def _construct_node_from_actions(self,
                                     current_node: Tree,
                                     remaining_actions: List[List[str]]) -> List[List[str]]:
        """
        Given a current node in the logical form tree, and a list of actions in an action sequence,
        this method fills in the children of the current node from the action sequence, then
        returns whatever actions are left.

        For example, we could get a node with type ``c``, and an action sequence that begins with
        ``c -> [<r,c>, r]``.  This method will add two children to the input node, consuming
        actions from the action sequence for nodes of type ``<r,c>`` (and all of its children,
        recursively) and ``r`` (and all of its children, recursively).  This method assumes that
        action sequences are produced `depth-first`, so all actions for the subtree under ``<r,c>``
        appear before actions for the subtree under ``r``.  If there are any actions in the action
        sequence after the ``<r,c>`` and ``r`` subtrees have terminated in leaf nodes, they will be
        returned.
        """
        if not remaining_actions:
            logger.error("No actions left to construct current node: %s", current_node)
            raise ParsingError("Incomplete action sequence")
        left_side, right_side = remaining_actions.pop(0)
        if left_side != current_node.label():
            logger.error("Current node: %s", current_node)
            logger.error("Next action: %s -> %s", left_side, right_side)
            logger.error("Remaining actions were: %s", remaining_actions)
            raise ParsingError("Current node does not match next action")
        if right_side[0] == '[':
            # This is a non-terminal expansion, with more than one child node.
            for child_type in right_side[1:-1].split(', '):
                child_node = Tree(child_type, [])
                current_node.append(child_node)  # you add a child to an nltk.Tree with `append`
                # For now, we assume that all children in a list like this are non-terminals, so we
                # recurse on them.  I'm pretty sure that will always be true for the way our
                # grammar induction works.  We can revisit this later if we need to.
                remaining_actions = self._construct_node_from_actions(child_node, remaining_actions)
        else:
            # The current node is a pre-terminal; we'll add a single terminal child.  By
            # construction, the right-hand side of our production rules are only ever terminal
            # productions or lists of non-terminals.
            current_node.append(Tree(right_side, []))  # you add a child to an nltk.Tree with `append`
        return remaining_actions
def _construct_node_from_actions ( self , current_node : Tree , remaining_actions : List [ List [ str ] ] ) -> List [ List [ str ] ] : if not remaining_actions : logger . error ( "No actions left to construct current node: %s" , current_node ) raise ParsingError ( "Incomplete action sequence" ) left_side , right_side = remaining_actions . pop ( 0 ) if left_side != current_node . label ( ) : logger . error ( "Current node: %s" , current_node ) logger . error ( "Next action: %s -> %s" , left_side , right_side ) logger . error ( "Remaining actions were: %s" , remaining_actions ) raise ParsingError ( "Current node does not match next action" ) if right_side [ 0 ] == '[' : for child_type in right_side [ 1 : - 1 ] . split ( ', ' ) : child_node = Tree ( child_type , [ ] ) current_node . append ( child_node ) remaining_actions = self . _construct_node_from_actions ( child_node , remaining_actions ) else : current_node . append ( Tree ( right_side , [ ] ) ) return remaining_actions
Given a current node in the logical form tree, and a list of actions in an action sequence,
        this method fills in the children of the current node from the action sequence, then
        returns whatever actions are left.

        For example, we could get a node with type ``c``, and an action sequence that begins with
        ``c -> [<r,c>, r]``.  This method will add two children to the input node, consuming
        actions from the action sequence for nodes of type ``<r,c>`` (and all of its children,
        recursively) and ``r`` (and all of its children, recursively).  This method assumes that
        action sequences are produced `depth-first`, so all actions for the subtree under ``<r,c>``
        appear before actions for the subtree under ``r``.  If there are any actions in the action
        sequence after the ``<r,c>`` and ``r`` subtrees have terminated in leaf nodes, they will be
        returned.