[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.