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From: sommar@enea.UUCP
Newsgroups: comp.lang.misc,comp.lang.c
Subject: Re: software ICs vs. libraries
Message-ID: <2426@enea.UUCP>
Date: Fri, 30-Oct-87 17:30:23 EST
Article-I.D.: enea.2426
Posted: Fri Oct 30 17:30:23 1987
Date-Received: Tue, 3-Nov-87 02:17:31 EST
References: <1691@culdev1.UUCP> <932@sugar.UUCP>
Reply-To: sommar@enea.UUCP(Erland Sommarskog)
Followup-To: comp.lang.misc
Organization: ENEA DATA Svenska AB, Sweden
Lines: 34
Xref: utgpu comp.lang.misc:791 comp.lang.c:4981

peter@sugar.UUCP (Peter da Silva) writes:
>In article <1691@culdev1.UUCP>, drw@culdev1.UUCP (Dale Worley) writes:
>> Another feature of "software ICs" comes from the fact that they are
>> part of an object-oriented system.  One can actually write, say, a
>> linked list manager that will work on objects of *any* type.  In most
>> languages, this is impossible to do in a library routine.
>
>You can do it in 'C'. In fact the standard 'C' library for the Amiga comes
>with exactly this tool.
>   <description of interface deleted>
>This deals with objects called "nodes". But, of course, you can pass any 
>struct
>to these functions so long as the first element of the struct is a list or a
>node. This is one place 'C' outshines more modern and more heavily typed
>languages like Modula.

Of course you could do this in assembler too, n'est-ce pas? Just stack
an address to a block on the stack. The first word(s) in the block are 
the pointer to next block. And damn you if you forget them. The problem 
with C and assembler is that they leave the user to be reponsible for 
the correctness. If he forget the pointers in the struct, he may have 
a hard time to find out why the program crashes.
  Now, I don't speak Modula-2, so I can't speak for it. (But I can 
believe da Silva is right. My impression of Modula-2 has always been
that it is just another Pascal dialect :-)
  Finally some high-level languages in which you can write the 
linked-list manager *with* type checking are Simula and Ada. (But you 
don't write it in Simula, the manager is already there as a part of the 
language.)
-- 
Erland Sommarskog       
ENEA Data, Stockholm    
sommar@enea.UUCP        
                    It could have been worse; it could have been Pepsi.