RosettaCodeData/Task/Roman-numerals-Decode/Golo/roman-numerals-decode.golo
2019-09-12 10:33:56 -07:00

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#!/usr/bin/env golosh
----
This module converts a Roman numeral into a decimal number.
----
module Romannumeralsdecode
augment java.lang.Character {
function decode = |this| -> match {
when this == 'I' then 1
when this == 'V' then 5
when this == 'X' then 10
when this == 'L' then 50
when this == 'C' then 100
when this == 'D' then 500
when this == 'M' then 1000
otherwise 0
}
}
augment java.lang.String {
function decode = |this| {
var accumulator = 0
foreach i in [0..this: length()] {
let currentChar = this: charAt(i)
let nextChar = match {
when i + 1 < this: length() then this: charAt(i + 1)
otherwise null
}
if (currentChar: decode() < (nextChar?: decode() orIfNull 0)) {
# if this is something like IV or IX or whatever
accumulator = accumulator - currentChar: decode()
} else {
accumulator = accumulator + currentChar: decode()
}
}
return accumulator
}
}
function main = |args| {
println("MCMXC = " + "MCMXC": decode())
println("MMVIII = " + "MMVIII": decode())
println("MDCLXVI = " + "MDCLXVI": decode())
}