<p>The Dragon Book includes an exercise on converting integers to roman numerals using a syntax-directed translation scheme.</p>

<p>How can this be completed?</p>

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 '0' or negative.