| """ |
| Grammar-complete Python Parser |
| ============================== |
| |
| A fully-working Python 2 & 3 parser (but not production ready yet!) |
| |
| This example demonstrates usage of the included Python grammars |
| """ |
| import sys |
| import os, os.path |
| from io import open |
| import glob, time |
|
|
| from lark import Lark |
| from lark.indenter import Indenter |
|
|
| |
|
|
| class PythonIndenter(Indenter): |
| NL_type = '_NEWLINE' |
| OPEN_PAREN_types = ['LPAR', 'LSQB', 'LBRACE'] |
| CLOSE_PAREN_types = ['RPAR', 'RSQB', 'RBRACE'] |
| INDENT_type = '_INDENT' |
| DEDENT_type = '_DEDENT' |
| tab_len = 8 |
|
|
| kwargs = dict(rel_to=__file__, postlex=PythonIndenter(), start='file_input') |
|
|
| python_parser2 = Lark.open('python2.lark', parser='lalr', **kwargs) |
| python_parser3 = Lark.open('python3.lark',parser='lalr', **kwargs) |
| python_parser2_earley = Lark.open('python2.lark', parser='earley', lexer='standard', **kwargs) |
|
|
| try: |
| xrange |
| except NameError: |
| chosen_parser = python_parser3 |
| else: |
| chosen_parser = python_parser2 |
|
|
|
|
| def _read(fn, *args): |
| kwargs = {'encoding': 'iso-8859-1'} |
| with open(fn, *args, **kwargs) as f: |
| return f.read() |
|
|
| def _get_lib_path(): |
| if os.name == 'nt': |
| if 'PyPy' in sys.version: |
| return os.path.join(sys.prefix, 'lib-python', sys.winver) |
| else: |
| return os.path.join(sys.prefix, 'Lib') |
| else: |
| return [x for x in sys.path if x.endswith('%s.%s' % sys.version_info[:2])][0] |
|
|
| def test_python_lib(): |
| path = _get_lib_path() |
|
|
| start = time.time() |
| files = glob.glob(path+'/*.py') |
| for f in files: |
| print( f ) |
| chosen_parser.parse(_read(os.path.join(path, f)) + '\n') |
|
|
| end = time.time() |
| print( "test_python_lib (%d files), time: %s secs"%(len(files), end-start) ) |
|
|
| def test_earley_equals_lalr(): |
| path = _get_lib_path() |
|
|
| files = glob.glob(path+'/*.py') |
| for f in files: |
| print( f ) |
| tree1 = python_parser2.parse(_read(os.path.join(path, f)) + '\n') |
| tree2 = python_parser2_earley.parse(_read(os.path.join(path, f)) + '\n') |
| assert tree1 == tree2 |
|
|
|
|
| if __name__ == '__main__': |
| test_python_lib() |
| |
| |
|
|
|
|
