Combine the contexts from subtrees
Combine the contexts from subtrees
combine is used after recursively transforming the subtrees, to combine the multiple contexts into one context to use in the post operation. The order of the context is from left to right in the tree structure.
Combine is always invoked, even on a single element sublist or on an empty list. The tree argument is the current tree, before applying the recursive transformation. Same for the context argument, it is the current context at that transformation step.
a post-transformation to be applied to the term
a post-transformation to be applied to the term
If defined (default to None), the term will be mapped after performing the recursion in the subtrees. This should only do the mapping, without any recursive call.
a pre-transformation to be applied to the term
a pre-transformation to be applied to the term
If defined (default to None), the term will be mapped before performing the recursion in the subtrees. This should only do the mapping, without any recursive call.