From b7d6b15de8a50e740d7121e16b77ab3e74c27320 Mon Sep 17 00:00:00 2001
From: Jakob Odersky <jakob@odersky.com>
Date: Thu, 27 Apr 2017 15:31:05 -0700
Subject: Initial commit

---
 src/main/scala/Main.scala | 58 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/main/scala/Main.scala

(limited to 'src')

diff --git a/src/main/scala/Main.scala b/src/main/scala/Main.scala
new file mode 100644
index 0000000..c19d3ec
--- /dev/null
+++ b/src/main/scala/Main.scala
@@ -0,0 +1,58 @@
+package macros
+
+import scala.collection.immutable.Map
+
+object Test extends App {
+
+  sealed trait JsValue
+  case class JsObject(fields: Map[String, JsValue]) extends JsValue
+  case class JsString(str: String) extends JsValue
+  case class JsNumber(num: Int) extends JsValue
+
+  trait MyWriter[A] {
+    def write(value: A): JsValue
+    def other(a: A): Int = 2
+  }
+  trait BaseWriters {
+    implicit val idWriter = new MyWriter[JsValue] {
+      def write(value: JsValue) = value
+    }
+    implicit val intWriter = new MyWriter[Int] {
+      def write(value: Int) = JsNumber(value)
+    }
+    implicit val stringWriter = new MyWriter[String] {
+      def write(value: String) = JsString(value)
+    }
+  }
+  trait CompositeWriters {
+    implicit def mapWriter[A: MyWriter] = new MyWriter[Map[String, A]] {
+      def write(mp: Map[String, A]) = {
+        def writeA(v: A) = implicitly[MyWriter[A]].write(v)
+        JsObject(mp.map { case (k, v) => k -> writeA(v) })
+      }
+    }
+  }
+
+  object Util {
+    def save[A: MyWriter](a: A): Unit = {
+      val x = implicitly[MyWriter[A]].write(a)
+      println("saving " + x)
+    }
+  }
+
+  case class Foo(x: Int)
+  case class Composite(x: Int, y: String, other: Foo)
+
+  object Protocol
+      extends BaseWriters
+      with CompositeWriters
+      with ProductWriters[MyWriter]
+  import Protocol._
+
+  class Bar
+  Util.save(2)
+  //Util.save(new Bar)
+  Util.save(Composite(2, "some string", Foo(3)))
+  //Util.save((2, "some string", "1")
+
+}
-- 
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