[REBOL] Re: Help me, Obi Reb Kenobi, you're my only hope!
From: lmecir:mbox:vol:cz at: 1-Sep-2002 20:28
Hi again,
LM> The difference is, that in this case the result of the (first block2)
LM> expression evaluation "legally" exists, that is why I call it a "legal"
LM> error.
<<Gabriele>>
I see. I'd more likely have errors as first class, instead of a
DEFAULT function able to make the distinction. Anyway, it is
possible to discern the two cases with:
>> is-really-error?: func [code] [error? try compose [error? (code)]]
>> is-really-error? [first block]
== true
>> is-really-error? [first block2]
== false
I haven't tried it with any other case tough.
<</Gabriele>>
It looks to me, that the "first class error" and the "legal vs. illegal
error" distinction are two sides of the same coin.
Your IS-REALLY-ERROR? function works for simple code like above, but, AFAIK,
we cannot handle all possible cases, like e.g.:
is-really-error? [1 first block2] ; == true
(until errors will be "first class").
Ciao
-L
