[Brian Harring] > The issue I'm seeing is that the wart you're pointing at is a > general issue not limited to strings- everyone sooner or later > has flattening code that hits the "recursively iterate over > this container, except for instances of these classes".
Good recap. For more info, search comp.lang.python for previous discussions about a proposed iter_flatten() function. One of the conclusions was that a general algorithm would need to accept a user specified test for atomicity so it would know where to recurse and a where not to (the answer to that is application dependent). Another conclusion was that an iterator version of flattening was a just one of many possible algorithms for traversing a hierarchical structure (i.e. a pre-order tree traversal). But some use cases needed more control points than provided by overly specific solutions (os.walk() and depth-first puzzle solvers are prime examples). The discussion itself was an interesting case-study because the flattening algorithm variants out-numbered the use cases (IOW, it's more fun to write flatten() than to use it). It was also interesting because the problem produced a tail-wagging-the-dog effect as discussions went from "how can I write a more general flatten" and turned into "how can I can modify the language to make my flatten variant apply more generally". Raymond _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
