[Python-ideas] Allowing def to assign to anything

[Ian Kelly]

> On Sun, Oct 25, 2015 at 11:02 PM, Alexander Walters
> <tritium-list at sdamon.com> wrote:
>>
>> In my code, I write a lot of dispatch dictionaries (for lack of a switch
>> statement, but I will not hold my breath for that).  In trying to make
>> writing these dictionaries less annoying, I tend to use many lambdas.  I can
>> let you guess at what problems that has resulted in.  Of course, the
>> preferred way to write such dictionaries is by using a regular function, and
>> adding that function to a dictionary.  This isn't exactly a problem - it
>> works, and works well, but it is annoying to write, and leaves artifacts of
>> those functions in module scope.  I propose a little bit of sugar to make
>> this a little less annoying.
>>
>> If `def` is allowed to assign to anything (anything that is legal at the
>> left hand side of an = in that scope), annoying artifacts go away.  The
>> syntax I propose should be backwards compatible.
>>
>> ```
>> dispatch = {}
>>
>> def dispatch['foo'](bar):
>>     return bar * bar
>> ```

What about:

def foo(bar)[baz](x):
    return x

This seems like it would complicate parsing as the parser can't be
sure whether (bar) is a parameter list or an argument list until it
reaches the following [baz].