#Progress Trees

This is a library to help implement advancement trees, such as talent trees or research trees.

Licensed under version 2.1 of the LGPL, or any later version.

progress_tree.new_tree() - Creates an empty tree
progress_tree.new_player_data(tree[, learned]) - Creates an instance of player advancement data in a particular progress tree. The optional argument is a set of node names to start off with.
progress_tree.deserialize_player_data(tree, learned_string) - Deserializes player data in relation to a particular tree.

add(node_name, parents) - Adds a new node with the name node_name. parents is a list of parent node names, which must already exist in the tree (or you will get an error).
new_player_data(learned) - Method version of progress_tree.new_player_data
deserialize_player_data(learned_string) - Method version of progress_tree.deserialize_player_data

serialize() - Serializes the data to a string
knows(node_name) - Determines if the player has learned the node
can_learn(node_name) - Determines if the player has completed the prerequisites for the node
learn(node_name) - Adds the given node to the known nodes. It can fail and return false if the node doesn't exist in the tree, or if it has already been learned, but will return true if nothing goes wrong. It will not fail if not all prerequisites have been completed, though.