Add the loop_break_value feature to the reference #53
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An inline code snippet was using triple quotes instead of single ones, breaking syntax highlight in vim.
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The return value is |
src/expressions.md
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| @@ -600,6 +600,12 @@ within this loop may exit out of this loop or return control to its head. | |||
| See [break expressions](#break-expressions) and [continue | |||
| expressions](#continue-expressions). | |||
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| The return value of a `loop` expression is `!`, which can be coerced to any | |||
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Instead of saying that ! can be coerced to any type here, perhaps just link to the section on diverging functions.
src/expressions.md
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| The return value of a `loop` expression is `!`, which can be coerced to any | ||
| type. However, if there is a `break` expression in the loop, the return value | ||
| of the loop becomes the one of the value provided to the [break | ||
| expression](#break-expressions) causing the loop to end, which is `()` by |
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The comma there is improper English. I think it'd flow better with the information in its own sentence though. Perhaps "When the break expression has no return value it defaults to ()."
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Thanks! I'm not a native speaker so I'm still used to the italian idioms.
src/expressions.md
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| @@ -600,6 +600,12 @@ within this loop may exit out of this loop or return control to its head. | |||
| See [break expressions](#break-expressions) and [continue | |||
| expressions](#continue-expressions). | |||
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| The return value of a `loop` expression is `!`, which can be coerced to any | |||
| type. However, if there is a `break` expression in the loop, the return value | |||
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Does the break expression have to also break for the loop it's in? For instance, I would expect 'inner to still be considered diverging here? I'm not actually sure though.
'outer loop {
'inner loop {
break 'outer;
}
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I didn't write the implementation for the feature so I'm not sure, but I guess 'inner is not diverging, and has a return value of (), because it actually returns.
src/expressions.md
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| @@ -608,6 +613,14 @@ enclosing it. It is only permitted in the body of a loop. If the label is | |||
| present, then `break 'foo` terminates the loop with label `'foo`, which need not | |||
| be the innermost label enclosing the `break` expression, but must enclose it. | |||
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| When the `break` expression is enclosed in a `loop`, it has an optional return | |||
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Both commas in this sentence can be removed.
src/expressions.md
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| expression. When it's not provided it defaults to `()`. | ||
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| If both a label and a return value are present in the expression, the label | ||
| must be put before the return value. For example `break 'label 42` breaks the |
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Change put to placed, I think?
This commit introduces to the reference the changes made by the loop_break_value feature, defined in RFC 1624.
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Continued in #56. |
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Thanks for improving this @dhardy! |
I added to the reference the changes made by the
loop_break_valuefeature, which was accepted to be stabilized in rust-lang/rust#37339. As far as I can tell I added everything needed, but this is the first time I add something to the reference so it's quite possible I missed something!