Can't use decorators with function that have annotations which are built-ins or lambdas

[GoogleCodeExporter]

Here's some example code:

from functools import partial
from operator import gt
from decorator import decorator

@decorator
def dec(func, *args, **kwargs):
    return func(*args, **kwargs)

@dec
def foo(bar: partial(gt, 5)) -> lambda x: x:
    pass

Here's the resulting traceback:

Traceback (most recent call last):
  File "foo.py", line 10, in <module>
    def foo(bar: partial(gt, 5)) -> lambda x: x:
  File "<string>", line 2, in dec
  File "/Users/kamil/.virtualenvs/covenant/lib/python3.2/site-packages/decorator.py", line 200, in decorator
    evaldict, undecorated=func, __wrapped__=func)
  File "/Users/kamil/.virtualenvs/covenant/lib/python3.2/site-packages/decorator.py", line 187, in create
    evaldict, addsource, **attrs)
  File "/Users/kamil/.virtualenvs/covenant/lib/python3.2/site-packages/decorator.py", line 154, in make
    code = compile(src, '<string>', 'single')
  File "<string>", line 1
    def foo(bar: functools.partial(<built-in function gt>, 5)) -> <function <lambda> at 0x1005cf2f8):

The BIF case could possibly be solved by doing some parsing of the annotations 
returned from getfullargspec but I'm not aware of any method of getting the 
code to define the lambda again. Perhaps it would be best to just filter out 
the annotations from the function signature, but still assign them to 
__annotations__ attribute of the resulting function?

Original issue reported on code.google.com by kamil.ki...@gmail.com on 11 Mar 2012 at 1:08