add completions for swift command (the programming language CLI)

[rymcol]

• Have you checked if problem occurs with fish 2.3.1?
• Tried fish without third-party customizations (check sh -c 'env HOME=$(mktemp -d) fish')?

fish version installed (fish --version):

fish, version 2.3.1

OS/terminal used:

macOS Sierra 10.12 beta 4 / Terminal Version 2.7 (376)

When attempting to tab autocomplete on swift, such as swift build, the auto-complete suggests directories instead of swift commands.

Reproduction steps

Hard to explain? Link to a screen recording

1. Launch fish
2. Type "swift b"
3. Press tab

Expected results

Fish should suggest build as the autocompletion.

Actual results

~ $ swift b
Dropbox/  Library/  Public/  webroot/

[faho]

The swift completions just haven't been written yet. Patches welcome!

[rymcol]

@faho where are the completions stored?

[faho]

share/completions/$command.fish in this repo.

[faho]

Though if you'd like to write one, put it in ~/.config/fish/completions/swift.fish.

[krader1961]

Custom completions need to be written and submitted by someone motivated to do so. Like yourself, @rymcol. We're happy to provide advice on how to do so. But without such a submission this issue will simply bit rot.