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From: Richard D Riehle <laoXhai@ix.netcom.com>
Subject: Re: Expressive Case Statements (was: Software landmines)
Date: 1998/09/02
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X-NETCOM-Date: Wed Sep 02  1:06:29 PM CDT 1998
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Date: 1998-09-02T13:06:29-05:00
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In article <35ecc519.37879718@SantaClara01.news.InterNex.Net>,
	tmoran@bix.com (Tom Moran) wrote:

>Are the conditions in such a decision table always boolean, or might
>they be any enumerated type?
>Do you care if the compiler checks that you have branches for all
>possibilities (as in a case statement, but not in an elsif list)?

  Tom,

  Good question.  The model I am considering is,

       condition       condition entry 
        stub                stub
         ------------------------------------------
         c1  | T   T   T   T   F   F   F   F        
         ----|--------------------------------------         
         c2  | T   T   F   F   F   F   T   T
         ----|--------------------------------------         
         c3  | T   F   T   F   F   T   T   F
         ----|-------------------------------------         
         ==========================================
         A1  | X   X   X                   X               
         ----|--------------------------------------    
         A2  |     X   X 
         ----|--------------------------------------    
         A3  | X       X            X
         ----|--------------------------------------    
      Action               Action Entry
        Stub                   Stub

  With COBOL this can be expressed with a statment that maps directly
  to the picture.  This turns out to be wonderfully convenient when
  trying to determine how to convey the needs of a user to those of
  a programmer and vice versa.   I certainly know how to code this in
  a variety of brute-force methods.  I am trying to determine if there
  is some way I can generalize this as a class or as an Ada package
  that gives the programmer the same simplicity of expression I can
  achieve with the COBOL EVALUATE statement. 

  Richard Riehle
  richard@adaworks.com
  http://www.adaworks.com