[REBOL] Re: curious use of LENGTH?
From: rotenca:telvia:it at: 31-Jan-2002 14:51
Hi Joel,
> s: make string! 0
> foreach file dir [
> append s file
> while [((length? s) // max) <> 0] [append s " "]
> if (length? s) > 60 [
> print s
> clear s
> ]
> ]
> if length? s [print s]
> ]
> Notice the last line -- I have no clue what it means in REBOL to
> use an integer-valued expression as the condition of IF. I tried
> some small experiments, and in every case IF treated an integer
> as TRUE (including zero and negative values). I then tried
> variations on a string value FOO in the phrase IF LENGTH? FOO ...
> and always got the equivalent of TRUE, regardless of its length.
> (The only exception was when FOO was UNSET, in which case I got
> an error...)
>From Core 3-23 about 'if:
The condition is normally an expression that evaluates to true or false;
however,
other values can also be supplied. Only a false or a none value prevents the
block
from being evaluated. All other values (including zero) are treated as true,
and
cause the block to be evaluated.
> Any suggestions on why the above wasn't written simply as
>
> PRINT S
If 's would be empty, it would print a newline.
---
Ciao
Romano
