pre-PEP: Suite-Based Keywords - syntax proposal

[Kay Schluehr]

Steven Bethard wrote:

> So the object of a "where" is then always an ordered dict?

Yes.

> If so, then
> I guess I like this proposal best so far.
>
> However, it does seem to have the problem that you can't have any
> additional local variables so, for example, list comprehensions are
> probably not usable...
>
> Or can you still drop the argument to "where" and just use the names
> directly?  E.g.:
>
> x = property(fget=fget, doc=doc) where:
>      doc = "I'm the 'x' property."
>      def fget(self):
>          return self.__x

I can't see why this shouldn't work?

The specifiers behind "where" are present to determine the matching
behaviour. The order of a dict is caused by different specifiers i.e. a
dict- or tuple-like specifier. If a specifier is not present only names
can be matched regardless of a sequence and this is always possible
because we still have a dict with names as keys.

What should not be possible are statements like this:

 x = property(a, b) where:
      doc = "I'm the 'x' property."
      def fget(self):
          return self.__x

because there is no rule to match doc and fget onto a and b. In this
case we would need specifiers:

 x = property(a, b)
     where **a:
        doc = "I'm the 'x' property."
     where **b:
        def fget(self):
            return self.__x

Ciao,
Kay