From: Johann Hibschman <johann@...>
Date: 2000-11-14T17:40:01+09:00
Subject: [ruby-talk:6350] Re: Another Smalltalk control structure idea

Conrad Schneiker/Austin/Contr/IBM writes:

> Anyone know what the equivalent function is called in Mathematica? Maple?=20
> MathCAD? <Etc.>? (Or in CLOS/Lisp/Scheme? Or Haskell?)

Common Lisp uses "reduce."  In Scheme, I'm used to seeing this named
"fold-left" or "foldl" (or "fold-right" or "foldr", if the other way.)

(fold-left  f x0 '(x1 x2 x3)) = (f (f (f x0 x1) x2) x3)
(fold-right f x0 '(x1 x2 x3)) = (f x1 (f x2 (f x3 x0)))

Mathmatica, I forget.  I always liked reduce, myself; Common lisp has the
advantage that it can take the :from-end t keyword to get the alternate
behavior.

--J

-- 
Johann Hibschman                           johann@physics.berkeley.edu