a break for comprehensions

[Cliff Crawford]

* Tom Good <Tom_Good1 at excite.com> menulis:
| 
| You've inspired me to start writing a list-like wrapper for
| generators.  Here is what I have so far.  It combines some list syntax
| with lazy evaluation, and supports (some) slice operations on
| unbounded generators.
| [snip]
| 
| def main():
|     def gen():
|         x = 0
|         while 1:
|             x += 1
|             yield x
| 
|     glist = GenList(gen())
|     print glist[4]
|     print glist[:10]

This is neat :)  It looks like your class will work with any iterator,
not just generators.  So you could use it with, say, file objects:

file = GenList(iter(open('file.txt')))
print file[4]
print file[3:17]
# etc.

Also, I would propose adding

def __add__(iter1, iter2):
    def f():
        for val in iter1:
            yield val
        for val in iter2:
            yield val
    return GenList(f)

Then you can do stuff like the following, which simulates the Unix 'cat'
command (warning: untested):

files = reduce(lambda x, y: x+y, GenList(iter(open(sys.argv[1:]))))
for line in files:
    print line,


-- 
Cliff Crawford                           http://www.sowrong.org/
"Today's Goths, who generally tend to be in their teens and 20s,
have nothing to do with the Germanic Visigoths of Europe in the
third and fourth centuries A.D."               -- Jimmy Stewart