = get_first_grapheme(config.truncation_symbol);
 
     // TODO: Once error handling is implemented, warn the user if their config
-    // truncation length is nonsensical
+    //       truncation length is nonsensical
     let len = if config.truncation_length <= 0 {
         log::warn!(
             "\"truncation_length\" should be a positive value, found {}",
@@ -31,29 +28,50 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     let repo = context.get_repo().ok()?;
     let branch_name = repo.branch.as_ref()?;
-    let truncated_graphemes = get_graphemes(&branch_name, len);
-    // The truncation symbol should only be added if we truncated
-    let truncated_and_symbol = if len < graphemes_len(&branch_name) {
-        truncated_graphemes + &truncation_symbol
-    } else {
-        truncated_graphemes
-    };
 
-    module.create_segment(
-        "name",
-        &config.branch_name.with_value(&truncated_and_symbol),
-    );
+    let mut graphemes = get_graphemes(&branch_name);
+    let trunc_len = len.min(graphemes.len());
+
+    if trunc_len < graphemes.len() {
+        // The truncation symbol should only be added if we truncate
+        graphemes[trunc_len] = truncation_symbol;
+        graphemes.truncate(trunc_len + 1)
+    }
+
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "branch" => Some(Ok(graphemes.concat())),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `git_branch`: \n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }
 
-fn get_graphemes(text: &str, length: usize) -> String {
+fn get_first_grapheme(text: &str) -> &str {
     UnicodeSegmentation::graphemes(text, true)
-        .take(length)
-        .collect::<Vec<&str>>()
-        .concat()
+        .next()
+        .unwrap_or("")
 }
 
-fn graphemes_len(text: &str) -> usize {
-    UnicodeSegmentation::graphemes(&text[..], true).count()
+fn get_graphemes(text: &str) -> Vec<&str> {
+    UnicodeSegmentation::graphemes(text, true).collect()
 }

src/modules/git_commit.rs

@@ -2,23 +2,14 @@ use super::{Context, Module, RootModuleConfig};
 use git2::Repository;
 
 use crate::configs::git_commit::GitCommitConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the Git commit in the current directory
 ///
 /// Will display the commit hash if the current directory is a git repo
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("git_commit");
-    let config = GitCommitConfig::try_load(module.config);
-
-    module
-        .get_prefix()
-        .set_value(config.prefix)
-        .set_style(config.style);
-    module
-        .get_suffix()
-        .set_value(config.suffix)
-        .set_style(config.style);
-    module.set_style(config.style);
+    let config: GitCommitConfig = GitCommitConfig::try_load(module.config);
 
     let repo = context.get_repo().ok()?;
     let repo_root = repo.root.as_ref()?;
@@ -32,13 +23,30 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let git_head = git_repo.head().ok()?;
     let head_commit = git_head.peel_to_commit().ok()?;
     let commit_oid = head_commit.id();
-    module.create_segment(
-        "hash",
-        &config.hash.with_value(&id_to_hex_abbrev(
-            commit_oid.as_bytes(),
-            config.commit_hash_length,
-        )),
-    );
+
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "hash" => Some(Ok(id_to_hex_abbrev(
+                    commit_oid.as_bytes(),
+                    config.commit_hash_length,
+                ))),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `git_commit`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/git_state.rs

@@ -1,8 +1,9 @@
 use git2::RepositoryState;
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 use crate::configs::git_state::GitStateConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the state of the git repository at the current directory
 ///
@@ -12,37 +13,37 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("git_state");
     let config: GitStateConfig = GitStateConfig::try_load(module.config);
 
-    module.set_style(config.style);
-    module.get_prefix().set_value("(");
-    module.get_suffix().set_value(") ");
-
     let repo = context.get_repo().ok()?;
     let repo_root = repo.root.as_ref()?;
     let repo_state = repo.state?;
 
-    let state_description = get_state_description(repo_state, repo_root, config);
+    let state_description = get_state_description(repo_state, repo_root, &config)?;
 
-    let label = match &state_description {
-        StateDescription::Label(label) => label,
-        StateDescription::LabelAndProgress(label, _) => label,
-        StateDescription::Clean => {
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "state" => Some(state_description.label),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "progress_current" => state_description.current.as_ref().map(Ok),
+                "progress_total" => state_description.total.as_ref().map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `git_state`:\n{}", error);
             return None;
         }
-    };
-
-    module.create_segment(label.name, &label.segment);
-
-    if let StateDescription::LabelAndProgress(_, progress) = &state_description {
-        module.create_segment(
-            "progress_current",
-            &SegmentConfig::new(&format!(" {}", progress.current)),
-        );
-        module.create_segment("progress_divider", &SegmentConfig::new("/"));
-        module.create_segment(
-            "progress_total",
-            &SegmentConfig::new(&format!("{}", progress.total)),
-        );
-    }
+    });
 
     Some(module)
 }
@@ -53,40 +54,57 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 fn get_state_description<'a>(
     state: RepositoryState,
     root: &'a std::path::PathBuf,
-    config: GitStateConfig<'a>,
-) -> StateDescription<'a> {
+    config: &GitStateConfig<'a>,
+) -> Option<StateDescription<'a>> {
     match state {
-        RepositoryState::Clean => StateDescription::Clean,
-        RepositoryState::Merge => StateDescription::Label(StateLabel::new("merge", config.merge)),
-        RepositoryState::Revert => {
-            StateDescription::Label(StateLabel::new("revert", config.revert))
-        }
-        RepositoryState::RevertSequence => {
-            StateDescription::Label(StateLabel::new("revert", config.revert))
-        }
-        RepositoryState::CherryPick => {
-            StateDescription::Label(StateLabel::new("cherry_pick", config.cherry_pick))
-        }
-        RepositoryState::CherryPickSequence => {
-            StateDescription::Label(StateLabel::new("cherry_pick", config.cherry_pick))
-        }
-        RepositoryState::Bisect => {
-            StateDescription::Label(StateLabel::new("bisect", config.bisect))
-        }
-        RepositoryState::ApplyMailbox => StateDescription::Label(StateLabel::new("am", config.am)),
-        RepositoryState::ApplyMailboxOrRebase => {
-            StateDescription::Label(StateLabel::new("am_or_rebase", config.am_or_rebase))
-        }
-        RepositoryState::Rebase => describe_rebase(root, config.rebase),
-        RepositoryState::RebaseInteractive => describe_rebase(root, config.rebase),
-        RepositoryState::RebaseMerge => describe_rebase(root, config.rebase),
+        RepositoryState::Clean => None,
+        RepositoryState::Merge => Some(StateDescription {
+            label: config.merge,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::Revert => Some(StateDescription {
+            label: config.revert,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::RevertSequence => Some(StateDescription {
+            label: config.revert,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::CherryPick => Some(StateDescription {
+            label: config.cherry_pick,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::CherryPickSequence => Some(StateDescription {
+            label: config.cherry_pick,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::Bisect => Some(StateDescription {
+            label: config.bisect,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::ApplyMailbox => Some(StateDescription {
+            label: config.am,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::ApplyMailboxOrRebase => Some(StateDescription {
+            label: config.am_or_rebase,
+            current: None,
+            total: None,
+        }),
+        RepositoryState::Rebase => Some(describe_rebase(root, config.rebase)),
+        RepositoryState::RebaseInteractive => Some(describe_rebase(root, config.rebase)),
+        RepositoryState::RebaseMerge => Some(describe_rebase(root, config.rebase)),
     }
 }
 
-fn describe_rebase<'a>(
-    root: &'a PathBuf,
-    rebase_config: SegmentConfig<'a>,
-) -> StateDescription<'a> {
+fn describe_rebase<'a>(root: &'a PathBuf, rebase_config: &'a str) -> StateDescription<'a> {
     /*
      *  Sadly, libgit2 seems to have some issues with reading the state of
      *  interactive rebases. So, instead, we'll poke a few of the .git files
@@ -98,12 +116,12 @@ fn describe_rebase<'a>(
     let dot_git = root.join(".git");
 
     let has_path = |relative_path: &str| {
-        let path = dot_git.join(Path::new(relative_path));
+        let path = dot_git.join(PathBuf::from(relative_path));
         path.exists()
     };
 
     let file_to_usize = |relative_path: &str| {
-        let path = dot_git.join(Path::new(relative_path));
+        let path = dot_git.join(PathBuf::from(relative_path));
         let contents = crate::utils::read_file(path).ok()?;
         let quantity = contents.trim().parse::<usize>().ok()?;
         Some(quantity)
@@ -112,7 +130,7 @@ fn describe_rebase<'a>(
     let paths_to_progress = |current_path: &str, total_path: &str| {
         let current = file_to_usize(current_path)?;
         let total = file_to_usize(total_path)?;
-        Some(StateProgress { current, total })
+        Some((current, total))
     };
 
     let progress = if has_path("rebase-merge") {
@@ -123,32 +141,15 @@ fn describe_rebase<'a>(
         None
     };
 
-    match progress {
-        None => StateDescription::Label(StateLabel::new("rebase", rebase_config)),
-        Some(progress) => {
-            StateDescription::LabelAndProgress(StateLabel::new("rebase", rebase_config), progress)
-        }
+    StateDescription {
+        label: rebase_config,
+        current: Some(format!("{}", progress.unwrap().0)),
+        total: Some(format!("{}", progress.unwrap().1)),
     }
 }
 
