: (map) ( a n - a a')   cells over + swap ;
: map[   postpone (map)  postpone ?do ; immediate
: ]map   1 cells postpone literal  postpone +loop ; immediate

create array 1000 cells allot   
: init  1000 0 DO I  array I cells + !  LOOP ;
init
: step  0  array 1000 map[ i @ + ]map drop ;
: bench  100000 0 DO step LOOP ;
bench

\ Article: 127752 of comp.lang.forth
\ Path: tunews.univie.ac.at!aconews-feed.univie.ac.at!newsfeed.wu-wien.ac.at!newsfeed.utanet.at!feeder1.cambrium.nl!feeder4.cambrium.nl!feeder5.cambrium.nl!feed.tweaknews.nl!63.218.45.10.MISMATCH!nx01.iad01.newshosting.com!newshosting.com!140.99.99.194.MISMATCH!news-in-02.newsfeed.easynews.com!easynews.com!easynews!sn-xt-sjc-02!sn-xt-sjc-08!sn-post-sjc-02!sn-post-sjc-01!supernews.com!news.supernews.com!not-for-mail
\ From: Andrew Haley <andrew29@littlepinkcloud.invalid>
\ Newsgroups: comp.lang.forth
\ Subject: Re: Factor, Postscript, and Forth: A case study
\ Date: Fri, 04 May 2007 12:28:40 -0000
\ Message-ID: <133m9nohdhdje47@news.supernews.com>
\ References: <2007May3.220119@mips.complang.tuwien.ac.at>
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\ Lines: 34
\ Xref: tunews.univie.ac.at comp.lang.forth:127752

\ In comp.lang.forth Anton Ertl <anton@mips.complang.tuwien.ac.at> wrote:
\ > At the recent Forth-Tagung, Ulrich Hoffman gave a talk about Factor, a
\ > language that's somewhere between Forth (mainly in syntax) and
\ > Postscript (mainly in semantics, in particular the dynamic type
\ > checking).

\ > Eventually we decided to write and benchmark a small example in all
\ > three languages: Generate an array of 1000 integers, then sum all the
\ > elements 100000 times.

\ > Here's the Forth version:

\ > : map-array ( ... addr u xt -- ... )
\ >     \ executes xt ( ... x -- ... ) for every element of the array starting
\ >     \ at addr and containing u elements
\ >     { xt }
\ >     cells over + swap ?do
\ >         i @ xt execute
\ >     1 cells +loop ;

\ The classic Forth way to do this would be with compiling words, not by
\ passing an xt:

\ : (map) ( a n - a a')   cells over + swap ;
\ : map[   postpone (map)  postpone ?do ; immediate
\ : ]map   postpone cell  postpone +loop ; immediate

\ : step  0  array 1000 map[ + ]map  drop ;

\ I'm not saying that there's anything wrong with your map-array, but I
\ don't think you'd write it that way unless trying to translate the
\ idiom from another languyage into Forth.

\ Andrew.