Disallow spaces between @, attribute name and ( in Swift 6
#71237
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ahoppen
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ahoppen
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@, attribute name and (.@, attribute name and ( in Swift 6
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Oh, does this fix the issue with writing let closure = { @MainActor (a, b) in
print(a, b)
} |
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It doesn’t actually fix the issue because there’s no behavior change (for source compatibility reasons). But it will produce a warning in Swift 5 and an error in Swift 6. let closure = { @MainActor (a, b) in // error: extraneous whitespace between attribute name and '('
}My thought was that we should stage this as a diagnostic and then we can change the parsing behavior to unambiguously parse |
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test/Parse/attribute_spacing.swift
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| @ MainActor // expected-error {{extraneous whitespace between '@' and attribute name}} | ||
| class Foo { | ||
| func foo(_ x: @ escaping () -> Int) {} // expected-error {{extraneous whitespace between '@' and attribute name}} | ||
| } |
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Worth adding tests to cover the warning behavior and the newline case?
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I don’t think adding a dedicated test case for the warning is worth it. See #71238 (comment)
What do you mean by the newline case?
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What do you mean by the newline case?
The case where the @ is on the previous line
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Added a test case for
let closure = { @MainActor
(a, b) in
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Sorry I should have been clearer, I meant e.g:
@
MainActor
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@swift-ci Please smoke test |
This allows us to resolve disambiguities of whether a parenthesis belong to an argument to the attribute or if it is eg. the start of a tuple.
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@swift-ci Please smoke test |
@and attribute name in Swift 6 mode@and the attribute name (or even having them on different lines) is weird and shouldn’t be allowed