def spass

bendtorch@1.3.0.0 · spec.bend:183

import Base

183# one pass of main.bend's tree_sum (ts_pass): neighbours added in pairs, an odd last cell carried up as it is
184def spass(xs: List<&2, Sum>) -> List<&2, Sum>:
185  match xs:
186    case Nil{}:
187      Nil{}
188    case Con{a, Nil{}}:
189      a <> Nil{}
190    case Con{a, Con{b, t}}:
191      SAdd{a, b} <> spass(t)