Class Parser

const src: string = ...
for (const token of new Parser().parse(src)) {
  // token: Token
}

To use the parser with a user-provided lexer:

function* parse(source: string, lexer: Lexer) {
  const parser = new Parser()
  for (const lexeme of lexer.lex(source))
    yield* parser.next(lexeme)
  yield* parser.end()
}

const src: string = ...
const lexer = new Lexer()
for (const token of parse(src, lexer)) {
  // token: Token
}