string 0;                       \use zero-terminated strings
code CrLf=9, IntOut=11;

func Roman(Str);                \Convert Roman numeral string to decimal value
char Str;
int  I, Val, Val0, Sum;
[I:= 0;  Sum:= 0;  Val0:= 5000;
loop    [case Str(I) of
          ^M: Val:= 1000;
          ^D: Val:= 500;
          ^C: Val:= 100;
          ^L: Val:= 50;
          ^X: Val:= 10;
          ^V: Val:= 5;
          ^I: Val:= 1
        other return Sum;       \zero string terminator
        I:= I+1;
        Sum:= Sum + Val;
        if Val > Val0 then Sum:= Sum - 2*Val0;
        Val0:= Val;
        ];
];

[IntOut(0, Roman("MCMXC"));    CrLf(0);
 IntOut(0, Roman("MMVIII"));   CrLf(0);
 IntOut(0, Roman("MDCLXVI"));  CrLf(0);
]