Remove claim on possible optional bindings in repeat-while conditions

[SimplyDanny]

The claim is immediatly disproved on the grammer rule description below that states that the while condition is an expression. An expression in turn does not comprise an optional binding. The grammar rule seems to be correct since it matches with the bahavior of the Swift compiler and the SwiftSyntax library.

[amartini51]

Can you share an example of some code that this text suggests should work, but which isn't accepted by the compiler?

When I run the code below, it produces the expected output:

var x: Int? = 3
while let y = x {
    print(x as Any)
    print(y as Any)
    x = nil
}
// Prints Optional(3)
// Prints 3

Looking at the grammar:

1. while-statement contains condition-list
2. condition-list can produce a single condition
3. condition can produces expression as you noted, but also optional-binding-condition

So the grammar appears to match the code listing above also.

[SimplyDanny]

This is all about repeat-while statements which only allow expressions in their while-condition as the grammar states and the compiler expects. An example from a Swift playground:

[amartini51]

Thanks for that context — looking at the diff, I found the wrong part of the book. The original text that you corrected looks like it was a copy/paste error. Your change looks good to me!

@swift-ci Please test.