🚀 go-pugleaf

re: If there were sufficiently smart compilers, there would be no programmers.

Great quote!  I love it!

[Seriusly, though, that *is* the goal of much computer science work --
to make computer usage more available to the non-programmer (and we
*all* know that to use a computer effectively is to hack it.)  On the
other hand, you can't get blood out of a turnip . . . ]



re: Date: Wed, 19 Aug 1992 23:15:50 GMT
    From: dcmartin@fascet.msi.com (David C. Martin)
    Subject: Re: Beginner's Question - CLOS

    . . . In fact, you can determine at compile time
    what the argument types are and then put in the appropriate call to the
    appropriate function.

    Date: Thu, 20 Aug 1992 01:48:16 GMT
    From: dcmartin@fascet.msi.com (David C. Martin)
    Subject: Re: Beginner's question and method lookup
    . . . 
    You might be surprised at the work that both Franz and Lucid have done with
    their CLOS implementations.  I have talked about this issue with John
    Foderero @ Franz and he has put hooks in so that if you wish to have
    static class hierarchies you can do complete determination, i.e. static 
    binding for the executable.

David, if it were possible to do  "complete determination i.e. static 
binding for the executable"  at compile time, then there would be no 
need for "virtual" functions in C++.   Do you understand the fundamental
problem posed by having same-named methods on a class and and on a
derived (sub) class?  the dispatch from a higher method cannot determine
at compile time whether or not a sub-called method[*] is the one defined
on the same statically determinable class or one of those defined on a 
derived (sub) class.  I talked about this topic at the CLOS versus C++ 
debate last week at the 1992 Lisp Users and Vendors conference.

John Burger also alluded to this problem in his message of 
Thu, 20 Aug 1992 07:23:55 GMT, as did Barry Margolin in his msg
of 20 Aug 1992 16:06:25 GMT.  But perhaps they weren't forceful enough.


-- JonL --


[*] "sub-called method" -- I just mean that if a method on function FOO
    calls a function BAR (which is also defined by "methods"), then the
    call to BAR from within the method on FOO will lead to the execution 
    of some method on BAR, which I am calling the "sub-called method".