Self function

[bearophileHUGS at lycos.com]

Carl Banks:

>1. Singly-linked lists can and should be handled with iteration.<

I was talking about a binary tree with list-like topology, of course.


>All recursion does it make what you're doing a lot less readable for almost all programmers.<

I can't agree. If the data structure is recursive (like a tree, or
even sometimes graphs, etc) a recursive algorithm is shorter, more
readable and more natural.

An example, a postorder recursive visit:

def postorder_scan(root):
    if root is not None:
        if root.left is not None:
            for n in postorder_scan(root.left):
                yield n
        if root.right is not None:
            for n in postorder_scan(root.right):
                yield n
        yield root

Try to write that in an iterative way, not adding any new field to the
nodes, and you will see.
And even if you add a "visited" new boolean field to nodes, the
resulting code isn't as nice as the recursive one yet.


> 2. You should be using a Python list anyway.

I should use D when I have to use such algorithms, I know.

Bye,
bearophile