_gem

#compdef gem

# My first zsh completion function, for the gem command.  It lets you type 'gem <tab>' to complete gem commands
# (including installed ones) and for some commands (currently just open and update) allows you to complete gem
# names as well.  The implementation isn't ideal, so I'd appreciate advice on how I can improve it, particularly
# the 'caching' of the gem_commands and installed_gems.

_gem_commands () {
  if [[ -z $gem_commands ]] ; then
    gem_commands=$(gem help commands | grep '^    [a-z]' | cut -d " " -f 5)
  fi
  
  # This seems unnecessary, but if I try to set gem_commands to an array, it falls over.
 
  typeset -a gem_command_array
  gem_command_array=($(echo $gem_commands))
  compadd $gem_command_array
}

_installed_gems () {
  if [[ -z $installed_gems ]] ; then
    installed_gems=($(gem list | grep '^[A-Za-z]' | cut -d " " -f 1))
  fi
  
  typeset -a installed_gem_array
  installed_gem_array=($(echo $installed_gems))
  compadd $installed_gem_array
}

if (( CURRENT == 2 )); then
  _gem_commands
else
  if [[ $words[2] == open || $words[2] == update ]] ; then
    _installed_gems
  fi
fi