Small restructuring

Cargo.lock

@@ -651,16 +651,72 @@ version = "0.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "futures"
+name = "futures-channel-preview"
-version = "0.1.27"
+version = "0.3.0-alpha.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "futures-core-preview"
+version = "0.3.0-alpha.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
-name = "futures-core"
+name = "futures-executor-preview"
-version = "0.2.1"
+version = "0.3.0-alpha.16"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 dependencies = [
- "either 1.5.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-util-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num_cpus 1.10.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "futures-io-preview"
+version = "0.3.0-alpha.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "futures-preview"
+version = "0.3.0-alpha.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-executor-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-io-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-sink-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-util-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "futures-sink-preview"
+version = "0.3.0-alpha.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "futures-util-preview"
+version = "0.3.0-alpha.16"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-io-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-sink-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
+ "memchr 2.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]
@@ -859,12 +915,12 @@ dependencies = [
  "cursive 0.12.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "derive-new 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "dunce 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)",
+ "futures-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)",
- "futures-core 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "indexmap 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
  "itertools 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "nom 5.0.0-beta1 (registry+https://github.com/rust-lang/crates.io-index)",
  "ordered-float 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "pancurses 0.16.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "prettyprint 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "prettytable-rs 0.8.0 (registry+https://github.com/rust-lang/crates.io-index)",
  "rustyline 4.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
@@ -1031,6 +1087,11 @@ dependencies = [
  "libc 0.2.55 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "pin-utils"
+version = "0.1.0-alpha.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "pkg-config"
 version = "0.3.14"
@@ -1395,6 +1456,11 @@ dependencies = [
  "libc 0.2.55 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "slab"
+version = "0.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "smallvec"
 version = "0.6.9"
@@ -1775,8 +1841,13 @@ dependencies = [
 "checksum flate2 1.0.7 (registry+https://github.com/rust-lang/crates.io-index)" = "f87e68aa82b2de08a6e037f1385455759df6e445a8df5e005b4297191dbf18aa"
 "checksum fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)" = "2fad85553e09a6f881f739c29f0b00b0f01357c743266d478b68951ce23285f3"
 "checksum fuchsia-cprng 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "a06f77d526c1a601b7c4cdd98f54b5eaabffc14d5f2f0296febdc7f357c6d3ba"
-"checksum futures 0.1.27 (registry+https://github.com/rust-lang/crates.io-index)" = "a2037ec1c6c1c4f79557762eab1f7eae1f64f6cb418ace90fae88f0942b60139"
+"checksum futures-channel-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "4cd523712fc272e9b714669165a2832debee5a5b7e409bfccdc7c0d5cd0cf07a"
-"checksum futures-core 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "7455c91eb2eae38f33b013f77ebe766c75761af333efd9d550e154045c63e225"
+"checksum futures-core-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "719770f328642b657b849856bb5a607db9538dd5bb3000122e5ead55d0a58c36"
+"checksum futures-executor-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "315dc58c908535d059576a329b86cd185933433382cfcd394fb2fa353330de03"
+"checksum futures-io-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "cca0bf7a1f39c9d32b797b0def93d5932aa71796236aad6b549bac6f7df159a3"
+"checksum futures-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "fcfeac5f016a4b5835bb93eb7961f50a64f0e001207562703d9ddf4109d7b263"
+"checksum futures-sink-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "49dcfdacd6b5974ca0b9b78bc38ffd1071da0206179735c3df82e279f5b784e4"
+"checksum futures-util-preview 0.3.0-alpha.16 (registry+https://github.com/rust-lang/crates.io-index)" = "f7a0451b9c5047c2b9ab93425ffd0793165511e93c04b977cd45fbd41c6e34b2"
 "checksum hashbrown 0.3.0 (registry+https://github.com/rust-lang/crates.io-index)" = "570178d5e4952010d138b0f1d581271ff3a02406d990f887d1e87e3d6e43b0ac"
 "checksum humantime 1.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "3ca7e5f2e110db35f93b837c81797f3714500b81d517bf20c431b16d3ca4f114"
 "checksum ident_case 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "b9e0384b61958566e926dc50660321d12159025e767c18e043daf26b70104c39"
@@ -1819,6 +1890,7 @@ dependencies = [
 "checksum parking_lot_core 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)" = "cb88cb1cb3790baa6776844f968fea3be44956cf184fa1be5a03341f5491278c"
 "checksum parse-zoneinfo 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "089a398ccdcdd77b8c38909d5a1e4b67da1bc4c9dbfe6d5b536c828eddb779e5"
 "checksum pdcurses-sys 0.7.1 (registry+https://github.com/rust-lang/crates.io-index)" = "084dd22796ff60f1225d4eb6329f33afaf4c85419d51d440ab6b8c6f4529166b"
+"checksum pin-utils 0.1.0-alpha.4 (registry+https://github.com/rust-lang/crates.io-index)" = "5894c618ce612a3fa23881b152b608bafb8c56cfc22f434a3ba3120b40f7b587"
 "checksum pkg-config 0.3.14 (registry+https://github.com/rust-lang/crates.io-index)" = "676e8eb2b1b4c9043511a9b7bea0915320d7e502b0a079fb03f9635a5252b18c"
 "checksum plist 0.4.1 (registry+https://github.com/rust-lang/crates.io-index)" = "f4739851c08dd9a62a78beff2edf1a438517268b2c563c42fc6d9d3139e42d2a"
 "checksum prettyprint 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "2705417f8aa07cb6308db42e55623479c1c9667942a4d5e4174c684e5da5590d"
@@ -1861,6 +1933,7 @@ dependencies = [
 "checksum shell-words 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)" = "39acde55a154c4cd3ae048ac78cc21c25f3a0145e44111b523279113dce0d94a"
 "checksum signal-hook 0.1.9 (registry+https://github.com/rust-lang/crates.io-index)" = "72ab58f1fda436857e6337dcb6a5aaa34f16c5ddc87b3a8b6ef7a212f90b9c5a"
 "checksum signal-hook-registry 1.0.1 (registry+https://github.com/rust-lang/crates.io-index)" = "cded4ffa32146722ec54ab1f16320568465aa922aa9ab4708129599740da85d7"
+"checksum slab 0.4.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c111b5bd5695e56cffe5129854aa230b39c93a305372fdbb2668ca2394eea9f8"
 "checksum smallvec 0.6.9 (registry+https://github.com/rust-lang/crates.io-index)" = "c4488ae950c49d403731982257768f48fada354a5203fe81f9bb6f43ca9002be"
 "checksum stable_deref_trait 1.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "dba1a27d3efae4351c8051072d619e3ade2820635c3958d826bfea39d59b54c8"
 "checksum stackvector 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "c049c77bf85fbc036484c97b008276d539d9ebff9dfbde37b632ebcd5b8746b6"