-enum StateDescription<'a> {
-    Clean,
-    Label(StateLabel<'a>),
-    LabelAndProgress(StateLabel<'a>, StateProgress),
-}
-
-struct StateLabel<'a> {
-    name: &'static str,
-    segment: SegmentConfig<'a>,
-}
-
-struct StateProgress {
-    current: usize,
-    total: usize,
-}
-
-impl<'a> StateLabel<'a> {
-    fn new(name: &'static str, segment: SegmentConfig<'a>) -> Self {
-        Self { name, segment }
-    }
+struct StateDescription<'a> {
+    label: &'a str,
+    current: Option<String>,
+    total: Option<String>,
 }

src/modules/git_status.rs

@@ -2,10 +2,13 @@ use git2::{Repository, Status};
 
 use super::{Context, Module, RootModuleConfig};
 
-use crate::config::SegmentConfig;
-use crate::configs::git_status::{CountConfig, GitStatusConfig};
-use std::borrow::BorrowMut;
-use std::collections::HashMap;
+use crate::configs::git_status::GitStatusConfig;
+use crate::context::Repo;
+use crate::formatter::StringFormatter;
+use crate::segment::Segment;
+use std::sync::{Arc, RwLock};
+
+const ALL_STATUS_FORMAT: &str = "$conflicted$stashed$deleted$renamed$modified$staged$untracked";
 
 /// Creates a module with the Git branch in the current directory
 ///
@@ -23,174 +26,233 @@ use std::collections::HashMap;
 ///   - `✘` — A file's deletion has been added to the staging area
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let repo = context.get_repo().ok()?;
-    let branch_name = repo.branch.as_ref()?;
-    let repo_root = repo.root.as_ref()?;
-    let mut repository = Repository::open(repo_root).ok()?;
+    let info = Arc::new(GitStatusInfo::load(repo));
 
     let mut module = context.new_module("git_status");
     let config: GitStatusConfig = GitStatusConfig::try_load(module.config);
 
-    module
-        .get_prefix()
-        .set_value(config.prefix)
-        .set_style(config.style);
-    module
-        .get_suffix()
-        .set_value(config.suffix)
-        .set_style(config.style);
-    module.set_style(config.style);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "all_status" => Some(ALL_STATUS_FORMAT),
+                _ => None,
+            })
+            .map_style(|variable: &str| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map_variables_to_segments(|variable: &str| {
+                let info = Arc::clone(&info);
+                let segments = match variable {
+                    "stashed" => info.get_stashed().and_then(|count| {
+                        format_count(config.stashed, "git_status.stashed", count)
+                    }),
+                    "ahead_behind" => info.get_ahead_behind().and_then(|(ahead, behind)| {
+                        if ahead > 0 && behind > 0 {
+                            format_text(config.diverged, "git_status.diverged", |variable| {
+                                match variable {
+                                    "ahead_count" => Some(ahead.to_string()),
+                                    "behind_count" => Some(behind.to_string()),
+                                    _ => None,
+                                }
+                            })
+                        } else if ahead > 0 && behind == 0 {
+                            format_count(config.ahead, "git_status.ahead", ahead)
+                        } else if behind > 0 && ahead == 0 {
+                            format_count(config.behind, "git_status.behind", behind)
+                        } else {
+                            None
+                        }
+                    }),
+                    "conflicted" => info.get_conflicted().and_then(|count| {
+                        format_count(config.conflicted, "git_status.conflicted", count)
+                    }),
+                    "deleted" => info.get_deleted().and_then(|count| {
+                        format_count(config.deleted, "git_status.deleted", count)
+                    }),
+                    "renamed" => info.get_renamed().and_then(|count| {
+                        format_count(config.renamed, "git_status.renamed", count)
+                    }),
+                    "modified" => info.get_modified().and_then(|count| {
+                        format_count(config.modified, "git_status.modified", count)
+                    }),
+                    "staged" => info
+                        .get_staged()
+                        .and_then(|count| format_count(config.staged, "git_status.staged", count)),
+                    "untracked" => info.get_untracked().and_then(|count| {
+                        format_count(config.untracked, "git_status.untracked", count)
+                    }),
+                    _ => None,
+                };
+                segments.map(Ok)
+            })
+            .parse(None)
+    });
 
-    let repo_status = get_repo_status(repository.borrow_mut());
-    log::debug!("Repo status: {:?}", repo_status);
-
-    let ahead_behind = get_ahead_behind(&repository, branch_name);
-    if ahead_behind == Ok((0, 0)) {
-        log::trace!("No ahead/behind found");
-    } else {
-        log::debug!("Repo ahead/behind: {:?}", ahead_behind);
-    }
-
-    // Add the conflicted segment
-    if let Ok(repo_status) = repo_status {
-        create_segment_with_count(
-            &mut module,
-            "conflicted",
-            repo_status.conflicted,
-            &config.conflicted,
-            config.conflicted_count,
-        );
-    }
-
-    // Add the ahead/behind segment
-    if let Ok((ahead, behind)) = ahead_behind {
-        let add_ahead = |m: &mut Module<'a>| {
-            create_segment_with_count(
-                m,
-                "ahead",
-                ahead,
-                &config.ahead,
-                CountConfig {
-                    enabled: config.show_sync_count,
-                    style: None,
-                },
-            );
-        };
-
-        let add_behind = |m: &mut Module<'a>| {
-            create_segment_with_count(
-                m,
-                "behind",
-                behind,
-                &config.behind,
-                CountConfig {
-                    enabled: config.show_sync_count,
-                    style: None,
-                },
-            );
-        };
-
-        if ahead > 0 && behind > 0 {
-            module.create_segment("diverged", &config.diverged);
-
-            if config.show_sync_count {
-                add_ahead(&mut module);
-                add_behind(&mut module);
+    module.set_segments(match parsed {
+        Ok(segments) => {
+            if segments.is_empty() {
+                return None;
+            } else {
+                segments
             }
         }
-
-        if ahead > 0 && behind == 0 {
-            add_ahead(&mut module);
+        Err(error) => {
+            log::warn!("Error in module `git_status`:\n{}", error);
+            return None;
         }
-
-        if behind > 0 && ahead == 0 {
-            add_behind(&mut module);
-        }
-    }
-
-    // Add the stashed segment
-    if let Ok(repo_status) = repo_status {
-        create_segment_with_count(
-            &mut module,
-            "stashed",
-            repo_status.stashed,
-            &config.stashed,
-            config.stashed_count,
-        );
-    }
-
-    // Add all remaining status segments
-    if let Ok(repo_status) = repo_status {
-        create_segment_with_count(
-            &mut module,
-            "deleted",
-            repo_status.deleted,
-            &config.deleted,
-            config.deleted_count,
-        );
-
-        create_segment_with_count(
-            &mut module,
-            "renamed",
-            repo_status.renamed,
-            &config.renamed,
-            config.renamed_count,
-        );
-
-        create_segment_with_count(
-            &mut module,
-            "modified",
-            repo_status.modified,
-            &config.modified,
-            config.modified_count,
-        );
-
-        create_segment_with_count(
-            &mut module,
-            "staged",
-            repo_status.staged,
-            &config.staged,
-            config.staged_count,
-        );
-
-        create_segment_with_count(
-            &mut module,
-            "untracked",
-            repo_status.untracked,
-            &config.untracked,
-            config.untracked_count,
-        );
-    }
-
-    if module.is_empty() {
-        return None;
-    }
+    });
 
     Some(module)
 }
 
-fn create_segment_with_count<'a>(
-    module: &mut Module<'a>,
-    name: &str,
-    count: usize,
-    config: &SegmentConfig<'a>,
-    count_config: CountConfig,
-) {
-    if count > 0 {
-        module.create_segment(name, &config);
+struct GitStatusInfo<'a> {
+    repo: &'a Repo,
+    ahead_behind: RwLock<Option<Result<(usize, usize), git2::Error>>>,
+    repo_status: RwLock<Option<Result<RepoStatus, git2::Error>>>,
+    stashed_count: RwLock<Option<Result<usize, git2::Error>>>,
+}
 
-        if count_config.enabled {
-            module.create_segment(
-                &format!("{}_count", name),
-                &SegmentConfig::new(&count.to_string()).with_style(count_config.style),
-            );
+impl<'a> GitStatusInfo<'a> {
+    pub fn load(repo: &'a Repo) -> Self {
+        Self {
+            repo,
+            ahead_behind: RwLock::new(None),
+            repo_status: RwLock::new(None),
+            stashed_count: RwLock::new(None),
         }
     }
+
+    fn get_branch_name(&self) -> String {
+        self.repo
+            .branch
+            .clone()
+            .unwrap_or_else(|| String::from("master"))
+    }
+
+    fn get_repository(&self) -> Option<Repository> {
+        // bare repos don't have a branch name, so `repo.branch.as_ref` would return None,
+        // but git treats "master" as the default branch name
+        let repo_root = self.repo.root.as_ref()?;
+        Repository::open(repo_root).ok()
+    }
+
+    pub fn get_ahead_behind(&self) -> Option<(usize, usize)> {
+        {
+            let data = self.ahead_behind.read().unwrap();
+            if let Some(result) = data.as_ref() {
+                return match result.as_ref() {
+                    Ok(ahead_behind) => Some(*ahead_behind),
+                    Err(error) => {
+                        log::warn!("Warn: get_ahead_behind: {}", error);
+                        None
+                    }
+                };
+            };
+        }
+
+        {
+            let repo = self.get_repository()?;
+            let branch_name = self.get_branch_name();
+            let mut data = self.ahead_behind.write().unwrap();
+            *data = Some(get_ahead_behind(&repo, &branch_name));
+            match data.as_ref().unwrap() {
+                Ok(ahead_behind) => Some(*ahead_behind),
+                Err(error) => {
+                    log::warn!("Warn: get_ahead_behind: {}", error);
+                    None
+                }
+            }
+        }
+    }
+
+    pub fn get_repo_status(&self) -> Option<RepoStatus> {
+        {
+            let data = self.repo_status.read().unwrap();
+            if let Some(result) = data.as_ref() {
+                return match result.as_ref() {
+                    Ok(repo_status) => Some(*repo_status),
+                    Err(error) => {
+                        log::warn!("Warn: get_repo_status: {}", error);
+                        None
+                    }
+                };
+            };
+        }
+
+        {
+            let mut repo = self.get_repository()?;
+            let mut data = self.repo_status.write().unwrap();
+            *data = Some(get_repo_status(&mut repo));
+            match data.as_ref().unwrap() {
+                Ok(repo_status) => Some(*repo_status),
+                Err(error) => {
+                    log::warn!("Warn: get_repo_status: {}", error);
+                    None
+                }
+            }
+        }
+    }
+
+    pub fn get_stashed(&self) -> Option<usize> {
+        {
+            let data = self.stashed_count.read().unwrap();
+            if let Some(result) = data.as_ref() {
+                return match result.as_ref() {
+                    Ok(stashed_count) => Some(*stashed_count),
+                    Err(error) => {
+                        log::warn!("Warn: get_stashed_count: {}", error);
+                        None
+                    }
+                };
+            };
+        }
+
+        {
+            let mut repo = self.get_repository()?;
+            let mut data = self.stashed_count.write().unwrap();
+            *data = Some(get_stashed_count(&mut repo));
+            match data.as_ref().unwrap() {
+                Ok(stashed_count) => Some(*stashed_count),
+                Err(error) => {
+                    log::warn!("Warn: get_stashed_count: {}", error);
+                    None
+                }
+            }
+        }
+    }
+
+    pub fn get_conflicted(&self) -> Option<usize> {
+        self.get_repo_status().map(|data| data.conflicted)
+    }
+
+    pub fn get_deleted(&self) -> Option<usize> {
+        self.get_repo_status().map(|data| data.deleted)
+    }
+
+    pub fn get_renamed(&self) -> Option<usize> {
+        self.get_repo_status().map(|data| data.renamed)
+    }
+
+    pub fn get_modified(&self) -> Option<usize> {
+        self.get_repo_status().map(|data| data.modified)
+    }
+
+    pub fn get_staged(&self) -> Option<usize> {
+        self.get_repo_status().map(|data| data.staged)
+    }
+
+    pub fn get_untracked(&self) -> Option<usize> {
+        self.get_repo_status().map(|data| data.untracked)
+    }
 }
 
 /// Gets the number of files in various git states (staged, modified, deleted, etc...)
 fn get_repo_status(repository: &mut Repository) -> Result<RepoStatus, git2::Error> {
     let mut status_options = git2::StatusOptions::new();
 
+    let mut repo_status = RepoStatus::default();
+
     match repository.config()?.get_entry("status.showUntrackedFiles") {
         Ok(entry) => status_options.include_untracked(entry.value() != Some("no")),
         _ => status_options.include_untracked(true),
@@ -201,76 +263,21 @@ fn get_repo_status(repository: &mut Repository) -> Result<RepoStatus, git2::Erro
         .renames_index_to_workdir(true)
         .include_unmodified(true);
 
-    let statuses: Vec<Status> = repository
-        .statuses(Some(&mut status_options))?
-        .iter()
-        .map(|s| s.status())
-        .collect();
+    let statuses = repository.statuses(Some(&mut status_options))?;
 
     if statuses.is_empty() {
         return Err(git2::Error::from_str("Repo has no status"));
     }
 
-    let statuses_count = count_statuses(statuses);
-
-    let repo_status: RepoStatus = RepoStatus {
-        conflicted: *statuses_count.get("conflicted").unwrap_or(&0),
-        deleted: *statuses_count.get("deleted").unwrap_or(&0),
-        renamed: *statuses_count.get("renamed").unwrap_or(&0),
-        modified: *statuses_count.get("modified").unwrap_or(&0),
-        staged: *statuses_count.get("staged").unwrap_or(&0),
-        untracked: *statuses_count.get("untracked").unwrap_or(&0),
-        stashed: stashed_count(repository)?,
-    };
+    statuses
+        .iter()
+        .map(|s| s.status())
+        .for_each(|status| repo_status.add(status));
 
     Ok(repo_status)
 }
 
-fn count_statuses(statuses: Vec<Status>) -> HashMap<&'static str, usize> {
-    let mut predicates: HashMap<&'static str, fn(git2::Status) -> bool> = HashMap::new();
-    predicates.insert("conflicted", is_conflicted);
-    predicates.insert("deleted", is_deleted);
-    predicates.insert("renamed", is_renamed);
-    predicates.insert("modified", is_modified);
-    predicates.insert("staged", is_staged);
-    predicates.insert("untracked", is_untracked);
-
-    statuses.iter().fold(HashMap::new(), |mut map, status| {
-        for (key, predicate) in predicates.iter() {
-            if predicate(*status) {
-                let entry = map.entry(key).or_insert(0);
-                *entry += 1;
-            }
-        }
-        map
-    })
-}
-
-fn is_conflicted(status: Status) -> bool {
-    status.is_conflicted()
-}
-
-fn is_deleted(status: Status) -> bool {
-    status.is_wt_deleted() || status.is_index_deleted()
-}
-
-fn is_renamed(status: Status) -> bool {
-    status.is_wt_renamed() || status.is_index_renamed()
-}
-
-fn is_modified(status: Status) -> bool {
-    status.is_wt_modified()
-}
-
-fn is_staged(status: Status) -> bool {
-    status.is_index_modified() || status.is_index_new()
-}
-
-fn is_untracked(status: Status) -> bool {
-    status.is_wt_new()
-}
-
-fn stashed_count(repository: &mut Repository) -> Result<usize, git2::Error> {
+fn get_stashed_count(repository: &mut Repository) -> Result<usize, git2::Error> {
     let mut count = 0;
     repository.stash_foreach(|_, _, _| {
         count += 1;
@@ -303,5 +310,65 @@ struct RepoStatus {
     modified: usize,
     staged: usize,
     untracked: usize,
-    stashed: usize,
+}
+
+impl RepoStatus {
+    fn is_conflicted(status: Status) -> bool {
+        status.is_conflicted()
+    }
+
+    fn is_deleted(status: Status) -> bool {
+        status.is_wt_deleted() || status.is_index_deleted()
+    }
+
+    fn is_renamed(status: Status) -> bool {
+        status.is_wt_renamed() || status.is_index_renamed()
+    }
+
+    fn is_modified(status: Status) -> bool {
+        status.is_wt_modified()
+    }
+
+    fn is_staged(status: Status) -> bool {
+        status.is_index_modified() || status.is_index_new()
+    }
+
+    fn is_untracked(status: Status) -> bool {
+        status.is_wt_new()
+    }
+
+    fn add(&mut self, s: Status) {
+        self.conflicted += RepoStatus::is_conflicted(s) as usize;
+        self.deleted += RepoStatus::is_deleted(s) as usize;
+        self.renamed += RepoStatus::is_renamed(s) as usize;
+        self.modified += RepoStatus::is_modified(s) as usize;
+        self.staged += RepoStatus::is_staged(s) as usize;
+        self.untracked += RepoStatus::is_untracked(s) as usize;
+    }
+}
+
+fn format_text<F>(format_str: &str, config_path: &str, mapper: F) -> Option<Vec<Segment>>
+where
+    F: Fn(&str) -> Option<String> + Send + Sync,
+{
+    if let Ok(formatter) = StringFormatter::new(format_str) {
+        formatter
+            .map(|variable| mapper(variable).map(Ok))
+            .parse(None)
+            .ok()
+    } else {
+        log::error!("Error parsing format string `{}`", &config_path);
+        None
+    }
+}
+
+fn format_count(format_str: &str, config_path: &str, count: usize) -> Option<Vec<Segment>> {
+    if count == 0 {
+        return None;
+    }
+
+    format_text(format_str, config_path, |variable| match variable {
+        "count" => Some(count.to_string()),
+        _ => None,
+    })
 }

src/modules/golang.rs

@@ -1,6 +1,7 @@
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::go::GoConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Go version
@@ -34,14 +35,33 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let mut module = context.new_module("golang");
-    let config: GoConfig = GoConfig::try_load(module.config);
+    let config = GoConfig::try_load(module.config);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => {
+                    format_go_version(&utils::exec_cmd("go", &["version"])?.stdout.as_str()).map(Ok)
+                }
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
-
-    let formatted_version =
-        format_go_version(&utils::exec_cmd("go", &["version"])?.stdout.as_str())?;
-    module.create_segment("version", &config.version.with_value(&formatted_version));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `golang`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/hg_branch.rs

@@ -3,6 +3,7 @@ use unicode_segmentation::UnicodeSegmentation;
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::hg_branch::HgBranchConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the Hg bookmark or branch in the current directory
 ///
@@ -15,12 +16,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let mut module = context.new_module("hg_branch");
-    let config = HgBranchConfig::try_load(module.config);
-    module.set_style(config.style);
-
-    module.get_prefix().set_value("on ");
-
-    module.create_segment("symbol", &config.symbol);
+    let config: HgBranchConfig = HgBranchConfig::try_load(module.config);
 
     // TODO: Once error handling is implemented, warn the user if their config
     // truncation length is nonsensical
@@ -46,10 +42,30 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         truncated_graphemes
     };
 
-    module.create_segment(
-        "name",
-        &config.branch_name.with_value(&truncated_and_symbol),
-    );
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "branch" => Some(Ok(truncated_and_symbol.as_str())),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `hg_branch`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/hostname.rs

@@ -1,10 +1,11 @@
 use std::env;
 
-use super::{Context, Module, SegmentConfig};
+use super::{Context, Module};
 use std::ffi::OsString;
 
 use crate::config::RootModuleConfig;
 use crate::configs::hostname::HostnameConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the system hostname
 ///
@@ -42,10 +43,26 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         host.as_ref()
     };
 
-    module.set_style(config.style);
-    let hostname_stacked = format!("{}{}{}", config.prefix, host, config.suffix);
-    module.create_segment("hostname", &SegmentConfig::new(&hostname_stacked));
-    module.get_prefix().set_value("on ");
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "hostname" => Some(Ok(host)),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `hostname`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/java.rs

@@ -1,6 +1,7 @@
 use crate::configs::java::JavaConfig;
+use crate::formatter::StringFormatter;
 
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::modules::utils::java_version_parser;
 use crate::utils;
@@ -25,12 +26,31 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         Some(java_version) => {
             let mut module = context.new_module("java");
             let config: JavaConfig = JavaConfig::try_load(module.config);
-            module.set_style(config.style);
-
             let formatted_version = format_java_version(java_version)?;
-            module.create_segment("symbol", &config.symbol);
-            module.create_segment("version", &SegmentConfig::new(&formatted_version));
 
+            let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+                formatter
+                    .map_meta(|var, _| match var {
+                        "symbol" => Some(config.symbol),
+                        _ => None,
+                    })
+                    .map_style(|variable| match variable {
+                        "style" => Some(Ok(config.style)),
+                        _ => None,
+                    })
+                    .map(|variable| match variable {
+                        "version" => Some(Ok(&formatted_version)),
+                        _ => None,
+                    })
+                    .parse(None)
+            });
+            module.set_segments(match parsed {
+                Ok(segments) => segments,
+                Err(error) => {
+                    log::warn!("Error in module `java`:\n{}", error);
+                    return None;
+                }
+            });
             Some(module)
         }
         None => None,

src/modules/jobs.rs

@@ -1,14 +1,12 @@
-use super::{Context, Module};
+use super::{Context, Module, RootModuleConfig};
 
-use crate::config::{RootModuleConfig, SegmentConfig};
 use crate::configs::jobs::JobsConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a segment to show if there are any active jobs running
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("jobs");
-    let config: JobsConfig = JobsConfig::try_load(module.config);
-
-    module.set_style(config.style);
+    let config = JobsConfig::try_load(module.config);
 
     let props = &context.properties;
     let num_of_jobs = props
@@ -20,11 +18,37 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     if num_of_jobs == 0 {
         return None;
     }
-    module.create_segment("symbol", &config.symbol);
-    if num_of_jobs > config.threshold {
-        module.create_segment("number", &SegmentConfig::new(&num_of_jobs.to_string()));
-    }
-    module.get_prefix().set_value("");
+
+    let module_number = if num_of_jobs > config.threshold {
+        num_of_jobs.to_string()
+    } else {
+        "".to_string()
+    };
+
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "number" => Some(Ok(module_number.clone())),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `jobs`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/julia.rs

@@ -1,6 +1,7 @@
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::julia::JuliaConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Julia version
@@ -21,14 +22,34 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let mut module = context.new_module("julia");
-    let config: JuliaConfig = JuliaConfig::try_load(module.config);
+    let config = JuliaConfig::try_load(module.config);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => {
+                    format_julia_version(&utils::exec_cmd("julia", &["--version"])?.stdout.as_str())
+                        .map(Ok)
+                }
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
-
-    let formatted_version =
-        format_julia_version(&utils::exec_cmd("julia", &["--version"])?.stdout.as_str())?;
-    module.create_segment("version", &config.version.with_value(&formatted_version));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `julia`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/kubernetes.rs

@@ -6,10 +6,9 @@ use std::path;
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::kubernetes::KubernetesConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
-const KUBERNETES_PREFIX: &str = "on ";
-
 fn get_kube_context(contents: &str) -> Option<(String, String)> {
     let yaml_docs = YamlLoader::load_from_str(&contents).ok()?;
     if yaml_docs.is_empty() {
@@ -63,23 +62,44 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
                 return None;
             };
 
-            module.set_style(config.style);
-            module.get_prefix().set_value(KUBERNETES_PREFIX);
+            let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+                formatter
+                    .map_meta(|variable, _| match variable {
+                        "symbol" => Some(config.symbol),
+                        _ => None,
+                    })
+                    .map_style(|variable| match variable {
+                        "style" => Some(Ok(config.style)),
+                        _ => None,
+                    })
+                    .map(|variable| match variable {
+                        "context" => match config.context_aliases.get(&kube_ctx) {
+                            None => Some(Ok(kube_ctx.as_str())),
+                            Some(&alias) => Some(Ok(alias)),
+                        },
+                        _ => None,
+                    })
+                    .map(|variable| match variable {
+                        "namespace" => {
+                            if kube_ns != "" {
+                                Some(Ok(kube_ns.as_str()))
+                            } else {
+                                None
+                            }
+                        }
+                        _ => None,
+                    })
+                    .parse(None)
+            });
 
-            module.create_segment("symbol", &config.symbol);
+            module.set_segments(match parsed {
+                Ok(segments) => segments,
+                Err(error) => {
+                    log::warn!("Error in module `kubernetes`: \n{}", error);
+                    return None;
+                }
+            });
 
-            let displayed_context = match config.context_aliases.get(&kube_ctx) {
-                None => &kube_ctx,
-                Some(&alias) => alias,
-            };
-
-            module.create_segment("context", &config.context.with_value(&displayed_context));
-            if kube_ns != "" {
-                module.create_segment(
-                    "namespace",
-                    &config.namespace.with_value(&format!(" ({})", kube_ns)),
-                );
-            }
             Some(module)
         }
         None => None,

src/modules/line_break.rs

@@ -1,5 +1,5 @@
 use super::{Context, Module};
-use crate::config::SegmentConfig;
+use crate::segment::Segment;
 
 /// Creates a module for the line break
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
@@ -7,10 +7,11 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     let mut module = context.new_module("line_break");
 
-    module.get_prefix().set_value("");
-    module.get_suffix().set_value("");
-
-    module.create_segment("character", &SegmentConfig::new(LINE_ENDING));
+    module.set_segments(vec![Segment {
+        _name: "line_break".to_string(),
+        style: None,
+        value: LINE_ENDING.to_string(),
+    }]);
 
     Some(module)
 }

src/modules/memory_usage.rs

@@ -4,6 +4,7 @@ use sysinfo::{RefreshKind, SystemExt};
 use super::{Context, Module, RootModuleConfig, Shell};
 
 use crate::configs::memory_usage::MemoryConfig;
+use crate::formatter::StringFormatter;
 
 fn format_kib(n_kib: u64) -> String {
     let byte = Byte::from_unit(n_kib as f64, ByteUnit::KiB).unwrap_or_else(|_| Byte::from_bytes(0));
@@ -12,6 +13,14 @@ fn format_kib(n_kib: u64) -> String {
     display_bytes
 }
 
+fn format_pct(pct_number: f64, pct_sign: &str) -> String {
+    format!("{:.0}{}", pct_number, pct_sign)
+}
+
+fn format_usage_total(usage: u64, total: u64) -> String {
+    format!("{}/{}", format_kib(usage), format_kib(total))
+}
+
 /// Creates a module with system memory usage information
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("memory_usage");
@@ -19,7 +28,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
 
     // TODO: Update when v1.0 printing refactor is implemented to only
     // print escapes in a prompt context.
-    let percent_sign = match context.shell {
+    let pct_sign = match context.shell {
         Shell::Zsh => "%%", // % is an escape in zsh, see PROMPT in `man zshmisc`
         _ => "%",
     };
@@ -28,54 +37,52 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
-
     let system = sysinfo::System::new_with_specifics(RefreshKind::new().with_memory());
-
     let used_memory_kib = system.get_used_memory();
     let total_memory_kib = system.get_total_memory();
-
-    let percent_mem_used = (used_memory_kib as f64 / total_memory_kib as f64) * 100.;
+    let ram_used = (used_memory_kib as f64 / total_memory_kib as f64) * 100.;
+    let ram_pct = format_pct(ram_used, pct_sign);
 
     let threshold = config.threshold;
-
-    if percent_mem_used.round() < threshold as f64 {
+    if ram_used.round() < threshold as f64 {
         return None;
     }
 
-    let show_percentage = config.show_percentage;
-
-    let ram = if show_percentage {
-        format!("{:.0}{}", percent_mem_used, percent_sign)
-    } else {
-        format!(
-            "{}/{}",
-            format_kib(used_memory_kib),
-            format_kib(total_memory_kib)
-        )
-    };
-    module.create_segment("ram", &config.ram.with_value(&ram));
-
-    // swap only shown if enabled and there is swap on the system
+    let ram = format_usage_total(used_memory_kib, total_memory_kib);
     let total_swap_kib = system.get_total_swap();
-    if config.show_swap && total_swap_kib > 0 {
-        let used_swap_kib = system.get_used_swap();
-        let percent_swap_used = (used_swap_kib as f64 / total_swap_kib as f64) * 100.;
+    let used_swap_kib = system.get_used_swap();
+    let percent_swap_used = (used_swap_kib as f64 / total_swap_kib as f64) * 100.;
+    let swap_pct = format_pct(percent_swap_used, pct_sign);
+    let swap = format_usage_total(used_swap_kib, total_swap_kib);
 
