Add DynamicTransform class.

This is used with the FunctionInterface::DynamicTransformCont method to
convert a call of arguments using dynamic array handles to a function
templated on concrete types.

vtkm/cont/DynamicArrayHandle.h

@@ -26,6 +26,7 @@
 #include <vtkm/cont/ContainerListTag.h>
 #include <vtkm/cont/ErrorControlBadValue.h>
 
+#include <vtkm/cont/internal/DynamicTransform.h>
 #include <vtkm/cont/internal/SimplePolymorphicContainer.h>
 
 #include <boost/smart_ptr/shared_ptr.hpp>
@@ -246,6 +247,9 @@ template<typename TypeList, typename ContainerList>
 class DynamicArrayHandleCast : public vtkm::cont::DynamicArrayHandle
 {
 public:
+  VTKM_CONT_EXPORT
+  DynamicArrayHandleCast() : DynamicArrayHandle() {  }
+
   VTKM_CONT_EXPORT
   DynamicArrayHandleCast(const vtkm::cont::DynamicArrayHandle &array)
     : DynamicArrayHandle(array) {  }
@@ -285,6 +289,18 @@ public:
   }
 };
 
+template<>
+struct DynamicTransformTraits<vtkm::cont::DynamicArrayHandle> {
+  typedef vtkm::cont::internal::DynamicTransformTagCastAndCall DynamicTag;
+};
+
+template<typename TypeList, typename ContainerList>
+struct DynamicTransformTraits<
+    vtkm::cont::internal::DynamicArrayHandleCast<TypeList,ContainerList> >
+{
+  typedef vtkm::cont::internal::DynamicTransformTagCastAndCall DynamicTag;
+};
+
 } // namespace internal
 
 }

vtkm/cont/internal/CMakeLists.txt

@@ -32,6 +32,7 @@ set(headers
   DeviceAdapterError.h
   DeviceAdapterTag.h
   DeviceAdapterTagSerial.h
+  DynamicTransform.h
   IteratorFromArrayPortal.h
   SimplePolymorphicContainer.h
   )

vtkm/cont/internal/DynamicTransform.h

+//============================================================================
+//  Copyright (c) Kitware, Inc.
+//  All rights reserved.
+//  See LICENSE.txt for details.
+//  This software is distributed WITHOUT ANY WARRANTY; without even
+//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+//  PURPOSE.  See the above copyright notice for more information.
+//
+//  Copyright 2014 Sandia Corporation.
+//  Copyright 2014 UT-Battelle, LLC.
+//  Copyright 2014. Los Alamos National Security
+//
+//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
+//  the U.S. Government retains certain rights in this software.
+//
+//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
+//  Laboratory (LANL), the U.S. Government retains certain rights in
+//  this software.
+//============================================================================
+#ifndef vtk_m_cont_internal_DynamicTransform_h
+#define vtk_m_cont_internal_DynamicTransform_h
+
+#include "vtkm/internal/ExportMacros.h"
+
+namespace vtkm {
+namespace cont {
+namespace internal {
+
+namespace detail {
+
+template<typename ContinueFunctor>
+struct DynamicArrayTransformCastAndCall
+{
+  const ContinueFunctor &Continue;
+
+  VTKM_CONT_EXPORT
+  DynamicArrayTransformCastAndCall(const ContinueFunctor &continueFunc)
+    : Continue(continueFunc) {  }
+
+  template<typename T>
+  VTKM_CONT_EXPORT
+  void operator()(const T &x) const {
+    this->Continue(x);
+  }
+};
+
+} // namespace detail
+
+/// Tag used to identify an object that is a dynamic object that contains a
+/// CastAndCall method that iterates over all possible dynamic choices to run
+/// templated code.
+///
+struct DynamicTransformTagCastAndCall {  };
+
+/// Tag used to identify an object that is a static object that, when used with
+/// a \c DynamicTransform should just pass itself as a concrete object.
+///
+struct DynamicTransformTagStatic {  };
+
+/// A traits class that identifies whether an object used in a \c
+/// DynamicTransform should use a \c CastAndCall functionality or treated as a
+/// static object. The default implementation identifies the object as static
+/// (as most objects are bound to be). Dynamic objects that implement
+/// \c CastAndCall should specialize (or partially specialize) this traits class
+/// to identify the object as dynamic. VTK-m classes like \c DynamicArray are
+/// already specialized.
+///
+template<typename T>
+struct DynamicTransformTraits {
+  /// A type set to either \c DynamicTransformTagStatic or \c
+  /// DynamicTransformTagCastAndCall. The default implementation is set to \c
+  /// DynamicTransformTagStatic. Dynamic objects that implement \c CastAndCall
+  /// should specialize this class redefine it to \c
+  /// DynamicTransformTagCastAndCall.
+  ///
+  typedef vtkm::cont::internal::DynamicTransformTagStatic DynamicTag;
+};
+
+/// This functor can be used as the transform in the \c DynamicTransformCont
+/// method of \c FunctionInterface. It will allow dynamic objects like
+/// \c DynamicArray to be cast to their concrete types for templated operation.
+///
+struct DynamicTransform
+{
+  template<typename InputType, typename ContinueFunctor>
+  VTKM_CONT_EXPORT
+  void operator()(const InputType &input,
+                  const ContinueFunctor &continueFunc) const
+  {
+    this->DoTransform(
+          input,
+          continueFunc,
+          typename vtkm::cont::internal::DynamicTransformTraits<InputType>::DynamicTag());
+  }
+
+private:
+  template<typename InputType, typename ContinueFunctor>
+  VTKM_CONT_EXPORT
+  void DoTransform(const InputType &input,
+                   const ContinueFunctor &continueFunc,
+                   vtkm::cont::internal::DynamicTransformTagStatic) const
+  {
+    continueFunc(input);
+  }
+
+  template<typename InputType, typename ContinueFunctor>
+  VTKM_CONT_EXPORT
+  void DoTransform(const InputType &dynamicInput,
+                   const ContinueFunctor &continueFunc,
+                   vtkm::cont::internal::DynamicTransformTagCastAndCall) const
+  {
+    dynamicInput.CastAndCall(
+          detail::DynamicArrayTransformCastAndCall<ContinueFunctor>(continueFunc));
+  }
+};
+
+}
+}
+} // namespace vtkm::cont::internal
+
+#endif //vtk_m_cont_internal_DynamicTransform_h

