From a11f302c9deaabce30593b50f5958a9d65b6ceae Mon Sep 17 00:00:00 2001
From: Jeremy Fincher <jemfinch@users.sourceforge.net>
Date: Wed, 16 Apr 2003 05:26:24 +0000
Subject: [PATCH] Added perlReToPythonRe and perlReToReplacer and associated
 tests.

---
 src/utils.py       | 29 +++++++++++++++++++++++++++++
 test/utils_test.py | 22 ++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/src/utils.py b/src/utils.py
index 50e5c254a..18c347649 100755
--- a/src/utils.py
+++ b/src/utils.py
@@ -37,6 +37,7 @@ from __future__ import generators
 
 from fix import *
 
+import re
 import string
 import sgmllib
 import htmlentitydefs
@@ -198,4 +199,32 @@ def dqrepr(s):
     """Returns a repr() of s guaranteed to be in double quotes."""
     return '"' + repr("'\x00" + s)[6:]
 
+nonEscapedSlashes = re.compile(r'(?<!\\)/')
+def perlReToPythonRe(s):
+    (kind, regexp, flags) = nonEscapedSlashes.split(s)
+    regexp = regexp.replace('\\/', '/')
+    if kind not in ('', 'm'):
+        raise ValueError, 'Invalid kind: must be in ("", "m")'
+    flag = 0
+    try:
+        for c in flags.upper():
+            flag &= getattr(re, c)
+    except AttributeError:
+        raise ValueError, 'Invalid flag: %s' % c
+    return re.compile(regexp, flag)
+    
+def perlReToReplacer(s):
+    (kind, regexp, replace, flags) = nonEscapedSlashes.split(s)
+    if kind != 's':
+        raise ValueError, 'Invalid kind: must be "s"'
+    g = False
+    if 'g' in flags:
+        g = True
+        flags = filter('g'.__ne__, flags)
+    r = perlReToPythonRe('/'.join(('', regexp, flags)))
+    if g:
+        return lambda s: r.sub(replace, s)
+    else:
+        return lambda s: r.sub(replace, s, 1)
+
 # vim:set shiftwidth=4 tabstop=8 expandtab textwidth=78:
diff --git a/test/utils_test.py b/test/utils_test.py
index cba207c59..d074694fa 100644
--- a/test/utils_test.py
+++ b/test/utils_test.py
@@ -109,3 +109,25 @@ class UtilsTest(unittest.TestCase):
             self.assertEqual(r, utils.dqrepr(s))
             self.assertEqual(s, eval(utils.dqrepr(s)))
              
+    def testPerlReToPythonRe(self):
+        r = utils.perlReToPythonRe('m/foo/')
+        self.failUnless(r.search('foo'))
+        r = utils.perlReToPythonRe('/foo/')
+        self.failUnless(r.search('foo'))
+        r = utils.perlReToPythonRe('m/\\//')
+        self.failUnless(r.search('/'))
+
+    def testPerlReToReplacer(self):
+        f = utils.perlReToReplacer('s/foo/bar/')
+        self.assertEqual(f('foobarbaz'), 'barbarbaz')
+        f = utils.perlReToReplacer('s/fool/bar/')
+        self.assertEqual(f('foobarbaz'), 'foobarbaz')
+        f = utils.perlReToReplacer('s/foo//')
+        self.assertEqual(f('foobarbaz'), 'barbaz')
+        f = utils.perlReToReplacer('s/ba//')
+        self.assertEqual(f('foobarbaz'), 'foorbaz')
+        f = utils.perlReToReplacer('s/ba//g')
+        self.assertEqual(f('foobarbaz'), 'foorz')
+        f = utils.perlReToReplacer('s/ba\\///g')
+        self.assertEqual(f('fooba/rba/z'), 'foorz')
+