Cargo.toml

@@ -21,11 +21,14 @@ conch-parser = "0.1.1"
 nom = "5.0.0-beta1"
 subprocess = "0.1.18"
 dunce = "1.0.0"
-futures = "0.1.27"
-futures-core = "0.2.1"
 indexmap = "1.0.2"
 chrono-humanize = "0.0.11"
 byte-unit = "2.1.0"
 ordered-float = "1.0.2"
 prettyprint = "0.6.0"
 cursive = { version = "0.12.0", features = ["pancurses-backend"], default-features = false }
+futures-preview = "0.3.0-alpha.16"
+
+[dependencies.pancurses]
+version = "0.16"
+features = ["win32a"]

src/cli.rs

@@ -0,0 +1,240 @@
+use crate::prelude::*;
+
+use crate::commands::classified::{ClassifiedCommand, ExternalCommand, InternalCommand};
+use crate::commands::command::ReturnValue;
+use crate::context::Context;
+crate use crate::env::Host;
+crate use crate::errors::ShellError;
+crate use crate::format::{EntriesListView, GenericView};
+use crate::object::Value;
+
+use rustyline::error::ReadlineError;
+use rustyline::{self, ColorMode, Config, Editor};
+use std::collections::VecDeque;
+use std::error::Error;
+use std::sync::Arc;
+
+#[derive(Debug)]
+pub enum MaybeOwned<'a, T> {
+    Owned(T),
+    Borrowed(&'a T),
+}
+
+impl<T> MaybeOwned<'a, T> {
+    crate fn borrow(&self) -> &T {
+        match self {
+            MaybeOwned::Owned(v) => v,
+            MaybeOwned::Borrowed(v) => v,
+        }
+    }
+}
+
+pub fn cli() -> Result<(), Box<Error>> {
+    let config = Config::builder().color_mode(ColorMode::Forced).build();
+    let h = crate::shell::Helper::new();
+    let mut rl: Editor<crate::shell::Helper> = Editor::with_config(config);
+
+    #[cfg(windows)]
+    {
+        let _ = ansi_term::enable_ansi_support();
+    }
+
+    rl.set_helper(Some(h));
+    if rl.load_history("history.txt").is_err() {
+        println!("No previous history.");
+    }
+
+    let mut context = Context::basic()?;
+
+    {
+        use crate::commands::*;
+
+        context.add_commands(vec![
+            ("format", Arc::new(format)),
+            ("format-list", Arc::new(format_list)),
+            ("ps", Arc::new(ps::ps)),
+            ("ls", Arc::new(ls::ls)),
+            ("cd", Arc::new(cd::cd)),
+            ("view", Arc::new(view::view)),
+            ("skip", Arc::new(skip::skip)),
+            ("take", Arc::new(take::take)),
+            ("select", Arc::new(select::select)),
+            ("reject", Arc::new(reject::reject)),
+            ("to-array", Arc::new(to_array::to_array)),
+            ("where", Arc::new(where_::r#where)),
+            ("sort-by", Arc::new(sort_by::sort_by)),
+        ]);
+    }
+
+    loop {
+        let readline = rl.readline(&format!("{}> ", context.env.cwd().display().to_string()));
+
+        match process_line(readline, &mut context) {
+            LineResult::Success(line) => {
+                rl.add_history_entry(line.clone());
+            }
+
+            LineResult::Error(err) => {
+                context.host.stdout(&err);
+            }
+
+            LineResult::Break => {
+                break;
+            }
+
+            LineResult::FatalError(err) => {
+                context
+                    .host
+                    .stdout(&format!("A surprising fatal error occurred.\n{:?}", err));
+            }
+        }
+    }
+    rl.save_history("history.txt").unwrap();
+
+    Ok(())
+}
+
+enum LineResult {
+    Success(String),
+    Error(String),
+    Break,
+
+    #[allow(unused)]
+    FatalError(ShellError),
+}
+
+fn process_line(readline: Result<String, ReadlineError>, ctx: &mut Context) -> LineResult {
+    match &readline {
+        Ok(line) if line.trim() == "exit" => LineResult::Break,
+
+        Ok(line) if line.trim() == "" => LineResult::Success(line.clone()),
+
+        Ok(line) => {
+            let result = match crate::parser::shell_parser(&line) {
