Implement partial assessment in SWI-Prolog

Question

I am writing a partial evaluator for Prolog requests. I tried to expand the query using expand_goal/2, but in this case it just combines Inputwith Output:

:- initialization(main).
main :-
    Input=is_between(1,A,3),expand_goal(Input,Output),writeln(Output).
is_between(A,B,C) :- 
    B>A,B<C.

I also tried using term_expansion/2, but this causes the program to crash:

:- initialization(main).
main :-
    Input=is_between(1,A,3),term_expansion(Input,Output),writeln(Output).
is_between(A,B,C) :- 
    B>A,B<C.

Is there a built-in predicate in SWI-Prolog that can execute macro decomposition of queries at runtime, how did I try to do this?

Answer 1

You can extend the Prolog clause using the built-in predicate clause/2. This predicate expands the sentence as a hygiene macro :

:- initialization(main).
main :- clause(is_between(1,2,3),B),writeln(B).
is_between(A,B,C) :- A<B,C>B.

This example is printed 1<2,3>2.

, findall/3 :

:- initialization(main).
main :- find_all_clauses(is_between(1,2,3),B),writeln(B).

find_all_clauses(Predicate,Output) :-
    findall(Predicate1,clause(Predicate,Predicate1),Output1),
    list_to_disjunction(Output1,Output).

list_to_disjunction([A],A).
list_to_disjunction([A|B],(A;B1)) :- list_to_disjunction(B,B1).

is_between(A,B,C) :- A<B,C>B.
is_between(A,B,C) :- B>A,B<C.

1<2,3>2;2>1,2<3.

, . , logen.