Module ast-hashtable: Re-implement over a proper hash table structure.
Class ast_expression: This part of the tree (and sub parts) is currently quite messy. When I come to actually using this for something practicle, I may end up re-writing it. That will be post the first "release" though.
Global ast_extend_concatenation (ast_concatenation *element, ast_expression *repeat, void *data): Better implement repetition of elements.
Global ast_new_concatenation (ast_concatenation_type type, ast_expression *repeat, void *first_value): Better implement repetition of elements.
Global ast_new_number (ast_number_base base, ast_number_representation representation, char *digits): Implement proper representation converstion.
Class ast_type_declaration: Clean this up to avoid accessing members which are mutually exclusive