I still have to disagree on that. Tuple patterns are not consistent in Swift.
Here is a small proof of my claim:
enum Foo {
case a(b: Int)
}
switch Foo.a(b: 10) {
case .a(b: let x):
print(x)
}
let tuple = (x: 2, y: 20)
switch tuple {
case (x: let a, y: let b):
print(a); print(b)
}
(x: let a, y: let b): (x: Int, y: Int) = tuple // Error!!!
Tuple destructuring only works using the shorthand pattern, which _can_ lead to
all those puzzles from the discussion.
The shorthand form ‘Is good and beautiful’ (German proverb), but it can do more
harm than it should. Personally I would entirely ban the shorthand version
unless we’ve got a superior version of it without all these issues.
By the way not only tuples are affected by the mentioned puzzle:
enum Foo {
case sum(x: Int, y: Int)
}
switch Foo.sum(x: 3, y: 1) {
case let .sum(x: Int, y: Double):
print(Int + Double) // prints 4
}
--
Adrian Zubarev
Sent with Airmail
Am 8. Mai 2017 um 09:28:52, Xiaodi Wu via swift-evolution
(swift-evolution@swift.org) schrieb:
But, in any case, with respect to consistency with the rest of the language,
tuple patterns with labels are *supremely* consistent.
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