Różnice między wybraną wersją a wersją aktualną.
|
pl:prolog:pllib:interactive_interpreter [2019/06/27 15:50] |
pl:prolog:pllib:interactive_interpreter [2019/06/27 15:50] (aktualna) |
||
|---|---|---|---|
| Linia 1: | Linia 1: | ||
| + | ====== Interactive interpreter ====== | ||
| + | {{tag>interpreter interactive}} | ||
| + | ===== Description ===== | ||
| + | An interactive rule interpreter | ||
| + | |||
| + | **Source**: The Art of Prolog | ||
| + | ===== Download ===== | ||
| + | Program source code: {{interactive_interpreter.pl}} | ||
| + | ===== Listing ===== | ||
| + | <code prolog> | ||
| + | /* | ||
| + | solve(Goal,Result) :- | ||
| + | Given a set of rules of the form rule(A,B,Name), Goal has | ||
| + | Result yes if it follows from the rules and no if it does not. | ||
| + | The user is prompted for missing information. | ||
| + | */ | ||
| + | :- op(40,xfy,&). | ||
| + | :- op(30,xf,is_true). | ||
| + | :- op( 900, fy, not). | ||
| + | |||
| + | solve(A,yes) :- fact(A). | ||
| + | solve(A,Result) :- rule(A,B,Name), solve_body(B,Result). | ||
| + | solve(A,Result) :- askable(A), solve_askable(A,Result). | ||
| + | solve(A,no). | ||
| + | |||
| + | solve_body(A&B,Result) :- | ||
| + | solve_body(A,ResultA), solve_and(ResultA,B,Result). | ||
| + | solve_body(A is_true,Result) :- solve(A,Result). | ||
| + | |||
| + | solve_and(no,A,no). | ||
| + | solve_and(yes,B,Result) :- solve(B,Result). | ||
| + | |||
| + | solve_askable(A,Result) :- | ||
| + | not known(A), ask(A,Response), respond(Response,A,Result). | ||
| + | |||
| + | % The following predicates facilitate interaction with the user. | ||
| + | |||
| + | ask(A,Response) :- display_query(A), read(Response). | ||
| + | |||
| + | respond(yes,A,yes) :- assert(known_to_be_true(A)). | ||
| + | respond(no,A,no) :- assert(known_to_be_false(A)). | ||
| + | |||
| + | known(A) :- known_to_be_true(A). | ||
| + | known(A) :- known_to_be_false(A). | ||
| + | |||
| + | display_query(A) :- write(A), write('? '). | ||
| + | |||
| + | % Program 17.19: An interactive rule interpreter | ||
| + | </code> | ||
| + | ===== Comments ===== | ||