+                Err(err) => {
+                    return LineResult::Error(format!("{:?}", err));
+                }
+
+                Ok(val) => val,
+            };
+
+            let parsed = result.1;
+
+            let mut input = VecDeque::new();
+
+            for item in parsed {
+                input = match process_command(item.clone(), input, ctx) {
+                    Ok(val) => val,
+                    Err(err) => return LineResult::Error(format!("{}", err.description())),
+                };
+            }
+
+            if input.len() > 0 {
+                if equal_shapes(&input) {
+                    let array = crate::commands::stream_to_array(input);
+                    let args = CommandArgs::from_context(ctx, vec![], array);
+                    match format(args) {
+                        Ok(_) => {}
+                        Err(err) => return LineResult::Error(err.to_string()),
+                    }
+                } else {
+                    let args = CommandArgs::from_context(ctx, vec![], input);
+                    match format(args) {
+                        Ok(_) => {}
+                        Err(err) => return LineResult::Error(err.to_string()),
+                    }
+                }
+            }
+
+            LineResult::Success(line.to_string())
+        }
+        Err(ReadlineError::Interrupted) => {
+            println!("CTRL-C");
+            LineResult::Break
+        }
+        Err(ReadlineError::Eof) => {
+            println!("CTRL-D");
+            LineResult::Break
+        }
+        Err(err) => {
+            println!("Error: {:?}", err);
+            LineResult::Break
+        }
+    }
+}
+
+fn process_command(
+    parsed: Vec<crate::parser::Item>,
+    input: VecDeque<Value>,
+    context: &mut Context,
+) -> Result<VecDeque<Value>, ShellError> {
+    let command = classify_command(&parsed, context)?;
+
+    command.run(input, context)
+}
+
+fn classify_command(
+    command: &[crate::parser::Item],
+    context: &Context,
+) -> Result<ClassifiedCommand, ShellError> {
+    let command_name = &command[0].name()?;
+
+    let arg_list: Vec<Value> = command[1..].iter().map(|i| i.as_value()).collect();
+    let arg_list_strings: Vec<String> = command[1..].iter().map(|i| i.print()).collect();
+
+    match *command_name {
+        other => match context.has_command(*command_name) {
+            true => {
+                let command = context.get_command(command_name);
+                Ok(ClassifiedCommand::Internal(InternalCommand {
+                    command,
+                    args: arg_list,
+                }))
+            }
+            false => Ok(ClassifiedCommand::External(ExternalCommand {
+                name: other.to_string(),
+                args: arg_list_strings,
+            })),
+        },
+    }
+}
+
+fn format(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let last = args.input.len() - 1;
+    for (i, item) in args.input.iter().enumerate() {
+        let view = GenericView::new(item);
+        crate::format::print_view(&view, args.host);
+
+        if last != i {
+            println!("");
+        }
+    }
+
+    Ok(VecDeque::new())
+}
+
+fn format_list(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
+    let view = EntriesListView::from_stream(args.input);
+    crate::format::print_view(&view, args.host);
+
+    Ok(VecDeque::new())
+}
+
+fn equal_shapes(input: &VecDeque<Value>) -> bool {
+    let mut items = input.iter();
+
+    let item = match items.next() {
+        Some(item) => item,
+        None => return false,
+    };
+
+    let desc = item.data_descriptors();
+
+    for item in items {
+        if desc != item.data_descriptors() {
+            return false;
+        }
+    }
+
+    true
+}

