diff --git a/Lib/json/__init__.py b/Lib/json/__init__.py
index 56116f4..4338a03 100644
--- a/Lib/json/__init__.py
+++ b/Lib/json/__init__.py
@@ -1,11 +1,13 @@
-r"""A simple, fast, extensible JSON encoder and decoder
-
-JSON (JavaScript Object Notation) <http://json.org> is a subset of
+r"""JSON (JavaScript Object Notation) <http://json.org> is a subset of
 JavaScript syntax (ECMA-262 3rd edition) used as a lightweight data
 interchange format.
 
-json exposes an API familiar to uses of the standard library
-marshal and pickle modules.
+:mod:`json` exposes an API familiar to users of the standard library
+:mod:`marshal` and :mod:`pickle` modules. It is the externally maintained
+version of the :mod:`json` library contained in Python 2.6, but maintains
+compatibility with Python 2.4 and Python 2.5 and (currently) has
+significant performance advantages, even without using the optional C
+extension for speedups.
 
 Encoding basic Python object hierarchies::
 
@@ -32,23 +34,28 @@
     >>> json.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))
     '[1,2,3,{"4":5,"6":7}]'
 
-Pretty printing (using repr() because of extraneous whitespace in the output)::
+Pretty printing::
 
     >>> import json
-    >>> print repr(json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4))
-    '{\n    "4": 5, \n    "6": 7\n}'
+    >>> s = json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4)
+    >>> print '\n'.join([l.rstrip() for l in  s.splitlines()])
+    {
+        "4": 5,
+        "6": 7
+    }
 
 Decoding JSON::
 
     >>> import json
-    >>> json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]')
-    [u'foo', {u'bar': [u'baz', None, 1.0, 2]}]
-    >>> json.loads('"\\"foo\\bar"')
-    u'"foo\x08ar'
+    >>> obj = [u'foo', {u'bar': [u'baz', None, 1.0, 2]}]
+    >>> json.loads('["foo", {"bar":["baz", null, 1.0, 2]}]') == obj
+    True
+    >>> json.loads('"\\"foo\\bar"') == u'"foo\x08ar'
+    True
     >>> from StringIO import StringIO
     >>> io = StringIO('["streaming API"]')
-    >>> json.load(io)
-    [u'streaming API']
+    >>> json.load(io)[0] == 'streaming API'
+    True
 
 Specializing JSON object decoding::
 
@@ -61,43 +68,36 @@
     >>> json.loads('{"__complex__": true, "real": 1, "imag": 2}',
     ...     object_hook=as_complex)
     (1+2j)
-    >>> import decimal
-    >>> json.loads('1.1', parse_float=decimal.Decimal)
-    Decimal('1.1')
+    >>> from decimal import Decimal
+    >>> json.loads('1.1', parse_float=Decimal) == Decimal('1.1')
+    True
 
-Extending JSONEncoder::
+Specializing JSON object encoding::
 
     >>> import json
-    >>> class ComplexEncoder(json.JSONEncoder):
-    ...     def default(self, obj):
-    ...         if isinstance(obj, complex):
-    ...             return [obj.real, obj.imag]
-    ...         return json.JSONEncoder.default(self, obj)
+    >>> def encode_complex(obj):
+    ...     if isinstance(obj, complex):
+    ...         return [obj.real, obj.imag]
+    ...     raise TypeError(repr(o) + " is not JSON serializable")
     ...
-    >>> dumps(2 + 1j, cls=ComplexEncoder)
+    >>> json.dumps(2 + 1j, default=encode_complex)
     '[2.0, 1.0]'
-    >>> ComplexEncoder().encode(2 + 1j)
+    >>> json.JSONEncoder(default=encode_complex).encode(2 + 1j)
     '[2.0, 1.0]'
-    >>> list(ComplexEncoder().iterencode(2 + 1j))
-    ['[', '2.0', ', ', '1.0', ']']
+    >>> ''.join(json.JSONEncoder(default=encode_complex).iterencode(2 + 1j))
+    '[2.0, 1.0]'
 
 
-Using json.tool from the shell to validate and
-pretty-print::
+Using json.tool from the shell to validate and pretty-print::
 
-    $ echo '{"json":"obj"}' | python -mjson.tool
+    $ echo '{"json":"obj"}' | python -m json.tool
     {
         "json": "obj"
     }
-    $ echo '{ 1.2:3.4}' | python -mjson.tool
+    $ echo '{ 1.2:3.4}' | python -m json.tool
     Expecting property name: line 1 column 2 (char 2)
-
-Note that the JSON produced by this module's default settings
-is a subset of YAML, so it may be used as a serializer for that as well.
-
 """
-
-__version__ = '1.9'
+__version__ = '2.0.9'
 __all__ = [
     'dump', 'dumps', 'load', 'loads',
     'JSONDecoder', 'JSONEncoder',
@@ -125,28 +125,29 @@
     """Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
     ``.write()``-supporting file-like object).
 
-    If ``skipkeys`` is ``True`` then ``dict`` keys that are not basic types
+    If ``skipkeys`` is true then ``dict`` keys that are not basic types
     (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
     will be skipped instead of raising a ``TypeError``.
 
-    If ``ensure_ascii`` is ``False``, then the some chunks written to ``fp``
+    If ``ensure_ascii`` is false, then the some chunks written to ``fp``
     may be ``unicode`` instances, subject to normal Python ``str`` to
     ``unicode`` coercion rules. Unless ``fp.write()`` explicitly
     understands ``unicode`` (as in ``codecs.getwriter()``) this is likely
     to cause an error.
 
-    If ``check_circular`` is ``False``, then the circular reference check
+    If ``check_circular`` is false, then the circular reference check
     for container types will be skipped and a circular reference will
     result in an ``OverflowError`` (or worse).
 
-    If ``allow_nan`` is ``False``, then it will be a ``ValueError`` to
+    If ``allow_nan`` is false, then it will be a ``ValueError`` to
     serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``)
     in strict compliance of the JSON specification, instead of using the
     JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
 
-    If ``indent`` is a non-negative integer, then JSON array elements and object
-    members will be pretty-printed with that indent level. An indent level
-    of 0 will only insert newlines. ``None`` is the most compact representation.
+    If ``indent`` is a non-negative integer, then JSON array elements and
+    object members will be pretty-printed with that indent level. An indent
+    level of 0 will only insert newlines. ``None`` is the most compact
+    representation.
 
     If ``separators`` is an ``(item_separator, dict_separator)`` tuple
     then it will be used instead of the default ``(', ', ': ')`` separators.
@@ -163,8 +164,8 @@
 
     """
     # cached encoder
-    if (skipkeys is False and ensure_ascii is True and
-        check_circular is True and allow_nan is True and
+    if (not skipkeys and ensure_ascii and
+        check_circular and allow_nan and
         cls is None and indent is None and separators is None and
         encoding == 'utf-8' and default is None and not kw):
         iterable = _default_encoder.iterencode(obj)
@@ -186,19 +187,19 @@
         encoding='utf-8', default=None, **kw):
     """Serialize ``obj`` to a JSON formatted ``str``.
 
