Move subcommand functions into Subcommand (#918)

src/common.rs

@@ -31,7 +31,7 @@ pub(crate) use typed_arena::Arena;
 pub(crate) use unicode_width::{UnicodeWidthChar, UnicodeWidthStr};
 
 // modules
-pub(crate) use crate::{config_error, setting};
+pub(crate) use crate::{completions, config, config_error, setting};
 
 // functions
 pub(crate) use crate::{load_dotenv::load_dotenv, output::output, unindent::unindent};

src/completions.rs

@@ -0,0 +1,174 @@
+pub(crate) const FISH_RECIPE_COMPLETIONS: &str = r#"function __fish_just_complete_recipes
+    just --summary 2> /dev/null | tr " " "\n" || echo ""
+end
+
+# don't suggest files right off
+complete -c just -n "__fish_is_first_arg" --no-files
+
+# complete recipes
+complete -c just -a '(__fish_just_complete_recipes)'
+
+# autogenerated completions
+"#;
+
+pub(crate) const ZSH_COMPLETION_REPLACEMENTS: &[(&str, &str)] = &[
+  (
+    r#"    _arguments "${_arguments_options[@]}" \"#,
+    r#"    local common=("#,
+  ),
+  (
+    r#"'*--set=[Override <VARIABLE> with <VALUE>]' \"#,
+    r#"'*--set[Override <VARIABLE> with <VALUE>]: :_just_variables' \"#,
+  ),
+  (
+    r#"'-s+[Show information about <RECIPE>]' \
+'--show=[Show information about <RECIPE>]' \"#,
+    r#"'-s+[Show information about <RECIPE>]: :_just_commands' \
+'--show=[Show information about <RECIPE>]: :_just_commands' \"#,
+  ),
+  (
+    "'::ARGUMENTS -- Overrides and recipe(s) to run, defaulting to the first recipe in the \
+     justfile:_files' \\
+&& ret=0
+\x20\x20\x20\x20
+",
+    r#")
+
+    _arguments "${_arguments_options[@]}" $common \
+        '1: :_just_commands' \
+        '*: :->args' \
+        && ret=0
+
+    case $state in
+        args)
+            curcontext="${curcontext%:*}-${words[2]}:"
+
+            local lastarg=${words[${#words}]}
+            local recipe
+
+            local cmds; cmds=(
+                ${(s: :)$(_call_program commands just --summary)}
+            )
+
+            # Find first recipe name
+            for ((i = 2; i < $#words; i++ )) do
+                if [[ ${cmds[(I)${words[i]}]} -gt 0 ]]; then
+                    recipe=${words[i]}
+                    break
+                fi
+            done
+
+            if [[ $lastarg = */* ]]; then
+                # Arguments contain slash would be recognised as a file
+                _arguments -s -S $common '*:: :_files'
+            elif [[ $lastarg = *=* ]]; then
+                # Arguments contain equal would be recognised as a variable
+                _message "value"
+            elif [[ $recipe ]]; then
+                # Show usage message
+                _message "`just --show $recipe`"
+                # Or complete with other commands
+                #_arguments -s -S $common '*:: :_just_commands'
+            else
+                _arguments -s -S $common '*:: :_just_commands'
+            fi
+        ;;
+    esac
+
+    return ret
+"#,
+  ),
+  (
+    "    local commands; commands=(
+\x20\x20\x20\x20\x20\x20\x20\x20
+    )",
+    r#"    [[ $PREFIX = -* ]] && return 1
+    integer ret=1
+    local variables; variables=(
+        ${(s: :)$(_call_program commands just --variables)}
+    )
+    local commands; commands=(
+        ${${${(M)"${(f)$(_call_program commands just --list)}":#    *}/ ##/}/ ##/:Args: }
+    )
+"#,
+  ),
+  (
+    r#"    _describe -t commands 'just commands' commands "$@""#,
+    r#"    if compset -P '*='; then
+        case "${${words[-1]%=*}#*=}" in
+            *) _message 'value' && ret=0 ;;
+        esac
+    else
+        _describe -t variables 'variables' variables -qS "=" && ret=0
+        _describe -t commands 'just commands' commands "$@"
+    fi
+"#,
+  ),
+  (
+    r#"_just "$@""#,
+    r#"(( $+functions[_just_variables] )) ||
+_just_variables() {
+    [[ $PREFIX = -* ]] && return 1
+    integer ret=1
+    local variables; variables=(
+        ${(s: :)$(_call_program commands just --variables)}
+    )
+
+    if compset -P '*='; then
+        case "${${words[-1]%=*}#*=}" in
+            *) _message 'value' && ret=0 ;;
+        esac
+    else
+        _describe -t variables 'variables' variables && ret=0
+    fi
+
+    return ret
+}
+
+_just "$@""#,
+  ),
+];
+
+pub(crate) const POWERSHELL_COMPLETION_REPLACEMENTS: &[(&str, &str)] = &[(
+  r#"$completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
+        Sort-Object -Property ListItemText"#,
+  r#"function Get-JustFileRecipes([string[]]$CommandElements) {
+        $justFileIndex = $commandElements.IndexOf("--justfile");
+
+        if ($justFileIndex -ne -1 && $justFileIndex + 1 -le $commandElements.Length) {
+            $justFileLocation = $commandElements[$justFileIndex + 1]
+        }
+
+        $justArgs = @("--summary")
+
+        if (Test-Path $justFileLocation) {
+            $justArgs += @("--justfile", $justFileLocation)
+        }
+
+        $recipes = $(just @justArgs) -split ' '
+        return $recipes | ForEach-Object { [CompletionResult]::new($_) }
+    }
+
+    $elementValues = $commandElements | Select-Object -ExpandProperty Value
+    $recipes = Get-JustFileRecipes -CommandElements $elementValues
+    $completions += $recipes
+    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
+        Sort-Object -Property ListItemText"#,
+)];
+
+pub(crate) const BASH_COMPLETION_REPLACEMENTS: &[(&str, &str)] = &[(
+  r#"            if [[ ${cur} == -* || ${COMP_CWORD} -eq 1 ]] ; then
+                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
+                return 0
+            fi"#,
+  r#"                if [[ ${cur} == -* ]] ; then
+                    COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
+                    return 0
+                elif [[ ${COMP_CWORD} -eq 1 ]]; then
+                    local recipes=$(just --summary --color never 2> /dev/null)
+                    if [[ $? -eq 0 ]]; then
+                        COMPREPLY=( $(compgen -W "${recipes}" -- "${cur}") )
+                        return 0
+                    fi
+                fi"#,
+)];

