def Tape.next

bend-trace-context@0.2.0.0 · trace_context.bend:943

import Base

943# A deterministic word source for tests and replay: each read takes the next
944# result, and an empty tape fails with code 1, tape-exhausted.
945def Tape.next(tape: List<&1, Result<&1, &1, U32 & String, U32>>) ->
946  List<&1, Result<&1, &1, U32 & String, U32>> & Result<&1, &1, U32 & String, U32>:
947  match tape:
948    case Nil{}:
949      (Nil{}, Fail{(1, "tape-exhausted")})
950    case Con{word, rest}:
951      (rest, word)