List.length: def of Base
Import: import Base
Lines 925-930 of Base/base.bend: https://jend.leeeet.dev/read.txt?path=Base/base.bend&start_line=925&end_line=930

import Base

def List.length(a, -A: Kind(a), xs: List<a, A>) -> Nat:
  match xs:
    case Nil{}:
      0n
    case h <> t:
      1n+List.length(a, A, t)

Uses (2):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat