@top Document { heading line* }

heading { Heading "\n" }
line    { Indent* (AutoLink | Word) (AutoLink | Word | Spaces)* "\n" }

@tokens {
  space       { $[ \t] }
  letter      { ![ \t\n]+ }
  Heading     { letter+ }
  Indent      { space }
  Spaces      { space+ }
  AutoLink    { ("http" | "https") "://" letter+ }
  Word        { letter+ }
  @precedence { AutoLink, Word }
}