src/config.rs

@@ -11,7 +11,6 @@ pub(crate) const CHOOSE_HELP: &str = "Select one or more recipes to run using a
 
 pub(crate) const DEFAULT_SHELL: &str = "sh";
 pub(crate) const DEFAULT_SHELL_ARG: &str = "-cu";
-pub(crate) const INIT_JUSTFILE: &str = "default:\n\techo 'Hello, world!'\n";
 
 #[derive(Debug, PartialEq)]
 pub(crate) struct Config {
@@ -532,163 +531,7 @@ impl Config {
     })
   }
 
-  pub(crate) fn run_subcommand<'src>(self, loader: &'src Loader) -> Result<(), Error<'src>> {
+  pub(crate) fn require_unstable(&self, message: &str) -> Result<(), Error<'static>> {
-    use Subcommand::*;
-
-    if self.subcommand == Init {
-      return self.init();
-    }
-
-    if let Completions { shell } = self.subcommand {
-      return Subcommand::completions(&shell);
-    }
-
-    let search = Search::find(&self.search_config, &self.invocation_directory)?;
-
-    if self.subcommand == Edit {
-      return Self::edit(&search);
-    }
-
-    let src = loader.load(&search.justfile)?;
-
-    let tokens = Lexer::lex(&src)?;
-    let ast = Parser::parse(&tokens)?;
-    let justfile = Analyzer::analyze(ast.clone())?;
-
-    if self.verbosity.loud() {
-      for warning in &justfile.warnings {
-        warning.write(&mut io::stderr(), self.color.stderr()).ok();
-      }
-    }
-
-    match &self.subcommand {
-      Choose { overrides, chooser } =>
-        self.choose(justfile, &search, overrides, chooser.as_deref())?,
-      Command { overrides, .. } => self.run(justfile, &search, overrides, &[])?,
-      Dump => Self::dump(ast),
-      Evaluate { overrides, .. } => self.run(justfile, &search, overrides, &[])?,
-      Format => self.format(ast, &search)?,
-      List => self.list(justfile),
-      Run {
-        arguments,
-        overrides,
-      } => self.run(justfile, &search, overrides, arguments)?,
-      Show { ref name } => Self::show(&name, justfile)?,
-      Summary => self.summary(justfile),
-      Variables => Self::variables(justfile),
-      Completions { .. } | Edit | Init => unreachable!(),
-    }
-
-    Ok(())
-  }
-
-  fn choose<'src>(
-    &self,
-    justfile: Justfile<'src>,
-    search: &Search,
-    overrides: &BTreeMap<String, String>,
-    chooser: Option<&str>,
-  ) -> Result<(), Error<'src>> {
-    let recipes = justfile
-      .public_recipes(self.unsorted)
-      .iter()
-      .filter(|recipe| recipe.min_arguments() == 0)
-      .cloned()
-      .collect::<Vec<&Recipe<Dependency>>>();
-
-    if recipes.is_empty() {
-      return Err(Error::NoChoosableRecipes);
-    }
-
-    let chooser = chooser
-      .map(OsString::from)
-      .or_else(|| env::var_os(CHOOSER_ENVIRONMENT_KEY))
-      .unwrap_or_else(|| OsString::from(CHOOSER_DEFAULT));
-
-    let result = justfile
-      .settings
-      .shell_command(self)
-      .arg(&chooser)
-      .current_dir(&search.working_directory)
-      .stdin(Stdio::piped())
-      .stdout(Stdio::piped())
-      .spawn();
-
-    let mut child = match result {
-      Ok(child) => child,
-      Err(io_error) => {
-        return Err(Error::ChooserInvoke {
-          shell_binary: justfile.settings.shell_binary(self).to_owned(),
-          shell_arguments: justfile.settings.shell_arguments(self).join(" "),
-          chooser,
-          io_error,
-        });
-      },
-    };
-
-    for recipe in recipes {
-      if let Err(io_error) = child
-        .stdin
-        .as_mut()
-        .expect("Child was created with piped stdio")
-        .write_all(format!("{}\n", recipe.name).as_bytes())
-      {
-        return Err(Error::ChooserWrite { io_error, chooser });
-      }
-    }
-
-    let output = match child.wait_with_output() {
-      Ok(output) => output,
-      Err(io_error) => {
-        return Err(Error::ChooserRead { io_error, chooser });
-      },
-    };
-
-    if !output.status.success() {
-      return Err(Error::ChooserStatus {
-        status: output.status,
-        chooser,
-      });
-    }
-
-    let stdout = String::from_utf8_lossy(&output.stdout);
-
-    let recipes = stdout
-      .trim()
-      .split_whitespace()
-      .map(str::to_owned)
-      .collect::<Vec<String>>();
-
-    self.run(justfile, search, overrides, &recipes)
-  }
-
-  fn dump(ast: Ast) {
-    print!("{}", ast);
-  }
-
-  pub(crate) fn edit(search: &Search) -> Result<(), Error<'static>> {
-    let editor = env::var_os("VISUAL")
-      .or_else(|| env::var_os("EDITOR"))
-      .unwrap_or_else(|| "vim".into());
-
-    let error = Command::new(&editor)
-      .current_dir(&search.working_directory)
-      .arg(&search.justfile)
-      .status();
-
-    let status = match error {
-      Err(io_error) => return Err(Error::EditorInvoke { editor, io_error }),
-      Ok(status) => status,
-    };
-
-    if !status.success() {
-      return Err(Error::EditorStatus { editor, status });
-    }
-
-    Ok(())
-  }
-
-  fn require_unstable(&self, message: &str) -> Result<(), Error<'static>> {
     if self.unstable {
       Ok(())
     } else {
@@ -698,183 +541,8 @@ impl Config {
     }
   }
 
