Upgraded included simplejson to 2.0.7.

Also changed importing logic to prefer a system-installed version of
simplejson (unless it's an earlier version that does not contian the C
speedups), then the json module from Python 2.6, then the version
shipped with Django.

Fixed #9266.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@9707 bcc190cf-cafb-0310-a4f2-bffc1f526a37

1 files changed, 247 insertions, 280 deletions

diff --git a/django/utils/simplejson/__init__.py b/django/utils/simplejson/__init__.py
index 130940f358..2be6c3909c 100644
--- a/django/utils/simplejson/__init__.py
+++ b/django/utils/simplejson/__init__.py
@@ -1,376 +1,343 @@
-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.
 
-simplejson exposes an API familiar to uses of the standard library
-marshal and pickle modules.
+:mod:`simplejson` 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::
-    
-    >>> import simplejson
-    >>> simplejson.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}])
+
+    >>> import simplejson as json
+    >>> json.dumps(['foo', {'bar': ('baz', None, 1.0, 2)}])
     '["foo", {"bar": ["baz", null, 1.0, 2]}]'
-    >>> print simplejson.dumps("\"foo\bar")
+    >>> print json.dumps("\"foo\bar")
     "\"foo\bar"
-    >>> print simplejson.dumps(u'\u1234')
+    >>> print json.dumps(u'\u1234')
     "\u1234"
-    >>> print simplejson.dumps('\\')
+    >>> print json.dumps('\\')
     "\\"
-    >>> print simplejson.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True)
+    >>> print json.dumps({"c": 0, "b": 0, "a": 0}, sort_keys=True)
     {"a": 0, "b": 0, "c": 0}
     >>> from StringIO import StringIO
     >>> io = StringIO()
-    >>> simplejson.dump(['streaming API'], io)
+    >>> json.dump(['streaming API'], io)
     >>> io.getvalue()
     '["streaming API"]'
 
 Compact encoding::
 
-    >>> import simplejson
-    >>> simplejson.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))
+    >>> import simplejson as json
+    >>> json.dumps([1,2,3,{'4': 5, '6': 7}], separators=(',',':'))
     '[1,2,3,{"4":5,"6":7}]'
 
 Pretty printing::
 
-    >>> import simplejson
-    >>> print simplejson.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4)
+    >>> import simplejson as json
+    >>> s = json.dumps({'4': 5, '6': 7}, sort_keys=True, indent=4)
+    >>> print '\n'.join([l.rstrip() for l in  s.splitlines()])
     {
-        "4": 5, 
+        "4": 5,
         "6": 7
     }
 
 Decoding JSON::
-    
-    >>> import simplejson
-    >>> simplejson.loads('["foo", {"bar":["baz", null, 1.0, 2]}]')
-    [u'foo', {u'bar': [u'baz', None, 1.0, 2]}]
-    >>> simplejson.loads('"\\"foo\\bar"')
-    u'"foo\x08ar'
+
+    >>> import simplejson as json
+    >>> 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"]')
-    >>> simplejson.load(io)
-    [u'streaming API']
+    >>> json.load(io)[0] == 'streaming API'
+    True
 
 Specializing JSON object decoding::
 
-    >>> import simplejson
+    >>> import simplejson as json
     >>> def as_complex(dct):
     ...     if '__complex__' in dct:
     ...         return complex(dct['real'], dct['imag'])
     ...     return dct
-    ... 
-    >>> simplejson.loads('{"__complex__": true, "real": 1, "imag": 2}',
+    ...
+    >>> json.loads('{"__complex__": true, "real": 1, "imag": 2}',
     ...     object_hook=as_complex)
     (1+2j)
     >>> import decimal
-    >>> simplejson.loads('1.1', parse_float=decimal.Decimal)
-    Decimal("1.1")
+    >>> json.loads('1.1', parse_float=decimal.Decimal) == decimal.Decimal('1.1')
+    True
 
