Rot13 in Kotlin

Welcome to the Rot13 in Kotlin page! Here, you'll find the source code for this program as well as a description of how the program works.

Current Solution

data class EncodingBounds(val lowerBound: Int, val upperBound: Int)

fun encodingBoundsForCharValue(c: Char): EncodingBounds? {
    val lowerCaseBounds = EncodingBounds('a'.toInt(), 'z'.toInt())
    val upperCaseBounds = EncodingBounds('A'.toInt(), 'Z'.toInt())
    return when (c) {
        in 'a'..'z' -> lowerCaseBounds
        in 'A'..'Z' -> upperCaseBounds
        else -> null
    }
}

fun calculateRotatedChar(char: Char, rotation: Int, bounds: EncodingBounds): Char {
    val rotatedCharVal = char.toInt() + rotation
    val remainder = rotatedCharVal - (bounds.upperBound + 1)
    return (if (rotatedCharVal > bounds.upperBound) bounds.lowerBound + remainder else rotatedCharVal).toChar()
}

fun parseInput(args: Array<String>): String? {
    if (args.isEmpty()) {
        return null
    }
    val text = args[0]
    if (text.isEmpty()) {
        return null
    }
    return text
}

fun rot13Encode(text: String): String {
    val rotation = 13

    return text.map { c ->
        val bounds = encodingBoundsForCharValue(c)
        if (bounds == null) {
            c.toString()
        } else {
            calculateRotatedChar(c, rotation, bounds).toString()
        }
    }.reduce { encodedText, encodedChar ->
        encodedText + encodedChar
    }

}

fun main(args: Array<String>) {
    val strToEncode = parseInput(args)
    if (strToEncode == null) {
        println("Usage: please provide a string to encrypt")
    } else {
        println(rot13Encode(strToEncode))
    }
}

Rot13 in Kotlin was written by:

• Cristiano Lopes
• Jeremy Grifski

If you see anything you'd like to change or update, please consider contributing.

How to Implement the Solution

No 'How to Implement the Solution' section available. Please consider contributing.

How to Run the Solution

No 'How to Run the Solution' section available. Please consider contributing.