def _linearized_rep_to_tree_rep()

in utils/trees.py [0:0]

• 29 lines of code
• 7 McCabe index (conditional complexity)

    def _linearized_rep_to_tree_rep(self, flat_string):
        '''
        Get the tree representation for flat input string `flat_string`
        Example input string:
        "(ORDER can i have (PIZZAORDER (NUMBER a ) (SIZE large ) (TOPPING bbq pulled pork ) ) please )"

        Invalid flat strings include those with misplaced brackets, mismatched brackets,
        or semantic nodes with no children

        :param flat_string: (str) input flat string to construct a tree, if possible.
        :raises ValueError: when s is not a valid flat string
        :raises IndexError: when s is not a valid flat string
        
        :return: (AnyNode) returns a pointer to a tree node.
        '''
        # Keep track of all the semantics in the input string.
        semantic_stack = [AnyNode(id=TopSemanticTree.ROOT_SYMBOL)]

        for token in flat_string.split():
            if '(' in token:
                node = AnyNode(id=token.strip('('), parent=semantic_stack[-1])
                semantic_stack.append(node)
            elif token == ')':
                # If the string is not valid an error will be thrown here.
                # E.g. (PIZZAORDER (SIZE LARGE ) ) ) ) ) ) )
                try:
                    # If there are no children within this semantic node, throw an error
                    # E.g. (PIZZAORDER (SIZE LARGE ) (NOT ) )
                    if not semantic_stack[-1].children:
                        raise Exception("Semantic node with no children")
                    semantic_stack.pop()
                except Exception as e:
                    raise IndexError(e) from e
            else:
                AnyNode(id=token, parent=semantic_stack[-1])
        # If there are more than one elements in semantic stack, that means
        # the input string is malformed, i.e. it cant be used to construct a tree
        if len(semantic_stack) > 1:
            raise ValueError()
        return semantic_stack[-1]