[Prolog] evaluate string to expression

[agnes]

Prolog newbie here. I don't know if Prolog's actually popular at any place, but I have a simple question.

Is it possible in Prolog to have a function evaluatefun like

fun(Cm, Meters, Result) :-
	Result is Cm * Meters.

evaluatefun( (fun(arg1, arg2, Result)), 50, 10) :- ...

Where (fun(arg1, arg2, Result) (put as first parameter to evaluatefun) is actually passed as a string/constant - and then fun (the function itself) is evaluated with parameters 50 and 10 as first two parameters.

So (fun(arg1, arg2, Result) is a string/constant put as first parameter to evaluatefun, but the idea is to evaluate/call/run the passed string/constant ánd parameters, as the related existing function with parameters.

[debsankha]

call predicate is what you are asking for.

call(fun,10,2,Res).

will do the job.

[agnes]

Thanks, I have it working now with

costfun(Cm, Meters, Result) :-
	Result is Cm * Meters.

evaluatefun([Fun,[X, Y, Result]], A, B) :-
	call(Fun,A,B,Result).

?- evaluatefun([costfun,[Arg1,Arg2,Result]], 50, 10).
Result = 500.

Although, now Fun does have to be passed as [Fun,[X, Y, Result]] instead of (Fun,(X, Y, Result)).