Classical FP problem in python : Hamming problem
Steven Bethard
steven.bethard at gmail.com
Wed Jan 26 18:54:09 EST 2005
Francis Girard wrote:
> For the imerge function, what we really need to make the formulation clear is
> a way to look at the next element of an iteratable without consuming it. Or
> else, a way to put back "consumed" elements in the front an iteration flow,
> much like the list constructors in FP languages like Haskell.
>
> It is simple to encapsulate an iterator inside another iterator class that
> would do just that. Here's one. The additional "fst" method returns the next
> element to consume without consuming it and the "isBottom" checks if there is
> something left to consume from the iteration flow, without actually consuming
> anything. I named the class "IteratorDeiterator" for lack of imagination :
>
[snip]
Another implementation is my peekable class:
http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/304373
It allows you to peek several elements ahead if that's necessary.
Steve
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