-Extending JSONEncoder::
-    
-    >>> import simplejson
-    >>> class ComplexEncoder(simplejson.JSONEncoder):
-    ...     def default(self, obj):
-    ...         if isinstance(obj, complex):
-    ...             return [obj.real, obj.imag]
-    ...         return simplejson.JSONEncoder.default(self, obj)
-    ... 
-    >>> dumps(2 + 1j, cls=ComplexEncoder)
+Specializing JSON object encoding::
+
+    >>> import simplejson as json
+    >>> def encode_complex(obj):
+    ...     if isinstance(obj, complex):
+    ...         return [obj.real, obj.imag]
+    ...     raise TypeError("%r is not JSON serializable" % (o,))
+    ...
+    >>> json.dumps(2 + 1j, default=encode_complex)
+    '[2.0, 1.0]'
+    >>> json.JSONEncoder(default=encode_complex).encode(2 + 1j)
     '[2.0, 1.0]'
-    >>> ComplexEncoder().encode(2 + 1j)
+    >>> ''.join(json.JSONEncoder(default=encode_complex).iterencode(2 + 1j))
     '[2.0, 1.0]'
-    >>> list(ComplexEncoder().iterencode(2 + 1j))
-    ['[', '2.0', ', ', '1.0', ']']
-    
 
-Using simplejson from the shell to validate and
-pretty-print::
-    
+
+Using simplejson.tool from the shell to validate and pretty-print::
+
     $ echo '{"json":"obj"}' | python -msimplejson.tool
     {
         "json": "obj"
     }
     $ echo '{ 1.2:3.4}' | python -msimplejson.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__ = '1.9.2'
-__all__ = [
-    'dump', 'dumps', 'load', 'loads',
-    'JSONDecoder', 'JSONEncoder',
-]
-
-if __name__ == '__main__':
-    import warnings
-    warnings.warn('python -msimplejson is deprecated, use python -msiplejson.tool', DeprecationWarning)
-    from django.utils.simplejson.decoder import JSONDecoder
-    from django.utils.simplejson.encoder import JSONEncoder
-else:
-    from decoder import JSONDecoder
-    from encoder import JSONEncoder
 
-_default_encoder = JSONEncoder(
-    skipkeys=False,
-    ensure_ascii=True,
-    check_circular=True,
-    allow_nan=True,
-    indent=None,
-    separators=None,
-    encoding='utf-8',
-    default=None,
-)
+# Django modification: try to use the system version first, providing it's
+# either of a later version of has the C speedups in place. Otherwise, fall
+# back to our local copy.
 
-def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
-        allow_nan=True, cls=None, indent=None, separators=None,
-        encoding='utf-8', default=None, **kw):
-    """
-    Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
-    ``.write()``-supporting file-like object).
+__version__ = '2.0.7'
 
-    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``.
+use_system_version = False
+try:
+    # The system-installed version has priority providing it is either not an
+    # earlier version or it contains the C speedups.
+    import simplejson
+    if (simplejson.__version__.split('.') >= __version__.split('.') or
+            hasattr(simplejson, '_speedups')):
+        from simplejson import *
+        use_system_version = True
+except ImportError:
+    pass
 
-    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 not use_system_version:
+    try:
+        from json import *      # Python 2.6 preferred over local copy.
+        use_system_version = True
+    except ImportError:
+        pass
 
-    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 all else fails, we have a bundled version that can be used.
+if not use_system_version:
+    __all__ = [
+        'dump', 'dumps', 'load', 'loads',
+        'JSONDecoder', 'JSONEncoder',
+    ]
 
-    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.
+    from django.utils.simplejson.decoder import JSONDecoder
+    from django.utils.simplejson.encoder import JSONEncoder
 
-    If ``separators`` is an ``(item_separator, dict_separator)`` tuple
-    then it will be used instead of the default ``(', ', ': ')`` separators.
-    ``(',', ':')`` is the most compact JSON representation.
+    _default_encoder = JSONEncoder(
+        skipkeys=False,
+        ensure_ascii=True,
+        check_circular=True,
+        allow_nan=True,
+        indent=None,
+        separators=None,
+        encoding='utf-8',
+        default=None,
+    )
 
-    ``encoding`` is the character encoding for str instances, default is UTF-8.
+    def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True,
+            allow_nan=True, cls=None, indent=None, separators=None,
+            encoding='utf-8', default=None, **kw):
+        """Serialize ``obj`` as a JSON formatted stream to ``fp`` (a
+        ``.write()``-supporting file-like object).
 
