{"ast_node_type":"variable","tokens":[{"end":72,"kind":"keyword","start":0,"text":"let"}]}
            let element = bx.extract_element(vector, index).to_rvalue();
            let index = bx.context.new_rvalue_from_long(bx.ulong_type, i as i64);
            let result = bx.context.new_cast(None, bx.pop_count(element), elem_ty);