ast_value *cp = ast_value_new(self->expression.node.context, self->name, self->expression.vtype);
if (self->expression.next) {
cp->expression.next = ast_type_copy(self->expression.node.context, self->expression.next);
ast_value *cp = ast_value_new(self->expression.node.context, self->name, self->expression.vtype);
if (self->expression.next) {
cp->expression.next = ast_type_copy(self->expression.node.context, self->expression.next);