Yielding a chain of values

[Reinhold Birkenfeld]

Kay Schluehr wrote:
> Reinhold Birkenfeld wrote:
> 
>> > 	x = [ yield r for r in iterable ]
>>
>> Which is quite different from
>>
>> x = (yield) in iterable
>>
>> which is currently (PEP 342) equivalent to
>>
>> _ = (yield)
>> x = _ in iterable
>>
>> So, no further tinkering with yield, I'm afraid.
>>
>> Reinhold
> 
> Is the statement
> 
>    yield from iterable
> 
> also in danger to be ambigous?
> 
> The resolution of "(yield) from iterable" into
> 
>  _ = (yield)
>  x = _ from iterable
> 
> would not result in valid Python syntax.

Right.

Problem is, how would you define the "from" syntax: Is its use as
an expression allowed? What value does it have, then?

Reinhold