New completion for ImageMagick 7 (magick command)

[robbyrob42]

ImageMagick 7 unified all tools under a single magick command, replacing the standalone binaries from IM6 (convert, identify, mogrify, etc.). The existing _imagemagick completion covers IM6 but has no support for the magick command or IM7's option set.

This adds _magick which:

• Completes magick and all legacy tool names via #compdef
• Dispatches magick <tool> subcommands (identify, compare, etc.) to tool-specific option sets
• Handles bare magick [options...] input output (convert-style) usage
• Completes enum values for colorspace, compose, compress, filter, gravity, metric, morphology, distort, evaluate, layers, and more — all sourced from magick -help and magick -list output
• Filters file completion to common image formats with fallback to all files
• Uses _pick_variant to detect IM7 and falls back to _files on IM6, so it coexists safely with _imagemagick
• Supports _call_function hooks for user-overridable subcommand completions

Tested against ImageMagick 7.1.2-17 on macOS (Homebrew). Follows the completion style guide conventions.

Note: _imagemagick and _magick both register #compdef for the legacy binary names (convert, identify, etc.). On systems with IM7, the zsh maintainers may want to decide how to handle the overlap — e.g., updating _imagemagick to defer to _magick when IM7 is detected, or deprecating _imagemagick in favor of this file.

[okdana]

our normal policy is to just target the latest version for completion functions. i guess imagemagick is like a python 2->3 thing though where people have stayed on 6 for years and years. debian didn't even package im7 until trixie. so. idk

i don't have time/energy to do a full review of this atm but

spot-checking the options, it looks like there's still a tonne of overlap with im6. we also have a _graphicsmagick that seems largely identical. i'm sure it's not perfect, but do you reckon it's close enough that your function could just replace those two entirely (with some minor changes like supporting gm in addition to magick)? i haven't used im/gm in a long time so i'm not very familiar

[okapia]

Our naming convention is that a completion for, e.g. imagemagick is called _imagemagick, regardless of what the command is called. So e.g. subversion is _subversion, not _svn and _libvirt is the function for virsh. Mostly, follow the naming used for Linux etc packages. Also on naming, if separate functions are used for subcommands, use a hyphen, e.g. _magick-convert. Use underscores for helpers,, e.g. _imagemagick_files. However, I don't see anything wrong with the approach taken by the existing _imagemagick where it isn't broken into smaller functions.

It'd be easier to review this, if it was based on the old function because we now need to check whether any old functionality that would still be applicable is being lost. I wouldn't bother checking for ImageMagick 6 at the top, Just complete 7 options and if there are a few extra then so-be-it. That's more useful than degrading to just file completion.

[robbyrob42]

appreciate the feedback, i'll iterate and come back