18 Oct 2025

How to write good rust code

Results vs Options

Use options where there is no context to be given. A failure in an external command, for example, is not an Option. There's almost always context behind the failure.
Don't try to be fault tolerant, especially when you have a lot of possible input space and not a lot of output space. It is bound to fail. Fail hard and fail fast. Similar response also goes for running external commands and parsing their output.
Parse, don't validate.
Use anyhow to propagate error message contexts.
Make sure that any error message is good enough to be propagated upwards as is, unless it's supposed to be a generic function that just fails on failure. Examples include supac's run_command and run_command_for_stdout functions. These preferably need more specific contexts on what's happening.
- The above is true usually when the function is being exported for regular use and does something where the arguments are the principal focus for the side effect being done.
Prefer using Err over logging. Only prefer logging if there's scope of recovery/possibility of a default value to be used. Use debug logging for things in gen.
Fail hard and fail fast, even for optional parsing. What's ill-configured is ill-configured.
ANYHOW CAN BE USED AS MAIN'S RETURN TYPE!!!