Function canrun::collections::lvec::member

pub fn member<T, IntoT, IntoLVecT>(
    item: IntoT,
    collection: IntoLVecT
) -> Member<T>where
    T: Unify,
    IntoT: Into<Value<T>>,
    IntoLVecT: Into<Value<LVec<T>>>,

Create a Goal that attempts to unify a Value<T> with any of the items in a LVec<T>.

This goal will fork the state for each match found.

Examples:

use canrun::{LVar, all, unify, lvec, Query};

let x = LVar::new();
let xs = LVar::new();
let goal = all![
    unify(&x, 1),
    unify(&xs, lvec![1, 2, 3]),
    lvec::member(x, xs),
];
let results: Vec<_> = goal.query(x).collect();
assert_eq!(results, vec![1]);

let x = LVar::new();
let goal = all![
    lvec::member(x, lvec![1, 2, 3]),
];
let results: Vec<_> = goal.query(x).collect();
assert_eq!(results, vec![1, 2, 3]);