ometa TestParser <: Parser {
  number   = digit+,
  TagLetter     = letter,
  Tag       = "<" TagLetter+ ">",
  expr = (Tag | number | spaces )+
}
//TestParser.matchAll('6', 'number')
//TestParser.matchAll('a_b', 'Word')
TestParser.matchAll('6 <ab>', 'Tag')