Make regex dependency optional. Fixes #13.

Author: rczajka

README.textile

@@ -6,7 +6,9 @@ python-textile is a Python port of Textile, Dean Allen's humane web text generat
 
 h2. Installation
 
-Install the 'textile' folder on your python path, or @pip install textile@
+Install the 'textile' folder on your python path, or @pip install textile@.
+Optional dependencies require PIL/Pillow (for checking images size)
+and regex (for faster unicode-aware string matching).
 
 h2. Usage
 

setup.py

@@ -2,7 +2,7 @@
 import os
 import sys
 
-install_requires = ['regex']
+install_requires = []
 
 try:
     from collections import OrderedDict

textile/core.py

@@ -19,8 +19,6 @@
 
 """
 
-import re
-import regex
 import uuid
 
 from textile.tools import sanitizer, imagesize
@@ -48,6 +46,18 @@
     from HTMLParser import HTMLParser
 
 
+try:
+    # Use regex module for matching uppercase characters if installed,
+    # otherwise fall back to finding all the uppercase chars in a loop.
+    import regex as re
+    upper_re_s = r'\p{Lu}'
+except ImportError:
+    import re
+    from sys import maxunicode
+    upper_re_s = "".join([unichr(c) for c in
+        xrange(maxunicode) if unichr(c).isupper()])
+
+
 def _normalize_newlines(string):
     out = string.strip()
     out = re.sub(r'\r\n', '\n', out)
@@ -181,10 +191,10 @@ def __init__(self, restricted=False, lite=False, noimage=False,
             # plus/minus
             re.compile(r'[([]\+\/-[])]', re.I | re.U),
             # 3+ uppercase acronym
-            regex.compile(r'\b([\p{Lu}][\p{Lu}0-9]{2,})\b(?:[(]([^)]*)[)])'),
+            re.compile(r'\b([%s][%s0-9]{2,})\b(?:[(]([^)]*)[)])' % (upper_re_s, upper_re_s)),
             # 3+ uppercase
-            regex.compile(r"""(?:(?<=^)|(?<=\s)|(?<=[>\(;-]))([\p{Lu}]{3,})(\w*)(?=\s|%s|$)(?=[^">]*?(<|$))""" %
-                self.pnct_re_s),
+            re.compile(r"""(?:(?<=^)|(?<=\s)|(?<=[>\(;-]))([%s]{3,})(\w*)(?=\s|%s|$)(?=[^">]*?(<|$))""" %
+                (upper_re_s, self.pnct_re_s)),
         ]
 
         # These are the changes that need to be made for characters that occur

tox.ini

@@ -8,3 +8,9 @@ deps = nose
        regex
        Pillow
 commands = nosetests --id-file=.noseids.{envname}
+
+[testenv:pypy]
+deps = nose
+       coverage
+       html5lib
+       Pillow