[swift-evolution] [Pitch] Retiring `where` from for-in loops

[Sean Heber]

> Here, though emotion is hardly a worthy barometer, I had quite a visceral reaction to the example given at one point:
> 
> ```
> for number in fibonacci where number % 2 == 0 while number < 4_000_000 {...}
> ```
> 
> This, IMO, is long enough to cause a heart attack.

To me, that looks almost beautiful - it says exactly what it means!

l8r
Sean