Without knowing the contents of $self->{children} or the side-effects/return values of $node->traversal()

Presumably, traversal traverses a tree. The children of a node are likely of the same type as that node, which makes traversal a recursive function.

I cannot provide any additional insight.

The OP's first snippet returns the nodes of the tree in pre-order.

The OP's second snippet is obviously broken, traversing the entire tree to get only the nodes of depth one and two.

In reply to Re^2: map & arrays & recursion by ikegami
in thread map & arrays & recursion by Anonymous Monk

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