ast_expression *func_try(size_t offset, const char *compare);
ast_expression *func_self(const char *name, const char *from);
ast_expression *func(const char *name);
ast_expression *func_try(size_t offset, const char *compare);
ast_expression *func_self(const char *name, const char *from);
ast_expression *func(const char *name);