local(_@_K_E_Y_S);
foreach (_@_D_A_T_A) {
    push(_@_K_E_Y_S, _K_E_Y_E_X_P_R);
}
sub _S_O_R_T_F_U_N_C { _B_Y_K_E_Y_E_X_P_R; }
_@_S_O_R_T_D_A_T_A = _@_D_A_T_A[sort _S_O_R_T_F_U_N_C $[.._$_#_D_A_T_A];
