Apparent progress

2 files changed, 209 insertions, 31 deletions

diff --git a/core/src/main/scala/generic.scala b/core/src/main/scala/generic.scala
index 86b4d24..ffb2c14 100644
--- a/core/src/main/scala/generic.scala
+++ b/core/src/main/scala/generic.scala
@@ -17,7 +17,7 @@ object GlobalMutableState {
   private[magnolia] var state: Map[Pos, ListMap[c.universe.Type forSome { val c: whitebox.Context }, c.universe.TermName forSome { val c: whitebox.Context }]] = Map()
   
   private[magnolia] def push(c: whitebox.Context)(key: c.universe.Type, value: c.universe.TermName): Unit = {
-    println(s"push($key)")
+    println(s"push($key, $value)")
     state = state.updated(Pos(c.enclosingPosition), state.get(Pos(c.enclosingPosition)).map { m =>
       m.updated(key, value)
     }.getOrElse(ListMap(key -> value)))
@@ -30,11 +30,12 @@ object GlobalMutableState {
     println("state = "+state)
   }
   
-  private[magnolia] def has(c: whitebox.Context)(key: c.universe.Type): Option[c.universe.TermName] =
+  private[magnolia] def has(c: whitebox.Context)(key: c.universe.Type): Option[c.universe.TermName] = {
     try state(Pos(c.enclosingPosition)).get(key).asInstanceOf[Option[c.universe.TermName]] catch {
       case e: Exception =>
         ???
     }
+  }
 
   private[magnolia] var searchType: AnyRef = null
 }
@@ -70,26 +71,34 @@ abstract class GenericMacro(whiteboxContext: whitebox.Context) {
 
   def getImplicit(genericType: c.universe.Type,
                   typeConstructor: c.universe.Type,
-                  myName: c.universe.TermName,
-                  count: Int): c.Tree = {
+                  myName: c.universe.TermName): c.Tree = {
     
     import c.universe._
-    println(s"getImplicit1($genericType, $count)")
+    //println(s"getImplicit1($genericType)")
     val x = GlobalMutableState.has(c)(genericType)
-    x.foreach { y => println("y = "+y) }
     val result = x.map { nm =>
       q"$nm"
     }.orElse {
       val searchType = appliedType(typeConstructor, genericType)
       if(GlobalMutableState.has(c)(genericType).isEmpty) {
         GlobalMutableState.searchType = genericType
-        val inferredImplicit = try Some(c.inferImplicitValue(searchType, false, false)) catch {
+        val inferredImplicit = try Some({
+          //println(s"ONE: $genericType -> $myName")
+          //GlobalMutableState.push(c)(genericType, myName)
+          val imp = c.inferImplicitValue(searchType, false, false)
+          //GlobalMutableState.pop(c)
+          q"""{
+            def $myName = $imp
+            $myName
+          }"""
+        }) catch {
           case e: Exception => None
         }
+
         object transformer extends Transformer {
           override def transform(tree: Tree): Tree = tree match {
             case ta@TypeApply(Select(Literal(Constant(method: String)), TermName("asInstanceOf")), List(tpe)) =>
-              println(s"Found typeapply: ${tpe}")
+              println(s"FOUND TYPEAPPLY: ${ta}")
               val m = TermName(method)
               q"$m"
             case _ => super.transform(tree)
@@ -97,31 +106,29 @@ abstract class GenericMacro(whiteboxContext: whitebox.Context) {
         }
 
         inferredImplicit.map { imp =>
-          c.resetLocalAttrs(imp)
-          transformer.transform(imp)
-          c.typecheck(imp)
+          val x = c.untypecheck(imp)
+          val z = c.untypecheck(transformer.transform(imp))
+          println("x: "+x+", z: "+z)
+          z
         }.orElse {
-          directInferImplicit(genericType, typeConstructor, count + 1)
+          directInferImplicit(genericType, typeConstructor)
         }
       } else {
-        directInferImplicit(genericType, typeConstructor, count + 1)
+        directInferImplicit(genericType, typeConstructor)
       }
     }.getOrElse {
       println("Really failed to find extractor for type "+genericType)
       c.abort(c.enclosingPosition, "Could not find extractor for type "+genericType)
     }
 
-    //println("  = "+result)
-
     result
   }
   
   def directInferImplicit(genericType: c.universe.Type,
-         typeConstructor: c.universe.Type,
-         count: Int): Option[c.Tree] = {
+         typeConstructor: c.universe.Type): Option[c.Tree] = {
     import c.universe._
    
