prolog 将函数作为变量传递，如何添加参数？

Question

我有这个任意函数，我需要用不同的变量多次调用它。
顺便说一句，这是 SWI-Prolog

perform(V1,V2,V3,Function,Result):-
    % 
    % do little stuf.
    %
    Function(Arg1,Arg2,Result).

这给出了语法错误。

但是将函数作为变量传递而不添加参数可以正常工作，如下面的代码所示:

perform(Function):-
    Function.

sayHello:-
    write('hello').

:-perform(sayHello).

那么如何给可变函数添加参数呢？

Answer 1

特别是在 SWI-Prolog 中，您可以使用 call .引用手册:

call(:Goal, +ExtraArg1, ...)

Append ExtraArg1, ExtraArg2, ... to the argument list of Goal and call the result. For example, call(plus(1), 2, X) will call plus(1, 2, X), binding X to 3. The call/[2..] construct is handled by the compiler. The predicates call/[2-8] are defined as real (meta-)predicates and are available to inspection through current_predicate/1, predicate_property/2, etc. Higher arities are handled by the compiler and runtime system, but the predicates are not accessible for inspection.

其中加号表示 argument must be fully instantiated to a term that satisfies the required argument type , 冒号表示 agument is a meta-argument (这也意味着“+”)。