@@ -42,9 +42,9 @@ Sean M. Burke <sburke@cpan.org>.
 Module content
 --------------
 
-The module exports a single function that takes an Unicode object (Python
-2.x) or string (Python 3.x) and returns a string (that can be encoded to
-ASCII bytes in Python 3.x)::
+The module exports a function that takes an Unicode object (Python 2.x) or
+string (Python 3.x) and returns a string (that can be encoded to ASCII bytes in
+Python 3.x)::
 
     >>> from unidecode import unidecode
     >>> unidecode(u'ko\u017eu\u0161\u010dek')
@@ -54,6 +54,17 @@ ASCII bytes in Python 3.x)::
     >>> unidecode(u"\u5317\u4EB0")
     'Bei Jing '
 
+For use cases where most strings passed are ASCII and only some occassional
+non-ASCII ones, use the `unidecode_fast` function::
+
+    >>> from unidecode import unidecode_fast
+    >>> unidecode_fast(u'Hello world!')
+    'Hello world!'
+
+This function about five times faster if the string only contains ASCII
+characters, but sligthly slower than using `unidecode` directly non-ASCII chars
+are present.
+
 A utility is also included that allows you to transliterate text from the
 command line in several ways. Reading from standard input::
 
 
@@ -2,7 +2,7 @@
 # vim:ts=4 sw=4 expandtab softtabstop=4
 import unittest
 import sys
-from unidecode import unidecode
+from unidecode import unidecode, unidecode_fast
 import warnings
 
 # workaround for Python < 2.7
@@ -502,5 +502,16 @@ def test_unicode_text_converter(self):
 
             self.assertEqual('THE QUICK BROWN FOX JUMPS OVER THE LAZY DOG 1234567890', o)
 
+
+class TestUnidecodeFast(unittest.TestCase):
+    def test_ascii_fast(self):
+        out = unidecode_fast(_u('Hello, World!'))
+        self.assertEqual(out, 'Hello, World!')
+
+    def test_nonascii_fast(self):
+        out = unidecode_fast(_u('příliš žluťoučký kůň pěl ďábelské ódy'))
+        self.assertEqual(out, 'prilis zlutoucky kun pel dabelske ody')
+
+
 if __name__ == "__main__":
     unittest.main()
@@ -19,18 +19,42 @@
 
 Cache = {}
 
+
+def _warn_if_not_unicode(string):
+    if version_info[0] < 3 and not isinstance(string, unicode):
+        warnings.warn(  "Argument %r is not an unicode object. "
+                        "Passing an encoded string will likely have "
+                        "unexpected results." % (type(string),),
+                        RuntimeWarning, 2)
+
+
+def unidecode_fast(string):
+    """
+    Try to transliterate using ASCII codec. If it fails, fall back to
+    transliteration using the character tables.
+
+    This is approx. five times faster if the string only contains ASCII
+    characters, but sligthly slower than using unidecode directly non-ASCII
+    chars are present.
+    """
+    _warn_if_not_unicode(string)
+    try:
+        bytestring = string.encode('ASCII')
+    except UnicodeEncodeError:
+        return unidecode(string)
+    if version_info[0] >= 3:
+        return string
+    else:
+        return bytestring
+
+
 def unidecode(string):
     """Transliterate an Unicode object into an ASCII string
 
     >>> unidecode(u"\u5317\u4EB0")
     "Bei Jing "
     """
-
-    if version_info[0] < 3 and not isinstance(string, unicode):
-        warnings.warn(  "Argument %r is not an unicode object. "
-                        "Passing an encoded string will likely have "
-                        "unexpected results." % (type(string),),
-			RuntimeWarning, 2)
+    _warn_if_not_unicode(string)
 
     retval = []