-  fn format(&self, ast: Ast, search: &Search) -> Result<(), Error<'static>> {
+  pub(crate) fn run<'src>(self, loader: &'src Loader) -> Result<(), Error<'src>> {
-    self.require_unstable("The `--fmt` command is currently unstable.")?;
+    self.subcommand.run(&self, loader)
-
-    if let Err(io_error) =
-      File::create(&search.justfile).and_then(|mut file| write!(file, "{}", ast))
-    {
-      Err(Error::WriteJustfile {
-        justfile: search.justfile.clone(),
-        io_error,
-      })
-    } else {
-      if self.verbosity.loud() {
-        eprintln!("Wrote justfile to `{}`", search.justfile.display());
-      }
-      Ok(())
-    }
-  }
-
-  pub(crate) fn init(&self) -> Result<(), Error<'static>> {
-    let search = Search::init(&self.search_config, &self.invocation_directory)?;
-
-    if search.justfile.is_file() {
-      Err(Error::InitExists {
-        justfile: search.justfile,
-      })
-    } else if let Err(io_error) = fs::write(&search.justfile, INIT_JUSTFILE) {
-      Err(Error::WriteJustfile {
-        justfile: search.justfile,
-        io_error,
-      })
-    } else {
-      if self.verbosity.loud() {
-        eprintln!("Wrote justfile to `{}`", search.justfile.display());
-      }
-      Ok(())
-    }
-  }
-
-  fn list(&self, justfile: Justfile) {
-    // Construct a target to alias map.
-    let mut recipe_aliases: BTreeMap<&str, Vec<&str>> = BTreeMap::new();
-    for alias in justfile.aliases.values() {
-      if alias.is_private() {
-        continue;
-      }
-
-      if !recipe_aliases.contains_key(alias.target.name.lexeme()) {
-        recipe_aliases.insert(alias.target.name.lexeme(), vec![alias.name.lexeme()]);
-      } else {
-        let aliases = recipe_aliases.get_mut(alias.target.name.lexeme()).unwrap();
-        aliases.push(alias.name.lexeme());
-      }
-    }
-
-    let mut line_widths: BTreeMap<&str, usize> = BTreeMap::new();
-
-    for (name, recipe) in &justfile.recipes {
-      if recipe.private {
-        continue;
-      }
-
-      for name in iter::once(name).chain(recipe_aliases.get(name).unwrap_or(&Vec::new())) {
-        let mut line_width = UnicodeWidthStr::width(*name);
-
-        for parameter in &recipe.parameters {
-          line_width += UnicodeWidthStr::width(format!(" {}", parameter).as_str());
-        }
-
-        if line_width <= 30 {
-          line_widths.insert(name, line_width);
-        }
-      }
-    }
-
-    let max_line_width = cmp::min(line_widths.values().cloned().max().unwrap_or(0), 30);
-
-    let doc_color = self.color.stdout().doc();
-    print!("{}", self.list_heading);
-
-    for recipe in justfile.public_recipes(self.unsorted) {
-      let name = recipe.name();
-
-      for (i, name) in iter::once(&name)
-        .chain(recipe_aliases.get(name).unwrap_or(&Vec::new()))
-        .enumerate()
-      {
-        print!("{}{}", self.list_prefix, name);
-        for parameter in &recipe.parameters {
-          if self.color.stdout().active() {
-            print!(" {:#}", parameter);
-          } else {
-            print!(" {}", parameter);
-          }
-        }
-
-        // Declaring this outside of the nested loops will probably be more efficient,
-        // but it creates all sorts of lifetime issues with variables inside the loops.
-        // If this is inlined like the docs say, it shouldn't make any difference.
