Add completions for Arcanist

[Hunsu]

Add completions for Arcanist, the tool used to interact with Phabricator instance.

[siteshwar]

It should be a local variable :

set -l cmd (commandline -opc)

[Hunsu]

Done. I really don't know what that line does. I just copied it from git.fish.

[faho]

You really don't want this idiom. We removed it from the codebase (IIRC entirely) for a reason. This will break when you alias arc (because of the $cmd[1] = 'arc', when you do something; and arc or similar and when you enter an option before a command (which arc might or might not support).

What you want is, depending on how arc works, do something like

for token in $cmd
    switch $token
        case '-*'
            continue
        case '*'
            return 1
     end
     return 0

This will assume the first non-option is a command.

If you want to be more precise (because e.g. arc can take arguments to options before the command), take a look at the new git.fish.

[faho]

skip_next is never set to 0 and hence effectively unused.

Please remove it.

[faho]

Those were my last two nitpicks, I think.

Sorry for the delay.

[faho]

Merged, thanks!