Add native Zsh completion

Replace the auto-generated Zsh completion with a full completion script.
This script improves completion support for options and arguments,
which is hard to obtain from an auto-generated completion.

- Full completion support for external commands and options when using
  `--exec`/`--exec-batch`.

- The completion for `--type` and `--color` adds descriptions instead of
  just values.

- Complete files when using `--ignore-file`.

- Stop completing files for the pattern argument.

- Improve completion for path arguments. Only directories are
  completed.

- Single-use options are not offered again.

- Updated exclusions lists for mutual-exclusive options.

- Add support for hidden options (as defined in `app.rs`). They are not
  offered for completion, but if present are considered (and their value
  may be completed).

Full support for exclusion lists depends of options groups, which was
added in Zsh 5.4. Older Zsh versions, as commented in the completion
script, will just offer most options.

The format of the completion script was taken from ripgrep completion
script. Command completion for `--exec`/`--exec-batch` was taken from
Zsh's `_find` completion.

build.rs

@@ -26,6 +26,5 @@ fn main() {
     let mut app = build_app();
     app.gen_completions("fd", Shell::Bash, &outdir);
     app.gen_completions("fd", Shell::Fish, &outdir);
-    app.gen_completions("fd", Shell::Zsh, &outdir);
     app.gen_completions("fd", Shell::PowerShell, &outdir);
 }

ci/before_deploy.bash

@@ -40,7 +40,7 @@ pack() {
     # various autocomplete
     cp target/"$TARGET"/release/build/"$PROJECT_NAME"-*/out/"$PROJECT_NAME".bash "$tempdir/$package_name/autocomplete/${PROJECT_NAME}.bash-completion"
     cp target/"$TARGET"/release/build/"$PROJECT_NAME"-*/out/"$PROJECT_NAME".fish "$tempdir/$package_name/autocomplete"
-    cp target/"$TARGET"/release/build/"$PROJECT_NAME"-*/out/_"$PROJECT_NAME" "$tempdir/$package_name/autocomplete"
+    cp contrib/completion/_"$PROJECT_NAME" "$tempdir/$package_name/autocomplete"
 
     # archiving
     pushd "$tempdir"
@@ -145,7 +145,7 @@ EOF
     # completions
     install -Dm644 target/$TARGET/release/build/$PROJECT_NAME-*/out/$PROJECT_NAME.bash "$tempdir/usr/share/bash-completion/completions/${PROJECT_NAME}"
     install -Dm644 target/$TARGET/release/build/$PROJECT_NAME-*/out/$PROJECT_NAME.fish "$tempdir/usr/share/fish/completions/$PROJECT_NAME.fish"
-    install -Dm644 target/$TARGET/release/build/$PROJECT_NAME-*/out/_$PROJECT_NAME "$tempdir/usr/share/zsh/vendor-completions/_$PROJECT_NAME"
+    install -Dm644 contrib/completion/_"$PROJECT_NAME" "$tempdir/usr/share/zsh/vendor-completions/_$PROJECT_NAME"
 