-    println(s"directInferImplicit($genericType, $count)")
+    //println(s"directInferImplicit($genericType)")
 
     val myName: TermName = TermName(c.freshName(genericType.typeSymbol.name.encodedName.toString.toLowerCase+"Extractor"))
     val typeSymbol = genericType.typeSymbol
@@ -137,8 +144,9 @@ abstract class GenericMacro(whiteboxContext: whitebox.Context) {
         case m: MethodSymbol if m.isCaseAccessor => m.asMethod
       }.map { param =>
         val returnType = param.returnType
+        println(s"TWO: $genericType -> $myName")
         GlobalMutableState.push(c)(genericType, myName)
-        val imp = getImplicit(returnType, typeConstructor, myName, count)
+        val imp = getImplicit(returnType, typeConstructor, myName)
         GlobalMutableState.pop(c)
         val dereferenced = dereferenceValue(c)(q"src", param.name.toString)
         callDelegateMethod(c)(imp, dereferenced)
@@ -148,8 +156,9 @@ abstract class GenericMacro(whiteboxContext: whitebox.Context) {
     } else if(isSealedTrait) {
       val subtypes = classType.get.knownDirectSubclasses.to[List]
       Some(subtypes.map(_.asType.toType).map { searchType =>
+        println(s"THREE: $genericType -> $myName")
         GlobalMutableState.push(c)(genericType, myName)
-        val res = getImplicit(searchType, typeConstructor, myName, count)
+        val res = getImplicit(searchType, typeConstructor, myName)
         GlobalMutableState.pop(c)
         res
       }.reduce(coproductReduction(c))).map { imp =>
@@ -181,36 +190,32 @@ abstract class GenericMacro(whiteboxContext: whitebox.Context) {
   def generic[T: c.WeakTypeTag, Tc: c.WeakTypeTag]: c.Tree = try {
     import c.universe._
 
-    println("Entering generic for type "+weakTypeOf[T])
+    //println("Entering generic for type "+weakTypeOf[T])
 
     val genericType: Type = weakTypeOf[T]
     val reentrant = genericType == GlobalMutableState.searchType
-    println(s"LAST TYPE = ${GlobalMutableState.searchType}; THIS TYPE = $genericType")
+    //println(s"previous: ${GlobalMutableState.searchType}; THIS TYPE = $genericType")
     val result: Option[c.Tree] = if(reentrant) {
-      println("Reentrant.")
+      //println("Reentrant.")
       throw ReentrantException()
     } else if(GlobalMutableState.searchType != null) {
       GlobalMutableState.has(c)(genericType) match {
         case None =>
           val typeConstructor: Type = weakTypeOf[Tc].typeConstructor
-          directInferImplicit(genericType, typeConstructor, 0)
+          directInferImplicit(genericType, typeConstructor)
         case Some(t) =>
           val str = t.toString
           val typeConstructor: Type = weakTypeOf[Tc].typeConstructor
           val searchType = appliedType(typeConstructor, genericType)
+          println(s"$str ===>>> ${searchType}")
           Some(q"$str.asInstanceOf[${searchType}]")
       }
     } else {
       val typeConstructor: Type = weakTypeOf[Tc].typeConstructor
-      directInferImplicit(genericType, typeConstructor, 0)
+      directInferImplicit(genericType, typeConstructor)
     }
     
-    println(result)
-    try result.map { tree => c.typecheck(tree) } catch {
-      case e: Exception =>
-        println(result)
-        println("Failed to typecheck because: "+e)
-    }
+    println("Final result: "+result)
 
