How should this completion work?

[xdanielc]

So I wanted to create my custom completion and first of all, I had to use carapace/specs folder, I asked AI and it told me to use /comp

I copied the settings of the first example to see what it does and undestand how it behaves.

First this page:
https://carapace-sh.github.io/carapace-bin/spec.html
Tells me to go to this page for more info
https://carapace-sh.github.io/carapace-spec/carapace-spec.html

The thing is that then, I don't have the video in the second page, which would have helped me as it shows how optarg? can have values with optarg=foo

Anyway, my big problem is that I want something like this pncheck -flag (always first, nonrepeateble and optional) filename (only png)

I would like flags to complete after I write - and the filename if I don't write anything else. This is my file, nce I put everything after completion, the flags don't complete anymore:

name: pngcheck
description: Test PNG, JNG or MNG image files for corruption, and print size/type info.
flags:
  -c?: colorize output (for ANSI terminals)
  -p?: print contents of PLTE, tRNS, hIST, sPLT and PPL
  -q?: test quietly (output only errors)
  -s?: search for PNGs within another file
  -t?: print contents of tEXt chunks
  -v?: test verbosely (print most chunk data)
  -vv?: test very verbosely (decode & print line filters)
  -w?: suppress windowBits test (a more-stringent compression check)
  -x?: search for PNGs within another file and extract them when found
completion:
  positional:
    - "$files([*.png, *.jng, *.mng])"
    - [$"directories"]

[xdanielc]

Ok, after many trials and error, looks like this mght be the most optimal completion, notice how there's no wildcards on the file type. I still get folders despite using $files()

name: pngcheck
description: Test PNG, JNG or MNG image files for corruption, and print size/type info.
flags:
  -c?: colorize output (for ANSI terminals)
  -p?: print contents of PLTE, tRNS, hIST, sPLT and PPL
  -q?: test quietly (output only errors)
  -s?: search for PNGs within another file
  -t?: print contents of tEXt chunks
  -v?: test verbosely (print most chunk data)
  -vv?: test very verbosely (decode & print line filters)
  -w?: suppress windowBits test (a more-stringent compression check)
  -x?: search for PNGs within another file and extract them when found
**completion:
  positional:
    - ["$files([.png, .jng, .mng])"]**

[rsteube]

Optarg just means that the argument is optional.
The flag then only accepts it attached with =:

-o
-o positionalArgumentNotBelongingToFlag
-o=flagArgument

So for most of these you problably don't need a suffix at all.
https://carapace-sh.github.io/carapace-spec/carapace-spec/command/flags.html

[rsteube]

Ok, i think you are looking for non-interspersed parsing mode which stops after the first positional argument:

# yaml-language-server: $schema=https://carapace.sh/schemas/command.json
name: pngcheck
description: Test PNG, JNG or MNG image files for corruption, and print size/type info.
parsing: non-interspersed
flags:
  -c: colorize output (for ANSI terminals)
  -p: print contents of PLTE, tRNS, hIST, sPLT and PPL
  -q: test quietly (output only errors)
  -s: search for PNGs within another file
  -t: print contents of tEXt chunks
  -v*: test verbosely (print most chunk data)
  -w: suppress windowBits test (a more-stringent compression check)
  -x: search for PNGs within another file and extract them when found
completion:
  positionalany: ["$files([.png, .jng, .mng])"]

-vv is possible, but long shorthands break POSIX flag chaining (e.g. -cpq). So setting it repeatable with * might be better here.

[rsteube]

fyi: #2967

[xdanielc]

Thanks. Will try it. Is also the comment really necessary?
I wish there were more yaml examples to play within the docs as it would had helped me.
Also thanks for taking the time to make the completion in go. There are many other PNG CLIs, specially for this image format that I wanna try out when I have time. Back like a year or two ago I installed all and then realized PNG Gaunlent mixes the three best ones and runs then in the correct order to optimize the size as much as possible.

Anyway I'm going on a tangent. I'll see how completion goes on those.

[rsteube]

The header is just for LSP completion (editor) and not necessary: https://json-schema.org/