-        let print_doc = |doc| {
-          print!(
-            " {:padding$}{} {}",
-            "",
-            doc_color.paint("#"),
-            doc_color.paint(doc),
-            padding = max_line_width
-              .saturating_sub(line_widths.get(name).cloned().unwrap_or(max_line_width))
-          );
-        };
-
-        match (i, recipe.doc) {
-          (0, Some(doc)) => print_doc(doc),
-          (0, None) => (),
-          _ => {
-            let alias_doc = format!("alias for `{}`", recipe.name);
-            print_doc(&alias_doc);
-          },
-        }
-        println!();
-      }
-    }
-  }
-
-  fn run<'src>(
-    &self,
-    justfile: Justfile<'src>,
-    search: &Search,
-    overrides: &BTreeMap<String, String>,
-    arguments: &[String],
-  ) -> Result<(), Error<'src>> {
-    if let Err(error) = InterruptHandler::install(self.verbosity) {
-      warn!("Failed to set CTRL-C handler: {}", error);
-    }
-
-    justfile.run(&self, search, overrides, arguments)
-  }
-
-  fn show<'src>(name: &str, justfile: Justfile<'src>) -> Result<(), Error<'src>> {
-    if let Some(alias) = justfile.get_alias(name) {
-      let recipe = justfile.get_recipe(alias.target.name.lexeme()).unwrap();
-      println!("{}", alias);
-      println!("{}", recipe);
-      Ok(())
-    } else if let Some(recipe) = justfile.get_recipe(name) {
-      println!("{}", recipe);
-      Ok(())
-    } else {
-      Err(Error::UnknownRecipes {
-        recipes:    vec![name.to_owned()],
-        suggestion: justfile.suggest_recipe(name),
-      })
-    }
-  }
-
-  fn summary(&self, justfile: Justfile) {
-    if justfile.count() == 0 {
-      if self.verbosity.loud() {
-        eprintln!("Justfile contains no recipes.");
-      }
-    } else {
-      let summary = justfile
-        .public_recipes(self.unsorted)
-        .iter()
-        .map(|recipe| recipe.name())
-        .collect::<Vec<&str>>()
-        .join(" ");
-      println!("{}", summary);
-    }
-  }
-
-  fn variables(justfile: Justfile) {
-    for (i, (_, assignment)) in justfile.assignments.iter().enumerate() {
-      if i > 0 {
-        print!(" ");
-      }
-      print!("{}", assignment.name);
-    }
-    println!();
   }
 }
 
@@ -1716,9 +1384,4 @@ ARGS:
       assert_eq!(overrides, map!{"bar": "baz"});
     },
   }
-
-  #[test]
-  fn init_justfile() {
-    testing::compile(INIT_JUSTFILE);
-  }
 }

src/justfile.rs

@@ -81,6 +81,10 @@ impl<'src> Justfile<'src> {
     overrides: &BTreeMap<String, String>,
     arguments: &[String],
   ) -> RunResult<'src, ()> {
+    if let Err(error) = InterruptHandler::install(config.verbosity) {
+      warn!("Failed to set CTRL-C handler: {}", error);
+    }
+
     let unknown_overrides = overrides
       .keys()
       .filter(|name| !self.assignments.contains_key(name.as_str()))

src/lib.rs

@@ -70,6 +70,7 @@ mod common;
 mod compile_error;
 mod compile_error_kind;
 mod compiler;
+mod completions;
 mod config;
 mod config_error;
 mod count;

src/run.rs

@@ -26,7 +26,7 @@ pub fn run() -> Result<(), i32> {
     .and_then(|config| {
       color = config.color;
       verbosity = config.verbosity;
-      config.run_subcommand(&loader)
+      config.run(&loader)
     })
     .map_err(|error| {
       if !verbosity.quiet() {

src/subcommand.rs

@@ -1,5 +1,7 @@
 use crate::common::*;
 
