OptionalSort := proc(input, {
    ordering :: Or(procedures,identical("lexicographic")) := "lexicographic",
    column :: posint := 1,
    reverse :: truefalse := false
} )
    local compare;
    if ordering = "lexicographic" then
        compare := (x,y)->evalb(`if`(reverse,x[column]>=y[column],x[column]<=y[column]));
    else
    	compare := (x,y)->`if`(reverse,ordering(x[column],y),ordering(y,x));
    end if;
    sort( input, compare );
end proc: