Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!sdd.hp.com!spool.mu.edu!uwm.edu!bionet!agate!ucbvax!LAGUNA.METAPHOR.COM!alex
From: alex@LAGUNA.METAPHOR.COM (Bob Alexander)
Newsgroups: comp.lang.icon
Subject: Re:  Using the ``map'' function
Message-ID: <9104040251.AA09079@laguna.Metaphor.COM>
Date: 4 Apr 91 02:51:32 GMT
Article-I.D.: laguna.9104040251.AA09079
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: inet
Organization: The Internet
Lines: 31

Hi Paul --

In your initial procedure (the slow one) it's likely that much of the
time used in repeatedly executing

	   return map(key, collator, &ascii[33:128])

is due to the fact that every call converts the cset, &ascii, to a
string.

Also, there is an optimization in the iconx code for map() such that
the internal translation table is not rebuilt if the second and third
arguments are the same (i.e. identical descriptors) as for the previous
map() call.  That optimization cannot be used in your proc.

Given all that, I'll bet this will execute a lot faster (the proof is
left to the reader :)

	procedure keytrans(key)
	   static collator, ascii
	   initial {
	      collator := ...
	      ascii := &ascii[33:128]
	   }
	   return map(key, collator, ascii)
	end

-- Bob Alexander

Metaphor Computer Systems   (415) 961-3600 x751   alex@metaphor.com
====^=== Mountain View, CA  ...{uunet}!{decwrl,apple}!metaphor!alex