Improve documentation for select!{} #6572
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| /// 5. Once an `<async expression>` returns a value, attempt to apply the value | ||
| /// to the provided `<pattern>`, if the pattern matches, evaluate `<handler>` | ||
| /// and return. If the pattern **does not** match, disable the current branch | ||
| /// and for the remainder of the current call to `select!`. Continue from step 3. |
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Branches become disabled if the pattern doesn't match, which can in turn trigger the else branch. So it makes more sense to me to have the else branch below this.
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The else branch can also be triggered before anything is polled if all the expressions are disabled via their condition, or if there are no expressions to begin with.
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We could perhaps list it twice, but I don't think it makes sense to remove the mention of else at the end.
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At present, step 5 about else is never reached by following the lifecycle as written. Do you have any suggestions for rewording it to make it more correct?
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You can say "if all branches are disabled, go to step 6" and keep the step at the end?
Darksonn
added
A-tokio
Motivation
The lifecycle explanation for
select!{}was a little bumpy, since the step where all<async expression>s are disabled was never actually encountered (step 4 always went back to step 3).Solution
Reorder the steps in the explanation, and also reword them slightly to clarify control flow.