| | """ |
| | 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() |
| | |
| | |
| |
|
| |
|
