pre-PEP: Suite-Based Keywords

[Brian Sabbey]

Reinhold Birkenfeld wrote:
> Brian Sabbey wrote:
>> Here is a pre-PEP for what I call "suite-based keyword arguments". The
>> mechanism described here is intended to act as a complement to thunks.
>> Please let me know what you think.
>>
>> Suite-Based Keyword Arguments
>> -----------------------------
>>
>> Passing complicated arguments to functions is currently awkward in Python.
>> For example, the typical way to define a class property winds up polluting
>> the class's namespace with the property's get/set methods.  By allowing
>> keyword arguments to be defined in a suite following a function call,
>> complicated arguments can be passed in a cleaner, easier way.
>>
>> Examples
>> ========
>>
>> Using suite-based keyword arguments, the code
>>
>> f(x = 1)
>>
>> is equivalent to
>>
>> f():
>>     x = 1
>
> Pretty cool, but it interferes with current suites.
>
> How would you write
>
> if f(x=1):
>    print "yes"
>
> using suite-based keyword args?
>
> Reinhold
>

You wouldn't be able to use suite keywords in that situation.  Also, one 
would not be able to use suite keywords when there is more than one 
function call on the same line:

y = f()*g():
  	x = 1    # ??  not allowed

There is only so much suites can do.  Cases in which you want to do both 
are probably far enough between that it seems acceptable to me to require 
two suites:

t = f():
          x = 1
if t:
          y = 1

In general, I think that anything more than just a function call with an 
optional assignment should be disallowed:

y = [f()]:      #  ? probably shouldn't be allowed
  	x = 1

-Brian