-    If ``skipkeys`` is ``True`` then ``dict`` keys that are not basic types
+    If ``skipkeys`` is false then ``dict`` keys that are not basic types
     (``str``, ``unicode``, ``int``, ``long``, ``float``, ``bool``, ``None``)
     will be skipped instead of raising a ``TypeError``.
 
-    If ``ensure_ascii`` is ``False``, then the return value will be a
+    If ``ensure_ascii`` is false, then the return value will be a
     ``unicode`` instance subject to normal Python ``str`` to ``unicode``
     coercion rules instead of being escaped to an ASCII ``str``.
 
-    If ``check_circular`` is ``False``, then the circular reference check
+    If ``check_circular`` is false, then the circular reference check
     for container types will be skipped and a circular reference will
     result in an ``OverflowError`` (or worse).
 
-    If ``allow_nan`` is ``False``, then it will be a ``ValueError`` to
+    If ``allow_nan`` is false, then it will be a ``ValueError`` to
     serialize out of range ``float`` values (``nan``, ``inf``, ``-inf``) in
     strict compliance of the JSON specification, instead of using the
     JavaScript equivalents (``NaN``, ``Infinity``, ``-Infinity``).
@@ -223,8 +224,8 @@
 
     """
     # cached encoder
-    if (skipkeys is False and ensure_ascii is True and
-        check_circular is True and allow_nan is True and
+    if (not skipkeys and ensure_ascii and
+        check_circular and allow_nan and
         cls is None and indent is None and separators is None and
         encoding == 'utf-8' and default is None and not kw):
         return _default_encoder.encode(obj)
@@ -242,8 +243,8 @@
 
 def load(fp, encoding=None, cls=None, object_hook=None, parse_float=None,
         parse_int=None, parse_constant=None, **kw):
-    """Deserialize ``fp`` (a ``.read()``-supporting file-like object
-    containing a JSON document) to a Python object.
+    """Deserialize ``fp`` (a ``.read()``-supporting file-like object containing
+    a JSON document) to a Python object.
 
     If the contents of ``fp`` is encoded with an ASCII based encoding other
     than utf-8 (e.g. latin-1), then an appropriate ``encoding`` name must
diff --git a/Lib/json/decoder.py b/Lib/json/decoder.py
index e80b935..c7f04f9 100644
--- a/Lib/json/decoder.py
+++ b/Lib/json/decoder.py
@@ -1,10 +1,10 @@
 """Implementation of JSONDecoder
 """
-
 import re
 import sys
+import struct
 
-from json.scanner import Scanner, pattern
+from json.scanner import make_scanner
 try:
     from _json import scanstring as c_scanstring
 except ImportError:
@@ -14,7 +14,14 @@
 
 FLAGS = re.VERBOSE | re.MULTILINE | re.DOTALL
 
-NaN, PosInf, NegInf = float('nan'), float('inf'), float('-inf')
+def _floatconstants():
+    _BYTES = '7FF80000000000007FF0000000000000'.decode('hex')
+    if sys.byteorder != 'big':
+        _BYTES = _BYTES[:8][::-1] + _BYTES[8:][::-1]
+    nan, inf = struct.unpack('dd', _BYTES)
+    return nan, inf, -inf
+
+NaN, PosInf, NegInf = _floatconstants()
 
 
 def linecol(doc, pos):
@@ -27,49 +34,26 @@
 
 
 def errmsg(msg, doc, pos, end=None):
+    # Note that this function is called from _json
     lineno, colno = linecol(doc, pos)
     if end is None:
         fmt = '{0}: line {1} column {2} (char {3})'
         return fmt.format(msg, lineno, colno, pos)
+        #fmt = '%s: line %d column %d (char %d)'
+        #return fmt % (msg, lineno, colno, pos)
     endlineno, endcolno = linecol(doc, end)
     fmt = '{0}: line {1} column {2} - line {3} column {4} (char {5} - {6})'
     return fmt.format(msg, lineno, colno, endlineno, endcolno, pos, end)
+    #fmt = '%s: line %d column %d - line %d column %d (char %d - %d)'
+    #return fmt % (msg, lineno, colno, endlineno, endcolno, pos, end)
 
 
 _CONSTANTS = {
     '-Infinity': NegInf,
     'Infinity': PosInf,
     'NaN': NaN,
-    'true': True,
-    'false': False,
-    'null': None,
 }
 
-
-def JSONConstant(match, context, c=_CONSTANTS):
-    s = match.group(0)
-    fn = getattr(context, 'parse_constant', None)
-    if fn is None:
-        rval = c[s]
-    else:
-        rval = fn(s)
-    return rval, None
-pattern('(-?Infinity|NaN|true|false|null)')(JSONConstant)
-
-
-def JSONNumber(match, context):
-    match = JSONNumber.regex.match(match.string, *match.span())
-    integer, frac, exp = match.groups()
-    if frac or exp:
-        fn = getattr(context, 'parse_float', None) or float
-        res = fn(integer + (frac or '') + (exp or ''))
-    else:
-        fn = getattr(context, 'parse_int', None) or int
-        res = fn(integer)
-    return res, None
-pattern(r'(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?')(JSONNumber)
-
-
 STRINGCHUNK = re.compile(r'(.*?)(["\\\x00-\x1f])', FLAGS)
 BACKSLASH = {
     '"': u'"', '\\': u'\\', '/': u'/',
@@ -78,8 +62,16 @@
 
 DEFAULT_ENCODING = "utf-8"
 
+def py_scanstring(s, end, encoding=None, strict=True,
+        _b=BACKSLASH, _m=STRINGCHUNK.match):
+    """Scan the string s for a JSON string. End is the index of the
+    character in s after the quote that started the JSON string.
+    Unescapes all valid JSON string escape sequences and raises ValueError
+    on attempt to decode an invalid string. If strict is False then literal
+    control characters are allowed in the string.
 
