Combine OutputComponents and PredefinedStyles

This commit tries to simply the change. Instead of separating an
`OutputComponent` and a `PredefinedStyle`, I have combined the two into
just `OutputComponent`.

To still have the styles work, I added an impl to `OutputComponent` with
a function `components` which returns the components related to the
specified component.

For a simple output component this is trivial, but for the predefined
styles this is a list of other components.

The evaluating of the command-line parameter simplified significantly,
making use of Claps `values_t!` macro to parse the supplied parameters
into a `Vec<OutputComponent>`. After that it is simply a task of
combining all supplied output components into one vector.

Important: this means that the styles are now additive, rather than one
of the predefined styles overruling other parameters supplied.

Cargo.lock

@@ -68,7 +68,6 @@ dependencies = [
  "clap 2.31.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "console 0.6.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "directories 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "git2 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "lazy_static 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -195,11 +194,6 @@ dependencies = [
  "shared_child 0.3.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
-[[package]]
-name = "either"
-version = "1.5.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-
 [[package]]
 name = "error-chain"
 version = "0.11.0"
@@ -826,7 +820,6 @@ dependencies = [
 "checksum directories 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "fc2561db021b6f1321d0f16b67ed28ce843ef4610dfaa432e3ffa2e8a3050ebf"
 "checksum dtoa 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "09c3753c3db574d215cba4ea76018483895d7bff25a31b49ba45db21c48e50ab"
 "checksum duct 0.10.0 (registry+https://github.com/rust-lang/crates.io-index)" = "166298c17c5b4fe5997b962c2f22e887c7c5adc44308eb9103ce5b66af45a423"
-"checksum either 1.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3be565ca5c557d7f59e7cfcf1844f9e3033650c929c6566f511e8005f205c1d0"
 "checksum error-chain 0.11.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ff511d5dc435d703f4971bc399647c9bc38e20cb41452e3b9feb4765419ed3f3"
 "checksum flate2 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "9fac2277e84e5e858483756647a9d0aa8d9a2b7cba517fd84325a0aaa69a0909"
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"

Cargo.toml

@@ -13,7 +13,6 @@ version = "0.3.0"
 atty = "0.2.2"
 ansi_term = "0.10"
 console = "0.6"
-either = "1.4"
 error-chain = "0.11"
 directories = "0.10"
 lazy_static = "1.0"

src/main.rs

@@ -14,7 +14,6 @@ extern crate ansi_term;
 extern crate atty;
 extern crate console;
 extern crate directories;
-extern crate either;
 extern crate git2;
 extern crate syntect;
 
@@ -37,7 +36,6 @@ use ansi_term::Style;
 use atty::Stream;
 use clap::{App, AppSettings, Arg, ArgGroup, SubCommand};
 use directories::ProjectDirs;
-use either::Either;
 use git2::{DiffOptions, IntoCString, Repository};
 
 use syntect::dumps::{dump_to_file, from_binary, from_reader};
@@ -54,6 +52,7 @@ lazy_static! {
 mod errors {
     error_chain! {
         foreign_links {
+            Clap(::clap::Error);
             Io(::std::io::Error);
         }
 
@@ -72,12 +71,32 @@ mod errors {
 
 use errors::*;
 
-#[derive(Debug, Eq, PartialEq)]
+#[derive(Debug, Eq, PartialEq, Copy, Clone)]
 pub enum OutputComponent {
     Changes,
     Grid,
     Header,
     Numbers,
+    Full,
+    Plain,
+}
+
+impl OutputComponent {
+    fn components(&self) -> &'static [OutputComponent] {
+        match *self {
+            OutputComponent::Changes => &[OutputComponent::Changes],
+            OutputComponent::Grid => &[OutputComponent::Grid],
+            OutputComponent::Header => &[OutputComponent::Header],
+            OutputComponent::Numbers => &[OutputComponent::Numbers],
+            OutputComponent::Full => &[
+                OutputComponent::Changes,
+                OutputComponent::Grid,
+                OutputComponent::Header,
+                OutputComponent::Numbers,
+            ],
+            OutputComponent::Plain => &[],
+        }
+    }
 }
 
