[Python-Dev] PEP 334 - Simple Coroutines via SuspendIteration

[Jp Calderone]

Clark C. Evans wrote:
> Josiah Carlson kindly pointed out (off list), that my use of
> SuspendIteration violates the standard idiom of exceptions 
> terminating the current function. This got past me, beacuse 
> I think a generator not as a function, but rather as a shortcut 
> to creating iterators.  The offending code is,
> 
> |     def NonBlockingResource():
> |         yield "one"
> |         while True:
> |             rand = randint(1,10)
> |             if 2 == rand:
> |                 break
> |             raise SuspendIteration()
> |         yield "two"
> 
> There are two solutions:
>   (a) introduce a new keyword 'suspend'; or,
>   (b) don't do that.
>   
> It is not essential to the proposal that the generator syntax produce
> iterators that can SuspendIteration, it is only essential that the
> implementation of generators pass-through this exception. Most
> non-blocking resources will be low-level components from an async
> database or socket library; they can make iterators the old way.
> 

   What about this?

     def somefunc():
         raise SuspendIteration()
         return 'foo'

     def genfunc():
         yield somefunc()

   Jp