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From: dewar@merv.cs.nyu.edu (Robert Dewar)
Subject: Re: Perhaps there _is_ a conspiracy against Ada
Date: 1997/04/24
Message-ID: <dewar.861936361@merv>#1/1
X-Deja-AN: 237229083
References: <1997apr13.153233.1@eisner>
 <5iurff$2a8@newssvr01-int.news.prodigy.com> <335AEF0A.7F79@dynamite.com.au>
 <335ec70b.5444825@news.airmail.net> <335D804C.74E9@bix.com>
 <335ec9e1.15714756@news.airmail.net>
Organization: New York University
Newsgroups: comp.lang.ada
Date: 1997-04-24T00:00:00+00:00
List-Id: <comp.lang.ada>


<<And just how did you attach callback functions to GUI objects
since the language did not support passing functions or procedures as
arguments?  Sure, each vendor defined a way to do that, but I had a
requirement to port this program to multiple architectures and compilers.>>

The ability to port a program does not mean that you require that the
program be movable with zero changes, just that the parts that need
changing are well defined and easily changed.

In fact a number of compilers implemented the semi-standard for subprogram
pointers defined by the CIFO specification, so programs written to the
CIFO spec would in fact work on quite a variety of compilers.

Note that if you required 100% portability with zero change, then you
would say that no C program is portable, which is an exaggeration!