This function is used at development time (for code generation and the internal type system) to get the type of the AST node produced by the given rule.
For data type rules, the name of the rule is returned,
e.g. "INT_value returns number: MY_INT;" returns "INT_value".
This function is used at development time (for code generation and the internal type system) to get the type of the AST node produced by the given rule. For data type rules, the name of the rule is returned, e.g. "INT_value returns number: MY_INT;" returns "INT_value".