Added regex module option.

lark/lexer.py

@@ -1,6 +1,9 @@
 ## Lexer Implementation
 
-import re
+try:
+    import regex as re
+except ImportError:
+    import re
 
 from .utils import Str, classify, get_regexp_width, Py36, Serialize
 from .exceptions import UnexpectedCharacters, LexError, UnexpectedToken

lark/parser_frontends.py

@@ -1,4 +1,7 @@
-import re
+try:
+    import regex as re
+except ImportError:
+    import re
 from functools import partial
 
 from .utils import get_regexp_width, Serialize

setup.py

@@ -1,4 +1,7 @@
-import re
+try:
+    import regex as re
+except ImportError:
+    import re
 from setuptools import find_packages, setup
 
 __version__ ,= re.findall('__version__ = "(.*)"', open('lark/__init__.py').read())

tests/test_nearley/nearley

@@ -1 +1 @@
-Subproject commit a46b37471db486db0f6e1ce6a2934fb238346b44
+Subproject commit cf8925f729bde741a3076c5856c0c0862bc7f5de

tests/test_parser.py

@@ -1,7 +1,10 @@
 # -*- coding: utf-8 -*-
 from __future__ import absolute_import
 
-import re
+try:
+    import regex as re
+except ImportError:
+    import re
 import unittest
 import logging
 import os