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Document breaking out of a named code block #140197

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May 2, 2025
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Document breaking out of a named code block #140197

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36ae657
Document breaking out of a named code block
ktnlvr Apr 23, 2025
175f717
Simplify docs for breaking out of a named code block
ktnlvr May 1, 2025
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27 changes: 27 additions & 0 deletions library/std/src/keyword_docs.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -109,6 +109,33 @@ mod as_keyword {}
/// println!("{result}");
/// ```
///
/// It is also possible to exit from any *labelled* block returning the value early.
/// If no value specified `break;` returns `()`.
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Odd stutter here. I think it should be "If no value is specified for" or "is given to", then "it returns ()".

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This is a verbatim restatement of a sentence from the previous paragraph:

This is only valid with loop and not with any other type of loop.
If no value is specified, break; returns ().

It is also possible to exit from any labelled block returning the value early.
If no value specified break; returns ().

Does a comma suffice or should the text above be rephrased too?

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The comma is the minimum for it to be valid, as far as I can tell. I do not think it is sufficient for it to be very comprehensible. So if you wish to revise both cases to be consistent, that is fine with me.

///
/// ```rust
/// let inputs = vec!["Cow", "Cat", "Dog", "Snake", "Cod"];
///
/// let mut results = vec![];
/// for input in inputs {
/// let result = 'filter: {
/// if input.len() > 3 {
/// break 'filter Err("Too long");
/// };
///
/// if !input.contains("C") {
/// break 'filter Err("No Cs");
/// };
///
/// Ok(input.to_uppercase())
/// };
///
/// results.push(result);
/// }
///
/// // [Ok("COW"), Ok("CAT"), Err("No Cs"), Err("Too long"), Ok("COD")]
/// println!("{:?}", results)
/// ```
///
/// For more details consult the [Reference on "break expression"] and the [Reference on "break and
/// loop values"].
///
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