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Under the "Improving our I/O Project" section, there's this little paragraph: It would be nice if we could use ? on the Option returned from next, but ? on
by curun1r 10y ago
Under the "Improving our I/O Project" section, there's this little paragraph:
It would be nice if we could use ? on the Option
returned from next, but ? only works with Result
values currently. Even if we could use ? on Option
like we can on Result, the value we would get would
be borrowed, and we want to move the String from
the iterator into Config.
It seems remiss to not mention that Option/Result have combinators/adapters too, no?
let search = match args.next() {
Some(arg) => arg,
None => return Err("Didn't get a search string"),
};
becomes:
let search = args.next().ok_or("Didn't get a search string")?;
I'm not the most fluent in Rust, so please tell me whether the above two snippets are not equivalent in some way.
It might actually be a nice segue into a page on the combinators of Option and Result, since functional-style Rust seems to benefit from liberal use of them.
- steveklabnik 10y agoThis is a great suggestion! I'm on mobile right now, but I'll file an issue when I get home, or if you feel like it, please do!
- pitaj 10y agoPlease don't quote with code blocks.
- curun1r 10y agoUmm...If I don't quote the entire code snippet, I'll end up with just the indented lines being quoted...the joys of HN formatting.
- pitaj 10y agoI was speaking with reference to "It would be nice..." which you quoted using a pre/code block (prepending four spaces). Please only use that for actual code, and use `>` at the start of the line to signify a quote, like so: > Umm...If I don't quote the entire code snippet, I'll end up with just the indented lines being quoted...the joys of HN formatting. This allows for responsive formatting on different screen sizes, and is especially beneficial for mobile users.