smatch keyword_if_match;
if (regex_search(input, keyword_if_match, keyword_if_regex)) {
Token token(KEYWORD_IF, to_upper(keyword_if_match.str()), line, column);
tokens.push_back(token);
input = input.substr(keyword_if_match.length());
column += keyword_if_match.length();
continue;
}void printTree(Node* root, int level) {
for (int i = 0; i < level; i++) {
cout << " ";
}
cout << root->value << endl;
for (Node* child : root->children) {
printTree(child, level + 1);
}
}