clean up

src/main/kotlin/blitz/DelegateProperties.kt

@@ -0,0 +1,21 @@
+package blitz
+
+fun <T, O: Any> caching(tiedGet: Provider<T>, calc: (T) -> O) = object : Lazy<O> {
+    private var lastTiedV = tiedGet()
+    private var lastV: O? = null
+
+    override val value: O get() {
+        val nTied = tiedGet()
+        if (lastTiedV != nTied) {
+            lastTiedV = nTied
+            lastV = calc(nTied)
+            return lastV!!
+        }
+        if (lastV == null)
+            lastV = calc(nTied)
+        return lastV!!
+    }
+
+    override fun isInitialized(): Boolean =
+        lastTiedV == tiedGet() && lastV != null
+}