JireMap.kt

import java.util.*

class JireMap<K, V>(val capacity: Int = 16) : Iterable<JireMap.Entry<K, V>> {

	data class Entry<K, V>(val key: K, val value: V, var next: Entry<K, V>? = null)

	private var table = arrayOfNulls<Entry<K, V>>(capacity)

	fun K.hash() = Math.abs(hashCode()) % table.size

	@JvmName("put")
	operator fun set(key: K, value: V) {
		key!!

		val hash = key.hash()
		val entry = Entry(key, value)

		if (table[hash] != null) {
			var previous: Entry<K, V>? = null
			var current = table[hash]
			while (current != null) {
				if (key.equals(current.key)) {
					if (previous == null) {
						entry.next = current.next
						table[hash] = entry
						return
					} else {
						entry.next = current.next
						previous.next = entry
						return
					}
				}
				previous = current
				current = current.next
			}
			previous!!.next = entry
		} else table[hash] = entry
	}

	operator fun get(key: K): V? {
		key!!

		val hash = key.hash()
		if (table[hash] != null) {
			var temp = table[hash]
			while (temp != null) {
				if (key.equals(temp.key)) return temp.value
				temp = temp.next
			}
		}

		return null
	}

	private val iterator = object : Iterator<Entry<K, V>> {

		internal var next: Entry<K, V>? = null
		internal var current: Entry<K, V>? = null
		internal var index = 0

		fun reset() {
			current = null
			next = null
			index = 0
			while (index < table.size) {
				next = table[index++]
				if (next != null) break
			}
		}

		override fun next(): Entry<K, V> {
			var e = next ?: throw NoSuchElementException()
			current = e
			next = current!!.next
			if (next == null) while (index < table.size) {
				next = table[index++]
				if (next != null) break
			}
			return e
		}

		override fun hasNext(): Boolean {
			val hasNext = next != null
			if (!hasNext) iterating = false
			return hasNext
		}

	}

	private var iterating = false

	override fun iterator(): Iterator<Entry<K, V>> {
		if (iterating) throw IllegalStateException("You cannot iterate within an iteration!")

		iterating = true
		iterator.reset()

		return iterator
	}

	fun clear() {
		for (i in 0..table.size - 1) table[i] = null
	}

	fun putAll(map: JireMap<K, V>) {
		for ((k, v) in map) this[k] = v
	}

}