Path: utzoo!attcan!uunet!husc6!bloom-beacon!tut.cis.ohio-state.edu!mailrus!ncar!ames!pasteur!ucbvax!BGUVM.BITNET!GDAU100
From: GDAU100@BGUVM.BITNET ("Jonathan B. Owen")
Newsgroups: comp.lang.ada
Subject: Code generation for generic packages - Question
Message-ID: <8811161812.AA18571@ajpo.sei.cmu.edu>
Date: 16 Nov 88 18:27:44 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 38
X-Unparsable-Date: Wed, 16 Nov 88 19:51:34 IST

I use generic packages quite extensivly.  This does not mean I understand
what code is generated out of the sources I write.  This can be a problem
when trying to consider code efficiency...

What is performed in run-time each time the following is invoked:

     procedure GENERIC_QUESTION( name : string ) is

         subtype this_string_type is String(name'RANGE);
         package THIS_CRUNCH is new STRING_CRUNCH( this_string_type );

     begin
         THIS_CRUNCH.STEP_ON_STRING( name );
     end GENERIC_QUESTION;

When is the code produced?  My immediate guess, is that the package
THIS_CRUNCH is creates ONCE for type "string" and not each time the
procedure is invoked with a different string.  Am I right?

I came up with the above code while writing it, so don't try to make
sense out of it.  Also, I have not thought out if the above is
necessary for creating a generic package for each subtype of type
"string".  What I do know, is that I have encountered the need to
declare a subtype as a function of an unconstrained formal parameter.
And then, with this subtype, declare an instantiation of a generic
package.

                          Thanks for any clarification,

                                                 JB
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