Re: Separate interface and implemenation problem..

On Thu, 4 Jun 2009, MRe wrote:


Python does this, FWIW. Like:

node = TreeNode()

Although that actually isn't special syntax. It's a method call. Via an
overloaded operator.

The operator in question is (), the call operator. The class 'type', which
is python's answer to Class, overloads it. So, if you have an instance of
type, you can call it as if it was a method - and what the method does is
create a new instance of that type.

This lets you do fun stuff like:

if (shouldCreateList()):
  typeToCreate = list
else:
  typeToCreate = set
collection = typeToCreate(someElements)

For which there's no really good analogue in java. I think the closest
thing we have would be reflection using a Constructor object, although
what we'd actually do is use a factory.

tom

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