refactor

src/main/kotlin/blitz/collections/Contents.kt

@@ -0,0 +1,51 @@
+package blitz.collections
+
+class Contents<T> internal constructor(
+    private val iterable: Iterable<T>
+): Iterable<T> {
+    override fun iterator(): Iterator<T> =
+        iterable.iterator()
+
+    override fun equals(other: Any?): Boolean {
+        if (other !is Contents<*>)
+            return false
+
+        val it1 = this.iterable.iterator()
+        val it2 = other.iterable.iterator()
+
+        while (true) {
+            val hasNext1 = it1.hasNext()
+            val hasNext2 = it2.hasNext()
+
+            if ((hasNext1 && !hasNext2) || (hasNext2 && !hasNext1))
+                return false
+
+            if (!hasNext1)
+                return true
+
+            if (it1.next() != it2.next())
+                return false
+        }
+    }
+
+    override fun hashCode(): Int =
+        iterable.hashCode()
+
+    override fun toString(): String =
+        joinToString(
+            separator = ", ",
+            prefix = "[",
+            postfix = "]"
+        ) {
+            it.toString()
+        }
+}
+
+val <T> Iterable<T>.contents get() =
+    Contents(this)
+
+val <T> Sequence<T>.contents get() =
+    Contents(this.asIterable())
+
+val <T> Array<T>.contents get() =
+    Contents(this.asIterable())