API Thoughts?

Hey, Currently working on the Binary Tree implementations for the ADT extension and was wondering what people thought as more intuitive, something like: $tree = tree_new(AVL_TREE); tree_insert($tree, $element, "compare_func"); // ... Or: $tree = avl_tree_new(); avl_tree_insert($tree, $element, "compare_func"); Basically the difference between a generalized tree api, where you pass a constant to the constructor (if you allow me to use that term :), or where every form of the tree has a different set of functions (currently planned are Red-black tree's, AVL tree's, Simple Binary Search Tree's and Btree's). Thoughts? I'm currently leaning towards the first one... -Sterling