translation-scheme

The Dragon Book includes an exercise on converting integers to roman numerals using a syntax-directed translation scheme. How can this be completed? I would consider parsing from right-to-left. First, I would map the units column: 0 -> '' 1 -> 'I' 2 -> 'II' 3 -> 'III' 4 -> 'IV' ... 9 -> 'IX' Then, if there was a second column (e.g. second from the right = tens column), I would use that to map to 0 -> '' 1 -> 'X' 2 -> 'XX' ... 9 -> 'XC' That would need to be prepended to the initial output. Repeat for next columns (hundreds, thousands) until you run out of letters. Double-check the number isn't