     result.getOrElse {
       println("FAIL.")
diff --git a/core/src/main/scala/generic.scala~ b/core/src/main/scala/generic.scala~
new file mode 100644
index 0000000..4767435
--- /dev/null
+++ b/core/src/main/scala/generic.scala~
@@ -0,0 +1,173 @@
+package magnolia
+
+import scala.reflect._, macros._
+import macrocompat.bundle
+import scala.util.Try
+
+import scala.collection.immutable.ListMap
+
+object GlobalMutableState {
+  private[magnolia] var state: ListMap[AnyRef, AnyRef] = ListMap()
+  
+  private[magnolia] def push(key: AnyRef, value: AnyRef): Unit = {
+    state += ((key, value))
+  }
+  
+  private[magnolia] def pop(): Unit = {
+    state = state.init
+  }
+  
+  private[magnolia] def has(c: whitebox.Context)(key: AnyRef): Option[c.universe.Tree] =
+    state.get(key).asInstanceOf[Option[c.universe.Tree]]
+
+  private[magnolia] var searchType: AnyRef = null
+}
+
+@bundle
+class Macros(val context: whitebox.Context) extends GenericMacro(context) {
+  
+  
+  protected def classBody(context: whitebox.Context)(genericType: context.Type, implementation: context.Tree): context.Tree = {
+    import context.universe._
+    q"""def extract(src: _root_.magnolia.Thing): $genericType = $implementation"""
+  }
+
+  protected def dereferenceValue(context: whitebox.Context)(value: context.Tree, elem: String): context.Tree = {
+    import context.universe._
+    q"$value.access($elem)"
+  }
+  
+  protected def callDelegateMethod(context: whitebox.Context)(value: context.Tree, argument: context.Tree): context.Tree = {
+    import context.universe._
+    q"$value.extract($argument)"
+  }
+  
+  protected def coproductReduction(context: whitebox.Context)(left: context.Tree, right: context.Tree): context.Tree = {
+    import context.universe._
+    q"$left.orElse($right)"
+  }
+}
+
+abstract class GenericMacro(whiteboxContext: whitebox.Context) {
+
+  val c = whiteboxContext
+
+  def getImplicit(genericType: c.universe.Type,
+                  typeConstructor: c.universe.Type,
+                  myName: c.universe.TermName,
+                  count: Int): c.Tree = {
+    
+    import c.universe._
+    println(s"getImplicit($genericType, $count)")
+    val result = GlobalMutableState.has(c)(genericType).map { nm => q"$nm" }.orElse {
+      val searchType = appliedType(typeConstructor, genericType)
+      if(GlobalMutableState.has(c)(genericType).isEmpty) {
+        scala.util.Try {
+          GlobalMutableState.searchType = genericType
+          c.inferImplicitValue(searchType, false, false)
+        }.toOption.orElse {
+          println("Recursing")
+          directInferImplicit(genericType, typeConstructor, count + 1)
+        }
+      } else {
+        directInferImplicit(genericType, typeConstructor, count + 1)
+      }
+    }.getOrElse {
+      println("Failed 2.")
+      c.abort(c.enclosingPosition, "Could not find extractor for type "+genericType)
+    }
+
+
+    result
+  }
+  
+  def directInferImplicit(genericType: c.universe.Type,
+         typeConstructor: c.universe.Type,
+         count: Int): Option[c.Tree] = {
+    import c.universe._
+   
+    println(s"directInferImplicit($genericType, $count)")
+
+    val myName: TermName = TermName(c.freshName(genericType.typeSymbol.name.encodedName.toString.toLowerCase+"Extractor"))
+    val typeSymbol = genericType.typeSymbol
+    val classType = if(typeSymbol.isClass) Some(typeSymbol.asClass) else None
+    val isCaseClass = classType.map(_.isCaseClass).getOrElse(false)
+    val isSealedTrait = classType.map(_.isSealed).getOrElse(false)
+    val isAnyVal = genericType <:< typeOf[AnyVal]
+    
+    val resultType = appliedType(typeConstructor, genericType)
+
+    val construct = if(isCaseClass) {
+      val implicits = genericType.decls.collect {
+        case m: MethodSymbol if m.isCaseAccessor => m.asMethod
+      }.map { param =>
+        val returnType = param.returnType
+        GlobalMutableState.push(genericType, myName)
+        val imp = getImplicit(returnType, typeConstructor, myName, count)
+        GlobalMutableState.pop()
+        val dereferenced = dereferenceValue(c)(q"src", param.name.toString)
+        callDelegateMethod(c)(imp, dereferenced)
+      }
+
+      Some(q"new $genericType(..$implicits)")
+    } else if(isSealedTrait) {
+      val subtypes = classType.get.knownDirectSubclasses.to[List]
+      Some(subtypes.map(_.asType.toType).map { searchType =>
+        GlobalMutableState.push(genericType, myName)
+        val res = getImplicit(searchType, typeConstructor, myName, count)
+        GlobalMutableState.pop()
+        res
+      }.reduce(coproductReduction(c))).map { imp =>
+        callDelegateMethod(c)(imp, q"src")
+      }
+      
+    } else None
+
+    val result = construct.map { const =>
+      
+      val methodImplementation = classBody(c)(genericType, const)
+      q"""{
+        def $myName: $resultType = new $resultType {
+          $methodImplementation
+        }
+        $myName
+      }"""
+    }
+
+
+    result
+  }
+  
+  protected def classBody(c: whitebox.Context)(genericType: c.Type, implementation: c.Tree): c.Tree
+  protected def coproductReduction(c: whitebox.Context)(left: c.Tree, right: c.Tree): c.Tree
+  protected def dereferenceValue(c: whitebox.Context)(value: c.Tree, elem: String): c.Tree
+  protected def callDelegateMethod(c: whitebox.Context)(value: c.Tree, argument: c.Tree): c.Tree
+
+  def generic[T: c.WeakTypeTag, Tc: c.WeakTypeTag]: c.Tree = {
+    import c.universe._
+
+    val genericType: Type = weakTypeOf[T]
+    val reentrant = genericType == GlobalMutableState.searchType
+    if(reentrant) {
+      println("Reentrant.")
+      ???
+    }
+    val typeConstructor: Type = weakTypeOf[Tc].typeConstructor
+
+    val result = directInferImplicit(genericType, typeConstructor, 0)
+
+    println(result)
+    try result.map { tree => c.typecheck(tree) } catch {
+      case e: Exception =>
+        println(result)
+        println("Failed to typecheck because: "+e)
+    }
+
+    result.getOrElse {
+      println("Count not infer extractor...")
+      c.abort(c.enclosingPosition, "Could not infer extractor. Sorry.")
+    }
+  }
+
+}
+