Bulls and cows

Arturo

<lang rebol>rand: first.n: 4 unique map 1..10 => [sample 0..9] bulls: 0

while [bulls <> 4][

   bulls: new 0

cows: new 0

   got: strip input "make a guess: "
   if? or? not? numeric? got
           4 <> size got -> print "Malformed answer. Try again!"
   else [
       loop.with:'i split got 'digit [
           if? (to :integer digit) = rand \ i -> inc 'bulls
           else [
               if contains? rand to :integer digit -> inc 'cows
           ]
       ]
       print ["Bulls:" bulls "Cows:" cows "\n"]
   ]

] print color.green "** Well done! You made the right guess!!"</lang>