Support single-character flags

[mmkal]

Feature request

It would be good to be able to define a flag that's only one character.

Motivations

I came across it while implementing trpc-cli, which uses cleye under the hood.

There are valid use cases for for single-character flags that aren't abbreviations, like plot --x 1 --y 2

Alternatives

Of course it will usually be possible to do awkward workarounds like plot --xx 1 --yy 2, and use x and y as aliases, and override documentation to suggest only using plot -x 1 -y 2, but this is cumbersome.

Additional context

I imagine the restriction is because it muddies the water a bit with aliases (would be confusing to have --x mean one thing, but -x be an alias for something else). If that's the reason for the restriction, maybe there could be a check added to make sure the alias exactly matches the "long" form.

Bugs are expected to be fixed by those affected by it

• I'm interested in working on this issue

Compensating engineering work financially will speed up resolution

• I'm willing to offer financial support

[privatenumber]

Thanks for your sponsorship!

The x/y coordinates input are compelling use-cases for supporting this, and I'm happy to brainstorm how we can make this happen.

I think there could be a conflict with type-flag's alias grouping, which is a common practice in many UNIX commands. For example git commit -am 'message' groups flags a and m. I think this functionality might be mutually exclusive with single-character flag names.

EDIT: Or maybe not if we add support for alias-only flags. Thereby supporting your use-case with -x (not --x). Would this work?

[mmkal]

I think that would work, yes. It'd probably be how most users would guess a cli should be used too. It kinda forces a particular usage but that's ok because it's a more convenient usage.

It'd be good enough for trpc-cli I think - a use case I wanted to cover was just throwing pretty much any trpc router at it and getting a functional CLI. That broke down for single-letter input props but a change like you suggest would cover them.

(V welcome re sponsorship. Thank you for your libraries - I am using more and more I find!)

[privatenumber]

I marked this as "pr welcome".

I'm not able to make time for this at the moment but feel free to tackle it if you'd like.