Cli.utf8_tail: def of cli@0.2.0.0
Import: import cli@0.2.0.0/cli.bend as Cli
Lines 7929-7938 of cli@0.2.0.0/cli.bend: https://jend.leeeet.dev/read.txt?path=cli@0.2.0.0/cli.bend&start_line=7929&end_line=7938

import Base

# The code point acc continues to through the first more bytes of rest,
# each a continuation byte (80..BF); None if rest ends first or one is not.
def utf8_tail(rest: List<&2, U32>, more: Nat, acc: U32) -> Maybe<&2, U32>:
  match rest more:
    case Nil{} 0n: Some{acc}
    case Nil{} 1n+m: None{}
    case Con{b, t} 0n: Some{acc}
    case Con{+b, t} 1n+m:
      utf8_next(U32.is_lt((b - 128 : U32), 64),
        utf8_tail(t, m, (acc * 64 + (b - 128) : U32)))

Uses (9):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Maybe
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.add
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_lt
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.mul
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.sub
  https://jend.leeeet.dev/definition.txt?path=cli@0.2.0.0/cli.bend&name=utf8_next