cleanup: removed special cases from string escaping code

Cython/Utils.py

@@ -100,15 +100,18 @@ class EncodedString(unicode):
 #            getattr(other, 'encoding', '') == self.encoding
 
 def _to_oct_sequence(s):
-    return ''.join(['\\%03o' % ord(c) for c in s])
+    if s in '\n\r\t':
+        return repr(s)[1:-1]
+    else:
+        return ''.join(['\\%03o' % ord(c) for c in s])
 
-_c_special = ('\0', '??', '<:', ':>', '<%', '%>', '%:', '%:')
+_c_special = ('\0', '\n','\r','\t', '??', '<:', ':>', '<%', '%>', '%:', '%:')
 _c_special_replacements = zip(_c_special, map(_to_oct_sequence, _c_special))
 
 def _build_special_test():
     subexps = []
-    for special in _c_special + ('\n','\r','\t'):
-        regexp = ''.join(['[%s]' % c for c in special ])
+    for special in _c_special:
+        regexp = ''.join(['[%s]' % c for c in special])
         subexps.append(regexp)
     return re.compile('(' + '|'.join(subexps) + ')').search
 
@@ -116,7 +119,6 @@ _has_specials = _build_special_test()
 
 def escape_byte_string(s):
     if _has_specials(s):
-        s = s.replace('\n', r'\n').replace('\r', r'\r').replace('\t', r'\t')
         for special, replacement in _c_special_replacements:
             s = s.replace(special, replacement)
     try: