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From: beard@ux5.lbl.gov (Patrick C Beard)
Newsgroups: comp.sys.mac.hypercard
Subject: Re: global variables in code resources
Keywords: global variables, code resources, XCMD's, XFCN's
Message-ID: <6287@helios.ee.lbl.gov>
Date: 26 Jul 90 19:36:29 GMT
References: <12642@june.cs.washington.edu> <1296@radius.com>
Sender: usenet@helios.ee.lbl.gov
Reply-To: beard@ux5.lbl.gov (Patrick C Beard)
Organization: Berkeley Systems, Inc.
Lines: 59
X-Local-Date: 26 Jul 90 12:36:29 PDT

In article <1296@radius.com> lemke@radius.com (Steve Lemke) writes:
#moore@cs.washington.edu (Charles Moore) writes:
#
#>I am becoming increasingly frustrated by the prohibition against
#>global variables in code resources.  Is there any way around this?
#
#>One possibility for me, since I am writing a HyperCard XFCN is to make
#>callbacks to HyperCard and use HyperCard globals.  I'd like to avoid
#>this, though, since I assume callbacks to HyperCard will generally be
#>slow.  Also, it seems inelegant since I won't need this information
#>anymore when my XFCN completes.
#
#>Does anybody have any suggestions?
#
#Sure.  Use THINK Pascal 3.0.  I quote from the manual (page 157):
#
#     Global data in code resources:
#
#     Code resources cannot have global data.  You can take advantage
#     of Pascal's nested procedures to simulate global data.  Just nest
#     all of the routines in your program within "main".
#
#Thus you would have something like this:
#
#unit blah;
#interface
#    procedure main;
#implementation
#    procedure main;
#    var
#    global:integer;
#       procedure other;
#       begin
#       end;
#       procedure another;
#       main
#       end;
#    begin
#    end;
#end.
#
#>Charles Moore
#
#--Steve

I don't agree.  THINK Pascal 3.0's lack of support for global variables
is appalling.  THINK C 4.0 supports REAL global variables that persist and
are accessible across files.  The other day I was modifying a code
resource written in THINK Pascal, and because I couldn't use REAL globals,
I had to add a ton of if statements in awkward places.  Sometimes REAL
globals solve problems in the most elegant way.

Use THINK C!

--
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-  Patrick Beard, Macintosh Programmer                        (beard@lbl.gov) -
-  Berkeley Systems, Inc.  ".......<dead air>.......Good day!" - Paul Harvey  -
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