On Mon, Apr 18, 2016 at 8:54 PM, Stanislav Malyshev <smalys...@gmail.com>
wrote:
> Hi!
>
> > catch constitutes a formal signature, exactly like a function signature.
> In
> > my mind, this proposal and the union types proposal are intrinsically
> tied.
> > If we have one, we must have the other. If not, we're inducing a sadness.
>
> This has nothing to do with union types. It is just a shortcut for
> repeated catch() clauses, it does not introduce anything into type
> system, capture existing use case, and doesn't make anything more
> complicated. While union types introduce a lot of new things, make
> everything dealing with types more complicated and the need for them,
> unless we import a real lot of other concepts like type pattern matching
> is quite unclear. So I don't think this has much in common.
>
It's about the perception of consistency. "Oh, I can do this! Neat:"
function neat(Foo | Bar $a) { ... }
"But I can't do this? WTF?"
catch (FooException | BarException $ex) { ... }
And vice-versa. The perception revolves around the fact that both appear to
be signatured, regardless of how they're implemented in the engine.
