def distance

bend-edit-distance@0.2.2.0 · src/Myers.bend:686

import Base
import bend-edit-distance@0.2.2.0/src/Sequence.bend as S

686def distance(query: String, target: String) -> Nat:
687  match query target:
688    case SNil{} _:
689      S.length(target)
690    case SCon{h, t} SNil{}:
691      1n+S.length(t)
692    case SCon{qh, qt} SCon{th, tt}:
693      +q = {SCon{qh, qt} : String}
694      +t = {SCon{th, tt} : String}
695      +qn +tn = S.length(q) S.length(t)
696      align_shorter(q, t, qn, tn, Nat.is_le(qn, tn))