-        let swap = if show_percentage {
-            format!("{:.0}{}", percent_swap_used, percent_sign)
-        } else {
-            format!(
-                "{}/{}",
-                format_kib(used_swap_kib),
-                format_kib(total_swap_kib)
-            )
-        };
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "ram" => Some(Ok(&ram)),
+                "ram_pct" => Some(Ok(&ram_pct)),
+                // swap only shown if there is swap on the system
+                "swap" if total_swap_kib > 0 => Some(Ok(&swap)),
+                "swap_pct" if total_swap_kib > 0 => Some(Ok(&swap_pct)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-        module.create_segment("separator", &config.separator);
-        module.create_segment("swap", &config.swap.with_value(&swap));
-    }
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `memory_usage`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/mod.rs

@@ -45,7 +45,7 @@ mod zig;
 #[cfg(feature = "battery")]
 mod battery;
 
-use crate::config::{RootModuleConfig, SegmentConfig};
+use crate::config::RootModuleConfig;
 use crate::context::{Context, Shell};
 use crate::module::Module;
 

src/modules/nim.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::nim::NimConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Nim version
@@ -19,16 +20,38 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    let nim_version_output = utils::exec_cmd("nim", &["--version"])?.stdout;
-    let formatted_nim_version = format!("v{}", parse_nim_version(&nim_version_output)?);
-
     let mut module = context.new_module("nim");
     let config = NimConfig::try_load(module.config);
 
-    module.set_style(config.style);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => utils::exec_cmd("nim", &["--version"])
+                    .map(|command_output| command_output.stdout)
+                    .and_then(|nim_version_output| {
+                        Some(format!("v{}", parse_nim_version(&nim_version_output)?))
+                    })
+                    .map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(&formatted_nim_version));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `nim`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/nix_shell.rs

@@ -1,11 +1,9 @@
 use std::env;
 
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::nix_shell::NixShellConfig;
-
-// IN_NIX_SHELL should be "pure" or "impure" but lorri uses "1" for "impure"
-// https://github.com/target/lorri/issues/140
+use crate::formatter::StringFormatter;
 
 /// Creates a module showing if inside a nix-shell
 ///
@@ -13,43 +11,53 @@ use crate::configs::nix_shell::NixShellConfig;
 /// determine if it's inside a nix-shell and the name of it.
 ///
 /// The following options are availables:
-///     - use_name   (bool)   // print the name of the nix-shell
 ///     - impure_msg (string) // change the impure msg
 ///     - pure_msg (string)   // change the pure msg
 ///
 /// Will display the following:
-///     - name (pure)    // use_name == true in a pure nix-shell
-///     - name (impure)  // use_name == true in an impure nix-shell
-///     - pure           // use_name == false in a pure nix-shell
-///     - impure         // use_name == false in an impure nix-shell
+///     - pure (name)    // $name == "name" in a pure nix-shell
+///     - impure (name)  // $name == "name" in an impure nix-shell
+///     - pure           // $name == "" in a pure nix-shell
+///     - impure         // $name == "" in an impure nix-shell
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("nix_shell");
     let config: NixShellConfig = NixShellConfig::try_load(module.config);
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
-
+    let shell_name = env::var("name").ok();
     let shell_type = env::var("IN_NIX_SHELL").ok()?;
-    let shell_type_segment: SegmentConfig = match shell_type.as_ref() {
-        "1" | "impure" => config.impure_msg,
+    let shell_type_format = match shell_type.as_ref() {
+        "impure" => config.impure_msg,
         "pure" => config.pure_msg,
         _ => {
             return None;
         }
     };
 
-    if config.use_name {
-        if let Ok(name) = env::var("name") {
-            module.create_segment(
-                "nix_shell",
-                &shell_type_segment.with_value(&format!("{} ({})", name, shell_type_segment.value)),
-            );
-        } else {
-            module.create_segment("nix_shell", &shell_type_segment);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                "state" => Some(shell_type_format),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "name" => shell_name.as_ref().map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `nix_shell`:\n{}", error);
+            return None;
         }
-    } else {
-        module.create_segment("nix_shell", &shell_type_segment);
-    }
+    });
 
     Some(module)
 }

src/modules/nodejs.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::nodejs::NodejsConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Node.js version
@@ -27,16 +28,32 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    let node_version = utils::exec_cmd("node", &["--version"])?.stdout;
-
     let mut module = context.new_module("nodejs");
-    let config: NodejsConfig = NodejsConfig::try_load(module.config);
+    let config = NodejsConfig::try_load(module.config);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(utils::exec_cmd("node", &["--version"])?.stdout)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.set_style(config.style);
-
-    let formatted_version = node_version.trim();
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(formatted_version));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `nodejs`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/ocaml.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::ocaml::OCamlConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current OCaml version
@@ -35,14 +36,33 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         utils::exec_cmd("ocaml", &["-vnum"])?.stdout
     };
 
-    let formatted_version = format!("v{}", &ocaml_version.trim());
-
     let mut module = context.new_module("ocaml");
-    let config = OCamlConfig::try_load(module.config);
-    module.set_style(config.style);
+    let config: OCamlConfig = OCamlConfig::try_load(module.config);
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(format!("v{}", &ocaml_version))),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `ocaml`: \n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/package.rs

@@ -1,33 +1,47 @@
 use std::path::PathBuf;
 
-use super::{Context, Module};
+use super::{Context, Module, RootModuleConfig};
+use crate::configs::package::PackageConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 use regex::Regex;
 use serde_json as json;
 
-use super::{RootModuleConfig, SegmentConfig};
-use crate::configs::package::PackageConfig;
-
 /// Creates a module with the current package version
 ///
 /// Will display if a version is defined for your Node.js or Rust project (if one exists)
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("package");
     let config: PackageConfig = PackageConfig::try_load(module.config);
+    let module_version = get_package_version(&context.current_dir, &config)?;
 
-    match get_package_version(&context.current_dir, &config) {
-        Some(package_version) => {
-            module.set_style(config.style);
-            module.get_prefix().set_value("is ");
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(&module_version)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-            module.create_segment("symbol", &config.symbol);
-            module.create_segment("version", &SegmentConfig::new(&package_version));
-
-            Some(module)
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `package`:\n{}", error);
+            return None;
         }
-        None => None,
-    }
+    });
+
+    Some(module)
 }
 
 fn extract_cargo_version(file_contents: &str) -> Option<String> {

src/modules/php.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::php::PhpConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current PHP version
@@ -27,16 +28,33 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         ],
     ) {
         Some(php_cmd_output) => {
-            let php_version = php_cmd_output.stdout;
-
             let mut module = context.new_module("php");
             let config: PhpConfig = PhpConfig::try_load(module.config);
 
-            module.set_style(config.style);
+            let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+                formatter
+                    .map_meta(|variable, _| match variable {
+                        "symbol" => Some(config.symbol),
+                        _ => None,
+                    })
+                    .map_style(|variable| match variable {
+                        "style" => Some(Ok(config.style)),
+                        _ => None,
+                    })
+                    .map(|variable| match variable {
+                        "version" => format_php_version(&php_cmd_output.stdout).map(Ok),
+                        _ => None,
+                    })
+                    .parse(None)
+            });
 
-            let formatted_version = format_php_version(&php_version)?;
-            module.create_segment("symbol", &config.symbol);
-            module.create_segment("version", &SegmentConfig::new(&formatted_version));
+            module.set_segments(match parsed {
+                Ok(segments) => segments,
+                Err(error) => {
+                    log::warn!("Error in module `php`:\n{}", error);
+                    return None;
+                }
+            });
 
             Some(module)
         }

src/modules/purescript.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::purescript::PureScriptConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current PureScript version
@@ -20,14 +21,34 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let purs_version = utils::exec_cmd("purs", &["--version"])?.stdout;
-    let formatted_version = Some(format!("v{}", purs_version.trim()))?;
 
     let mut module = context.new_module("purescript");
     let config: PureScriptConfig = PureScriptConfig::try_load(module.config);
-    module.set_style(config.style);
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(format!("v{}", purs_version.trim()))),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `purescript`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/python.rs

@@ -1,8 +1,9 @@
 use std::env;
 use std::path::Path;
 
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 use crate::configs::python::PythonConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Python version
@@ -41,25 +42,39 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
-
-    if config.pyenv_version_name {
-        let python_version = utils::exec_cmd("pyenv", &["version-name"])?.stdout;
-        module.create_segment("pyenv_prefix", &config.pyenv_prefix);
-        module.create_segment("version", &SegmentConfig::new(&python_version.trim()));
+    let python_version = if config.pyenv_version_name {
+        utils::exec_cmd("pyenv", &["version-name"])?.stdout
     } else {
-        let python_version = get_python_version(&config.python_binary)?;
-        let formatted_version = format_python_version(&python_version);
-        module.create_segment("version", &SegmentConfig::new(&formatted_version));
+        let version = get_python_version(&config.python_binary)?;
+        format_python_version(&version)
     };
+    let virtual_env = get_python_virtual_env();
 
-    if let Some(virtual_env) = get_python_virtual_env() {
-        module.create_segment(
-            "virtualenv",
-            &SegmentConfig::new(&format!(" ({})", virtual_env)),
-        );
-    };
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(python_version.trim())),
+                "virtualenv" => virtual_env.as_ref().map(|e| Ok(e.trim())),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `python`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/ruby.rs

@@ -1,6 +1,7 @@
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::ruby::RubyConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Ruby version
@@ -19,15 +20,34 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
-    let ruby_version = utils::exec_cmd("ruby", &["-v"])?.stdout;
-    let formatted_version = format_ruby_version(&ruby_version)?;
-
     let mut module = context.new_module("ruby");
-    let config: RubyConfig = RubyConfig::try_load(module.config);
-    module.set_style(config.style);
+    let config = RubyConfig::try_load(module.config);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => {
+                    format_ruby_version(&utils::exec_cmd("ruby", &["-v"])?.stdout.as_str()).map(Ok)
+                }
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &SegmentConfig::new(&formatted_version));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `ruby`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/rust.rs

@@ -5,6 +5,7 @@ use std::{env, fs};
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::rust::RustConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the current Rust version
 ///
@@ -22,6 +23,39 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         return None;
     }
 
+    let mut module = context.new_module("rust");
+    let config = RustConfig::try_load(module.config);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|var, _| match var {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                // This may result in multiple calls to `get_module_version` when a user have
+                // multiple `$version` variables defined in `format`.
+                "version" => get_module_version(context).map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
+
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `rust`:\n{}", error);
+            return None;
+        }
+    });
+
+    Some(module)
+}
+
+fn get_module_version(context: &Context) -> Option<String> {
     // `$CARGO_HOME/bin/rustc(.exe) --version` may attempt installing a rustup toolchain.
     // https://github.com/starship/starship/issues/417
     //
@@ -56,14 +90,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         format_rustc_version(execute_rustc_version()?)
     };
 
-    let mut module = context.new_module("rust");
-    let config = RustConfig::try_load(module.config);
-    module.set_style(config.style);
-
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &config.version.with_value(&module_version));
-
-    Some(module)
+    Some(module_version)
 }
 
 fn env_rustup_toolchain() -> Option<String> {

src/modules/singularity.rs

@@ -1,28 +1,44 @@
 use std::env;
 
-use super::{Context, Module, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
-use crate::config::RootModuleConfig;
 use crate::configs::singularity::SingularityConfig;
+use crate::formatter::StringFormatter;
 
 /// Creates a module with the current Singularity image
 ///
 /// Will display the Singularity image if `$SINGULARITY_NAME` is set.
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
-    let singularity_env = env::var("SINGULARITY_NAME").unwrap_or_else(|_| "".into());
-    if singularity_env.trim().is_empty() {
-        return None;
-    }
+    let singularity_env = env::var("SINGULARITY_NAME").ok();
+    singularity_env.as_ref()?;
 
     let mut module = context.new_module("singularity");
-    let config = SingularityConfig::try_load(module.config);
+    let config: SingularityConfig = SingularityConfig::try_load(module.config);
 
-    module.get_prefix().set_value(config.label);
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "env" => singularity_env.as_ref().map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    let env_var_stacked = format!("{}{}{}", config.prefix, singularity_env, config.suffix);
-    module.create_segment("singularity", &SegmentConfig::new(&env_var_stacked));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `singularity`: \n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/terraform.rs

@@ -1,7 +1,9 @@
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::terraform::TerraformConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
+
 use std::env;
 use std::io;
 use std::path::PathBuf;
@@ -25,20 +27,34 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("terraform");
     let config: TerraformConfig = TerraformConfig::try_load(module.config);
 
-    module.set_style(config.style);
-    module.create_segment("symbol", &config.symbol);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => format_terraform_version(
+                    &utils::exec_cmd("terraform", &["version"])?.stdout.as_str(),
+                )
+                .map(Ok),
+                "workspace" => get_terraform_workspace(&context.current_dir).map(Ok),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    if config.show_version {
-        let terraform_version =
-            format_terraform_version(&utils::exec_cmd("terraform", &["version"])?.stdout.as_str())?;
-        module.create_segment("version", &config.version.with_value(&terraform_version));
-    }
-
-    let terraform_workspace = &get_terraform_workspace(&context.current_dir)?;
-    module.create_segment(
-        "workspace",
-        &config.workspace.with_value(&terraform_workspace),
-    );
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `terraform`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/time.rs

@@ -1,14 +1,11 @@
 use chrono::{DateTime, FixedOffset, Local, NaiveTime, Utc};
 
-use super::{Context, Module};
-
-use crate::config::{RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 use crate::configs::time::TimeConfig;
+use crate::formatter::StringFormatter;
 
 /// Outputs the current time
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
-    const TIME_PREFIX: &str = "at ";
-
     let mut module = context.new_module("time");
     let config: TimeConfig = TimeConfig::try_load(module.config);
     if config.disabled {
@@ -23,7 +20,7 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     }
 
     let default_format = if config.use_12hr { "%r" } else { "%T" };
-    let time_format = config.format.unwrap_or(default_format);
+    let time_format = config.time_format.unwrap_or(default_format);
 
     log::trace!(
         "Timer module is enabled with format string: {}",
@@ -44,17 +41,26 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
         format_time(&time_format, Local::now())
     };
 
-    module.set_style(config.style);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "time" => Some(Ok(&formatted_time_string)),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.get_prefix().set_value(TIME_PREFIX);
-
-    module.create_segment(
-        "time",
-        &SegmentConfig {
-            value: &formatted_time_string,
-            style: None,
-        },
-    );
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `time`: \n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/modules/username.rs

@@ -1,8 +1,9 @@
 use std::env;
 
-use super::{Context, Module, RootModuleConfig, SegmentConfig};
+use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::username::UsernameConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current user's username
@@ -23,13 +24,32 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let config: UsernameConfig = UsernameConfig::try_load(module.config);
 
     if user != logname || ssh_connection.is_some() || user_uid == ROOT_UID || config.show_always {
-        let module_style = match user_uid {
-            Some(0) => config.style_root,
-            _ => config.style_user,
-        };
-
-        module.set_style(module_style);
-        module.create_segment("username", &SegmentConfig::new(&user?));
+        let username = user?;
+        let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+            formatter
+                .map_style(|variable| match variable {
+                    "style" => {
+                        let module_style = match user_uid {
+                            Some(0) => config.style_root,
+                            _ => config.style_user,
+                        };
+                        Some(Ok(module_style))
+                    }
+                    _ => None,
+                })
+                .map(|variable| match variable {
+                    "user" => Some(Ok(&username)),
+                    _ => None,
+                })
+                .parse(None)
+        });
+        module.set_segments(match parsed {
+            Ok(segments) => segments,
+            Err(error) => {
+                log::warn!("Error in module `username`:\n{}", error);
+                return None;
+            }
+        });
 
         Some(module)
     } else {

src/modules/zig.rs

@@ -1,6 +1,7 @@
 use super::{Context, Module, RootModuleConfig};
 
 use crate::configs::zig::ZigConfig;
+use crate::formatter::StringFormatter;
 use crate::utils;
 
 /// Creates a module with the current Zig version
@@ -26,10 +27,30 @@ pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     let mut module = context.new_module("zig");
     let config = ZigConfig::try_load(module.config);
 
-    module.set_style(config.style);
+    let parsed = StringFormatter::new(config.format).and_then(|formatter| {
+        formatter
+            .map_meta(|variable, _| match variable {
+                "symbol" => Some(config.symbol),
+                _ => None,
+            })
+            .map_style(|variable| match variable {
+                "style" => Some(Ok(config.style)),
+                _ => None,
+            })
+            .map(|variable| match variable {
+                "version" => Some(Ok(zig_version.clone())),
+                _ => None,
+            })
+            .parse(None)
+    });
 
-    module.create_segment("symbol", &config.symbol);
-    module.create_segment("version", &config.version.with_value(&zig_version));
+    module.set_segments(match parsed {
+        Ok(segments) => segments,
+        Err(error) => {
+            log::warn!("Error in module `zig`:\n{}", error);
+            return None;
+        }
+    });
 
     Some(module)
 }

src/print.rs

@@ -1,14 +1,18 @@
 use ansi_term::ANSIStrings;
 use clap::ArgMatches;
 use rayon::prelude::*;
+use std::collections::BTreeSet;
 use std::fmt::{self, Debug, Write as FmtWrite};
 use std::io::{self, Write};
 use unicode_width::UnicodeWidthChar;
 
+use crate::configs::PROMPT_ORDER;
 use crate::context::{Context, Shell};
+use crate::formatter::{StringFormatter, VariableHolder};
 use crate::module::Module;
 use crate::module::ALL_MODULES;
 use crate::modules;
+use crate::segment::Segment;
 
 pub fn prompt(args: ArgMatches) {
     let context = Context::new(args);
@@ -21,34 +25,53 @@ pub fn get_prompt(context: Context) -> String {
     let config = context.config.get_root_config();
     let mut buf = String::new();
 
-    // Write a new line before the prompt
-    if config.add_newline {
-        writeln!(buf).unwrap();
-    }
-
     // A workaround for a fish bug (see #739,#279). Applying it to all shells
     // breaks things (see #808,#824,#834). Should only be printed in fish.
     if let Shell::Fish = context.shell {
         buf.push_str("\x1b[J"); // An ASCII control code to clear screen
     }
 
-    let modules = compute_modules(&context);
-
-    let mut print_without_prefix = true;
-    let printable = modules.iter();
-
-    for module in printable {
-        // Skip printing the prefix of a module after the line_break
-        if print_without_prefix {
-            let module_without_prefix = module.to_string_without_prefix(context.shell);
-            write!(buf, "{}", module_without_prefix).unwrap()
+    let formatter = if let Ok(formatter) = StringFormatter::new(config.format) {
+        formatter
+    } else {
+        log::error!("Error parsing `format`");
+        buf.push_str(">");
+        return buf;
+    };
+    let modules = formatter.get_variables();
+    let formatter = formatter.map_variables_to_segments(|module| {
+        // Make $all display all modules
+        if module == "all" {
+            Some(Ok(PROMPT_ORDER
+                .par_iter()
+                .flat_map(|module| {
+                    handle_module(module, &context, &modules)
+                        .into_iter()
+                        .flat_map(|module| module.segments)
+                        .collect::<Vec<Segment>>()
+                })
+                .collect::<Vec<_>>()))
+        } else if context.is_module_disabled_in_config(&module) {
+            None
         } else {
-            let module = module.ansi_strings_for_shell(context.shell);
-            write!(buf, "{}", ANSIStrings(&module)).unwrap();
+            // Get segments from module
+            Some(Ok(handle_module(module, &context, &modules)
+                .into_iter()
+                .flat_map(|module| module.segments)
+                .collect::<Vec<Segment>>()))
         }
+    });
 