-def py_scanstring(s, end, encoding=None, strict=True, _b=BACKSLASH, _m=STRINGCHUNK.match):
+    Returns a tuple of the decoded string and the index of the character in s
+    after the end quote."""
     if encoding is None:
         encoding = DEFAULT_ENCODING
     chunks = []
@@ -92,14 +84,18 @@
                 errmsg("Unterminated string starting at", s, begin))
         end = chunk.end()
         content, terminator = chunk.groups()
+        # Content is contains zero or more unescaped string characters
         if content:
             if not isinstance(content, unicode):
                 content = unicode(content, encoding)
             _append(content)
+        # Terminator is the end of string, a literal control character,
+        # or a backslash denoting that an escape sequence follows
         if terminator == '"':
             break
         elif terminator != '\\':
             if strict:
+                #msg = "Invalid control character %r at" % (terminator,)
                 msg = "Invalid control character {0!r} at".format(terminator)
                 raise ValueError(errmsg(msg, s, end))
             else:
@@ -110,136 +106,157 @@
         except IndexError:
             raise ValueError(
                 errmsg("Unterminated string starting at", s, begin))
+        # If not a unicode escape sequence, must be in the lookup table
         if esc != 'u':
             try:
-                m = _b[esc]
+                char = _b[esc]
             except KeyError:
-                msg = "Invalid \\escape: {0!r}".format(esc)
+                msg = "Invalid \\escape: " + repr(esc)
                 raise ValueError(errmsg(msg, s, end))
             end += 1
         else:
+            # Unicode escape sequence
             esc = s[end + 1:end + 5]
             next_end = end + 5
-            msg = "Invalid \\uXXXX escape"
-            try:
-                if len(esc) != 4:
-                    raise ValueError
-                uni = int(esc, 16)
-                if 0xd800 <= uni <= 0xdbff and sys.maxunicode > 65535:
-                    msg = "Invalid \\uXXXX\\uXXXX surrogate pair"
-                    if not s[end + 5:end + 7] == '\\u':
-                        raise ValueError
-                    esc2 = s[end + 7:end + 11]
-                    if len(esc2) != 4:
-                        raise ValueError
-                    uni2 = int(esc2, 16)
-                    uni = 0x10000 + (((uni - 0xd800) << 10) | (uni2 - 0xdc00))
-                    next_end += 6
-                m = unichr(uni)
-            except ValueError:
+            if len(esc) != 4:
+                msg = "Invalid \\uXXXX escape"
                 raise ValueError(errmsg(msg, s, end))
+            uni = int(esc, 16)
+            # Check for surrogate pair on UCS-4 systems
+            if 0xd800 <= uni <= 0xdbff and sys.maxunicode > 65535:
+                msg = "Invalid \\uXXXX\\uXXXX surrogate pair"
+                if not s[end + 5:end + 7] == '\\u':
+                    raise ValueError(errmsg(msg, s, end))
+                esc2 = s[end + 7:end + 11]
+                if len(esc2) != 4:
+                    raise ValueError(errmsg(msg, s, end))
+                uni2 = int(esc2, 16)
+                uni = 0x10000 + (((uni - 0xd800) << 10) | (uni2 - 0xdc00))
+                next_end += 6
+            char = unichr(uni)
             end = next_end
-        _append(m)
+        # Append the unescaped character
+        _append(char)
     return u''.join(chunks), end
 
 
-# Use speedup
-if c_scanstring is not None:
-    scanstring = c_scanstring
-else:
-    scanstring = py_scanstring
+# Use speedup if available
+scanstring = c_scanstring or py_scanstring
 
-def JSONString(match, context):
-    encoding = getattr(context, 'encoding', None)
-    strict = getattr(context, 'strict', True)
-    return scanstring(match.string, match.end(), encoding, strict)
-pattern(r'"')(JSONString)
+WHITESPACE = re.compile(r'[ \t\n\r]*', FLAGS)
+WHITESPACE_STR = ' \t\n\r'
 
-
-WHITESPACE = re.compile(r'\s*', FLAGS)
-
-
-def JSONObject(match, context, _w=WHITESPACE.match):
+def JSONObject((s, end), encoding, strict, scan_once, object_hook,
+        _w=WHITESPACE.match, _ws=WHITESPACE_STR):
     pairs = {}
-    s = match.string
-    end = _w(s, match.end()).end()
+    # Use a slice to prevent IndexError from being raised, the following
+    # check will raise a more specific ValueError if the string is empty
     nextchar = s[end:end + 1]
-    # Trivial empty object
-    if nextchar == '}':
-        return pairs, end + 1
+    # Normally we expect nextchar == '"'
     if nextchar != '"':
-        raise ValueError(errmsg("Expecting property name", s, end))
+        if nextchar in _ws:
+            end = _w(s, end).end()
+            nextchar = s[end:end + 1]
+        # Trivial empty object
+        if nextchar == '}':
+            return pairs, end + 1
+        elif nextchar != '"':
+            raise ValueError(errmsg("Expecting property name", s, end))
     end += 1
-    encoding = getattr(context, 'encoding', None)
-    strict = getattr(context, 'strict', True)
-    iterscan = JSONScanner.iterscan
     while True:
         key, end = scanstring(s, end, encoding, strict)
-        end = _w(s, end).end()
+
+        # To skip some function call overhead we optimize the fast paths where
+        # the JSON key separator is ": " or just ":".
         if s[end:end + 1] != ':':
-            raise ValueError(errmsg("Expecting : delimiter", s, end))
-        end = _w(s, end + 1).end()
+            end = _w(s, end).end()
+            if s[end:end + 1] != ':':
+                raise ValueError(errmsg("Expecting : delimiter", s, end))
+
+        end += 1
+
         try:
-            value, end = iterscan(s, idx=end, context=context).next()
+            if s[end] in _ws:
+                end += 1
+                if s[end] in _ws:
+                    end = _w(s, end + 1).end()
+        except IndexError:
+            pass
+
+        try:
+            value, end = scan_once(s, end)
         except StopIteration:
             raise ValueError(errmsg("Expecting object", s, end))
         pairs[key] = value
-        end = _w(s, end).end()
-        nextchar = s[end:end + 1]
+
+        try:
+            nextchar = s[end]
+            if nextchar in _ws:
+                end = _w(s, end + 1).end()
+                nextchar = s[end]
+        except IndexError:
+            nextchar = ''
         end += 1
+
         if nextchar == '}':
             break
-        if nextchar != ',':
+        elif nextchar != ',':
             raise ValueError(errmsg("Expecting , delimiter", s, end - 1))
-        end = _w(s, end).end()
-        nextchar = s[end:end + 1]
+
+        try:
+            nextchar = s[end]
+            if nextchar in _ws:
+                end += 1
+                nextchar = s[end]
+                if nextchar in _ws:
+                    end = _w(s, end + 1).end()
+                    nextchar = s[end]
+        except IndexError:
+            nextchar = ''
+
         end += 1
         if nextchar != '"':
             raise ValueError(errmsg("Expecting property name", s, end - 1))
-    object_hook = getattr(context, 'object_hook', None)
+
     if object_hook is not None:
         pairs = object_hook(pairs)
     return pairs, end
-pattern(r'{')(JSONObject)
 
