--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/app/django/utils/functional.py Fri Jul 18 18:22:23 2008 +0000
@@ -0,0 +1,241 @@
+# License for code in this file that was taken from Python 2.5.
+
+# PYTHON SOFTWARE FOUNDATION LICENSE VERSION 2
+# --------------------------------------------
+#
+# 1. This LICENSE AGREEMENT is between the Python Software Foundation
+# ("PSF"), and the Individual or Organization ("Licensee") accessing and
+# otherwise using this software ("Python") in source or binary form and
+# its associated documentation.
+#
+# 2. Subject to the terms and conditions of this License Agreement, PSF
+# hereby grants Licensee a nonexclusive, royalty-free, world-wide
+# license to reproduce, analyze, test, perform and/or display publicly,
+# prepare derivative works, distribute, and otherwise use Python
+# alone or in any derivative version, provided, however, that PSF's
+# License Agreement and PSF's notice of copyright, i.e., "Copyright (c)
+# 2001, 2002, 2003, 2004, 2005, 2006, 2007 Python Software Foundation;
+# All Rights Reserved" are retained in Python alone or in any derivative
+# version prepared by Licensee.
+#
+# 3. In the event Licensee prepares a derivative work that is based on
+# or incorporates Python or any part thereof, and wants to make
+# the derivative work available to others as provided herein, then
+# Licensee hereby agrees to include in any such work a brief summary of
+# the changes made to Python.
+#
+# 4. PSF is making Python available to Licensee on an "AS IS"
+# basis. PSF MAKES NO REPRESENTATIONS OR WARRANTIES, EXPRESS OR
+# IMPLIED. BY WAY OF EXAMPLE, BUT NOT LIMITATION, PSF MAKES NO AND
+# DISCLAIMS ANY REPRESENTATION OR WARRANTY OF MERCHANTABILITY OR FITNESS
+# FOR ANY PARTICULAR PURPOSE OR THAT THE USE OF PYTHON WILL NOT
+# INFRINGE ANY THIRD PARTY RIGHTS.
+#
+# 5. PSF SHALL NOT BE LIABLE TO LICENSEE OR ANY OTHER USERS OF PYTHON
+# FOR ANY INCIDENTAL, SPECIAL, OR CONSEQUENTIAL DAMAGES OR LOSS AS
+# A RESULT OF MODIFYING, DISTRIBUTING, OR OTHERWISE USING PYTHON,
+# OR ANY DERIVATIVE THEREOF, EVEN IF ADVISED OF THE POSSIBILITY THEREOF.
+#
+# 6. This License Agreement will automatically terminate upon a material
+# breach of its terms and conditions.
+#
+# 7. Nothing in this License Agreement shall be deemed to create any
+# relationship of agency, partnership, or joint venture between PSF and
+# Licensee. This License Agreement does not grant permission to use PSF
+# trademarks or trade name in a trademark sense to endorse or promote
+# products or services of Licensee, or any third party.
+#
+# 8. By copying, installing or otherwise using Python, Licensee
+# agrees to be bound by the terms and conditions of this License
+# Agreement.
+
+
+def curry(_curried_func, *args, **kwargs):
+ def _curried(*moreargs, **morekwargs):
+ return _curried_func(*(args+moreargs), **dict(kwargs, **morekwargs))
+ return _curried
+
+### Begin from Python 2.5 functools.py ########################################
+
+# Summary of changes made to the Python 2.5 code below:
+# * swapped ``partial`` for ``curry`` to maintain backwards-compatibility
+# in Django.
+# * Wrapped the ``setattr`` call in ``update_wrapper`` with a try-except
+# block to make it compatible with Python 2.3, which doesn't allow
+# assigning to ``__name__``.
+
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007 Python Software Foundation.
+# All Rights Reserved.
+
+###############################################################################
+
+# update_wrapper() and wraps() are tools to help write
+# wrapper functions that can handle naive introspection
+
+WRAPPER_ASSIGNMENTS = ('__module__', '__name__', '__doc__')
+WRAPPER_UPDATES = ('__dict__',)
+def update_wrapper(wrapper,
+ wrapped,
+ assigned = WRAPPER_ASSIGNMENTS,
+ updated = WRAPPER_UPDATES):
+ """Update a wrapper function to look like the wrapped function
+
+ wrapper is the function to be updated
+ wrapped is the original function
+ assigned is a tuple naming the attributes assigned directly
+ from the wrapped function to the wrapper function (defaults to
+ functools.WRAPPER_ASSIGNMENTS)
+ updated is a tuple naming the attributes off the wrapper that
+ are updated with the corresponding attribute from the wrapped
+ function (defaults to functools.WRAPPER_UPDATES)
+ """
+ for attr in assigned:
+ try:
+ setattr(wrapper, attr, getattr(wrapped, attr))
+ except TypeError: # Python 2.3 doesn't allow assigning to __name__.
