chang-zsh-completion

autoload -U +X compinit && compinit
autoload -U +X bashcompinit && bashcompinit

function __chang() {
  local cmd_dir
  local comp_word
  local cword
  local -a completions

  cword=${COMP_WORDS[COMP_CWORD]}
  for comp_word in "${COMP_WORDS[@]:1:$(( COMP_CWORD > 0 ? COMP_CWORD - 1 : 0 ))}"; do
    cmd_dir=${cmd_dir:+$cmd_dir/}${comp_word}
  done

  cmd_dir=${PWD}/.chang/bin${cmd_dir:+/$cmd_dir}
  dirname=${cmd_dir##*/}

  COMPREPLY=()
  if [[ -d $cmd_dir ]]; then
    completions=($(find ${cmd_dir} -type f -or -type l))
    completions=(${completions[*]#$cmd_dir/})
    completions=(${completions[*]%%/*})
    for comp_word in "${completions[@]}"; do
      if [[
        $comp_word =~ ^$cword &&
        $comp_word != $dirname &&
        $cword != ${cmd_dir##*/}
      ]]; then
        COMPREPLY+=($comp_word)
      fi
    done
  fi
}

complete -F __chang chang