Mailing List Archive: Ifs Re:(2)

[REBOL] Ifs Re:(2)

From: lmecir:geocities at: 12-Oct-2000 8:23


Hi Joel,

I am not glad, that I must disappoint you, but see the following example:

a: 1
b: to paren! [to paren! [to paren! [to paren! [a: 0 - a]]]]
ifs-for-dummies b [negative: ["Negative"] zero: ["Zero"] positive:
["Positive"]]
== "Zero"

I think, you should read Exception #5 for Word Evaluation of my Rebol/Core
User's
Guide Comments once again and hope, that this will be interesting even for
others...

Regards
    Ladislav

P.S. My strong opinion is, that the best you can get is:

signed-if: func [
    {If positive do positive-block, zero do zero-block, negative do
negative-block}
    [throw]
    condition [number! char! money! time!]
    positive-block [block!]
    zero-block [block!]
    negative-block [block!]
] [
    either positive? condition [do positive-block] [
        either negative? condition [do negative-block] [do zero-block]
    ]
]

I am afraid, that Signed-if-for-dummies may become a victim of the GC bug
and similar issues, when used recursively...