> On May 27, 2016, at 6:26 PM, Brent Royal-Gordon <[email protected]> > wrote: > >> guard >> x == 0 && a == b && c == d && >> let y = optional, w = optional2, v = optional 3 && >> z == 2 >> else { ... } >> >> Figuring out where to break the first line into expression and into >> condition (after the `d`) could be very challenging to the compiler. > > I'm not sure it is. `let` and `case` are not valid in an expression, so an > `&&` followed by `let` or `case` must be joining clauses. On the other side > of things, Swift's `&&` doesn't ever produce an optional, so if we're parsing > an expression at the top level of an if-let, an `&&` must indicate the end of > the clause. An if-case *could* theoretically include an `&&`, but pattern > matching against a boolean value seems like a fairly useless thing to do in a > context that's specifically intended to test booleans.
Let me answer in another way that speaks to my background which isn't in compiler theory: The use of && may produce cognitive overload between the use in Boolean assertions and the use in separating condition clauses. -- E _______________________________________________ swift-evolution mailing list [email protected] https://lists.swift.org/mailman/listinfo/swift-evolution
