Witch of Git - mukan/blob - src/bin/readme_examples.rs

   1 use mukan::{all, and, call_fresh, delay, eq, fresh, or, reify_vars, Goal, State, Term};
   2
   3 fn main() {
   4     let goal = call_fresh(|x| eq(413, x));
   5     for soln in goal.solve(State::new()) {
   6         println!("{}", soln);
   7     }
   8
   9     let goal = call_fresh(|x| or(eq(612, x), eq(1025, x)));
  10     for soln in goal.solve(State::new()) {
  11         println!("{}", soln);
  12     }
  13
  14     let goal = fresh!((a, b, c) => all! {
  15         eq((a, b), c),
  16         eq((b, 8), c),
  17     });
  18     for soln in goal.solve(State::new()) {
  19         println!("{}", soln);
  20     }
  21
  22     let (vars, state) = State::with_vars(2);
  23     let (a, b) = (vars[0], vars[1]);
  24     let goal = fresh!((c) => all! {
  25         eq((a, b), c),
  26         eq((b, 8), c),
  27     });
  28     for soln in goal.solve(state) {
  29         println!("{:?}", reify_vars(&vars, soln));
  30     }
  31
  32     fn peano(n: impl Into<Term>) -> impl Goal {
  33         let n = n.into();
  34         or(
  35             eq(n.clone(), 0),
  36             fresh!((x) => and(
  37                 eq(n.clone(), (1, x)),
  38                 delay(move || peano(x)),
  39             )),
  40         )
  41     }
  42
  43     let (vars, state) = State::with_vars(1);
  44     let goal = peano(vars[0]);
  45     for soln in goal.solve(state).take(10) {
  46         println!("{:?}", reify_vars(&vars, soln));
  47     }
  48 }