To use, simply do:
>>> from simplepeg import SPEG
>>> parser = SPEG()
>>> parser.parse_grammar('GRAMMAR test b -> "a";')
>>> ast = parser.parse_text('a')
>>> print ast.to_json()
or:
>>> from simplepeg import SPEG
>>> parser = SPEG()
>>> ast = parser.parse('GRAMMAR test b -> "a";', 'a')
>>> print ast.to_json()