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From: wmb@SUN.COM (Mitch Bradley)
Newsgroups: comp.lang.forth
Subject: Other interpreted control structures
Message-ID: <8912301510.AA00672@jade.berkeley.edu>
Date: 29 Dec 89 23:02:28 GMT
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Reply-To: Forth Interest Group International List <FIGI-L%SCFVM.bitnet@jade.berkeley.edu>
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Here's a control structure that Don Hopkins and I came up with while
were were doing a Forth command language for a schematic drawing system.
This control structure combines the functions of FOR .. NEXT  and
IF .. ELSE .. THEN  in a convenient way:

   n  [  ... body ...  ]

  \ body is execute n times if n > 0

   n  [  ... body ...  ][  ... else ...  ]

  \ Body is executed n times if n > 0, otherwise else clause
  \ is executed

This is equivalent to IF ... ELSE ... THEN  if n is 0 or 1

We found this syntax to be very pleasant for interactive use.

The use of brackets for control structures is reminiscent of LaFarr
Stewart's LaForth system.

Mitch