Regex.lex: def of bend-kit-regex@0.8.0.0
Import: import bend-kit-regex@0.8.0.0/regex.bend as Regex
Lines 378-390 of bend-kit-regex@0.8.0.0/regex.bend: https://jend.leeeet.dev/read.txt?path=bend-kit-regex@0.8.0.0/regex.bend&start_line=378&end_line=390

import Base

# fuel: every step but the last eats at least one char.
def lex(fuel: Nat, st: Lx) -> Maybe<&2, List<&2, Tok>>:
  match fuel:
    case 0n:
      None{}
    case 1n+f:
      match st:
        case LGo{s, toks}:
          lex(f, lex.step(s, toks))
        case LDone{toks}:
          Some{List.reverse(&2, Tok, toks)}
        case LFail{}:
          None{}

Uses (7):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=List.reverse
  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=bend-kit-regex@0.8.0.0/regex.bend&name=Lx
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=Tok
  https://jend.leeeet.dev/definition.txt?path=bend-kit-regex@0.8.0.0/regex.bend&name=lex.step