-        print_without_prefix = module.get_name() == "line_break"
-    }
+    // Creates a root module and prints it.
+    let mut root_module = Module::new("Starship Root", "The root module", None);
+    root_module.set_segments(
+        formatter
+            .parse(None)
+            .expect("Unexpected error returned in root format variables"),
+    );
+
+    let module_strings = root_module.ansi_strings_for_shell(context.shell);
+    write!(buf, "{}", ANSIStrings(&module_strings)).unwrap();
 
     buf
 }
@@ -72,16 +95,15 @@ pub fn explain(args: ArgMatches) {
         desc: String,
     }
 
-    let dont_print = vec!["line_break", "character"];
+    let dont_print = vec!["line_break"];
 
     let modules = compute_modules(&context)
         .into_iter()
         .filter(|module| !dont_print.contains(&module.get_name().as_str()))
         .map(|module| {
-            let ansi_strings = module.ansi_strings();
             let value = module.get_segments().join("");
             ModuleInfo {
-                value: ansi_term::ANSIStrings(&ansi_strings[1..ansi_strings.len() - 1]).to_string(),
+                value: ansi_term::ANSIStrings(&module.ansi_strings()).to_string(),
                 value_len: value.chars().count() + count_wide_chars(&value),
                 desc: module.get_description().to_owned(),
             }
@@ -132,11 +154,38 @@ pub fn explain(args: ArgMatches) {
 }
 
 fn compute_modules<'a>(context: &'a Context) -> Vec<Module<'a>> {
-    enum Mod<'a> {
-        Builtin(&'a str),
-        Custom(&'a str),
+    let mut prompt_order: Vec<Module<'a>> = Vec::new();
+
+    let config = context.config.get_root_config();
+    let formatter = if let Ok(formatter) = StringFormatter::new(config.format) {
+        formatter
+    } else {
+        log::error!("Error parsing `format`");
+        return Vec::new();
+    };
+    let modules = formatter.get_variables();
+
+    for module in &modules {
+        // Manually add all modules if `$all` is encountered
+        if module == "all" {
+            for module in PROMPT_ORDER.iter() {
+                let modules = handle_module(module, &context, &modules);
+                prompt_order.extend(modules.into_iter());
+            }
+        } else {
+            let modules = handle_module(module, &context, &modules);
+            prompt_order.extend(modules.into_iter());
+        }
     }
 
+    prompt_order
+}
+
+fn handle_module<'a>(
+    module: &str,
+    context: &'a Context,
+    module_list: &BTreeSet<String>,
+) -> Vec<Module<'a>> {
     struct DebugCustomModules<'tmp>(&'tmp toml::value::Table);
 
     impl Debug for DebugCustomModules<'_> {
@@ -145,74 +194,63 @@ fn compute_modules<'a>(context: &'a Context) -> Vec<Module<'a>> {
         }
     }
 
-    let mut prompt_order: Vec<Mod> = Vec::new();
+    let mut modules: Vec<Option<Module>> = Vec::new();
 
-    // Write out a custom prompt order
-    let config_prompt_order = context.config.get_root_config().prompt_order;
-
-    for module in &config_prompt_order {
-        if ALL_MODULES.contains(module) {
-            // Write out a module if it isn't disabled
-            if !context.is_module_disabled_in_config(*module) {
-                prompt_order.push(Mod::Builtin(module));
-            }
-        } else if *module == "custom" {
-            // Write out all custom modules, except for those that are explicitly set
-            if let Some(custom_modules) = context.config.get_custom_modules() {
-                for (custom_module, config) in custom_modules {
-                    if should_add_implicit_custom_module(
-                        custom_module,
-                        config,
-                        &config_prompt_order,
-                    ) {
-                        prompt_order.push(Mod::Custom(custom_module));
-                    }
-                }
-            }
-        } else if module.starts_with("custom.") {
-            // Write out a custom module if it isn't disabled (and it exists...)
-            match context.is_custom_module_disabled_in_config(&module[7..]) {
-                Some(true) => (), // Module is disabled, we don't add it to the prompt
-                Some(false) => prompt_order.push(Mod::Custom(&module[7..])),
-                None => match context.config.get_custom_modules() {
-                    Some(modules) => log::debug!(
-                        "prompt_order contains custom module \"{}\", but no configuration was provided. Configuration for the following modules were provided: {:?}",
-                        module,
-                        DebugCustomModules(modules),
-                    ),
-                    None => log::debug!(
-                        "prompt_order contains custom module \"{}\", but no configuration was provided.",
-                        module,
-                    ),
-                },
-            }
-        } else {
-            log::debug!(
-                "Expected prompt_order to contain value from {:?}. Instead received {}",
-                ALL_MODULES,
-                module,
-            );
+    if ALL_MODULES.contains(&module) {
+        // Write out a module if it isn't disabled
+        if !context.is_module_disabled_in_config(module) {
+            modules.push(modules::handle(module, &context));
         }
+    } else if module == "custom" {
+        // Write out all custom modules, except for those that are explicitly set
+        if let Some(custom_modules) = context.config.get_custom_modules() {
+            let custom_modules = custom_modules
+                .iter()
+                .map(|(custom_module, config)| {
+                    if should_add_implicit_custom_module(custom_module, config, &module_list) {
+                        modules::custom::module(custom_module, &context)
+                    } else {
+                        None
+                    }
+                })
+                .collect::<Vec<Option<Module<'a>>>>();
+            modules.extend(custom_modules)
+        }
+    } else if module.starts_with("custom.") {
+        // Write out a custom module if it isn't disabled (and it exists...)
+        match context.is_custom_module_disabled_in_config(&module[7..]) {
+            Some(true) => (), // Module is disabled, we don't add it to the prompt
+            Some(false) => modules.push(modules::custom::module(&module[7..], &context)),
+            None => match context.config.get_custom_modules() {
+                Some(modules) => log::debug!(
+                    "prompt_order contains custom module \"{}\", but no configuration was provided. Configuration for the following modules were provided: {:?}",
+                    module,
+                    DebugCustomModules(modules),
+                    ),
+                None => log::debug!(
+                    "prompt_order contains custom module \"{}\", but no configuration was provided.",
+                    module,
+                    ),
+            },
+        }
+    } else {
+        log::debug!(
+            "Expected prompt_order to contain value from {:?}. Instead received {}",
+            ALL_MODULES,
+            module,
+        );
     }
 
-    prompt_order
-        .par_iter()
-        .map(|module| match module {
-            Mod::Builtin(builtin) => modules::handle(builtin, context),
-            Mod::Custom(custom) => modules::custom::module(custom, context),
-        }) // Compute segments
-        .flatten() // Remove segments set to `None`
-        .collect::<Vec<Module<'a>>>()
+    modules.into_iter().flatten().collect()
 }
 
 fn should_add_implicit_custom_module(
     custom_module: &str,
     config: &toml::Value,
-    config_prompt_order: &[&str],
+    module_list: &BTreeSet<String>,
 ) -> bool {
-    let is_explicitly_specified = config_prompt_order.iter().any(|x| {
-        x.len() == 7 + custom_module.len() && &x[..7] == "custom." && &x[7..] == custom_module
-    });
+    let explicit_module_name = format!("custom.{}", custom_module);
+    let is_explicitly_specified = module_list.contains(&explicit_module_name);
 
     if is_explicitly_specified {
         // The module is already specified explicitly, so we skip it

