lark/examples/python_parser.py

83 lines
2.3 KiB
Python

#
# 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
# __path__ = os.path.dirname(__file__)
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)
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 )
try:
# print list(python_parser.lex(_read(os.path.join(path, f)) + '\n'))
try:
xrange
except NameError:
python_parser3.parse(_read(os.path.join(path, f)) + '\n')
else:
python_parser2.parse(_read(os.path.join(path, f)) + '\n')
except:
print ('At %s' % f)
raise
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()
# test_earley_equals_lalr()
# python_parser3.parse(_read(sys.argv[1]) + '\n')