Sent from my iPad
> On Jan 22, 2017, at 3:15 PM, Chris Lattner <clatt...@nondot.org> wrote:
>
>
>>> On Jan 20, 2017, at 12:22 PM, Dave Abrahams via swift-evolution
>>> <swift-evolution@swift.org> wrote:
>>>
>>>
>>> Yeah, maybe there's a more general language feature that could replace
>>> 'fallthrough' here. Instead
>>> of labelling cases, we could support a 'reswitch' statement that
>>> redispatches the switch to the case
>>> matching the operand:
>>>
>>> switch some_value {
>>> case .REFINED:
>>> if !validate(some_value) { return NULL }
>>> reswitch .BASE
>>>
>>> case .BASE:
>>> handle_enum_value();
>>> }
>>
>> We should just call a spade a spade and spell that "goto" ;-)
>
> Goto has traditionally been used for unstructured control flow, but this form
> is still fully structured. You cannot produce irreducible loops, jump into
> scopes, over declarations, etc.
It would be useful to know the technical definition of "structured." The fact
is that there's a large category of sensible goto-like jumps that we probably
want to allow and I see no advantage to giving them all distinct names. I
don't believe users will distinguish them. We already have "break looplabel"
and, aside from the label being in the wrong place, it's effectively a goto.
It seems to me we should just have goto and either prohibit the troublesome
uses or give them reasonable semantics.
I could live with "break" as well as "goto", but it feels a bit like it's
pretending to be something it isn't, and there's the source compatibility
problem with the label position.
-Dave
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