-    ``default(obj)`` is a function that should return a serializable version
-    of obj or raise TypeError. The default simply raises TypeError.
+        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``.
 
-    To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
-    ``.default()`` method to serialize additional types), specify it with
-    the ``cls`` kwarg.
-    """
-    # cached encoder
-    if (skipkeys is False and ensure_ascii is True and
-        check_circular is True and allow_nan is True 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)
-    else:
-        if cls is None:
-            cls = JSONEncoder
-        iterable = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii,
-            check_circular=check_circular, allow_nan=allow_nan, indent=indent,
-            separators=separators, encoding=encoding,
-            default=default, **kw).iterencode(obj)
-    # could accelerate with writelines in some versions of Python, at
-    # a debuggability cost
-    for chunk in iterable:
-        fp.write(chunk)
+        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
+        for container types will be skipped and a circular reference will
+        result in an ``OverflowError`` (or worse).
 
-def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
-        allow_nan=True, cls=None, indent=None, separators=None,
-        encoding='utf-8', default=None, **kw):
-    """
-    Serialize ``obj`` to a JSON formatted ``str``.
+        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 ``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 ``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 ``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 ``separators`` is an ``(item_separator, dict_separator)`` tuple
+        then it will be used instead of the default ``(', ', ': ')`` separators.
+        ``(',', ':')`` is the most compact JSON representation.
 
-    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).
+        ``encoding`` is the character encoding for str instances, default is UTF-8.
 
-    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``).
+        ``default(obj)`` is a function that should return a serializable version
+        of obj or raise TypeError. The default simply raises TypeError.
 
-    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.
+        To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
+        ``.default()`` method to serialize additional types), specify it with
+        the ``cls`` kwarg.
 
-    If ``separators`` is an ``(item_separator, dict_separator)`` tuple
-    then it will be used instead of the default ``(', ', ': ')`` separators.
-    ``(',', ':')`` is the most compact JSON representation.
+        """
+        # cached encoder
+        if (skipkeys is False and ensure_ascii is True and
+            check_circular is True and allow_nan is True 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)
+        else:
+            if cls is None:
+                cls = JSONEncoder
+            iterable = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii,
+                check_circular=check_circular, allow_nan=allow_nan, indent=indent,
+                separators=separators, encoding=encoding,
+                default=default, **kw).iterencode(obj)
+        # could accelerate with writelines in some versions of Python, at
+        # a debuggability cost
+        for chunk in iterable:
+            fp.write(chunk)
 
-    ``encoding`` is the character encoding for str instances, default is UTF-8.
 
-    ``default(obj)`` is a function that should return a serializable version
-    of obj or raise TypeError. The default simply raises TypeError.
+    def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True,
+            allow_nan=True, cls=None, indent=None, separators=None,
+            encoding='utf-8', default=None, **kw):
+        """Serialize ``obj`` to a JSON formatted ``str``.
 
-    To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
-    ``.default()`` method to serialize additional types), specify it with
-    the ``cls`` kwarg.
-    """
-    # cached encoder
-    if (skipkeys is False and ensure_ascii is True and
-        check_circular is True and allow_nan is True 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)
-    if cls is None:
-        cls = JSONEncoder
-    return cls(
-        skipkeys=skipkeys, ensure_ascii=ensure_ascii,
-        check_circular=check_circular, allow_nan=allow_nan, indent=indent,
-        separators=separators, encoding=encoding, default=default,
-        **kw).encode(obj)
+        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 return value will be a
+        ``unicode`` instance subject to normal Python ``str`` to ``unicode``
+        coercion rules instead of being escaped to an ASCII ``str``.
 
-_default_decoder = JSONDecoder(encoding=None, object_hook=None)
+        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
+        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``).
 
