[REBOL] Re: ROUND function (like TRUNC, FLOOR, etc...)
From: joel:neely:fedex at: 18-Feb-2002 6:38
BEWARE: Totally unofficial and unsanctioned opinion...
[riusa--email--it]
wrote:
> after this... a curiosity: why Rebol does not implement native round
> functions?
>
It appears to me that -- for the most part -- REBOL includes as native
functions only those things that are:
* critical to the core mission of REBOL, and
* impractical to implement effectively as mezzanines.
For example, parsing of strings is crucial to the concept of REBOL as
a "messaging language". I also suspect that a version of PARSE built
on top of explicit string/series manipulation via INDEX, NEXT, BACK,
etc. would be substantially slower (based on small experiments, but
no inside knowledge...)
In contrast, a rounding function is both trivial to write
round: func [x [decimal!]][
to-integer x + either x < 0 [-0.5][0.5]
]
and only occasionally needed that it misses on both of the criteria
mentioned above.
I realize that this is not a perfect model (given the existence of
such trivial shortcuts as CONTEXT, DOES, and HAS) but nobody's
perfect! ;-)
-jn-
--
; sub REBOL {}; sub head ($) {@_[0]}
REBOL []
# despam: func [e] [replace replace/all e ":" "." "#" "@"]
; sub despam {my ($e) = @_; $e =~ tr/:#/.@/; return "\n$e"}
print head reverse despam "moc:xedef#yleen:leoj" ;
