+++ /dev/null
-"""
-Decorator module, see
-http://www.phyast.pitt.edu/~micheles/python/documentation.html
-for the documentation and below for the licence.
-"""
-
-## The basic trick is to generate the source code for the decorated function
-## with the right signature and to evaluate it.
-## Uncomment the statement 'print >> sys.stderr, func_src' in _decorator
-## to understand what is going on.
-
-__all__ = ["decorator", "new_wrapper", "getinfo"]
-
-import inspect, sys
-
-try:
- set
-except NameError:
- from sets import Set as set
-
-def getinfo(func):
- """
- Returns an info dictionary containing:
- - name (the name of the function : str)
- - argnames (the names of the arguments : list)
- - defaults (the values of the default arguments : tuple)
- - signature (the signature : str)
- - doc (the docstring : str)
- - module (the module name : str)
- - dict (the function __dict__ : str)
-
- >>> def f(self, x=1, y=2, *args, **kw): pass
-
- >>> info = getinfo(f)
-
- >>> info["name"]
- 'f'
- >>> info["argnames"]
- ['self', 'x', 'y', 'args', 'kw']
-
- >>> info["defaults"]
- (1, 2)
-
- >>> info["signature"]
- 'self, x, y, *args, **kw'
- """
- assert inspect.ismethod(func) or inspect.isfunction(func)
- regargs, varargs, varkwargs, defaults = inspect.getargspec(func)
- argnames = list(regargs)
- if varargs:
- argnames.append(varargs)
- if varkwargs:
- argnames.append(varkwargs)
- signature = inspect.formatargspec(regargs, varargs, varkwargs, defaults,
- formatvalue=lambda value: "")[1:-1]
- return dict(name=func.__name__, argnames=argnames, signature=signature,
- defaults = func.func_defaults, doc=func.__doc__,
- module=func.__module__, dict=func.__dict__,
- globals=func.func_globals, closure=func.func_closure)
-
-# akin to functools.update_wrapper
-def update_wrapper(wrapper, model, infodict=None):
- infodict = infodict or getinfo(model)
- try:
- wrapper.__name__ = infodict['name']
- except: # Python version < 2.4
- pass
- wrapper.__doc__ = infodict['doc']
- wrapper.__module__ = infodict['module']
- wrapper.__dict__.update(infodict['dict'])
- wrapper.func_defaults = infodict['defaults']
- wrapper.undecorated = model
- return wrapper
-
-def new_wrapper(wrapper, model):
- """
- An improvement over functools.update_wrapper. The wrapper is a generic
- callable object. It works by generating a copy of the wrapper with the
- right signature and by updating the copy, not the original.
- Moreovoer, 'model' can be a dictionary with keys 'name', 'doc', 'module',
- 'dict', 'defaults'.
- """
- if isinstance(model, dict):
- infodict = model
- else: # assume model is a function
- infodict = getinfo(model)
- assert not '_wrapper_' in infodict["argnames"], (
- '"_wrapper_" is a reserved argument name!')
- src = "lambda %(signature)s: _wrapper_(%(signature)s)" % infodict
- funcopy = eval(src, dict(_wrapper_=wrapper))
- return update_wrapper(funcopy, model, infodict)
-
-# helper used in decorator_factory
-def __call__(self, func):
- infodict = getinfo(func)
- for name in ('_func_', '_self_'):
- assert not name in infodict["argnames"], (
- '%s is a reserved argument name!' % name)
- src = "lambda %(signature)s: _self_.call(_func_, %(signature)s)"
- new = eval(src % infodict, dict(_func_=func, _self_=self))
- return update_wrapper(new, func, infodict)
-
-def decorator_factory(cls):
- """
- Take a class with a ``.caller`` method and return a callable decorator
- object. It works by adding a suitable __call__ method to the class;
- it raises a TypeError if the class already has a nontrivial __call__
- method.
- """
- attrs = set(dir(cls))
- if '__call__' in attrs:
- raise TypeError('You cannot decorate a class with a nontrivial '
- '__call__ method')
- if 'call' not in attrs:
- raise TypeError('You cannot decorate a class without a '
- '.call method')
- cls.__call__ = __call__
- return cls
-
-def decorator(caller):
- """
- General purpose decorator factory: takes a caller function as
- input and returns a decorator with the same attributes.
- A caller function is any function like this::
-
- def caller(func, *args, **kw):
- # do something
- return func(*args, **kw)
-
- Here is an example of usage:
-
- >>> @decorator
- ... def chatty(f, *args, **kw):
- ... print "Calling %r" % f.__name__
- ... return f(*args, **kw)
-
- >>> chatty.__name__
- 'chatty'
-
- >>> @chatty
- ... def f(): pass
- ...
- >>> f()
- Calling 'f'
-
- decorator can also take in input a class with a .caller method; in this
- case it converts the class into a factory of callable decorator objects.
- See the documentation for an example.
- """
- if inspect.isclass(caller):
- return decorator_factory(caller)
- def _decorator(func): # the real meat is here
- infodict = getinfo(func)
- argnames = infodict['argnames']
- assert not ('_call_' in argnames or '_func_' in argnames), (
- 'You cannot use _call_ or _func_ as argument names!')
- src = "lambda %(signature)s: _call_(_func_, %(signature)s)" % infodict
- # import sys; print >> sys.stderr, src # for debugging purposes
- dec_func = eval(src, dict(_func_=func, _call_=caller))
- return update_wrapper(dec_func, func, infodict)
- return update_wrapper(_decorator, caller)
-
-if __name__ == "__main__":
- import doctest; doctest.testmod()
-
-########################## LEGALESE ###############################
-
-## Redistributions of source code must retain the above copyright
-## notice, this list of conditions and the following disclaimer.
-## Redistributions in bytecode form must reproduce the above copyright
-## notice, this list of conditions and the following disclaimer in
-## the documentation and/or other materials provided with the
-## distribution.
-
-## THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
-## "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
-## LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
-## A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
-## HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
-## INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
-## BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
-## OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-## ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR
-## TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE
-## USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
-## DAMAGE.
fnp / wolnelektury.git / blobdiff