struct symbol *tab_lookup(struct symbol *tab, char *ident, short type);
struct symbol *tab_remove_symbol(struct symbol *tab, char *ident, short type);
struct symbol *tab_merge(struct symbol *tab, struct symbol *to_add, short check);
struct symbol *tab_lookup(struct symbol *tab, char *ident, short type);
struct symbol *tab_remove_symbol(struct symbol *tab, char *ident, short type);
struct symbol *tab_merge(struct symbol *tab, struct symbol *to_add, short check);