 impl FromStr for OutputComponent {
@@ -89,38 +108,8 @@ impl FromStr for OutputComponent {
             "grid" => Ok(OutputComponent::Grid),
             "header" => Ok(OutputComponent::Header),
             "numbers" => Ok(OutputComponent::Numbers),
-            _ => Err(ErrorKind::UnknownStyleName(s.to_owned()).into()),
+            "full" => Ok(OutputComponent::Full),
-        }
+            "plain" => Ok(OutputComponent::Plain),
-    }
-}
-
-#[derive(Debug, Eq, PartialEq)]
-enum PredefinedStyle {
-    Full,
-    Plain,
-}
-
-impl PredefinedStyle {
-    fn components(&self) -> &'static [OutputComponent] {
-        match *self {
-            PredefinedStyle::Full => &[
-                OutputComponent::Changes,
-                OutputComponent::Grid,
-                OutputComponent::Header,
-                OutputComponent::Numbers,
-            ],
-            PredefinedStyle::Plain => &[],
-        }
-    }
-}
-
-impl FromStr for PredefinedStyle {
-    type Err = Error;
-
-    fn from_str(s: &str) -> Result<Self> {
-        match s {
-            "full" => Ok(PredefinedStyle::Full),
-            "plain" => Ok(PredefinedStyle::Plain),
             _ => Err(ErrorKind::UnknownStyleName(s.to_owned()).into()),
         }
     }
@@ -609,63 +598,17 @@ fn run() -> Result<()> {
                 })
                 .unwrap_or_else(|| vec![None]); // read from stdin (None) if no args are given
 
-            // Split the user-supplied parameter on commas (','), then go over each part and map it
+            let output_components = values_t!(app_matches.values_of("style"), OutputComponent)?
-            // to either a predefined style or a simple output style. Once this mapping is done,
-            // split it up into two lists: one for the matched predefined styles and one for the
-            // simple output styles.
-            let (_predefined_styles, _output_components): (Vec<_>, Vec<_>) = app_matches
-                .values_of("style")
-                .unwrap()
-                .map(|s| {
-                    let predefined_style = PredefinedStyle::from_str(s);
-                    if let Ok(style) = predefined_style {
-                        Some(Either::Left(style))
-                    } else {
-                        match OutputComponent::from_str(s) {
-                            Ok(style) => Some(Either::Right(style)),
-                            Err(error) => {
-                                eprintln!("{}: {}", Red.paint("[bat error]"), error);
-                                None
-                            }
-                        }
-                    }
-                })
-                .filter_map(|s| s)
-                .partition(|style| match *style {
-                    Either::Left(_) => true,
-                    Either::Right(_) => false,
-                });
-
-            // Once we have the two lists of predefined styles and simple output styles, we take the
-            // first matched predefined style and use that as our style, discarding every other
-            // predefined or simple output style. If we have no predefined styles though, we take
-            // all matched simple output styles and pass those to the `Options` struct.
-            let output_components: Vec<OutputComponent>;
-            let output_components = if let Some(predefined_style) = _predefined_styles
                 .into_iter()
-                .map(|e| e.left().unwrap())
+                .map(|style| style.components())
-                .next()
+                .fold(vec![], |mut acc, x| {
-            {
+                    acc.extend_from_slice(x);
-                predefined_style.components()
+                    acc
-            } else {
+                });
-                output_components = _output_components
-                    .into_iter()
-                    .map(|e| e.right().unwrap())
-                    .collect::<Vec<_>>();
-
-                // If we are in this else-block, `output_components` is empty and the requested style
-                // wasn't the empty string, the user supplied only wrong style arguments. In this
-                // case we inform them about this.
-                if output_components.is_empty() && app_matches.value_of("style").unwrap() != "" {
-                    return Err(ErrorKind::NoCorrectStylesSpecified.into());
-                }
-
-                &output_components
-            };
 
             let options = Options {
                 true_color: is_truecolor_terminal(),
-                output_components,
+                output_components: &output_components,
                 language: app_matches.value_of("language"),
                 colored_output: match app_matches.value_of("color") {
                     Some("always") => true,