Scan.head.tail: def of yaml-for-bend@0.1.1.0
Import: import yaml-for-bend@0.1.1.0/scan.bend as Scan
Lines 987-995 of yaml-for-bend@0.1.1.0/scan.bend: https://jend.leeeet.dev/read.txt?path=yaml-for-bend@0.1.1.0/scan.bend&start_line=987&end_line=995

import Base
import yaml-for-bend@0.1.1.0/token.bend as T

# Past blanks and a comment (after a blank), to a line break or the end.
def head.tail(s: String, +at: T.Mark, +left: Nat, +comment: Bool, +gap: Bool) -> Cur:
  match s:
    case SNil{}:
      Cur{SNil{}, at, left}
    case SCon{+c, +t}:
      +hash = Bool.and(Char.is_eq(c, '#'), gap)
      when(Cur, Bool.or(is_break(c), Bool.not(Bool.or(comment, Bool.or(is_blank(c), hash)))), u => Cur{SCon{c, t}, at, left},
        u => head.tail(t, past(at, c), Nat.sub(left, 1n), Bool.or(comment, hash), is_blank(c)))

Uses (15):
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.and
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.not
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Bool.or
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Char
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Char.is_eq
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=Nat.sub
  https://jend.leeeet.dev/definition.txt?path=Base/base.bend&name=String
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=Cur
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=is_blank
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=is_break
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=past
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/scan.bend&name=when
  https://jend.leeeet.dev/definition.txt?path=yaml-for-bend@0.1.1.0/token.bend&name=Mark