-
-def JSONArray(match, context, _w=WHITESPACE.match):
+def JSONArray((s, end), scan_once, _w=WHITESPACE.match, _ws=WHITESPACE_STR):
     values = []
-    s = match.string
-    end = _w(s, match.end()).end()
-    # Look-ahead for trivial empty array
     nextchar = s[end:end + 1]
+    if nextchar in _ws:
+        end = _w(s, end + 1).end()
+        nextchar = s[end:end + 1]
+    # Look-ahead for trivial empty array
     if nextchar == ']':
         return values, end + 1
-    iterscan = JSONScanner.iterscan
+    _append = values.append
     while True:
         try:
-            value, end = iterscan(s, idx=end, context=context).next()
+            value, end = scan_once(s, end)
         except StopIteration:
             raise ValueError(errmsg("Expecting object", s, end))
-        values.append(value)
-        end = _w(s, end).end()
+        _append(value)
         nextchar = s[end:end + 1]
+        if nextchar in _ws:
+            end = _w(s, end + 1).end()
+            nextchar = s[end:end + 1]
         end += 1
         if nextchar == ']':
             break
-        if nextchar != ',':
+        elif nextchar != ',':
             raise ValueError(errmsg("Expecting , delimiter", s, end))
-        end = _w(s, end).end()
+
+        try:
+            if s[end] in _ws:
+                end += 1
+                if s[end] in _ws:
+                    end = _w(s, end + 1).end()
+        except IndexError:
+            pass
+
     return values, end
-pattern(r'\[')(JSONArray)
-
-
-ANYTHING = [
-    JSONObject,
-    JSONArray,
-    JSONString,
-    JSONConstant,
-    JSONNumber,
-]
-
-JSONScanner = Scanner(ANYTHING)
-
 
 class JSONDecoder(object):
     """Simple JSON <http://json.org> decoder
@@ -268,10 +285,8 @@
 
     It also understands ``NaN``, ``Infinity``, and ``-Infinity`` as
     their corresponding ``float`` values, which is outside the JSON spec.
-    """
 
-    _scanner = Scanner(ANYTHING)
-    __all__ = ['__init__', 'decode', 'raw_decode']
+    """
 
     def __init__(self, encoding=None, object_hook=None, parse_float=None,
             parse_int=None, parse_constant=None, strict=True):
@@ -282,8 +297,8 @@
         Note that currently only encodings that are a superset of ASCII work,
         strings of other encodings should be passed in as ``unicode``.
 
-        ``object_hook``, if specified, will be called with the result of
-        every JSON object decoded and its return value will be used in
+        ``object_hook``, if specified, will be called with the result
+        of every JSON object decoded and its return value will be used in
         place of the given ``dict``.  This can be used to provide custom
         deserializations (e.g. to support JSON-RPC class hinting).
 
@@ -298,21 +313,24 @@
         for JSON integers (e.g. float).
 
         ``parse_constant``, if specified, will be called with one of the
-        following strings: -Infinity, Infinity, NaN, null, true, false.
+        following strings: -Infinity, Infinity, NaN.
         This can be used to raise an exception if invalid JSON numbers
         are encountered.
 
         """
         self.encoding = encoding
         self.object_hook = object_hook
-        self.parse_float = parse_float
-        self.parse_int = parse_int
-        self.parse_constant = parse_constant
+        self.parse_float = parse_float or float
+        self.parse_int = parse_int or int
+        self.parse_constant = parse_constant or _CONSTANTS.__getitem__
         self.strict = strict
+        self.parse_object = JSONObject
+        self.parse_array = JSONArray
+        self.parse_string = scanstring
+        self.scan_once = make_scanner(self)
 
     def decode(self, s, _w=WHITESPACE.match):
-        """
-        Return the Python representation of ``s`` (a ``str`` or ``unicode``
+        """Return the Python representation of ``s`` (a ``str`` or ``unicode``
         instance containing a JSON document)
 
         """
@@ -322,18 +340,17 @@
             raise ValueError(errmsg("Extra data", s, end, len(s)))
         return obj
 
-    def raw_decode(self, s, **kw):
-        """Decode a JSON document from ``s`` (a ``str`` or ``unicode`` beginning
-        with a JSON document) and return a 2-tuple of the Python
+    def raw_decode(self, s, idx=0):
+        """Decode a JSON document from ``s`` (a ``str`` or ``unicode``
+        beginning with a JSON document) and return a 2-tuple of the Python
         representation and the index in ``s`` where the document ended.
 
         This can be used to decode a JSON document from a string that may
         have extraneous data at the end.
 
         """
-        kw.setdefault('context', self)
         try:
-            obj, end = self._scanner.iterscan(s, **kw).next()
+            obj, end = self.scan_once(s, idx)
         except StopIteration:
             raise ValueError("No JSON object could be decoded")
         return obj, end
diff --git a/Lib/json/encoder.py b/Lib/json/encoder.py
index b1dd570..027a1a6 100644
--- a/Lib/json/encoder.py
+++ b/Lib/json/encoder.py
@@ -1,15 +1,15 @@
 """Implementation of JSONEncoder
 """
-
 import re
-import math
 
 try:
     from _json import encode_basestring_ascii as c_encode_basestring_ascii
 except ImportError:
     c_encode_basestring_ascii = None
-
-__all__ = ['JSONEncoder']
+try:
+    from _json import make_encoder as c_make_encoder
+except ImportError:
+    c_make_encoder = None
 
 ESCAPE = re.compile(r'[\x00-\x1f\\"\b\f\n\r\t]')
 ESCAPE_ASCII = re.compile(r'([\\"]|[^\ -~])')
@@ -25,30 +25,12 @@
 }
 for i in range(0x20):
     ESCAPE_DCT.setdefault(chr(i), '\\u{0:04x}'.format(i))
+    #ESCAPE_DCT.setdefault(chr(i), '\\u%04x' % (i,))
 
+# Assume this produces an infinity on all machines (probably not guaranteed)
+INFINITY = float('1e66666')
 FLOAT_REPR = repr
 
-def floatstr(o, allow_nan=True):
-    # Check for specials.  Note that this type of test is processor- and/or
-    # platform-specific, so do tests which don't depend on the internals.
-
-    if math.isnan(o):
-        text = 'NaN'
-    elif math.isinf(o):
-        if math.copysign(1., o) == 1.:
-            text = 'Infinity'
-        else:
-            text = '-Infinity'
-    else:
-        return FLOAT_REPR(o)
-
-    if not allow_nan:
-        msg = "Out of range float values are not JSON compliant: " + repr(o)
-        raise ValueError(msg)
-
-    return text
-
-
 def encode_basestring(s):
     """Return a JSON representation of a Python string
 
@@ -59,6 +41,9 @@
 
 
 def py_encode_basestring_ascii(s):
+    """Return an ASCII-only JSON representation of a Python string
+
+    """
     if isinstance(s, str) and HAS_UTF8.search(s) is not None:
         s = s.decode('utf-8')
     def replace(match):
@@ -69,20 +54,19 @@
             n = ord(s)
             if n < 0x10000:
                 return '\\u{0:04x}'.format(n)
+                #return '\\u%04x' % (n,)
             else:
                 # surrogate pair
                 n -= 0x10000
                 s1 = 0xd800 | ((n >> 10) & 0x3ff)
                 s2 = 0xdc00 | (n & 0x3ff)
                 return '\\u{0:04x}\\u{1:04x}'.format(s1, s2)
+                #return '\\u%04x\\u%04x' % (s1, s2)
     return '"' + str(ESCAPE_ASCII.sub(replace, s)) + '"'
 
 
-if c_encode_basestring_ascii is not None:
-    encode_basestring_ascii = c_encode_basestring_ascii
-else:
-    encode_basestring_ascii = py_encode_basestring_ascii
-
+encode_basestring_ascii = (
+    c_encode_basestring_ascii or py_encode_basestring_ascii)
 
 class JSONEncoder(object):
     """Extensible JSON <http://json.org> encoder for Python data structures.
@@ -113,7 +97,6 @@
     implementation (to raise ``TypeError``).
 
