[Prothon-user] Terminology: generator/iterator/iterable

Mark Hahn <[email protected]>:

> I have an idea for making everything that normally returns a list in Python
> return a generator in Prothon

A point here about terminology: if you're trying to keep Prothon
terminology in sync with Python terminology, you should be aware that
there's a difference between an "iterator" and a "generator" in
Python, and I think you really mean "iterator" here.

In Python terms, an iterator is an object which responds to the
iteration protocol -- it has a next() method which returns the next
item or raises StopIteration.

A generator is a special kind of function that produces
iterators. Note that the generator itself is *not* and iterator -- it
*returns* an iterator when you call it.

Also note that generators are not the only things which produce
iterators -- they just happen to be one way of doing it. Built-in
methods such as dict.iteritems return iterators, but they don't
involve generators in any way.

The other term related to all this is "iterable", which is an object
having an __iter__ method that returns an iterator. It's important to
also not get "iterable" and "iterator" confused.

Greg Ewing, Computer Science Dept, +--------------------------------------+
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