GRIPS - A FUNCTIONAL LANGUAGE IN PROLOG
            Contributed by Jocelyn Paine, Oxford University.
                   Shelved on the 11th of January 1991


GRIPS is a pre-processor for  translating a functional version of Prolog
into Prolog.  By using  it, you can  eliminate the  tedium of  having to
think up variables to pass output from one predicate to the input of the
next, and of having to flatten arithmetic expressions into a sequence of
machine-code-like assignments.


Here are two example definitions.

        factorial(N) <- 1 if N =< 0.
        factorial(N) <- N * factorial(N-1) if N > 0.

        count( [] ) <- 0.
        count( [_|T] ) <- 1 + count(T).

You can load these by doing 'grips_consult' or 'grips_reconsult' on the
file they're in. You could then run the interpreter:

        ?- grips.
        |: do grips_reconsult('test.pl').
        Done
        |: factorial(3).
        Result = 6.
        |: factorial(factorial(3)).
        Result = 720.
        |: count( [a,b,c,d] ).
        Result = 4.
        |: 1 + count([a,b,c,d])/factorial(3).
        Result = 1.66667.
        |: pr( factorial(3,F) ).

        F = 6
        More (y/n)? |: y
        no
        |:


There is  a user manual for  GRIPS. There's also another  library entry,
COMPILER, which is a simple compiler written in GRIPS.


SIZE : 58 kilobytes.

CHECKED ON EDINBURGH-COMPATIBLE (POPLOG) PROLOG : yes.

PORTABILITY : should be no problems. See the comments in the code.

INTERNAL DOCUMENTATION  : as program comments  and some sections  in the
user guide.