     """
-    __all__ = ['__init__', 'default', 'encode', 'iterencode']
     item_separator = ', '
     key_separator = ': '
     def __init__(self, skipkeys=False, ensure_ascii=True,
@@ -121,25 +104,25 @@
             indent=None, separators=None, encoding='utf-8', default=None):
         """Constructor for JSONEncoder, with sensible defaults.
 
-        If skipkeys is False, then it is a TypeError to attempt
+        If skipkeys is false, then it is a TypeError to attempt
         encoding of keys that are not str, int, long, float or None.  If
         skipkeys is True, such items are simply skipped.
 
-        If ensure_ascii is True, the output is guaranteed to be str
+        If ensure_ascii is true, the output is guaranteed to be str
         objects with all incoming unicode characters escaped.  If
         ensure_ascii is false, the output will be unicode object.
 
-        If check_circular is True, then lists, dicts, and custom encoded
+        If check_circular is true, then lists, dicts, and custom encoded
         objects will be checked for circular references during encoding to
         prevent an infinite recursion (which would cause an OverflowError).
         Otherwise, no such check takes place.
 
-        If allow_nan is True, then NaN, Infinity, and -Infinity will be
+        If allow_nan is true, then NaN, Infinity, and -Infinity will be
         encoded as such.  This behavior is not JSON specification compliant,
         but is consistent with most JavaScript based encoders and decoders.
         Otherwise, it will be a ValueError to encode such floats.
 
-        If sort_keys is True, then the output of dictionaries will be
+        If sort_keys is true, then the output of dictionaries will be
         sorted by key; this is useful for regression tests to ensure
         that JSON serializations can be compared on a day-to-day basis.
 
@@ -161,175 +144,26 @@
         The default is UTF-8.
 
         """
+
         self.skipkeys = skipkeys
         self.ensure_ascii = ensure_ascii
         self.check_circular = check_circular
         self.allow_nan = allow_nan
         self.sort_keys = sort_keys
         self.indent = indent
-        self.current_indent_level = 0
         if separators is not None:
             self.item_separator, self.key_separator = separators
         if default is not None:
             self.default = default
         self.encoding = encoding
 
-    def _newline_indent(self):
-        return '\n' + (' ' * (self.indent * self.current_indent_level))
-
-    def _iterencode_list(self, lst, markers=None):
-        if not lst:
-            yield '[]'
-            return
-        if markers is not None:
-            markerid = id(lst)
-            if markerid in markers:
-                raise ValueError("Circular reference detected")
-            markers[markerid] = lst
-        yield '['
-        if self.indent is not None:
-            self.current_indent_level += 1
-            newline_indent = self._newline_indent()
-            separator = self.item_separator + newline_indent
-            yield newline_indent
-        else:
-            newline_indent = None
-            separator = self.item_separator
-        first = True
-        for value in lst:
-            if first:
-                first = False
-            else:
-                yield separator
-            for chunk in self._iterencode(value, markers):
-                yield chunk
-        if newline_indent is not None:
-            self.current_indent_level -= 1
-            yield self._newline_indent()
-        yield ']'
-        if markers is not None:
-            del markers[markerid]
-
-    def _iterencode_dict(self, dct, markers=None):
-        if not dct:
-            yield '{}'
-            return
-        if markers is not None:
-            markerid = id(dct)
-            if markerid in markers:
-                raise ValueError("Circular reference detected")
-            markers[markerid] = dct
-        yield '{'
-        key_separator = self.key_separator
-        if self.indent is not None:
-            self.current_indent_level += 1
-            newline_indent = self._newline_indent()
-            item_separator = self.item_separator + newline_indent
-            yield newline_indent
-        else:
-            newline_indent = None
-            item_separator = self.item_separator
-        first = True
-        if self.ensure_ascii:
-            encoder = encode_basestring_ascii
-        else:
-            encoder = encode_basestring
-        allow_nan = self.allow_nan
-        if self.sort_keys:
-            keys = dct.keys()
-            keys.sort()
-            items = [(k, dct[k]) for k in keys]
-        else:
-            items = dct.iteritems()
-        _encoding = self.encoding
-        _do_decode = (_encoding is not None
-            and not (_encoding == 'utf-8'))
-        for key, value in items:
-            if isinstance(key, str):
-                if _do_decode:
-                    key = key.decode(_encoding)
-            elif isinstance(key, basestring):
-                pass
-            # JavaScript is weakly typed for these, so it makes sense to
-            # also allow them.  Many encoders seem to do something like this.
-            elif isinstance(key, float):
-                key = floatstr(key, allow_nan)
-            elif isinstance(key, (int, long)):
-                key = str(key)
-            elif key is True:
-                key = 'true'
-            elif key is False:
-                key = 'false'
-            elif key is None:
-                key = 'null'
-            elif self.skipkeys:
-                continue
-            else:
-                raise TypeError("key {0!r} is not a string".format(key))
-            if first:
-                first = False
-            else:
-                yield item_separator
-            yield encoder(key)
-            yield key_separator
-            for chunk in self._iterencode(value, markers):
-                yield chunk
-        if newline_indent is not None:
-            self.current_indent_level -= 1
-            yield self._newline_indent()
-        yield '}'
-        if markers is not None:
-            del markers[markerid]
-
-    def _iterencode(self, o, markers=None):
-        if isinstance(o, basestring):
-            if self.ensure_ascii:
-                encoder = encode_basestring_ascii
-            else:
-                encoder = encode_basestring
-            _encoding = self.encoding
-            if (_encoding is not None and isinstance(o, str)
-                    and not (_encoding == 'utf-8')):
-                o = o.decode(_encoding)
-            yield encoder(o)
-        elif o is None:
-            yield 'null'
-        elif o is True:
-            yield 'true'
-        elif o is False:
-            yield 'false'
-        elif isinstance(o, (int, long)):
-            yield str(o)
-        elif isinstance(o, float):
-            yield floatstr(o, self.allow_nan)
-        elif isinstance(o, (list, tuple)):
-            for chunk in self._iterencode_list(o, markers):
-                yield chunk
-        elif isinstance(o, dict):
-            for chunk in self._iterencode_dict(o, markers):
-                yield chunk
-        else:
-            if markers is not None:
-                markerid = id(o)
-                if markerid in markers:
-                    raise ValueError("Circular reference detected")
-                markers[markerid] = o
-            for chunk in self._iterencode_default(o, markers):
-                yield chunk
-            if markers is not None:
-                del markers[markerid]
-
-    def _iterencode_default(self, o, markers=None):
-        newobj = self.default(o)
-        return self._iterencode(newobj, markers)
-
     def default(self, o):
-        """Implement this method in a subclass such that it returns a serializable
-        object for ``o``, or calls the base implementation (to raise a
-        ``TypeError``).
+        """Implement this method in a subclass such that it returns
+        a serializable object for ``o``, or calls the base implementation
+        (to raise a ``TypeError``).
 
