Are you still developing this?

[svenstaro]

Hi, I think this library could be quite useful if it had a few more validators and were generally maintained. Are you planning on developing/maintaining this?

[kbknapp]

@svenstaro sorry for the long reply, I would like to...however I have quite a bit on my plate right now.

Once v3 of clap is out, I want to split off some of the functionality into sub crates, at which point my grand idea is to move this repo over there.

That way there'd be something like:

• clap
  • clap_derive
  • clap_completions
  • clap_validators

[svenstaro]

Cool, sounds like a plan.

[chevdor]

@kbknapp sent a few PR hoping it revives some love for this repo 😄

[epage]

For anyone finding this crate and this issue, we are looking at moving away from validation to parsing with clap-rs/clap#3732. This introduces a new trait for people to implement, TypedValueParser, to validate and convert the value to the intended type (it is already implemented for Fn(&str) -> Result<T, E> to be compatible with FromStr). We also provide a macro, value_parser! that accepts a type and will find the right value parser for you (see clap-rs/clap#3755 for plugging into this mechanism). So you can just do value_parser!(u64) to ensure only positive numbers.

I can see crates being created to extend this with extra, reusable policy like

• A regex validator
• A ReadFile that will accept either a path or - for stdin and will lazily open the file and and allow people to read it.
  • Inspiration: https://click.palletsprojects.com/en/8.0.x/arguments/#file-arguments
• A WriteFile that will accept either a path or - for stdout and will lazily open the file and allow people write to it
  • This would have a flag for allowing atomic writes
  • Inspiration: https://click.palletsprojects.com/en/8.0.x/arguments/#file-arguments

I would expect these to be themed by functionality and dependencies (clap_regex, clap_file) rather than one giant crate.

[epage]

I should add this is only in master atm and will be coming with clap 3.2