+ pass
+ for attr in updated:
+ getattr(wrapper, attr).update(getattr(wrapped, attr))
+ # Return the wrapper so this can be used as a decorator via curry()
+ return wrapper
+
+def wraps(wrapped,
+ assigned = WRAPPER_ASSIGNMENTS,
+ updated = WRAPPER_UPDATES):
+ """Decorator factory to apply update_wrapper() to a wrapper function
+
+ Returns a decorator that invokes update_wrapper() with the decorated
+ function as the wrapper argument and the arguments to wraps() as the
+ remaining arguments. Default arguments are as for update_wrapper().
+ This is a convenience function to simplify applying curry() to
+ update_wrapper().
+ """
+ return curry(update_wrapper, wrapped=wrapped,
+ assigned=assigned, updated=updated)
+
+### End from Python 2.5 functools.py ##########################################
+
+def memoize(func, cache, num_args):
+ """
+ Wrap a function so that results for any argument tuple are stored in
+ 'cache'. Note that the args to the function must be usable as dictionary
+ keys.
+
+ Only the first num_args are considered when creating the key.
+ """
+ def wrapper(*args):
+ mem_args = args[:num_args]
+ if mem_args in cache:
+ return cache[mem_args]
+ result = func(*args)
+ cache[mem_args] = result
+ return result
+ return wraps(func)(wrapper)
+
+class Promise(object):
+ """
+ This is just a base class for the proxy class created in
+ the closure of the lazy function. It can be used to recognize
+ promises in code.
+ """
+ pass
+
+def lazy(func, *resultclasses):
+ """
+ Turns any callable into a lazy evaluated callable. You need to give result
+ classes or types -- at least one is needed so that the automatic forcing of
+ the lazy evaluation code is triggered. Results are not memoized; the
+ function is evaluated on every access.
+ """
+ class __proxy__(Promise):
+ # This inner class encapsulates the code that should be evaluated
+ # lazily. On calling of one of the magic methods it will force
+ # the evaluation and store the result. Afterwards, the result
+ # is delivered directly. So the result is memoized.
+ def __init__(self, args, kw):
+ self.__func = func
+ self.__args = args
+ self.__kw = kw
+ self.__dispatch = {}
+ for resultclass in resultclasses:
+ self.__dispatch[resultclass] = {}
+ for (k, v) in resultclass.__dict__.items():
+ setattr(self, k, self.__promise__(resultclass, k, v))
+ self._delegate_str = str in resultclasses
+ self._delegate_unicode = unicode in resultclasses
+ assert not (self._delegate_str and self._delegate_unicode), "Cannot call lazy() with both str and unicode return types."
+ if self._delegate_unicode:
+ # Each call to lazy() makes a new __proxy__ object, so this
+ # doesn't interfere with any other lazy() results.
+ __proxy__.__unicode__ = __proxy__.__unicode_cast
+ elif self._delegate_str:
+ __proxy__.__str__ = __proxy__.__str_cast
+
+ def __promise__(self, klass, funcname, func):
+ # Builds a wrapper around some magic method and registers that magic
+ # method for the given type and method name.
+ def __wrapper__(*args, **kw):
+ # Automatically triggers the evaluation of a lazy value and
+ # applies the given magic method of the result type.
+ res = self.__func(*self.__args, **self.__kw)
+ return self.__dispatch[type(res)][funcname](res, *args, **kw)
+
+ if klass not in self.__dispatch:
+ self.__dispatch[klass] = {}
+ self.__dispatch[klass][funcname] = func
+ return __wrapper__
+
+ def __unicode_cast(self):
+ return self.__func(*self.__args, **self.__kw)
+
+ def __str_cast(self):
+ return str(self.__func(*self.__args, **self.__kw))
+
+ def __cmp__(self, rhs):
+ if self._delegate_str:
+ s = str(self.__func(*self.__args, **self.__kw))
+ elif self._delegate_unicode:
+ s = unicode(self.__func(*self.__args, **self.__kw))
+ else:
+ s = self.__func(*self.__args, **self.__kw)
+ if isinstance(rhs, Promise):
+ return -cmp(rhs, s)
+ else:
+ return cmp(s, rhs)
+
+ def __mod__(self, rhs):
+ if self._delegate_str:
+ return str(self) % rhs
+ elif self._delegate_unicode:
+ return unicode(self) % rhs
+ else:
+ raise AssertionError('__mod__ not supported for non-string types')
+
+ def __deepcopy__(self, memo):
+ # Instances of this class are effectively immutable. It's just a
+ # collection of functions. So we don't need to do anything
+ # complicated for copying.
+ memo[id(self)] = self
+ return self
+
+ def __wrapper__(*args, **kw):
+ # Creates the proxy object, instead of the actual value.
+ return __proxy__(args, kw)
+
+ return wraps(func)(__wrapper__)
+
+def allow_lazy(func, *resultclasses):
+ """
+ A decorator that allows a function to be called with one or more lazy
+ arguments. If none of the args are lazy, the function is evaluated
+ immediately, otherwise a __proxy__ is returned that will evaluate the
+ function when needed.
+ """
+ def wrapper(*args, **kwargs):
+ for arg in list(args) + kwargs.values():
+ if isinstance(arg, Promise):
+ break
+ else:
+ return func(*args, **kwargs)
+ return lazy(func, *resultclasses)(*args, **kwargs)
+ return wraps(func)(wrapper)