-        For example, to support arbitrary iterators, you could implement
-        default like this::
+        For example, to support arbitrary iterators, you could
+        implement default like this::
 
             def default(self, o):
                 try:
@@ -364,12 +198,14 @@
         # This doesn't pass the iterator directly to ''.join() because the
         # exceptions aren't as detailed.  The list call should be roughly
         # equivalent to the PySequence_Fast that ''.join() would do.
-        chunks = list(self.iterencode(o))
+        chunks = self.iterencode(o, _one_shot=True)
+        if not isinstance(chunks, (list, tuple)):
+            chunks = list(chunks)
         return ''.join(chunks)
 
-    def iterencode(self, o):
-        """Encode the given object and yield each string representation as
-        available.
+    def iterencode(self, o, _one_shot=False):
+        """Encode the given object and yield each string
+        representation as available.
 
         For example::
 
@@ -381,4 +217,229 @@
             markers = {}
         else:
             markers = None
-        return self._iterencode(o, markers)
+        if self.ensure_ascii:
+            _encoder = encode_basestring_ascii
+        else:
+            _encoder = encode_basestring
+        if self.encoding != 'utf-8':
+            def _encoder(o, _orig_encoder=_encoder, _encoding=self.encoding):
+                if isinstance(o, str):
+                    o = o.decode(_encoding)
+                return _orig_encoder(o)
+
+        def floatstr(o, allow_nan=self.allow_nan,
+                _repr=FLOAT_REPR, _inf=INFINITY, _neginf=-INFINITY):
+            # Check for specials.  Note that this type of test is processor
+            # and/or platform-specific, so do tests which don't depend on the
+            # internals.
+
+            if o != o:
+                text = 'NaN'
+            elif o == _inf:
+                text = 'Infinity'
+            elif o == _neginf:
+                text = '-Infinity'
+            else:
+                return _repr(o)
+
+            if not allow_nan:
+                raise ValueError(
+                    "Out of range float values are not JSON compliant: " +
+                    repr(o))
+
+            return text
+
+
+        if (_one_shot and c_make_encoder is not None
+                and not self.indent and not self.sort_keys):
+            _iterencode = c_make_encoder(
+                markers, self.default, _encoder, self.indent,
+                self.key_separator, self.item_separator, self.sort_keys,
+                self.skipkeys, self.allow_nan)
+        else:
+            _iterencode = _make_iterencode(
+                markers, self.default, _encoder, self.indent, floatstr,
+                self.key_separator, self.item_separator, self.sort_keys,
+                self.skipkeys, _one_shot)
+        return _iterencode(o, 0)
+
+def _make_iterencode(markers, _default, _encoder, _indent, _floatstr,
+        _key_separator, _item_separator, _sort_keys, _skipkeys, _one_shot,
+        ## HACK: hand-optimized bytecode; turn globals into locals
+        False=False,
+        True=True,
+        ValueError=ValueError,
+        basestring=basestring,
+        dict=dict,
+        float=float,
+        id=id,
+        int=int,
+        isinstance=isinstance,
+        list=list,
+        long=long,
+        str=str,
+        tuple=tuple,
+    ):
+
+    def _iterencode_list(lst, _current_indent_level):
+        if not lst:
+            yield '[]'
+            return
+        if markers is not None:
+            markerid = id(lst)
+            if markerid in markers:
+                raise ValueError("Circular reference detected")
+            markers[markerid] = lst
+        buf = '['
+        if _indent is not None:
+            _current_indent_level += 1
+            newline_indent = '\n' + (' ' * (_indent * _current_indent_level))
+            separator = _item_separator + newline_indent
+            buf += newline_indent
+        else:
+            newline_indent = None
+            separator = _item_separator
+        first = True
+        for value in lst:
+            if first:
+                first = False
+            else:
+                buf = separator
+            if isinstance(value, basestring):
+                yield buf + _encoder(value)
+            elif value is None:
+                yield buf + 'null'
+            elif value is True:
+                yield buf + 'true'
+            elif value is False:
+                yield buf + 'false'
+            elif isinstance(value, (int, long)):
+                yield buf + str(value)
+            elif isinstance(value, float):
+                yield buf + _floatstr(value)
+            else:
+                yield buf
+                if isinstance(value, (list, tuple)):
+                    chunks = _iterencode_list(value, _current_indent_level)
+                elif isinstance(value, dict):
+                    chunks = _iterencode_dict(value, _current_indent_level)
+                else:
+                    chunks = _iterencode(value, _current_indent_level)
+                for chunk in chunks:
+                    yield chunk
+        if newline_indent is not None:
+            _current_indent_level -= 1
+            yield '\n' + (' ' * (_indent * _current_indent_level))
+        yield ']'
+        if markers is not None:
+            del markers[markerid]
+
+    def _iterencode_dict(dct, _current_indent_level):
+        if not dct:
+            yield '{}'
+            return
+        if markers is not None:
+            markerid = id(dct)
+            if markerid in markers:
+                raise ValueError("Circular reference detected")
+            markers[markerid] = dct
+        yield '{'
+        if _indent is not None:
+            _current_indent_level += 1
+            newline_indent = '\n' + (' ' * (_indent * _current_indent_level))
+            item_separator = _item_separator + newline_indent
+            yield newline_indent
+        else:
+            newline_indent = None
+            item_separator = _item_separator
+        first = True
+        if _sort_keys:
+            items = dct.items()
+            items.sort(key=lambda kv: kv[0])
+        else:
+            items = dct.iteritems()
+        for key, value in items:
+            if isinstance(key, basestring):
+                pass
+            # JavaScript is weakly typed for these, so it makes sense to
+            # also allow them.  Many encoders seem to do something like this.
+            elif isinstance(key, float):
+                key = _floatstr(key)
+            elif key is True:
+                key = 'true'
+            elif key is False:
+                key = 'false'
+            elif key is None:
+                key = 'null'
+            elif isinstance(key, (int, long)):
+                key = str(key)
+            elif _skipkeys:
+                continue
+            else:
+                raise TypeError("key " + repr(key) + " is not a string")
+            if first:
+                first = False
+            else:
+                yield item_separator
+            yield _encoder(key)
+            yield _key_separator
+            if isinstance(value, basestring):
+                yield _encoder(value)
+            elif value is None:
+                yield 'null'
+            elif value is True:
+                yield 'true'
+            elif value is False:
+                yield 'false'
+            elif isinstance(value, (int, long)):
+                yield str(value)
+            elif isinstance(value, float):
+                yield _floatstr(value)
+            else:
+                if isinstance(value, (list, tuple)):
+                    chunks = _iterencode_list(value, _current_indent_level)
+                elif isinstance(value, dict):
+                    chunks = _iterencode_dict(value, _current_indent_level)
+                else:
+                    chunks = _iterencode(value, _current_indent_level)
+                for chunk in chunks:
+                    yield chunk
+        if newline_indent is not None:
+            _current_indent_level -= 1
+            yield '\n' + (' ' * (_indent * _current_indent_level))
+        yield '}'
+        if markers is not None:
+            del markers[markerid]
+
+    def _iterencode(o, _current_indent_level):
+        if isinstance(o, basestring):
+            yield _encoder(o)
+        elif o is None:
+            yield 'null'
+        elif o is True:
+            yield 'true'
+        elif o is False:
+            yield 'false'
+        elif isinstance(o, (int, long)):
+            yield str(o)
+        elif isinstance(o, float):
+            yield _floatstr(o)
+        elif isinstance(o, (list, tuple)):
+            for chunk in _iterencode_list(o, _current_indent_level):
+                yield chunk
+        elif isinstance(o, dict):
+            for chunk in _iterencode_dict(o, _current_indent_level):
+                yield chunk
+        else:
+            if markers is not None:
+                markerid = id(o)
+                if markerid in markers:
+                    raise ValueError("Circular reference detected")
+                markers[markerid] = o
+            o = _default(o)
+            for chunk in _iterencode(o, _current_indent_level):
+                yield chunk
+            if markers is not None:
+                del markers[markerid]
+
+    return _iterencode
diff --git a/Lib/json/scanner.py b/Lib/json/scanner.py
index 4b065ab..00c5470 100644
--- a/Lib/json/scanner.py
+++ b/Lib/json/scanner.py
@@ -1,69 +1,66 @@
-"""Iterator based sre token scanner
-
+"""JSON token scanner
 """
-
 import re
-import sre_parse
-import sre_compile
-import sre_constants
+try:
+    from _json import make_scanner as c_make_scanner
+except ImportError:
+    c_make_scanner = None
 
