> Can we get some clarification as to why ‘where’ is being chosen to be retired
> here? I’m deeply disappointed by that decision as enabling the consistent use
> of comma as a separator does not preclude the use of where for simple cases
> that don’t require it. I’m all for having a more usable separator for complex
> conditionals, but I rarely need it, meanwhile in common, simple conditional
> bindings and patterns I find the ‘where’ keyword a lot more readable, i.e:
>
> if let value = foo where foo > 5 { … }
I think there may be a case for keeping the `where` keyword—but before, not
after, the equals sign.
if case .cartesian(let x, let y) where x != y = point { ... }
if let value where value > 5 = foo { ... }
Why? Consistency with other `case` statements. I recently made the same point
about `for` loops: `where` is part of the pattern-matching syntax, and it ought
to be attached to the pattern it refines. Letting it float into other parts of
the statement unmoors it from its meaning.
That will probably read strangely for some current uses of
`where`—specifically, ones that have a condition unconnected to the preceding
pattern—but that's when you should use a comma to introduce a separate Boolean
condition clause instead. Personally, I think the `if let value` example above
would probably be more appropriate as a Boolean condition clause, but tastes
differ.
--
Brent Royal-Gordon
Architechies
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