src/commands/classified.rs

@@ -11,7 +11,7 @@ impl ClassifiedCommand {
     crate fn run(
         self,
         input: VecDeque<Value>,
-        context: &mut crate::Context,
+        context: &mut Context,
     ) -> Result<VecDeque<Value>, ShellError> {
         match self {
             ClassifiedCommand::Internal(internal) => {
@@ -22,7 +22,7 @@ impl ClassifiedCommand {
                 for v in result {
                     match v {
                         ReturnValue::Action(action) => match action {
-                            crate::CommandAction::ChangeCwd(cwd) => context.env.cwd = cwd,
+                            CommandAction::ChangeCwd(cwd) => context.env.cwd = cwd,
                         },
 
                         ReturnValue::Value(v) => next.push_back(v),

src/commands/command.rs

@@ -1,12 +1,11 @@
 use crate::errors::ShellError;
 use crate::object::Value;
 use crate::prelude::*;
-use crate::Context;
 use std::path::PathBuf;
 
 pub struct CommandArgs<'caller> {
     pub host: &'caller mut dyn Host,
-    pub env: &'caller crate::Environment,
+    pub env: &'caller Environment,
     pub args: Vec<Value>,
     pub input: VecDeque<Value>,
 }

src/context.rs

@@ -4,8 +4,8 @@ use std::error::Error;
 use std::sync::Arc;
 
 pub struct Context {
-    commands: indexmap::IndexMap<String, Arc<dyn crate::Command>>,
+    commands: indexmap::IndexMap<String, Arc<dyn Command>>,
-    crate host: Box<dyn crate::Host>,
+    crate host: Box<dyn Host>,
     crate env: Environment,
 }
 
@@ -14,11 +14,11 @@ impl Context {
         Ok(Context {
             commands: indexmap::IndexMap::new(),
             host: Box::new(crate::env::host::BasicHost),
-            env: crate::Environment::basic()?,
+            env: Environment::basic()?,
         })
     }
 
