getargs VS argparse-benchmarks-rs

Actually, I would say getargs on this one. Full disclosure, I'm a major contributor to the library, but it is also faster than lexopt, and provides a bit more control.

I have benchmarked getargs to have significant performance gains from inlining.

I'd recommend getargs over argparse, it's also very well documented (but that version is not on crates.io yet)

It pains me that getargs 0.5.0 is still not released yet. If you can deal with a git dependency, I would highly recommend it, it can do exactly what you want with no fuss.

I'm currently working on bringing up getargs, which was abandoned on crates.io over 2 years ago. It has an API design that I agree with and I wanted to make it great, so I'm giving it a visit from the PR fairy.

If it's perfectly fine then it shouldn't be terribly difficult to write it in a way that the borrow checker is happy with. The problem is reformulating your problem such that it's easy to either annotate the lifetimes in that way or have the compiler infer them for you. And it's made more difficult if your libraries have incorrectly elided lifetimes.

You can check out the argparse-benchmarks-rs though that only gives a high level summary.

So besides the git2 conversation, I'd recommend using an argument parser even if its for something basic like lexopt just for help/version, at least you'd error for unrecognized arguments and can more easily expand it in the future.

Unclear whether it has a solid advantage over other things listed at rust-cli/argparse-benchmarks-rs or whether it's just an "I didn't research what already existed" project.

I'm tempted to collect all of these benchmark repos into a github org to make them easier to find. So far I know of parser, md, argparse, and template languages.

Not strictly an answer to your question, but https://github.com/rust-cli/argparse-benchmarks-rs provides a good survey of option parsing crates in Rust.

As others have mentioned clap is one of the more popular, featureful CLI parsers though it does come at a compile time and binary size cost. We are working on improving that. See argparse-benchmarks for by-the-numbers comparison for the different parsers (ie only stats and no full feature lists). Clap is used by ripgrep, cargo, and many other tools

Compared to lexopt, which inspired this effort, clap_lex makes some different trade offs for flexibility and ergonomics which allows it to handle every case clap needs. There is room for more ergonomic improvements as the MVP was written for clap's needs. argparse-benchmarks-rs has been updated and clap_lex is roughly in line with lexopt for build-times and binary size.

See https://github.com/rust-cli/argparse-benchmarks-rs/blob/main/examples/bpaf-app/app.rs

You can use this link: https://github.com/rust-cli/argparse-benchmarks-rs

btw there are the argparse benchmarks which can be interesting points of comparison (though I haven't decided what is the criteria for being added to it yet).