     # Control file
     mkdir "$tempdir/DEBIAN"

contrib/completion/_fd

@@ -0,0 +1,265 @@
+#compdef fd
+
+##
+# zsh completion function for fd
+#
+# Based on ripgrep completion function.
+# Originally based on code from the zsh-users project — see copyright notice
+# below.
+
+autoload -U is-at-least
+
+_fd() {
+  local curcontext="$curcontext" no='!' ret=1
+  local -a context line state state_descr _arguments_options fd_types fd_args
+  local -A opt_args
+
+  if is-at-least 5.2; then
+    _arguments_options=( -s -S )
+  else
+    _arguments_options=( -s )
+  fi
+
+  fd_types=(
+    {f,file}'\:"regular files"'
+    {d,directory}'\:"directories"'
+    {l,symlink}'\:"symbolic links"'
+    {e,empty}'\:"empty files or directories"'
+    {x,executable}'\:"executable (files)"'
+    {s,socket}'\:"sockets"'
+    {p,pipe}'\:"named pipes (FIFOs)"'
+  )
+
+  # Do not complete rare options unless either the current prefix
+  # matches one of those options or the user has the `complete-all`
+  # style set. Note that this prefix check has to be updated manually to account
+  # for all of the potential negation options listed below!
+  if
+    # (--[bpsu]* => match all options marked with '$no')
+    [[ $PREFIX$SUFFIX == --[bopsu]* ]] ||
+    zstyle -t ":complete:$curcontext:*" complete-all
+  then
+    no=
+  fi
+
+  # We make heavy use of argument groups here to prevent the option specs from
+  # growing unwieldy. These aren't supported in zsh <5.4, though, so we'll strip
+  # them out below if necessary. This makes the exclusions inaccurate on those
+  # older versions, but oh well — it's not that big a deal
+  fd_args=(
+    + '(hidden)' # hidden files
+    {-H,--hidden}'[search hidden files/directories]'
+
+    + '(no-ignore-full)' # all ignore files
+    '(no-ignore-partial)'{-I,--no-ignore}"[don't respect .(git|fd)ignore and global ignore files]"
+    $no'(no-ignore-partial)*'{-u,--unrestricted}'[alias for --no-ignore, when repeated also alias for --hidden]'
+
+    + no-ignore-partial # some ignore files
+    "(no-ignore-full --no-ignore-vcs)--no-ignore-vcs[don't respect .gitignore files]"
+    "!(no-ignore-full --no-global-ignore-file)--no-global-ignore-file[don't respect the global ignore file]"
+
+    + '(case)' # case-sensitivity
+    {-s,--case-sensitive}'[perform a case-sensitive search]'
+    {-i,--ignore-case}'[perform a case-insensitive search]'
+
+    + '(regex-pattern)' # regex-based search pattern
+    '(no-regex-pattern)--regex[perform a regex-based search (default)]'
+
+    + '(no-regex-pattern)' # non-regex-based search pattern
+    {-g,--glob}'[perform a glob-based search]'
+    {-F,--fixed-strings}'[treat pattern as literal string instead of a regex]'
+
+    + '(match-full)' # match against full path
+    {-p,--full-path}'[match the pattern against the full path instead of the basename]'
+
+    + '(follow)' # follow symlinks
+    {-L,--follow}'[follow symbolic links to directories]'
+
+    + '(abs-path)' # show absolute paths
+    '(long-listing)'{-a,--absolute-path}'[show absolute paths instead of relative paths]'
+
+    + '(null-sep)' # use null separator for output
+    '(long-listing)'{-0,--print0}'[separate search results by the null character]'
+
+    + '(long-listing)' # long-listing output
+    '(abs-path null-sep max-results exec-cmds)'{-l,--list-details}'[use a long listing format with file metadata]'
+
+    + '(max-results)' # max number of results
+    '(long-listing exec-cmds)--max-results=[limit number of search results to given count and quit]:count'
+    '(long-listing exec-cmds)-1[limit to a single search result and quit]'
+
+    + '(fs-errors)' # file-system errors
+    $no'--show-errors[enable the display of filesystem errors]'
+
+    + '(fs-traversal)' # file-system traversal
+    $no"--one-file-system[don't descend into directories on other file systems]"
+    '!--mount'
+    '!--xdev'
+
+    + dir-depth # directory depth
+    '(--exact-depth -d --max-depth)'{-d+,--max-depth=}'[set max directory depth to descend when searching]:depth'
+    '!(--exact-depth -d --max-depth)--maxdepth:depth'
+    '(--exact-depth --min-depth)--min-depth=[set directory depth to descend before start searching]:depth'
+    '(--exact-depth -d --max-depth --maxdepth --min-depth)--exact-depth=[only search at the exact given directory depth]:depth'
+
+    + filter-misc # filter search
+    '*'{-t+,--type=}"[filter search by type]:type:(($fd_types))"
+    '*'{-e+,--extension=}'[filter search by file extension]:extension'
+    '*'{-E+,--exclude=}'[exclude files/directories that match the given glob pattern]:glob pattern'
+    '*'{-S+,--size=}'[limit search by file size]:size limit:->size'
+    '(-o --owner)'{-o+,--owner=}'[filter by owning user and/or group]:owner and/or group:->owner'
+
+    + ignore-file # extra ignore files
+    '*--ignore-file=[add a custom, low-precedence ignore-file with .gitignore format]: :_files'
+
+    + '(filter-mtime-newer)' # filter by files modified after than
+    '--changed-within=[limit search to files/directories modified within the given date/duration]:date or duration'
+    '!--change-newer-than=:date/duration'
+    '!--newer=:date/duration'