+const INIT_JUSTFILE: &str = "default:\n\techo 'Hello, world!'\n";
+
 #[derive(PartialEq, Clone, Debug)]
 pub(crate) enum Subcommand {
   Choose {
@@ -34,183 +36,138 @@ pub(crate) enum Subcommand {
   Variables,
 }
 
-const FISH_RECIPE_COMPLETIONS: &str = r#"function __fish_just_complete_recipes
-    just --summary 2> /dev/null | tr " " "\n" || echo ""
-end
-
-# don't suggest files right off
-complete -c just -n "__fish_is_first_arg" --no-files
-
-# complete recipes
-complete -c just -a '(__fish_just_complete_recipes)'
-
-# autogenerated completions
-"#;
-
-const ZSH_COMPLETION_REPLACEMENTS: &[(&str, &str)] = &[
-  (
-    r#"    _arguments "${_arguments_options[@]}" \"#,
-    r#"    local common=("#,
-  ),
-  (
-    r#"'*--set=[Override <VARIABLE> with <VALUE>]' \"#,
-    r#"'*--set[Override <VARIABLE> with <VALUE>]: :_just_variables' \"#,
-  ),
-  (
-    r#"'-s+[Show information about <RECIPE>]' \
-'--show=[Show information about <RECIPE>]' \"#,
-    r#"'-s+[Show information about <RECIPE>]: :_just_commands' \
-'--show=[Show information about <RECIPE>]: :_just_commands' \"#,
-  ),
-  (
-    "'::ARGUMENTS -- Overrides and recipe(s) to run, defaulting to the first recipe in the \
-     justfile:_files' \\
-&& ret=0
-\x20\x20\x20\x20
-",
-    r#")
-
-    _arguments "${_arguments_options[@]}" $common \
-        '1: :_just_commands' \
-        '*: :->args' \
-        && ret=0
-
-    case $state in
-        args)
-            curcontext="${curcontext%:*}-${words[2]}:"
-
-            local lastarg=${words[${#words}]}
-            local recipe
-
-            local cmds; cmds=(
-                ${(s: :)$(_call_program commands just --summary)}
-            )
-
-            # Find first recipe name
-            for ((i = 2; i < $#words; i++ )) do
-                if [[ ${cmds[(I)${words[i]}]} -gt 0 ]]; then
-                    recipe=${words[i]}
-                    break
-                fi
-            done
-
-            if [[ $lastarg = */* ]]; then
-                # Arguments contain slash would be recognised as a file
-                _arguments -s -S $common '*:: :_files'
-            elif [[ $lastarg = *=* ]]; then
-                # Arguments contain equal would be recognised as a variable
-                _message "value"
-            elif [[ $recipe ]]; then
-                # Show usage message
-                _message "`just --show $recipe`"
-                # Or complete with other commands
-                #_arguments -s -S $common '*:: :_just_commands'
-            else
-                _arguments -s -S $common '*:: :_just_commands'
-            fi
-        ;;
-    esac
-
-    return ret
-"#,
-  ),
-  (
-    "    local commands; commands=(
-\x20\x20\x20\x20\x20\x20\x20\x20
-    )",
-    r#"    [[ $PREFIX = -* ]] && return 1
-    integer ret=1
-    local variables; variables=(
-        ${(s: :)$(_call_program commands just --variables)}
-    )
-    local commands; commands=(
-        ${${${(M)"${(f)$(_call_program commands just --list)}":#    *}/ ##/}/ ##/:Args: }
-    )
-"#,
-  ),
-  (
-    r#"    _describe -t commands 'just commands' commands "$@""#,
-    r#"    if compset -P '*='; then
-        case "${${words[-1]%=*}#*=}" in
-            *) _message 'value' && ret=0 ;;
-        esac
-    else
-        _describe -t variables 'variables' variables -qS "=" && ret=0
-        _describe -t commands 'just commands' commands "$@"
-    fi
-"#,
-  ),
-  (
-    r#"_just "$@""#,
-    r#"(( $+functions[_just_variables] )) ||
-_just_variables() {
-    [[ $PREFIX = -* ]] && return 1
-    integer ret=1
-    local variables; variables=(
-        ${(s: :)$(_call_program commands just --variables)}
-    )
-
-    if compset -P '*='; then
-        case "${${words[-1]%=*}#*=}" in
-            *) _message 'value' && ret=0 ;;
-        esac
-    else
-        _describe -t variables 'variables' variables && ret=0
-    fi
-
-    return ret
-}
-
-_just "$@""#,
-  ),
-];
-
-const POWERSHELL_COMPLETION_REPLACEMENTS: &[(&str, &str)] = &[(
-  r#"$completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
-        Sort-Object -Property ListItemText"#,
-  r#"function Get-JustFileRecipes([string[]]$CommandElements) {
-        $justFileIndex = $commandElements.IndexOf("--justfile");
-
-        if ($justFileIndex -ne -1 && $justFileIndex + 1 -le $commandElements.Length) {
-            $justFileLocation = $commandElements[$justFileIndex + 1]
-        }
-
-        $justArgs = @("--summary")
-
-        if (Test-Path $justFileLocation) {
-            $justArgs += @("--justfile", $justFileLocation)
-        }
-
-        $recipes = $(just @justArgs) -split ' '
-        return $recipes | ForEach-Object { [CompletionResult]::new($_) }
-    }
-
-    $elementValues = $commandElements | Select-Object -ExpandProperty Value
-    $recipes = Get-JustFileRecipes -CommandElements $elementValues
