Kotlin Matrix

matrix.kt

class Matrix<T>(val width: Int, val height: Int, init: () -> T) : Iterable<T> {
    private val data = List(width) { MutableList(height) { init() } }

    fun dimension() = width * height
    fun get(x: Int, y: Int): T = data[x][y]
    fun set(value: T, x: Int, y: Int) {
        data[x][y] = value
    }

    override fun iterator(): Iterator<T> {
        return MatrixIterator(this)
    }
}

class MatrixIterator<T>(private val matrix: Matrix<T>) : Iterator<T> {
    private val max = matrix.dimension()
    private var current = 0

    override fun hasNext(): Boolean {
        return current < max
    }

    override fun next(): T {
        val (x, y) = rowWiseSequenceToCoordinate(current)
        current += 1

        return matrix.get(x, y)
    }

    private fun rowWiseSequenceToCoordinate(sequence: Int): Pair<Int, Int> {
        val row = (sequence) % (matrix.width)
        val col = (sequence) / (matrix.width)

        return Pair(row, col)
    }
}