def wrap_pair.keep

unified-nsga-iii@0.2.2.0 · algorithm.bend:173

import Base

173# in_range: pair+1 < n → use `pair` (even-N sequence, and odd N before
174# the last parent). last: pair+1 == n → keep `pair` so parent N-1
175# enters SBX. Otherwise reset to 0 (cursor already past the end).
176def wrap_pair.keep(+pair: Nat, last: Bool) -> Nat:
177  match last:
178    case True{}:
179      pair
180    case False{}:
181      0n