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From: mlw@pyr.gatech.EDU (Michael Williams)
Newsgroups: comp.lang.pascal
Subject: Re: CASE for Strings? (MS-Dos TP)
Message-ID: <10010@pyr.gatech.EDU>
Date: 13 Apr 90 22:03:58 GMT
References: <8001@hydra.gatech.EDU>
Reply-To: mlw@pyr.UUCP (Michael Williams)
Organization: Georgia Institute of Technology
Lines: 34

In article <8001@hydra.gatech.EDU> ce1zzes@prism.gatech.EDU (Eric Sheppard) writes:
>I wish to perform functions according to commands parsed into a string array.
>The CASE operator only works for simple variable types. Is there an elegant way
>to perform the CASE for complex (string) variables? Desired sample construct:
>
>case Command of
>  '1STCOM' : FirstCommand;
>  '2NDCOM' : SecondCommand;
>   .
>   .
>end;

   The closest constuct I know of is :

   valid := '1STCOM 2NDCOM 3RDCOM 4THCOM 5THCOM';
   case pos(command,valid) of
      1 : FirstCommand;
      8 : SecondCommand;
     15 : ThirdCommand;
     22 : FourthCommand;
     29 : FifthCommand;
     else write('Invalid command!');
   end;

   This sounds like a scanner for a compiler, where you are checking for
keywords.  In this case, a 'perfect' hashing function would be preferable.

Hope this helps ...

-- 
Michael Williams
Georgia Institute of Technology, Atlanta Georgia, 30332
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