def group_into_tokens(characters):
tokens = []
next_index = 0
while (next_index < len(characters)):
token, next_index = get_token(characters, next_index)
tokens.append(token)
return tokens
def characters_to_nodes(characters):
# global left_bracket_cnt
length = len(characters)
index = 0
node_list = []
while index < length:
current_token, index = scan.get_token(characters, index)
# 将token转化为node
node = token_to_node(current_token)
node_list.append(node)
# modify_nodes(node_list)
return node_list