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From: KENCB@SLACVM.SLAC.STANFORD.EDU
Newsgroups: comp.lang.fortran
Subject: Re: A Q of constants
Message-ID: <91143.213654KENCB@SLACVM.SLAC.STANFORD.EDU>
Date: 24 May 91 05:36:54 GMT
References: <1991May24.111123.8396@cc.curtin.edu.au>
Organization: Stanford Linear Accelerator Center
Lines: 50

In article <1991May24.111123.8396@cc.curtin.edu.au>, tlynchmj@cc.curtin.edu.au
says:
>I want an array of characters to be initialiized as constants at compile time
>and it has to be ANSI standard, more specifically, it must compile under
>VAX-VMS F77 with the /STANDARD option invoked.
>
>I tried this...
>
>      CHARACTER SYMS(6)
>      PARAMETER (SYMS = 'abcdef')
>
>which gave me a 'symbol to big for constant' or something like that error.
>Then I tried this...
>
>      CHARACTER SYMS(6)
>      PARAMETER (SYMS(1) = 'a',
>     +           SYMS(2) = 'b',
>

   The trouble is you're trying to define an ARRAY as a PARAMETER.  You
can't in Fortran 77 (though I greatly wish one could :-).  Here's a
simple test program that compiles under VAX Fortran with the /STANDARD
qualifier and gives you three alternatives for what it appears you
want to do (excuse the non-standard mixed-case source ;-)

--------------------------------------------------------------------------
      Program Test
      Character c0(6)
      Character*6 c1
      Character*6 c2
      Parameter  (c2 = 'abcdef')
      Data c1 /'abcdef'/
      Data c0 /'a','b','c','d','e','f'/
      Write (6,'(X,6A/X,A/X,A)') (c0(i),i=1,6),c1,c2
      Stop
      End
--------------------------------------------------------------------

   Only the PARAMETER form gives you "an array of constants", and it's
not strictly an array.  However the standard Fortran 77 character handling
allows indexing into character strings which is nearly the same, e.g.
use C2(3:3) instead of C2(3).

 -Ken

 Dr. Kenneth H. Fairfield        Internet: Fairfield@Tpc.Slac.Stanford.Edu
 SLAC, P.O.Box 4349, Bin 98      DECnet:   45047::FAIRFIELD (TPC::)
 Stanford, CA   94309            BITNET    Fairfield@SlacTpc
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