tests/testsuite/aws.rs

@@ -22,7 +22,7 @@ fn region_set() -> io::Result<()> {
     let output = common::render_module("aws")
         .env("AWS_REGION", "ap-northeast-2")
         .output()?;
-    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  ap-northeast-2"));
+    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  (ap-northeast-2)"));
     let actual = String::from_utf8(output.stdout).unwrap();
     assert_eq!(expected, actual);
     Ok(())
@@ -37,7 +37,7 @@ fn region_set_with_alias() -> io::Result<()> {
             ap-southeast-2 = "au"
         })
         .output()?;
-    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  au"));
+    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  (au)"));
     let actual = String::from_utf8(output.stdout).unwrap();
     assert_eq!(expected, actual);
     Ok(())
@@ -49,7 +49,7 @@ fn default_region_set() -> io::Result<()> {
         .env("AWS_REGION", "ap-northeast-2")
         .env("AWS_DEFAULT_REGION", "ap-northeast-1")
         .output()?;
-    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  ap-northeast-1"));
+    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  (ap-northeast-1)"));
     let actual = String::from_utf8(output.stdout).unwrap();
     assert_eq!(expected, actual);
     Ok(())
@@ -112,7 +112,7 @@ region = us-east-2
     let output = common::render_module("aws")
         .env("AWS_CONFIG_FILE", config_path.to_string_lossy().as_ref())
         .output()?;
-    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  us-east-1"));
+    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  (us-east-1)"));
     let actual = String::from_utf8(output.stdout).unwrap();
     assert_eq!(expected, actual);
     dir.close()
@@ -155,10 +155,6 @@ fn profile_and_region_set_with_display_all() -> io::Result<()> {
     let output = common::render_module("aws")
         .env("AWS_PROFILE", "astronauts")
         .env("AWS_REGION", "ap-northeast-1")
-        .use_config(toml::toml! {
-            [aws]
-            displayed_items = "all"
-        })
         .output()?;
     let expected = format!(
         "on {} ",
@@ -173,10 +169,6 @@ fn profile_and_region_set_with_display_all() -> io::Result<()> {
 fn profile_set_with_display_all() -> io::Result<()> {
     let output = common::render_module("aws")
         .env("AWS_PROFILE", "astronauts")
-        .use_config(toml::toml! {
-            [aws]
-            displayed_items = "all"
-        })
         .output()?;
     let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  astronauts"));
     let actual = String::from_utf8(output.stdout).unwrap();
@@ -188,12 +180,8 @@ fn profile_set_with_display_all() -> io::Result<()> {
 fn region_set_with_display_all() -> io::Result<()> {
     let output = common::render_module("aws")
         .env("AWS_REGION", "ap-northeast-1")
-        .use_config(toml::toml! {
-            [aws]
-            displayed_items = "all"
-        })
         .output()?;
-    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  ap-northeast-1"));
+    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  (ap-northeast-1)"));
     let actual = String::from_utf8(output.stdout).unwrap();
     assert_eq!(expected, actual);
     Ok(())
@@ -206,7 +194,7 @@ fn profile_and_region_set_with_display_region() -> io::Result<()> {
         .env("AWS_DEFAULT_REGION", "ap-northeast-1")
         .use_config(toml::toml! {
             [aws]
-            displayed_items = "region"
+            format = "on [$symbol$region]($style) "
         })
         .output()?;
     let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  ap-northeast-1"));
@@ -222,7 +210,7 @@ fn profile_and_region_set_with_display_profile() -> io::Result<()> {
         .env("AWS_REGION", "ap-northeast-1")
         .use_config(toml::toml! {
             [aws]
-            displayed_items = "profile"
+            format = "on [$symbol$profile]($style) "
         })
         .output()?;
     let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  astronauts"));
@@ -237,10 +225,10 @@ fn region_set_with_display_profile() -> io::Result<()> {
         .env("AWS_REGION", "ap-northeast-1")
         .use_config(toml::toml! {
             [aws]
-            displayed_items = "profile"
+            format = "on [$symbol$profile]($style) "
         })
         .output()?;
-    let expected = "";
+    let expected = format!("on {} ", Color::Yellow.bold().paint("☁️  "));
     let actual = String::from_utf8(output.stdout).unwrap();
     assert_eq!(expected, actual);
     Ok(())
@@ -252,7 +240,7 @@ fn region_not_set_with_display_region() -> io::Result<()> {
     let output = common::render_module("aws")
         .use_config(toml::toml! {
             [aws]
-            displayed_items = "region"
+            format = "on [$symbol$region]($style) "
         })
         .output()?;
     let expected = "";

tests/testsuite/character.rs

@@ -4,7 +4,7 @@ use std::io;
 use crate::common::{self, TestCommand};
 
 #[test]
-fn char_module_success_status() -> io::Result<()> {
+fn success_status() -> io::Result<()> {
     let expected = format!("{} ", Color::Green.bold().paint("❯"));
 
     // Status code 0
@@ -23,7 +23,7 @@ fn char_module_success_status() -> io::Result<()> {
 }
 
 #[test]
-fn char_module_failure_status() -> io::Result<()> {
+fn failure_status() -> io::Result<()> {
     let expected = format!("{} ", Color::Red.bold().paint("❯"));
 
     let exit_values = ["1", "54321", "-5000"];
@@ -39,9 +39,9 @@ fn char_module_failure_status() -> io::Result<()> {
 }
 
 #[test]
-fn char_module_symbolyes_status() -> io::Result<()> {
+fn custom_symbol() -> io::Result<()> {
     let expected_fail = format!("{} ", Color::Red.bold().paint("✖"));
-    let expected_success = format!("{} ", Color::Green.bold().paint("❯"));
+    let expected_success = format!("{} ", Color::Green.bold().paint("➜"));
 
     let exit_values = ["1", "54321", "-5000"];
 
@@ -51,7 +51,9 @@ fn char_module_symbolyes_status() -> io::Result<()> {
         let output = common::render_module("character")
             .use_config(toml::toml! {
                 [character]
-                use_symbol_for_status = true
+                success_symbol = "[➜](bold green)"
+                error_symbol = "[✖](bold red)"
+
             })
             .arg(arg)
             .output()?;
@@ -63,7 +65,8 @@ fn char_module_symbolyes_status() -> io::Result<()> {
     let output = common::render_module("character")
         .use_config(toml::toml! {
             [character]
-            use_symbol_for_status = true
+            success_symbol = "[➜](bold green)"
+            error_symbol = "[✖](bold red)"
         })
         .arg("--status=0")
         .output()?;
@@ -74,11 +77,10 @@ fn char_module_symbolyes_status() -> io::Result<()> {
 }
 
 #[test]
-fn char_module_zsh_keymap() -> io::Result<()> {
-    let expected_vicmd = "❮";
-    // TODO make this less... well, stupid when ANSI escapes can be mocked out
-    let expected_specified = "I HIGHLY DOUBT THIS WILL SHOW UP IN OTHER OUTPUT";
-    let expected_other = "❯";
+fn zsh_keymap() -> io::Result<()> {
+    let expected_vicmd = format!("{} ", Color::Green.bold().paint("❮"));
+    let expected_specified = format!("{} ", Color::Green.bold().paint("V"));
+    let expected_other = format!("{} ", Color::Green.bold().paint("❯"));
 
     // zle keymap is vicmd
     let output = common::render_module("character")
@@ -86,19 +88,19 @@ fn char_module_zsh_keymap() -> io::Result<()> {
         .arg("--keymap=vicmd")
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
-    assert!(actual.contains(&expected_vicmd));
+    assert_eq!(expected_vicmd, actual);
 
     // specified vicmd character
     let output = common::render_module("character")
         .use_config(toml::toml! {
             [character]
-            vicmd_symbol = "I HIGHLY DOUBT THIS WILL SHOW UP IN OTHER OUTPUT"
+            vicmd_symbol = "[V](bold green)"
         })
         .env("STARSHIP_SHELL", "zsh")
         .arg("--keymap=vicmd")
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
-    assert!(actual.contains(&expected_specified));
+    assert_eq!(expected_specified, actual);
 
     // zle keymap is other
     let output = common::render_module("character")
@@ -106,17 +108,16 @@ fn char_module_zsh_keymap() -> io::Result<()> {
         .arg("--keymap=visual")
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
-    assert!(actual.contains(&expected_other));
+    assert_eq!(expected_other, actual);
 
     Ok(())
 }
 
 #[test]
-fn char_module_fish_keymap() -> io::Result<()> {
-    let expected_vicmd = "❮";
-    // TODO make this less... well, stupid when ANSI escapes can be mocked out
-    let expected_specified = "I HIGHLY DOUBT THIS WILL SHOW UP IN OTHER OUTPUT";
-    let expected_other = "❯";
+fn fish_keymap() -> io::Result<()> {
+    let expected_vicmd = format!("{} ", Color::Green.bold().paint("❮"));
+    let expected_specified = format!("{} ", Color::Green.bold().paint("V"));
+    let expected_other = format!("{} ", Color::Green.bold().paint("❯"));
 
     // fish keymap is default
     let output = common::render_module("character")
@@ -124,19 +125,19 @@ fn char_module_fish_keymap() -> io::Result<()> {
         .arg("--keymap=default")
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
-    assert!(actual.contains(&expected_vicmd));
+    assert_eq!(expected_vicmd, actual);
 
     // specified vicmd character
     let output = common::render_module("character")
         .use_config(toml::toml! {
             [character]
-            vicmd_symbol = "I HIGHLY DOUBT THIS WILL SHOW UP IN OTHER OUTPUT"
+            vicmd_symbol = "[V](bold green)"
         })
         .env("STARSHIP_SHELL", "fish")
         .arg("--keymap=default")
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
-    assert!(actual.contains(&expected_specified));
+    assert_eq!(expected_specified, actual);
 
     // fish keymap is other
     let output = common::render_module("character")
@@ -144,7 +145,7 @@ fn char_module_fish_keymap() -> io::Result<()> {
         .arg("--keymap=visual")
         .output()?;
     let actual = String::from_utf8(output.stdout).unwrap();
-    assert!(actual.contains(&expected_other));
+    assert_eq!(expected_other, actual);
 
     Ok(())
 }

tests/testsuite/cmd_duration.rs

@@ -64,7 +64,7 @@ fn config_1s_duration_prefix_underwent() -> io::Result<()> {
     let output = common::render_module("cmd_duration")
         .use_config(toml::toml! {
             [cmd_duration]
-            prefix = "underwent "
+            format = "underwent [$duration]($style) "
         })
         .arg("--cmd-duration=1000")
         .output()?;
@@ -80,7 +80,7 @@ fn config_5s_duration_prefix_underwent() -> io::Result<()> {
     let output = common::render_module("cmd_duration")
         .use_config(toml::toml! {
             [cmd_duration]
-            prefix = "underwent "
+            format = "underwent [$duration]($style) "
         })
         .arg("--cmd-duration=5000")
         .output()?;

tests/testsuite/common.rs

@@ -16,7 +16,7 @@ const EXE_PATH: &str = "./target/debug/starship.exe";
 const EXE_PATH: &str = "./target/debug/starship";
 
 /// Render the full starship prompt
-pub fn render_prompt() -> process::Command {
+pub fn _render_prompt() -> process::Command {
     let mut command = process::Command::new(EXE_PATH);
 
     command