RosettaCodeData/Task/Roman-numerals-Decode/Zkl/roman-numerals-decode.zkl
2017-09-25 22:28:19 +02:00

16 lines
580 B
Text

var romans = L(
L("M", 1000), L("CM", 900), L("D", 500), L("CD", 400), L("C", 100),
L("XC", 90), L("L", 50), L("XL", 40), L("X", 10), L("IX", 9),
L("V", 5), L("IV", 4), L("I", 1));
fcn toArabic(romanNumber){ // romanNumber needs to be upper case
if (not RegExp("^[CDILMVX]+$").matches(romanNumber))
throw(Exception.ValueError("Not a Roman number: %s".fmt(romanNumber)));
reg value = 0;
foreach R,N in (romans){
while (0 == romanNumber.find(R)){
value += N;
romanNumber = romanNumber[R.len(),*];
}
}
return(value);
}