grab-xkcd VS anyhow

We'll be updating our grab-xkcd program from a previous post with the new code, but in order to clearly demonstrate the different methods and not conflict with the original article I will use two new branches completions-ct for compile time completions, and completions-rt for run time completions. If the reader is feeling froggy, you can combine the two!

The full code from this article can be found at github.com/kbknapp/grab-xkcd

Depending on your use case, thiserror and/or anyhow.

There is ? as well as the anyhow(https://github.com/dtolnay/anyhow) crate that deals with long nested result chains.

There are crates out there that help you reduce this boiler plate. thiserror is good for creating custom errors and color-eyre or anyhow are good for dynamic errors.

Give anyhow a look.

I've brought anyhow::Result into scope, making error handling super easy to use. We don't need to specify all our Error types. It can automatically convert any errors that implement std::error::Error, which should be all of them. If an error propagates all the way up to main(), we'll get all the info it's captured printed to stdout.

Alternatively, if you've got a lot of error types and you're outside a library (so directly in a binary where you don't plan to reuse code elsewhere) you can use anyhow. This gives you an error type you can basically propagate any other error through. On top of that you can attach context information at every return. It's basically a more complicated Result>.

One approach is to define a separate error type for each crate and then use anyhow, eyre or Box to wrap the error, whever a function can return errors originating in several different crates.

Have you tried anyhow and thiserror for making it as simple as .context("Message") or ? to type-convert and propagate errors up the call stack?