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/*
* Convert integer to string of roman numerals
*
* Copyright © 2001 Keith Packard
* All Rights Reserved. See the file COPYING in this directory
* for licensing information.
*
* A classic, plus a good illustration of some
* of the structuring, typing, and nesting
* capabilities of the language.
*/
string function roman (int i)
{
if (i < 0)
return "-" + roman (-i);
typedef struct {
string ones, five, tens;
int base;
} digit;
digit[*] digits = {
(digit) { ones = "C", five = "D", tens = "M", base = 100 },
(digit) { ones = "X", five = "L", tens = "C", base = 10 },
(digit) { ones = "I", five = "V", tens = "X", base = 1 }
};
string function place (int i, digit dig)
{
string function lots (int i, string s)
{
if (i != 0)
return s + lots (i-1,s);
return "";
}
if (i < 4)
return lots (i, dig.ones);
if (i == 4)
return dig.ones + dig.five;
if (i < 9)
return dig.five + lots (i-5, dig.ones);
if (i == 9)
return dig.ones + dig.tens;
return lots (i // 10, dig.tens) + place (i % 10, dig);
}
int d;
for (d = 0; d < dim(digits); d++)
if (i >= digits[d].base)
return (place (i // digits[d].base, digits[d]) +
roman(i % digits[d].base));
return "";
}
printf ("%s\n", roman (string_to_integer (argv[1])));
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