cargo-script-mvs VS clap-rs

The eRFC was intentionally light on details so the Pre-RFC / IRLO thread and the demo best reflect what we hope to accomplish which are pretty detailed as-is.

> A) is easy to write one off scripts that do a job fast, with minimal thinking and effort. I am thinking of Python and Ruby. For me I can write code with high velocity in these languages.

Once I wrap up some other projects, I plan to explore this space a little bit within Rust.

imo the biggest bang for the buck is just having good `#!` support. Probably mid-year I expect to have a Pre-RFC up for single-file cargo packages. See https://github.com/epage/cargo-script-mvs/discussions/15.

A bigger effort is a batteries included, non-zero cost stdlib. I've started writing up my thoughts at https://github.com/ergo-rs/ergo.

For more background on why I think these are important, see https://epage.github.io/blog/2021/09/learning-rust/.

Would love feedback on these ideas and other ways to make Rust easy to use without sacrificing what makes Rust it is.

This is something I'm interested. Every time I write a bash or Python script, I think "why didn't I do this in Rust?". The first barrier is in the same line as your thoughts which is why I've been investigating the various cargo-script spin-offs and working towards an MVP for a Pre-RFC.

Something I've been thinking a lot about for Rust is what can and should a REPL experience be for a compiled language (ie what are reasonable compromises).

There seem to be two repls that haven't gotten much traction:

- https://github.com/google/evcxr/blob/main/evcxr_repl/README....

- https://github.com/sigmaSd/IRust

There have been little and big nits that have held me back from wanting to push these further, including

- Bad defaults (having to opt-in to panic handling)

- Command syntax feeling out of place and likely not beginner friendly

- Limits on variable preservation

- Lack of introspection (at least irust as `:type`)

So far I've been punting on wanting to improve this area by instead focusing on polishing up a rust script solution in the hopes of getting it merged: https://github.com/epage/cargo-script-mvs

rust-script is the most up-to-date version I could find. See https://github.com/epage/cargo-script-mvs/discussions/15

cargo-script has been forked or reimplemented several times.

cargo-script: I've done some initial analysis and recorded my thoughts on what cargo-script in Rust should look like. If people are interested in this or other individual / company on-boarding improvements, I'd love to talk!

Fully agree with this though I also feel there is room for experimentation and improvement in this area. I've previously blogged on this and have started researching cargo-script. Hopefully later I'll get to my standard-adjacent library.

We will be using the library for Clap - A simple-to-use, efficient, and full-featured library for parsing command line arguments and subcommands.

I recently came across this question (and associated answer) on the clap repository. The answer given is a good one. But I wanted to expand with my own findings and practices, which spurred the motivation for this post.

We can also use tuple-like struct syntax and named-field struct syntax for enum variants within our enum; this is because unlike in other OOP languages, Rust enums are actually sum types. You can read more about how powerful Rust enums are in another article we wrote here. You can have optional arguments by simply wrapping the types in Option, but if you want to add a flag to a command you can use bool, since clap recognises that flags are either there or not there. Let's have a look at what this might look like:

I began by developing a wrapper for the CurseForge API, which turned out to be a lengthy and challenging process but constituted the bulk of the work. Next, I coded the CLI, which was relatively straightforward. Instead of using the clap crate, a Rust tool for generating CLIs, I opted for the following line of code:

By this time I had already gotten tired of parsing arguments by myself and had looked for something to help with that. I found a really dang good argument parsing library called clap. What makes it so cool is it's largely declarative for common uses. You simply mark up a struct with attributes, and the parser automatically generates the usage and all the argument parsing code.

How CLI arguments are handled (using clap).

Is this just referring to wrapping based on the terminal width? That is supported with the wrap_help feature though I have been considering making it a default feature.

CLI, use Clap. If you want to get fancy, use Tui.

As our CLI is getting more complex, we'll use the clap crate to parse the command line arguments.