-    $completions += $recipes
-    $completions.Where{ $_.CompletionText -like "$wordToComplete*" } |
-        Sort-Object -Property ListItemText"#,
-)];
-
-const BASH_COMPLETION_REPLACEMENTS: &[(&str, &str)] = &[(
-  r#"            if [[ ${cur} == -* || ${COMP_CWORD} -eq 1 ]] ; then
-                COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
-                return 0
-            fi"#,
-  r#"                if [[ ${cur} == -* ]] ; then
-                    COMPREPLY=( $(compgen -W "${opts}" -- "${cur}") )
-                    return 0
-                elif [[ ${COMP_CWORD} -eq 1 ]]; then
-                    local recipes=$(just --summary --color never 2> /dev/null)
-                    if [[ $? -eq 0 ]]; then
-                        COMPREPLY=( $(compgen -W "${recipes}" -- "${cur}") )
-                        return 0
-                    fi
-                fi"#,
-)];
-
 impl Subcommand {
-  pub(crate) fn completions(shell: &str) -> RunResult<'static, ()> {
+  pub(crate) fn run<'src>(&self, config: &Config, loader: &'src Loader) -> Result<(), Error<'src>> {
+    use Subcommand::*;
+
+    if let Init = self {
+      return Self::init(config);
+    }
+
+    if let Completions { shell } = self {
+      return Self::completions(&shell);
+    }
+
+    let search = Search::find(&config.search_config, &config.invocation_directory)?;
+
+    if let Edit = self {
+      return Self::edit(&search);
+    }
+
+    let src = loader.load(&search.justfile)?;
+
+    let tokens = Lexer::lex(&src)?;
+    let ast = Parser::parse(&tokens)?;
+    let justfile = Analyzer::analyze(ast.clone())?;
+
+    if config.verbosity.loud() {
+      for warning in &justfile.warnings {
+        warning.write(&mut io::stderr(), config.color.stderr()).ok();
+      }
+    }
+
+    match self {
+      Choose { overrides, chooser } =>
+        Self::choose(&config, justfile, &search, overrides, chooser.as_deref())?,
+      Command { overrides, .. } => justfile.run(&config, &search, overrides, &[])?,
+      Dump => Self::dump(ast),
+      Evaluate { overrides, .. } => justfile.run(&config, &search, overrides, &[])?,
+      Format => Self::format(&config, ast, &search)?,
+      List => Self::list(&config, justfile),
+      Run {
+        arguments,
+        overrides,
+      } => justfile.run(&config, &search, overrides, arguments)?,
+      Show { ref name } => Self::show(&name, justfile)?,
+      Summary => Self::summary(&config, justfile),
+      Variables => Self::variables(justfile),
+      Completions { .. } | Edit | Init => unreachable!(),
+    }
+
+    Ok(())
+  }
+
+  fn choose<'src>(
+    config: &Config,
+    justfile: Justfile<'src>,
+    search: &Search,
+    overrides: &BTreeMap<String, String>,
+    chooser: Option<&str>,
+  ) -> Result<(), Error<'src>> {
+    let recipes = justfile
+      .public_recipes(config.unsorted)
+      .iter()
+      .filter(|recipe| recipe.min_arguments() == 0)
+      .cloned()
+      .collect::<Vec<&Recipe<Dependency>>>();
+
+    if recipes.is_empty() {
+      return Err(Error::NoChoosableRecipes);
+    }
+
+    let chooser = chooser
+      .map(OsString::from)
+      .or_else(|| env::var_os(config::CHOOSER_ENVIRONMENT_KEY))
+      .unwrap_or_else(|| OsString::from(config::CHOOSER_DEFAULT));
+
+    let result = justfile
+      .settings
+      .shell_command(&config)
+      .arg(&chooser)
+      .current_dir(&search.working_directory)
+      .stdin(Stdio::piped())
+      .stdout(Stdio::piped())
+      .spawn();
+
+    let mut child = match result {
+      Ok(child) => child,
+      Err(io_error) => {
+        return Err(Error::ChooserInvoke {
+          shell_binary: justfile.settings.shell_binary(&config).to_owned(),
+          shell_arguments: justfile.settings.shell_arguments(&config).join(" "),
+          chooser,
+          io_error,
+        });
+      },
+    };
+
+    for recipe in recipes {
+      if let Err(io_error) = child
+        .stdin
+        .as_mut()
+        .expect("Child was created with piped stdio")
+        .write_all(format!("{}\n", recipe.name).as_bytes())
+      {
+        return Err(Error::ChooserWrite { io_error, chooser });
+      }
+    }
+
+    let output = match child.wait_with_output() {
+      Ok(output) => output,
+      Err(io_error) => {
+        return Err(Error::ChooserRead { io_error, chooser });
+      },
+    };
+
+    if !output.status.success() {
+      return Err(Error::ChooserStatus {
+        status: output.status,
+        chooser,
+      });
+    }
+
+    let stdout = String::from_utf8_lossy(&output.stdout);
+
+    let recipes = stdout
+      .trim()
+      .split_whitespace()
+      .map(str::to_owned)
+      .collect::<Vec<String>>();
+
+    justfile.run(config, search, overrides, &recipes)
+  }
+
+  fn completions(shell: &str) -> RunResult<'static, ()> {
     use clap::Shell;
 
