/d1 2 dict def
d1 begin
    3 (Some Int) def
    3.0 (Some Real) def
end

/d2 2 dict def
d2 begin
    3.0 (Some Real) def
    3 (Some Int) def
end

/p1 { dup type == ( -> ) print == } def

(*** d1 ***\n) print
d1 { exch p1 p1 } forall
(*** d2 ***\n) print
d2 { exch p1 p1 } forall

============ OUTPUT ============
*** d1 ***
integertype
 -> 3
stringtype
 -> (Some Real)
*** d2 ***
realtype
 -> 3.0
stringtype
 -> (Some Int)