How to combine zsh autocomplete for wrapper function arguments and existing command

Question

I work mostly in gvim and many terminals. Originally, I preferred to open all my files in a single vim instance. To that end I used an alias to open files from my terminals in the current 'vim server'.

alias rv="gvim --remote-silent"

But having many files from multiple projects open in a single vim instance impacts my productivity, so I'm upgrading my alias to a function.

# main function
rv() {
 local args options server
 options=$(getopt -o hils:t: -l "help,info,list,set:,target:" -- "$@")
 if [[ $? -ne 0 ]]; then
 echo "Failed to parse options."
 return 1
 fi
 # a little magic, necessary when using getopt
 eval set -- "$options"
 # go through the options with a case and use shift to analyze one option at a time.
 while true; do
 case "1ドル" in
 -h|--help)
 echo "Usage: 0ドル [-hil] [--help] [--info] [--list]";
 echo " 0ドル {-s | --set} <name> [<file1 file2...>]";
 echo " 0ドル {-t | --target} <name>] <file1 file2...>";
 return 0;;
 -i|--info)
 gvim_show_info;
 return 0;;
 -l|--list)
 gvim_list_servers;
 return 0;;
 -s|--set)
 gvim_set_server_name ${2:u};
 shift 2;;
 -t|--target)
 server="2ドル";
 shift 2;;
 --)
 shift;
 break;;
 esac
 done
 if [[ "$#" -eq 0 ]]; then
 # if no files specified...
 if [[ -n "$server" ]]; then
 # throw error if --target option was specified.
 echo "Error! --target requires one or more filenames."
 return 1;
 fi
 else
 # if files were specified...
 if [[ -n "$server" ]]; then
 # if --target was specified
 gvim_run_remote $server "$@"
 else
 gvim_run_remote $(gvim_get_default_server) "$@"
 fi
 fi
 return 0;
}

Now this new rv has it's own options. I can use it to:

• list available vim servers (-l --list)
• set the default vim server for the current shell (-s --set)
• show the default vim server (-i --info)
• open files in a specific vim server (-t --target)
• open files in default vim server: rv files...

However, since I'm using a function for rv instead of an alias, I lose the zsh completion I previously enjoyed. I've read up on creating a completion function, _rv, that will show rv's options, but I want to combine my completion options with the existing vim completion options. I know there may be some conflicts with rv's -s and vim's -s, but I figure I can handle that elegantly with the -- separator.

TLDR; So, how do I create a completion script that combines the _arguments options for both _rv and _vim? I prefer to reuse _vim if possible instead of copy-pasting it's arguments list into _rv.

Here's my _rv. Updated 2014年6月10日 16:10

#compdef rv
_rv() {
 typeset -A opt_args
 local alternatives
 alternatives=(
 'args:rv options:_rv_options'
 'files:file:_vim_files'
 )
 _alternative $alternatives && return 0
 return 1
}
_rv_options() {
 local arguments
 arguments=(
 '(-i -l -s -t --info --list --set --target)'{-h,--help}'[Print usage info.]'
 '(-h -l -s -t --help --list --set --target)'{-i,--info}'[Print default vim server. As stored in $GVIM_SERVER.]'
 '(-i -h -s -t --info --help --set --target)'{-l,--list}'[Print list of existing vim servers.]'
 '(-i -h -l -t --info --help --list --target)'{-s,--set}'[Set default vim server for the current shell.]:vim servers:_rv_vim_servers'
 '(-i -h -l -s --info --help --list --set)'{-t,--target}'[Open files in a particular vim server.]:vim servers:_rv_vim_servers'
 )
 _arguments -s -C $arguments && return 0
 return 1
}
_rv_vim_servers() {
 local -a servers
 servers=( ${(f)"$(_call_program servers vim --serverlist 2>/dev/null)"} )
 _wanted servers expl server compadd -M 'm:{a-z}={A-Z}' -a servers && return
}
# invoke the completion command during autoload
_rv "$@"

Current Behavior

Currently _rv completion will is usable, but not ideal.

• When I type rv <TAB>, I do not see the vim options. Only rv options and file paths are displayed. _vim is completing file paths for me, so hooray to that!
• When I type rv -s <TAB>, I see the list of vim servers, but also the file paths are displayed. A file is not permitted at this point in the command, and should not appear in the autocomplete.

Expected Behavior

• When I type rv <TAB>, I expect to see: 1) rv options, 2) vim options, 3) file path list
• When I type rv -s <TAB>, I expect to see: 1) vim server names (as provided by _rv_vim_servers.
• When I type rv /valid/file/path/<TAB>, I expect to only see a file path list. Since _vim already has this capability, I would prefer to rely on it.

• clobrano: This unix.stackexchange.com/questions/128199/… could be useful.
• Lqueryvg: compdef has a -n option which says it "prevents any completions already defined for the command or context from being overwritten". So, have you tried compdef _vim rv followed by compdev -n _rv rv ?
• Olivier Dulac: 28 upvotes and no answer... and it's a question about zsh... I'll try to invoke @StéphaneChazelas for you ^^ (I try not to abuse this, but it's fun. Please Stephane, tell me if I should not do this... and I'll delete this and never do it again) ... If someone here may know the answer, it should be him
• Sparhawk: @OlivierDulac I think you only get notifications if you have already posted in the thread. (Duplicate names are allowed, so this makes sense.) You could possibly find him in chat though.
• Raphael Ahrens: Could it be possible to source the original _vim file, but before doing so overwrite the _arguments function with a custom local function? By doing so you would get the arguments from _vim. Maybe with a separate zsh process.

Answer 1

You can monkey-patch the _arguments function to extend the _vim completer:

#compdef rv
_rv_vim_servers() {
 local expl
 _wanted servers expl server \
 compadd -- ${(f)"$( _call_program servers vim --serverlist 2>/dev/null )"}
}
_rv() {
 autoload +X -Uz _arguments # Load the function body.
 functions -c _arguments _rv_arguments # Make a copy.
 # Replace the original function.
 _arguments() {
 # Call the original function with additional completions.
 _rv_arguments "$@" \
 '(-i -l -s -t --info --list --set --target)'{-h,--help}'[print usage info]' \
 '(-h -l -s -t --help --list --set --target)'{-i,--info}'[print default vim server as stored in $GVIM_SERVER]' \
 '(-i -h -s -t --info --help --set --target)'{-l,--list}'[print list of existing vim servers]' \
 '(-i -h -l -t --info --help --list --target)'{-s,--set}'[set default vim server for the current shell]:vim servers:_rv_vim_servers' \
 '(-i -h -l -s --info --help --list --set)'{-t,--target}'[open files in a particular vim server]:vim servers:_rv_vim_servers'
 }
 {
 _vim "$@"
 } always {
 functions -c _rv_arguments _arguments # Restore the original.
 unfunction _rv_arguments # Discard our copy.
 }
}
_rv "$@"

Answer 2

I found /usr/share/zsh/functions/Completion/Unix/_git which had some tips for aliases like this and ended up defining these functions for the aliases:

_git-ls () {
 # Just return the _git-ls-files autocomplete function
 _git-ls-files
}

Then, do a straight compdef g=git. The autocomplete system will see that you are running, for example, g ls and use the _git-ls autocomplete function.

As found Here

• Justin C: thanks, but not quite. your solution assumes I only want the auto-complete from _git-ls-files. This question has a git-ls (to stick with your convention) with its own options, and some of those options overlap with git-ls-files. Instead of writing autocomplete for all options of git-ls, how do I write an autocomplete that takes the autocomplete from _git-ls-files (which covers say 90%), and combines them with the autocomplete of the remaining (say 10%) options?