-from re import VERBOSE, MULTILINE, DOTALL
-from sre_constants import BRANCH, SUBPATTERN
+__all__ = ['make_scanner']
 
-__all__ = ['Scanner', 'pattern']
+NUMBER_RE = re.compile(
+    r'(-?(?:0|[1-9]\d*))(\.\d+)?([eE][-+]?\d+)?',
+    (re.VERBOSE | re.MULTILINE | re.DOTALL))
 
-FLAGS = (VERBOSE | MULTILINE | DOTALL)
+def py_make_scanner(context):
+    parse_object = context.parse_object
+    parse_array = context.parse_array
+    parse_string = context.parse_string
+    match_number = NUMBER_RE.match
+    encoding = context.encoding
+    strict = context.strict
+    parse_float = context.parse_float
+    parse_int = context.parse_int
+    parse_constant = context.parse_constant
+    object_hook = context.object_hook
 
-class Scanner(object):
-    def __init__(self, lexicon, flags=FLAGS):
-        self.actions = [None]
-        # Combine phrases into a compound pattern
-        s = sre_parse.Pattern()
-        s.flags = flags
-        p = []
-        for idx, token in enumerate(lexicon):
-            phrase = token.pattern
-            try:
-                subpattern = sre_parse.SubPattern(s,
-                    [(SUBPATTERN, (idx + 1, sre_parse.parse(phrase, flags)))])
-            except sre_constants.error:
-                raise
-            p.append(subpattern)
-            self.actions.append(token)
+    def _scan_once(string, idx):
+        try:
+            nextchar = string[idx]
+        except IndexError:
+            raise StopIteration
 
-        s.groups = len(p) + 1 # NOTE(guido): Added to make SRE validation work
-        p = sre_parse.SubPattern(s, [(BRANCH, (None, p))])
-        self.scanner = sre_compile.compile(p)
+        if nextchar == '"':
+            return parse_string(string, idx + 1, encoding, strict)
+        elif nextchar == '{':
+            return parse_object((string, idx + 1), encoding, strict,
+                _scan_once, object_hook)
+        elif nextchar == '[':
+            return parse_array((string, idx + 1), _scan_once)
+        elif nextchar == 'n' and string[idx:idx + 4] == 'null':
+            return None, idx + 4
+        elif nextchar == 't' and string[idx:idx + 4] == 'true':
+            return True, idx + 4
+        elif nextchar == 'f' and string[idx:idx + 5] == 'false':
+            return False, idx + 5
 
-    def iterscan(self, string, idx=0, context=None):
-        """Yield match, end_idx for each match
+        m = match_number(string, idx)
+        if m is not None:
+            integer, frac, exp = m.groups()
+            if frac or exp:
+                res = parse_float(integer + (frac or '') + (exp or ''))
+            else:
+                res = parse_int(integer)
+            return res, m.end()
+        elif nextchar == 'N' and string[idx:idx + 3] == 'NaN':
+            return parse_constant('NaN'), idx + 3
+        elif nextchar == 'I' and string[idx:idx + 8] == 'Infinity':
+            return parse_constant('Infinity'), idx + 8
+        elif nextchar == '-' and string[idx:idx + 9] == '-Infinity':
+            return parse_constant('-Infinity'), idx + 9
+        else:
+            raise StopIteration
 
-        """
-        match = self.scanner.scanner(string, idx).match
-        actions = self.actions
-        lastend = idx
-        end = len(string)
-        while True:
-            m = match()
-            if m is None:
-                break
-            matchbegin, matchend = m.span()
-            if lastend == matchend:
-                break
-            action = actions[m.lastindex]
-            if action is not None:
-                rval, next_pos = action(m, context)
-                if next_pos is not None and next_pos != matchend:
-                    # "fast forward" the scanner
-                    matchend = next_pos
-                    match = self.scanner.scanner(string, matchend).match
-                yield rval, matchend
-            lastend = matchend
+    return _scan_once
 
