def observe

bendtorch-core@0.1.0.0 · src/storage/model.bend:56

import Base

56def observe(-T: Data, d: Nat, array: Array<T>, path: Path(d)) -> Maybe<&2, T>:
57  match d array:
58    case 0n ALeaf{x}:
59      Some{x}
60    case 0n ANode{xs, ys}:
61      None{}
62    case 1n+p ALeaf{x}:
63      None{}
64    case 1n+p ANode{xs, ys}:
65      Step{bit, rest} = path
66      match bit:
67        case False{}:
68          observe(T, p, xs, rest)
69        case True{}:
70          observe(T, p, ys, rest)