[REBOL] Re: [none idiom found?] The best shortcut word for "not none?"
From: lmecir::mbox::vol::cz at: 5-Sep-2006 6:14
Gregg Irwin napsal(a):
> This is a *really* good question. I'm always amazed at the behavior
> we find that you might think would be a problem, but isn't, in
> practical use. I don't know that I've ever been bitten by the above,
> but it seems like an obvious flaw when you look at it that way.
>
If the CASES block you supply to SWITCH has got the expected format,
then you cannot have a problem. The fact is, that SWITCH does not check
whether the CASES block has got the expected format, though. Another
problem may occur if you supply a function instead of an "expected" block.
> Maybe this would be a good question for a blog post by Carl. I
> remember him saying once that FORALL and FORSKOP were originally
> intended as macros for WHILE, hence leaving the series at the tail. I
> wonder if the original goal for FOUND? considered its use with ANY and
> ALL, logic results, or just the result of FIND; and does SWITCH work
> that way by design, or was it just a convenient implementation with
> very little risk (i.e. expected behavior) in everyday use.
>
> -- Gregg
>
I bet that it is the case you described - a convenient implementation
not checking whether "the contract" holds, but am asking Carl anyway.
-L
