Code Kata: WordWrap

LukeAndCraig.kt

package uk.co.devls.coffeebook.test.unit

import org.amshove.kluent.`should equal`
import kotlin.test.*
import org.jetbrains.spek.api.Spek

class CodeDojoTest : Spek({
    describe("Wrapper") {
        it("should return empty string when provided empty string") {
            Wrapper().wrap("", 0).`should equal`("")
            Wrapper().wrap("This is cool", 50).`should equal`("This is cool")
            Wrapper().wrap("a a", 1).`should equal`("a\na")
            Wrapper().wrap("a a a", 1).`should equal`("a\na\na")
            Wrapper().wrap("a a a", 3).`should equal`("a a\na")
            Wrapper().wrap("a b c d e", 3).`should equal`("a b\nc d\ne")
            Wrapper().wrap("a b c d e f g", 3).`should equal`("a b\nc d\ne f\ng")
//            Wrapper().wrap("a b c d e f g h j", 3).`should equal`("a b\nc d\ne f\ng h\nj")
        }
    }
})
 

class Wrapper {
    fun wrap(input: String, cols: Int): String {
        if (input.length > cols) {
            if (cols == 1) {
                return input.replace(" ", "\n")
            } else {

                val beginning = input.slice(0..cols - 1) + "\n"
                var rest = ""
                var index = 0
                var nextIndex = index + 1

                if (input.length < cols*2) {

                }

                if (input.length > index*cols) {
                    index++
                    nextIndex = index + 1
                    rest = input.slice(cols..cols * 2).trim() + "\n"
                }

                if (input.length > index*cols) {
                    index += 2
                    nextIndex = index + 1
                    rest = input.slice(cols..cols * 2).trim() + "\n" + input.slice(cols * 2 + 1..cols * 3 + 1).trim() + "\n"
                }

                return beginning + rest + input.slice(cols * nextIndex + index..input.length - 1).trim()
            }
        }

        return input
    }
}

WordWrap.md

Problem Description

You need to write a class called Wrapper, that has a single static method named wrap that takes two arguments, a string, and a column number. The function returns the string, but with line breaks inserted at just the right places to make sure that no line is longer than the column number. You try to break lines at word boundaries.

Like a word processor, break the line by replacing the last space in a line with a newline.