+
+    + '(filter-mtime-older)' # filter by files modified before than
+    '--changed-before=[limit search to files/directories modified before the given date/duration]:date or duration'
+    '!--change-older-than=:date/duration'
+    '!--older=:date/duration'
+
+    + '(color)' # colorize output
+    {-c+,--color=}'[declare when to colorize search results]:when to colorize:((
+      auto\:"show colors if the output goes to an interactive console (default)"
+      never\:"do not use colorized output"
+      always\:"always use colorized output"
+    ))'
+
+    + '(threads)'
+    {-j+,--threads=}'[set the number of threads for searching and executing]:number of threads'
+
+    + '(exec-cmds)' # execute command
+    '(long-listing max-results)'{-x+,--exec=}'[execute command for each search result]:command: _command_names -e:*\;::program arguments: _normal'
+    '(long-listing max-results)'{-X+,--exec-batch=}'[execute command for all search results at once]:command: _command_names -e:*\;::program arguments: _normal'
+
+    + other
+    '!(--max-buffer-time)--max-buffer-time=[set amount of time to buffer before showing output]:time (ms)'
+
+    + '(about)' # about flags
+    '(: * -)'{-h,--help}'[display help message]'
+    '(: * -)'{-v,--version}'[display version information]'
+
+    + path-sep # set path separator for output
+    $no'(--path-separator)--path-separator=[set the path separator to use when printing file paths]:path separator'
+
+    + search-path
+    $no'(--base-directory)--base-directory=[change the current working directory to the given path]:directory:_files -/'
+    $no'(*)*--search-path=[set search path (instead of positional <path> arguments)]:directory:_files -/'
+
+    + args # positional arguments
+    '1: :_guard "^-*" pattern'
+    '(--search-path)*:directory:_files -/'
+  )
+
+  # Strip out argument groups where unsupported (see above)
+  is-at-least 5.4 ||
+  fd_args=( ${(@)args:#(#i)(+|[a-z0-9][a-z0-9_-]#|\([a-z0-9][a-z0-9_-]#\))} )
+
+  _arguments $_arguments_options : $fd_args && ret=0
+
+  case ${state} in
+    owner)
+      compset -P '(\\|)\!'
+      if compset -P '*:'; then
+        _groups && ret=0
+      else
+        if
+          compset -S ':*' ||
+          # Do not add the colon suffix when completing "!user<TAB>
+          # (with a starting double-quote) otherwise pressing tab again
+          # after the inserted colon "!user:<TAB> will complete history modifiers
+          [[ $IPREFIX == (\\|\!)*  && ($QIPREFIX == \"* && -z $QISUFFIX) ]]
+        then
+          _users && ret=0
+        else
+          local q
+          # Since quotes are needed when using the negation prefix !,
+          # automatically remove the colon suffix also when closing the quote
+          if [[ $QIPREFIX == [\'\"]* ]]; then
+            q=${QIPREFIX:0:1}
+          fi
+          _users -r ": \t\n\-$q" -S : && ret=0
+        fi
+      fi
+      ;;
+
+    size)
+      if compset -P '[-+][0-9]##'; then
+        local -a suff=(
+          'B:bytes'
+          'K:kilobytes  (10^3  = 1000   bytes)'
+          'M:megabytes  (10^6  = 1000^2 bytes)'
+          'G:gigabytes  (10^9  = 1000^3 bytes)'
+          'T:terabytes  (10^12 = 1000^4 bytes)'
+          'Ki:kibibytes  ( 2^10 = 1024   bytes)'
+          'Mi:mebibytes  ( 2^20 = 1024^2 bytes)'
+          'Gi:gigibytes  ( 2^30 = 1024^3 bytes)'
+          'Ti:tebibytes  ( 2^40 = 1024^4 bytes)'
+        )
+        _describe -t units 'size limit units' suff -V 'units'
+      elif compset -P '[-+]'; then
+        _message -e 'size limit number (full format: <+-><number><unit>)'
+      else
+        _values 'size limit prefix (full format: <prefix><number><unit>)' \
+          '\+[file size must be greater or equal to]'\
+          '-[file size must be less than or equal to]' && ret=0
+      fi
+      ;;
+  esac
+
+  return ret
+}
+
+_fd "$@"
+
+# ------------------------------------------------------------------------------
+# Copyright (c) 2011 Github zsh-users - http://github.com/zsh-users
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in the
+#       documentation and/or other materials provided with the distribution.
+#     * Neither the name of the zsh-users nor the
+#       names of its contributors may be used to endorse or promote products
+#       derived from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL ZSH-USERS BE LIABLE FOR ANY
+# DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+# (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+# LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+# ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# ------------------------------------------------------------------------------
+# Description
+# -----------
+#
+#  Completion script for fd
+#
+# ------------------------------------------------------------------------------
+# Authors
+# -------
+#
+#  * smancill (https://github.com/smancill)
+#
+# ------------------------------------------------------------------------------
+
+# Local Variables:
+# mode: shell-script
+# coding: utf-8-unix
+# indent-tabs-mode: nil
+# sh-indentation: 2
+# sh-basic-offset: 2
+# End:
+# vim: ft=zsh sw=2 ts=2 et