Function canrun::collections::lvec::slice
source · pub fn slice<T, SV, RV, CV>(slice: SV, range: RV, collection: CV) -> Slice<T>where
T: Unify,
LVec<T>: Unify,
SV: Into<Value<LVec<T>>>,
RV: Into<Value<Range<usize>>>,
CV: Into<Value<LVec<T>>>,
Expand description
Create a Goal
that attempts to unify an LVec<T>
with
a slice from another LVec<T>
defined by a Range
.
Examples:
use canrun::{all, unify, lvec, LVar, Query};
let needle = LVar::new();
let haystack = LVar::new();
let range = LVar::new();
let goal = all![
unify(&range, 0..2),
unify(&haystack, lvec![1, 2, 3]),
lvec::slice(&needle, &range, &haystack),
];
let results: Vec<_> = goal.query(needle).collect();
assert_eq!(results, vec![vec![1, 2]]);