-
-def pattern(pattern, flags=FLAGS):
-    def decorator(fn):
-        fn.pattern = pattern
-        fn.regex = re.compile(pattern, flags)
-        return fn
-    return decorator
+make_scanner = c_make_scanner or py_make_scanner
diff --git a/Lib/json/tests/test_check_circular.py b/Lib/json/tests/test_check_circular.py
new file mode 100644
index 0000000..3c3f96a
--- /dev/null
+++ b/Lib/json/tests/test_check_circular.py
@@ -0,0 +1,30 @@
+from unittest import TestCase
+import json
+
+def default_iterable(obj):
+    return list(obj)
+
+class TestCheckCircular(TestCase):
+    def test_circular_dict(self):
+        dct = {}
+        dct['a'] = dct
+        self.assertRaises(ValueError, json.dumps, dct)
+
+    def test_circular_list(self):
+        lst = []
+        lst.append(lst)
+        self.assertRaises(ValueError, json.dumps, lst)
+
+    def test_circular_composite(self):
+        dct2 = {}
+        dct2['a'] = []
+        dct2['a'].append(dct2)
+        self.assertRaises(ValueError, json.dumps, dct2)
+
+    def test_circular_default(self):
+        json.dumps([set()], default=default_iterable)
+        self.assertRaises(TypeError, json.dumps, [set()])
+
+    def test_circular_off_default(self):
+        json.dumps([set()], default=default_iterable, check_circular=False)
+        self.assertRaises(TypeError, json.dumps, [set()], check_circular=False)
diff --git a/Lib/json/tests/test_decode.py b/Lib/json/tests/test_decode.py
index 609f622..484cc94 100644
--- a/Lib/json/tests/test_decode.py
+++ b/Lib/json/tests/test_decode.py
@@ -13,3 +13,10 @@
         rval = json.loads('1', parse_int=float)
         self.assert_(isinstance(rval, float))
         self.assertEquals(rval, 1.0)
+
+    def test_decoder_optimizations(self):
+        # Several optimizations were made that skip over calls to
+        # the whitespace regex, so this test is designed to try and
+        # exercise the uncommon cases. The array cases are already covered.
+        rval = json.loads('{   "key"    :    "value"    ,  "k":"v"    }')
+        self.assertEquals(rval, {"key":"value", "k":"v"})
diff --git a/Lib/json/tests/test_dump.py b/Lib/json/tests/test_dump.py
index d288c0d..9fa0ba8 100644
--- a/Lib/json/tests/test_dump.py
+++ b/Lib/json/tests/test_dump.py
@@ -11,3 +11,11 @@
 
     def test_dumps(self):
         self.assertEquals(json.dumps({}), '{}')
+
+    def test_encode_truefalse(self):
+        self.assertEquals(json.dumps(
+                 {True: False, False: True}, sort_keys=True),
+                 '{"false": true, "true": false}')
+        self.assertEquals(json.dumps(
+                {2: 3.0, 4.0: 5L, False: 1, 6L: True, "7": 0}, sort_keys=True),
+                '{"false": 1, "2": 3.0, "4.0": 5, "6": true, "7": 0}')
diff --git a/Lib/json/tests/test_encode_basestring_ascii.py b/Lib/json/tests/test_encode_basestring_ascii.py
index 352423e..62abe5b 100644
--- a/Lib/json/tests/test_encode_basestring_ascii.py
+++ b/Lib/json/tests/test_encode_basestring_ascii.py
@@ -26,10 +26,14 @@
         self._test_encode_basestring_ascii(json.encoder.py_encode_basestring_ascii)
 
     def test_c_encode_basestring_ascii(self):
+        if not json.encoder.c_encode_basestring_ascii:
+            return
         self._test_encode_basestring_ascii(json.encoder.c_encode_basestring_ascii)
 
     def _test_encode_basestring_ascii(self, encode_basestring_ascii):
         fname = encode_basestring_ascii.__name__
         for input_string, expect in CASES:
             result = encode_basestring_ascii(input_string)
-            self.assertEquals(result, expect)
+            self.assertEquals(result, expect,
+                '{0!r} != {1!r} for {2}({3!r})'.format(
+                    result, expect, fname, input_string))
diff --git a/Lib/json/tests/test_fail.py b/Lib/json/tests/test_fail.py
index ee31bfa..72df517 100644
--- a/Lib/json/tests/test_fail.py
+++ b/Lib/json/tests/test_fail.py
@@ -73,4 +73,4 @@
             except ValueError:
                 pass
             else:
-                self.fail("Expected failure for fail%d.json: %r" % (idx, doc))
+                self.fail("Expected failure for fail{0}.json: {1!r}".format(idx, doc))
diff --git a/Lib/json/tests/test_float.py b/Lib/json/tests/test_float.py
index 9df6d1e..20d41d9 100644
--- a/Lib/json/tests/test_float.py
+++ b/Lib/json/tests/test_float.py
@@ -5,5 +5,11 @@
 
 class TestFloat(TestCase):
     def test_floats(self):
-        for num in [1617161771.7650001, math.pi, math.pi**100, math.pi**-100]:
+        for num in [1617161771.7650001, math.pi, math.pi**100, math.pi**-100, 3.1]:
             self.assertEquals(float(json.dumps(num)), num)
+            self.assertEquals(json.loads(json.dumps(num)), num)
+
+    def test_ints(self):
+        for num in [1, 1L, 1<<32, 1<<64]:
+            self.assertEquals(json.dumps(num), str(num))
+            self.assertEquals(int(json.dumps(num)), num)
diff --git a/Lib/json/tests/test_unicode.py b/Lib/json/tests/test_unicode.py
index 3ac4541..0b47cbb 100644
--- a/Lib/json/tests/test_unicode.py
+++ b/Lib/json/tests/test_unicode.py
@@ -51,5 +51,14 @@
     def test_unicode_decode(self):
         for i in range(0, 0xd7ff):
             u = unichr(i)
-            js = '"\\u{0:04x}"'.format(i)
-            self.assertEquals(json.loads(js), u)
+            s = '"\\u{0:04x}"'.format(i)
+            self.assertEquals(json.loads(s), u)
+
+    def test_default_encoding(self):
+        self.assertEquals(json.loads(u'{"a": "\xe9"}'.encode('utf-8')),
+            {'a': u'\xe9'})
+
+    def test_unicode_preservation(self):
+        self.assertEquals(type(json.loads(u'""')), unicode)
+        self.assertEquals(type(json.loads(u'"a"')), unicode)
+        self.assertEquals(type(json.loads(u'["a"]')[0]), unicode)
diff --git a/Lib/json/tool.py b/Lib/json/tool.py
index daedbb5..c37bb77 100644
--- a/Lib/json/tool.py
+++ b/Lib/json/tool.py
@@ -2,11 +2,11 @@
 
 Usage::
 
-    $ echo '{"json":"obj"}' | python -mjson.tool
+    $ echo '{"json":"obj"}' | python -m json.tool
     {
         "json": "obj"
     }
-    $ echo '{ 1.2:3.4}' | python -mjson.tool
+    $ echo '{ 1.2:3.4}' | python -m json.tool
     Expecting property name: line 1 column 2 (char 2)
 
 """
@@ -24,7 +24,7 @@
         infile = open(sys.argv[1], 'rb')
         outfile = open(sys.argv[2], 'wb')
     else:
-        raise SystemExit("{0} [infile [outfile]]".format(sys.argv[0]))
+        raise SystemExit(sys.argv[0] + " [infile [outfile]]")
     try:
         obj = json.load(infile)
     except ValueError, e: