generators

[John Belmonte <jvb@...>]

IBM developWorks has run a series of articles on Python's generators, 
which is basically the same construct as the semi-coroutines in the 
development version of Lua.  Note that in Python, any function 
containing a yield becomes a coroutine automatically (a point which the 
author doesn't seem to like), while in Lua coroutines must be created 
explicitly.

Fun stuff...

-John


"Iterators and simple generators", David Mertz
Python 2.2 introduces a new construct accompanied by a new keyword. The 
construct is generators, the keyword is yield. Generators make possible 
several new, powerful, and expressive programming idioms, but are also a 
little bit hard to get one's mind around at first glance. In this 
article, David provides a gentle introduction to generators, and also to 
the related topic of iterators.
<http://www-106.ibm.com/developerworks/opensource/library/l-pycon.html>

"Generator-based state machines", David Mertz
Introduced in Python 2.2, simple generators may be used to simplify 
state machines and to simulate coroutines. Coroutines are an exotic flow 
mechanism that few widely used languages -- not even non-Stackless 
Python -- allow. Python's new generators, however, get you almost all 
the way to coroutines, and the extra few steps can be faked.
<http://www-106.ibm.com/developerworks/opensource/library/l-pygen.html>

"Implementing 'weightless threads' with Python generators", David Mertz
David Mertz introduces weightless threads. Similar to Stackless Python 
microthreads, but using standard Python 2.2 -- they allow for extremely 
large numbers of cooperating processes with virtually no overhead.
<http://www-106.ibm.com/developerworks/opensource/library/l-pythrd.html>


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