Encoding.utf8.cont.in: def of bend-kit-encoding@0.5.0.0
Import: import bend-kit-encoding@0.5.0.0/encoding.bend as Encoding
Lines 108-114 of bend-kit-encoding@0.5.0.0/encoding.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-encoding@0.5.0.0/encoding.bend&start_line=108&end_line=114

import Base

# WHATWG: a byte that breaks a sequence yields U+FFFD and is read again as a lead.
def utf8.cont.in(+need: U32, cp: U32, +b: U32, out: String, ok: Bool) -> Utf8:
  match ok:
    case True{}:
      utf8.more((need - 1 : U32), (cp * 64 + U32.and(b, 63) : U32), out, U32.is_eq(need, 1))
    case False{}:
      utf8.lead(b, utf8.bad(out), U32.is_lt(b, 128))

Uses (13):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  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.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=U32.is_eq
  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=bend-kit-encoding@0.5.0.0/encoding.bend&name=Utf8
  https://jend.leeeet.dev/definition.txt?path=bend-kit-encoding@0.5.0.0/encoding.bend&name=utf8.bad
  https://jend.leeeet.dev/definition.txt?path=bend-kit-encoding@0.5.0.0/encoding.bend&name=utf8.lead
  https://jend.leeeet.dev/definition.txt?path=bend-kit-encoding@0.5.0.0/encoding.bend&name=utf8.more