-    pub fn add_commands(&mut self, commands: Vec<(&str, Arc<dyn crate::Command>)>) {
+    pub fn add_commands(&mut self, commands: Vec<(&str, Arc<dyn Command>)>) {
         for (name, command) in commands {
             self.commands.insert(name.to_string(), command);
         }

src/errors.rs

@@ -1,7 +1,6 @@
 #[allow(unused)]
 use crate::prelude::*;
 
-use crate::Value;
 use derive_new::new;
 
 #[derive(Debug, Ord, PartialOrd, Eq, PartialEq, new)]

src/format/entries.rs

@@ -1,6 +1,5 @@
 use crate::format::RenderView;
 use crate::prelude::*;
-use crate::Host;
 
 use derive_new::new;
 

src/format/generic.rs

@@ -1,6 +1,6 @@
 use crate::format::{EntriesView, RenderView, TableView};
 use crate::object::Value;
-use crate::Host;
+use crate::prelude::*;
 use derive_new::new;
 
 // A list is printed one line at a time with an optional separator between groups

src/format/list.rs

@@ -1,5 +1,5 @@
 use crate::format::RenderView;
-use crate::Host;
+use crate::prelude::*;
 use derive_new::new;
 
 // A list is printed one line at a time with an optional separator between groups

src/format/table.rs

@@ -1,6 +1,6 @@
 use crate::format::RenderView;
 use crate::object::Value;
-use crate::Host;
+use crate::prelude::*;
 use derive_new::new;
 use prettytable::{Cell, Row, Table};
 

src/main.rs

@@ -1,9 +1,7 @@
 #![feature(crate_visibility_modifier)]
 #![feature(in_band_lifetimes)]
 
-#[allow(unused)]
+mod cli;
-use crate::prelude::*;
-
 mod commands;
 mod context;
 mod env;
@@ -13,243 +11,10 @@ mod object;
 mod parser;
 mod prelude;
 mod shell;
+mod stream;
 
-use crate::commands::classified::{ClassifiedCommand, ExternalCommand, InternalCommand};
-use crate::commands::command::ReturnValue;
-crate use crate::commands::command::{Command, CommandAction};
-use crate::context::Context;
-crate use crate::env::{Environment, Host};
-crate use crate::errors::ShellError;
-crate use crate::format::{EntriesListView, GenericView};
-use crate::object::Value;
-
-use rustyline::error::ReadlineError;
-use rustyline::{self, ColorMode, Config, Editor};
-use std::collections::VecDeque;
 use std::error::Error;
-use std::sync::Arc;
-
-#[derive(Debug)]
-pub enum MaybeOwned<'a, T> {
-    Owned(T),
-    Borrowed(&'a T),
-}
-
-impl<T> MaybeOwned<'a, T> {
-    crate fn borrow(&self) -> &T {
-        match self {
-            MaybeOwned::Owned(v) => v,
-            MaybeOwned::Borrowed(v) => v,
-        }
-    }
-}
 
 fn main() -> Result<(), Box<Error>> {
-    let config = Config::builder().color_mode(ColorMode::Forced).build();
+    crate::cli::cli()
-    let h = crate::shell::Helper::new();
-    let mut rl: Editor<crate::shell::Helper> = Editor::with_config(config);
-
-    #[cfg(windows)]
-    {
-        let _ = ansi_term::enable_ansi_support();
-    }
-
-    rl.set_helper(Some(h));
-    if rl.load_history("history.txt").is_err() {
-        println!("No previous history.");
-    }
-
-    let mut context = Context::basic()?;
-
-    {
-        use crate::commands::*;
-
-        context.add_commands(vec![
-            ("format", Arc::new(format)),
-            ("format-list", Arc::new(format_list)),
-            ("ps", Arc::new(ps::ps)),
-            ("ls", Arc::new(ls::ls)),
-            ("cd", Arc::new(cd::cd)),
-            ("view", Arc::new(view::view)),
-            ("skip", Arc::new(skip::skip)),
-            ("take", Arc::new(take::take)),
-            ("select", Arc::new(select::select)),
-            ("reject", Arc::new(reject::reject)),
-            ("to-array", Arc::new(to_array::to_array)),
-            ("where", Arc::new(where_::r#where)),
-            ("sort-by", Arc::new(sort_by::sort_by)),
-        ]);
-    }
-
-    loop {
-        let readline = rl.readline(&format!("{}> ", context.env.cwd().display().to_string()));
-
-        match process_line(readline, &mut context) {
-            LineResult::Success(line) => {
-                rl.add_history_entry(line.clone());
-            }
-
-            LineResult::Error(err) => {
-                context.host.stdout(&err);
-            }
-
-            LineResult::Break => {
-                break;
-            }
-
-            LineResult::FatalError(err) => {
-                context
-                    .host
-                    .stdout(&format!("A surprising fatal error occurred.\n{:?}", err));
-            }
-        }
-    }
-    rl.save_history("history.txt").unwrap();
-
-    Ok(())
-}
-
-enum LineResult {
-    Success(String),
-    Error(String),
-    Break,
-
-    #[allow(unused)]
-    FatalError(ShellError),
-}
-
-fn process_line(readline: Result<String, ReadlineError>, ctx: &mut Context) -> LineResult {
-    match &readline {
-        Ok(line) if line.trim() == "exit" => LineResult::Break,
-
-        Ok(line) if line.trim() == "" => LineResult::Success(line.clone()),
-
-        Ok(line) => {
-            let result = match crate::parser::shell_parser(&line) {
-                Err(err) => {
-                    return LineResult::Error(format!("{:?}", err));
-                }
-
-                Ok(val) => val,
-            };
-
-            let parsed = result.1;
-
-            let mut input = VecDeque::new();
-
-            for item in parsed {
-                input = match process_command(item.clone(), input, ctx) {
-                    Ok(val) => val,
-                    Err(err) => return LineResult::Error(format!("{}", err.description())),
-                };
-            }
-
-            if input.len() > 0 {
-                if equal_shapes(&input) {
-                    let array = crate::commands::stream_to_array(input);
-                    let args = CommandArgs::from_context(ctx, vec![], array);
-                    match format(args) {
-                        Ok(_) => {}
-                        Err(err) => return LineResult::Error(err.to_string()),
-                    }
-                } else {
-                    let args = CommandArgs::from_context(ctx, vec![], input);
-                    match format(args) {
-                        Ok(_) => {}
-                        Err(err) => return LineResult::Error(err.to_string()),
-                    }
-                }
-            }
-
-            LineResult::Success(line.to_string())
-        }
-        Err(ReadlineError::Interrupted) => {
-            println!("CTRL-C");
-            LineResult::Break
-        }
-        Err(ReadlineError::Eof) => {
-            println!("CTRL-D");
-            LineResult::Break
-        }
-        Err(err) => {
-            println!("Error: {:?}", err);
-            LineResult::Break
-        }
-    }
-}
-
-fn process_command(
-    parsed: Vec<crate::parser::Item>,
-    input: VecDeque<Value>,
-    context: &mut Context,
-) -> Result<VecDeque<Value>, ShellError> {
-    let command = classify_command(&parsed, context)?;
-
-    command.run(input, context)
-}
-
-fn classify_command(
-    command: &[crate::parser::Item],
-    context: &Context,
-) -> Result<ClassifiedCommand, ShellError> {
-    let command_name = &command[0].name()?;
-
-    let arg_list: Vec<Value> = command[1..].iter().map(|i| i.as_value()).collect();
-    let arg_list_strings: Vec<String> = command[1..].iter().map(|i| i.print()).collect();
-
-    match *command_name {
-        other => match context.has_command(*command_name) {
-            true => {
-                let command = context.get_command(command_name);
-                Ok(ClassifiedCommand::Internal(InternalCommand {
-                    command,
-                    args: arg_list,
-                }))
-            }
-            false => Ok(ClassifiedCommand::External(ExternalCommand {
-                name: other.to_string(),
-                args: arg_list_strings,
-            })),
-        },
-    }
-}
-
-fn format(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-    let last = args.input.len() - 1;
-    for (i, item) in args.input.iter().enumerate() {
-        let view = GenericView::new(item);
-        crate::format::print_view(&view, args.host);
-
-        if last != i {
-            println!("");
-        }
-    }
-
-    Ok(VecDeque::new())
-}
-
-fn format_list(args: CommandArgs<'caller>) -> Result<VecDeque<ReturnValue>, ShellError> {
-    let view = EntriesListView::from_stream(args.input);
-    crate::format::print_view(&view, args.host);
-
-    Ok(VecDeque::new())
-}
-
-fn equal_shapes(input: &VecDeque<Value>) -> bool {
-    let mut items = input.iter();
-
-    let item = match items.next() {
-        Some(item) => item,
-        None => return false,
-    };
-
-    let desc = item.data_descriptors();
-
-    for item in items {
-        if desc != item.data_descriptors() {
-            return false;
-        }
-    }
-
-    true
 }

src/object/base.rs

@@ -1,6 +1,7 @@
 use crate::errors::ShellError;
 use crate::object::desc::DataDescriptor;
 use crate::parser::parse::Operator;
+use crate::prelude::*;
 use ansi_term::Color;
 use chrono::{DateTime, Utc};
 use chrono_humanize::Humanize;
@@ -75,21 +76,21 @@ impl Value {
         }
     }
 
-    crate fn get_data_by_key(&'a self, name: &str) -> crate::MaybeOwned<'a, Value> {
+    crate fn get_data_by_key(&'a self, name: &str) -> MaybeOwned<'a, Value> {
         match self {
-            Value::Primitive(_) => crate::MaybeOwned::Owned(Value::nothing()),
+            Value::Primitive(_) => MaybeOwned::Owned(Value::nothing()),
             Value::Object(o) => o.get_data_by_key(name),
-            Value::List(_) => crate::MaybeOwned::Owned(Value::nothing()),
+            Value::List(_) => MaybeOwned::Owned(Value::nothing()),
-            Value::Error(_) => crate::MaybeOwned::Owned(Value::nothing()),
+            Value::Error(_) => MaybeOwned::Owned(Value::nothing()),
         }
     }
 
-    crate fn get_data(&'a self, desc: &DataDescriptor) -> crate::MaybeOwned<'a, Value> {
+    crate fn get_data(&'a self, desc: &DataDescriptor) -> MaybeOwned<'a, Value> {
         match self {
-            Value::Primitive(_) => crate::MaybeOwned::Owned(Value::nothing()),
+            Value::Primitive(_) => MaybeOwned::Owned(Value::nothing()),
             Value::Object(o) => o.get_data(desc),
-            Value::List(_) => crate::MaybeOwned::Owned(Value::nothing()),
+            Value::List(_) => MaybeOwned::Owned(Value::nothing()),
-            Value::Error(_) => crate::MaybeOwned::Owned(Value::nothing()),
+            Value::Error(_) => MaybeOwned::Owned(Value::nothing()),
         }
     }
 

src/object/dict.rs

@@ -1,9 +1,7 @@
-#[allow(unused)]
 use crate::prelude::*;
 
 use crate::object::desc::DataDescriptor;
 use crate::object::{Primitive, Value};
-use crate::MaybeOwned;
 use indexmap::IndexMap;
 use std::cmp::{Ordering, PartialOrd};
 

src/parser/completer.rs

@@ -1,9 +1,10 @@
+use crate::prelude::*;
 use rustyline::{completion, Context};
 use std::collections::BTreeMap;
 
 #[allow(unused)]
 crate struct Completer {
-    commands: BTreeMap<String, Box<dyn crate::Command>>,
+    commands: BTreeMap<String, Box<dyn Command>>,
 }
 
 impl completion::Completer for Completer {

src/prelude.rs

@@ -1,4 +1,6 @@
-crate use crate::commands::command::{Command, CommandArgs, ReturnValue};
+crate use crate::cli::MaybeOwned;
+crate use crate::commands::command::{Command, CommandAction, CommandArgs, ReturnValue};
+crate use crate::context::Context;
 crate use crate::env::{Environment, Host};
 crate use crate::errors::ShellError;
 crate use crate::object::{Primitive, Value};