Add completion for the 'mix' Elixir tool

src/_mix

@@ -0,0 +1,67 @@
+#compdef mix
+# ------------------------------------------------------------------------------
+# Copyright (c) 2014 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 for the 'mix' tool provided with the Elixir programming language
+#  (http://elixir-lang.org).
+#
+# ------------------------------------------------------------------------------
+# Authors
+# -------
+#
+#  * Andrea Leopardi <an.leopardi@gmail.com>
+#
+# ------------------------------------------------------------------------------
+
+_mix() {
+  local raw_commands="$(mix help | grep "^mix \w\+")"
+
+  local -a commands
+
+  # Simple counter.
+  i=1
+
+  # The (f) modifier splits a string at its newlines.
+  for line in ${(f)raw_commands}; do
+    commands[$i]=$(          \
+      echo $line             \
+      | sed 's/^mix //'      \
+      | sed 's/[ ][ ]*# /:/' \
+      )
+    ((i++))
+  done
+
+  if (( CURRENT == 2 )); then
+    _describe -t commands 'commands' commands
+  fi
+
+  return 0
+}
+
+_mix