-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.
+        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 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
-    be specified. Encodings that are not ASCII based (such as UCS-2) are
-    not allowed, and should be wrapped with
-    ``codecs.getreader(fp)(encoding)``, or simply decoded to a ``unicode``
-    object and passed to ``loads()``
+        If ``separators`` is an ``(item_separator, dict_separator)`` tuple
+        then it will be used instead of the default ``(', ', ': ')`` separators.
+        ``(',', ':')`` is the most compact JSON representation.
 
-    ``object_hook`` is an optional function that will be called with the
-    result of any object literal decode (a ``dict``). The return value of
-    ``object_hook`` will be used instead of the ``dict``. This feature
-    can be used to implement custom decoders (e.g. JSON-RPC class hinting).
-    
-    To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
-    kwarg.
-    """
-    return loads(fp.read(),
-        encoding=encoding, cls=cls, object_hook=object_hook,
-        parse_float=parse_float, parse_int=parse_int,
-        parse_constant=parse_constant, **kw)
+        ``encoding`` is the character encoding for str instances, default is UTF-8.
 
+        ``default(obj)`` is a function that should return a serializable version
+        of obj or raise TypeError. The default simply raises TypeError.
 
-def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None,
-        parse_int=None, parse_constant=None, **kw):
-    """
-    Deserialize ``s`` (a ``str`` or ``unicode`` instance containing a JSON
-    document) to a Python object.
+        To use a custom ``JSONEncoder`` subclass (e.g. one that overrides the
+        ``.default()`` method to serialize additional types), specify it with
+        the ``cls`` kwarg.
 
-    If ``s`` is a ``str`` instance and is encoded with an ASCII based encoding
-    other than utf-8 (e.g. latin-1) then an appropriate ``encoding`` name
-    must be specified. Encodings that are not ASCII based (such as UCS-2)
-    are not allowed and should be decoded to ``unicode`` first.
+        """
+        # cached encoder
+        if (skipkeys is False and ensure_ascii is True and
+            check_circular is True and allow_nan is True 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)
+        if cls is None:
+            cls = JSONEncoder
+        return cls(
+            skipkeys=skipkeys, ensure_ascii=ensure_ascii,
+            check_circular=check_circular, allow_nan=allow_nan, indent=indent,
+            separators=separators, encoding=encoding, default=default,
+            **kw).encode(obj)
 
-    ``object_hook`` is an optional function that will be called with the
-    result of any object literal decode (a ``dict``). The return value of
-    ``object_hook`` will be used instead of the ``dict``. This feature
-    can be used to implement custom decoders (e.g. JSON-RPC class hinting).
 
-    ``parse_float``, if specified, will be called with the string
-    of every JSON float to be decoded. By default this is equivalent to
-    float(num_str). This can be used to use another datatype or parser
-    for JSON floats (e.g. decimal.Decimal).
+    _default_decoder = JSONDecoder(encoding=None, object_hook=None)
 
-    ``parse_int``, if specified, will be called with the string
-    of every JSON int to be decoded. By default this is equivalent to
-    int(num_str). This can be used to use another datatype or parser
-    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.
-    This can be used to raise an exception if invalid JSON numbers
-    are encountered.
+    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.
 
-    To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
-    kwarg.
-    """
-    if (cls is None and encoding is None and object_hook is None and
-            parse_int is None and parse_float is None and
-            parse_constant is None and not kw):
-        return _default_decoder.decode(s)
-    if cls is None:
-        cls = JSONDecoder
-    if object_hook is not None:
-        kw['object_hook'] = object_hook
-    if parse_float is not None:
-        kw['parse_float'] = parse_float
-    if parse_int is not None:
-        kw['parse_int'] = parse_int
-    if parse_constant is not None:
-        kw['parse_constant'] = parse_constant
-    return cls(encoding=encoding, **kw).decode(s)
+        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
+        be specified. Encodings that are not ASCII based (such as UCS-2) are
+        not allowed, and should be wrapped with
+        ``codecs.getreader(fp)(encoding)``, or simply decoded to a ``unicode``
+        object and passed to ``loads()``
 
+        ``object_hook`` is an optional function that will be called with the
+        result of any object literal decode (a ``dict``). The return value of
+        ``object_hook`` will be used instead of the ``dict``. This feature
+        can be used to implement custom decoders (e.g. JSON-RPC class hinting).
 
-#
-# Compatibility cruft from other libraries
-#
+        To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
+        kwarg.
 
+        """
+        return loads(fp.read(),
+            encoding=encoding, cls=cls, object_hook=object_hook,
+            parse_float=parse_float, parse_int=parse_int,
+            parse_constant=parse_constant, **kw)
 
-def decode(s):
-    """
-    demjson, python-cjson API compatibility hook. Use loads(s) instead.
-    """
-    import warnings
-    warnings.warn("simplejson.loads(s) should be used instead of decode(s)",
-        DeprecationWarning)
-    return loads(s)
 
+    def loads(s, encoding=None, cls=None, object_hook=None, parse_float=None,
+            parse_int=None, parse_constant=None, **kw):
+        """Deserialize ``s`` (a ``str`` or ``unicode`` instance containing a JSON
+        document) to a Python object.
 
-def encode(obj):
-    """
-    demjson, python-cjson compatibility hook. Use dumps(s) instead.
-    """
-    import warnings
-    warnings.warn("simplejson.dumps(s) should be used instead of encode(s)",
-        DeprecationWarning)
-    return dumps(obj)
+        If ``s`` is a ``str`` instance and is encoded with an ASCII based encoding
+        other than utf-8 (e.g. latin-1) then an appropriate ``encoding`` name
+        must be specified. Encodings that are not ASCII based (such as UCS-2)
+        are not allowed and should be decoded to ``unicode`` first.
 
+        ``object_hook`` is an optional function that will be called with the
+        result of any object literal decode (a ``dict``). The return value of
+        ``object_hook`` will be used instead of the ``dict``. This feature
+        can be used to implement custom decoders (e.g. JSON-RPC class hinting).
 
-def read(s):
-    """
-    jsonlib, JsonUtils, python-json, json-py API compatibility hook.
-    Use loads(s) instead.
-    """
-    import warnings
-    warnings.warn("simplejson.loads(s) should be used instead of read(s)",
-        DeprecationWarning)
-    return loads(s)
+        ``parse_float``, if specified, will be called with the string
+        of every JSON float to be decoded. By default this is equivalent to
+        float(num_str). This can be used to use another datatype or parser
+        for JSON floats (e.g. decimal.Decimal).
 
+        ``parse_int``, if specified, will be called with the string
+        of every JSON int to be decoded. By default this is equivalent to
+        int(num_str). This can be used to use another datatype or parser
+        for JSON integers (e.g. float).
 
-def write(obj):
-    """
-    jsonlib, JsonUtils, python-json, json-py API compatibility hook.
-    Use dumps(s) instead.
-    """
-    import warnings
-    warnings.warn("simplejson.dumps(s) should be used instead of write(s)",
-        DeprecationWarning)
-    return dumps(obj)
+        ``parse_constant``, if specified, will be called with one of the
+        following strings: -Infinity, Infinity, NaN, null, true, false.
+        This can be used to raise an exception if invalid JSON numbers
+        are encountered.
 
+        To use a custom ``JSONDecoder`` subclass, specify it with the ``cls``
+        kwarg.
 
-if __name__ == '__main__':
-    import simplejson.tool
-    simplejson.tool.main()
+        """
+        if (cls is None and encoding is None and object_hook is None and
+                parse_int is None and parse_float is None and
+                parse_constant is None and not kw):
+            return _default_decoder.decode(s)
+        if cls is None:
+            cls = JSONDecoder
+        if object_hook is not None:
+            kw['object_hook'] = object_hook
+        if parse_float is not None:
+            kw['parse_float'] = parse_float
+        if parse_int is not None:
+            kw['parse_int'] = parse_int
+        if parse_constant is not None:
+            kw['parse_constant'] = parse_constant
+        return cls(encoding=encoding, **kw).decode(s)