     fn replace(haystack: &mut String, needle: &str, replacement: &str) -> RunResult<'static, ()> {
@@ -237,19 +194,19 @@ impl Subcommand {
 
     match shell {
       Shell::Bash =>
-        for (needle, replacement) in BASH_COMPLETION_REPLACEMENTS {
+        for (needle, replacement) in completions::BASH_COMPLETION_REPLACEMENTS {
           replace(&mut script, needle, replacement)?;
         },
       Shell::Fish => {
-        script.insert_str(0, FISH_RECIPE_COMPLETIONS);
+        script.insert_str(0, completions::FISH_RECIPE_COMPLETIONS);
       },
       Shell::PowerShell =>
-        for (needle, replacement) in POWERSHELL_COMPLETION_REPLACEMENTS {
+        for (needle, replacement) in completions::POWERSHELL_COMPLETION_REPLACEMENTS {
           replace(&mut script, needle, replacement)?;
         },
 
       Shell::Zsh =>
-        for (needle, replacement) in ZSH_COMPLETION_REPLACEMENTS {
+        for (needle, replacement) in completions::ZSH_COMPLETION_REPLACEMENTS {
           replace(&mut script, needle, replacement)?;
         },
       Shell::Elvish => {},
@@ -259,4 +216,205 @@ impl Subcommand {
 
     Ok(())
   }
+
+  fn dump(ast: Ast) {
+    print!("{}", ast);
+  }
+
+  fn edit(search: &Search) -> Result<(), Error<'static>> {
+    let editor = env::var_os("VISUAL")
+      .or_else(|| env::var_os("EDITOR"))
+      .unwrap_or_else(|| "vim".into());
+
+    let error = Command::new(&editor)
+      .current_dir(&search.working_directory)
+      .arg(&search.justfile)
+      .status();
+
+    let status = match error {
+      Err(io_error) => return Err(Error::EditorInvoke { editor, io_error }),
+      Ok(status) => status,
+    };
+
+    if !status.success() {
+      return Err(Error::EditorStatus { editor, status });
+    }
+
+    Ok(())
+  }
+
+  fn format(config: &Config, ast: Ast, search: &Search) -> Result<(), Error<'static>> {
+    config.require_unstable("The `--fmt` command is currently unstable.")?;
+
+    if let Err(io_error) =
+      File::create(&search.justfile).and_then(|mut file| write!(file, "{}", ast))
+    {
+      Err(Error::WriteJustfile {
+        justfile: search.justfile.clone(),
+        io_error,
+      })
+    } else {
+      if config.verbosity.loud() {
+        eprintln!("Wrote justfile to `{}`", search.justfile.display());
+      }
+      Ok(())
+    }
+  }
+
+  fn init(config: &Config) -> Result<(), Error<'static>> {
+    let search = Search::init(&config.search_config, &config.invocation_directory)?;
+
+    if search.justfile.is_file() {
+      Err(Error::InitExists {
+        justfile: search.justfile,
+      })
+    } else if let Err(io_error) = fs::write(&search.justfile, INIT_JUSTFILE) {
+      Err(Error::WriteJustfile {
+        justfile: search.justfile,
+        io_error,
+      })
+    } else {
+      if config.verbosity.loud() {
+        eprintln!("Wrote justfile to `{}`", search.justfile.display());
+      }
+      Ok(())
+    }
+  }
+
+  fn list(config: &Config, justfile: Justfile) {
+    // Construct a target to alias map.
+    let mut recipe_aliases: BTreeMap<&str, Vec<&str>> = BTreeMap::new();
+    for alias in justfile.aliases.values() {
+      if alias.is_private() {
+        continue;
+      }
+
+      if !recipe_aliases.contains_key(alias.target.name.lexeme()) {
+        recipe_aliases.insert(alias.target.name.lexeme(), vec![alias.name.lexeme()]);
+      } else {
+        let aliases = recipe_aliases.get_mut(alias.target.name.lexeme()).unwrap();
+        aliases.push(alias.name.lexeme());
+      }
+    }
+
+    let mut line_widths: BTreeMap<&str, usize> = BTreeMap::new();
+
+    for (name, recipe) in &justfile.recipes {
+      if recipe.private {
+        continue;
+      }
+
+      for name in iter::once(name).chain(recipe_aliases.get(name).unwrap_or(&Vec::new())) {
+        let mut line_width = UnicodeWidthStr::width(*name);
+
+        for parameter in &recipe.parameters {
+          line_width += UnicodeWidthStr::width(format!(" {}", parameter).as_str());
+        }
+
+        if line_width <= 30 {
+          line_widths.insert(name, line_width);
+        }
+      }
+    }
+
+    let max_line_width = cmp::min(line_widths.values().cloned().max().unwrap_or(0), 30);
+
+    let doc_color = config.color.stdout().doc();
+    print!("{}", config.list_heading);
+
+    for recipe in justfile.public_recipes(config.unsorted) {
+      let name = recipe.name();
+
+      for (i, name) in iter::once(&name)
+        .chain(recipe_aliases.get(name).unwrap_or(&Vec::new()))
+        .enumerate()
+      {
+        print!("{}{}", config.list_prefix, name);
+        for parameter in &recipe.parameters {
+          if config.color.stdout().active() {
+            print!(" {:#}", parameter);
+          } else {
+            print!(" {}", parameter);
+          }
+        }
+
+        // Declaring this outside of the nested loops will probably be more efficient,
+        // but it creates all sorts of lifetime issues with variables inside the loops.
+        // If this is inlined like the docs say, it shouldn't make any difference.
+        let print_doc = |doc| {
+          print!(
+            " {:padding$}{} {}",
+            "",
+            doc_color.paint("#"),
+            doc_color.paint(doc),
+            padding = max_line_width
+              .saturating_sub(line_widths.get(name).cloned().unwrap_or(max_line_width))
+          );
+        };
+
+        match (i, recipe.doc) {
+          (0, Some(doc)) => print_doc(doc),
+          (0, None) => (),
+          _ => {
+            let alias_doc = format!("alias for `{}`", recipe.name);
+            print_doc(&alias_doc);
+          },
+        }
+        println!();
+      }
+    }
+  }
+
+  fn show<'src>(name: &str, justfile: Justfile<'src>) -> Result<(), Error<'src>> {
+    if let Some(alias) = justfile.get_alias(name) {
+      let recipe = justfile.get_recipe(alias.target.name.lexeme()).unwrap();
+      println!("{}", alias);
+      println!("{}", recipe);
+      Ok(())
+    } else if let Some(recipe) = justfile.get_recipe(name) {
+      println!("{}", recipe);
+      Ok(())
+    } else {
+      Err(Error::UnknownRecipes {
+        recipes:    vec![name.to_owned()],
+        suggestion: justfile.suggest_recipe(name),
+      })
+    }
+  }
+
+  fn summary(config: &Config, justfile: Justfile) {
+    if justfile.count() == 0 {
+      if config.verbosity.loud() {
+        eprintln!("Justfile contains no recipes.");
+      }
+    } else {
+      let summary = justfile
+        .public_recipes(config.unsorted)
+        .iter()
+        .map(|recipe| recipe.name())
+        .collect::<Vec<&str>>()
+        .join(" ");
+      println!("{}", summary);
+    }
+  }
+
+  fn variables(justfile: Justfile) {
+    for (i, (_, assignment)) in justfile.assignments.iter().enumerate() {
+      if i > 0 {
+        print!(" ");
+      }
+      print!("{}", assignment.name);
+    }
+    println!();
+  }
+}
+
+#[cfg(test)]
+mod tests {
+  use super::*;
+
+  #[test]
+  fn init_justfile() {
+    testing::compile(INIT_JUSTFILE);
+  }
 }