🚀 go-pugleaf

In article <721489167.F00001@ocitor.fidonet> Carl.Lemp@f2206.n124.z1.fidonet.org (Carl Lemp) writes:
>I've been trying to evaluate Prolog compilers for the PC but I have 
>no real experience with any of them.  Can anybody provide some 
>feedback on Prolog compilers they have used?  Especially things like 
>execution speed for large programs and memory usage.  Can any of the 
>prolog compilers produce programs that will compare in speed to 
>something in 'C'?

It is not uncommon for even a mediocre Prolog implementation to run faster
than the same program in Pascal or C.  Provided, of course, that the program
is something that really *needs* the crucial features of Prolog, namely
unification and backtracking.  Because Prolog is designed to do these things
all the time, Prolog implementations have very efficient algorithms for doing
them (including the associated memory management).  These algorithms are
likely to be faster than what you could quickly put together in Pascal or C.

In particular, "malloc" or "new" in C or Pascal respectively can turn out to
be a lot slower than the comparable memory management operations in Prolog,
because Prolog is implemented with the expectation that dynamic memory
management will be going on all the time, whereas C or Pascal implementors
tend to view dynamic mem. allocation as something you do only occasionally
and which therefore need not be terribly fast.

>I have used an old version of Turbo Prolog, do its limitations ( No 
>univ, no functor, no asserting rules, typed variables ) rally get in 
>the way for applications like Natural Language Processing?

Yes, because typically, in natural language processing, you'll want to
accept some natural language input, translate it into a Prolog query, and
then execute that query.  The lack of a "call" procedure in Turbo makes
this either clumsy or impossible depending on exactly how you set it up.


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:-  Michael A. Covington     internet mcovingt@uga.cc.uga.edu 
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