vtkm/cont/internal/testing/CMakeLists.txt

@@ -22,6 +22,7 @@
 set(unit_tests
   UnitTestArrayManagerExecutionShareWithControl.cxx
   UnitTestArrayPortalFromIterators.cxx
+  UnitTestDynamicTransform.cxx
   UnitTestIteratorFromArrayPortal.cxx
   )
 vtkm_unit_tests(SOURCES ${unit_tests})

vtkm/cont/internal/testing/UnitTestDynamicTransform.cxx

+//============================================================================
+//  Copyright (c) Kitware, Inc.
+//  All rights reserved.
+//  See LICENSE.txt for details.
+//  This software is distributed WITHOUT ANY WARRANTY; without even
+//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
+//  PURPOSE.  See the above copyright notice for more information.
+//
+//  Copyright 2014 Sandia Corporation.
+//  Copyright 2014 UT-Battelle, LLC.
+//  Copyright 2014. Los Alamos National Security
+//
+//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
+//  the U.S. Government retains certain rights in this software.
+//
+//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
+//  Laboratory (LANL), the U.S. Government retains certain rights in
+//  this software.
+//============================================================================
+
+#include "vtkm/cont/internal/DynamicTransform.h"
+
+#include "vtkm/cont/ArrayHandle.h"
+#include "vtkm/cont/DynamicArrayHandle.h"
+
+#include "vtkm/internal/FunctionInterface.h"
+
+#include "vtkm/cont/testing/Testing.h"
+
+namespace {
+
+static int g_FunctionCalls;
+
+#define TRY_TRANSFORM(expr) \
+  g_FunctionCalls = 0; \
+  expr; \
+  VTKM_TEST_ASSERT(g_FunctionCalls == 1, "Functor not called correctly.")
+
+struct TypeListTagString : vtkm::ListTagBase<std::string> { };
+
+struct ScalarFunctor {
+  void operator()(vtkm::Scalar) const {
+    std::cout << "    In Scalar functor." << std::endl;
+    g_FunctionCalls++;
+  }
+};
+
+struct ArrayHandleScalarFunctor {
+  template<typename T>
+  void operator()(const vtkm::cont::ArrayHandle<T> &) const {
+    VTKM_TEST_FAIL("Called wrong form of functor operator.");
+  }
+  void operator()(const vtkm::cont::ArrayHandle<vtkm::Scalar> &) const {
+    std::cout << "    In ArrayHandle<Scalar> functor." << std::endl;
+    g_FunctionCalls++;
+  }
+};
+
+struct ArrayHandleStringFunctor {
+  void operator()(const vtkm::cont::ArrayHandle<std::string> &) const {
+    std::cout << "    In ArrayHandle<string> functor." << std::endl;
+    g_FunctionCalls++;
+  }
+};
+
+struct FunctionInterfaceFunctor {
+  template<typename Signature>
+  void operator()(const vtkm::internal::FunctionInterface<Signature> &) const {
+    VTKM_TEST_FAIL("Called wrong form of functor operator.");
+  }
+  void operator()(
+      const vtkm::internal::FunctionInterface<
+        void(vtkm::cont::ArrayHandle<vtkm::Scalar>,
+             vtkm::cont::ArrayHandle<vtkm::Scalar>,
+             vtkm::cont::ArrayHandle<std::string>)> &) const {
+    std::cout << "    In FunctionInterface<...> functor." << std::endl;
+    g_FunctionCalls++;
+  }
+};
+
+void TestBasicTransform()
+{
+  std::cout << "Testing basic transform." << std::endl;
+
+  vtkm::cont::internal::DynamicTransform transform;
+
+  std::cout << "  Trying with simple scalar." << std::endl;
+  TRY_TRANSFORM(transform(vtkm::Scalar(5), ScalarFunctor()));
+
+  std::cout << "  Trying with basic scalar array." << std::endl;
+  vtkm::cont::ArrayHandle<vtkm::Scalar> concreteArray;
+  TRY_TRANSFORM(transform(concreteArray, ArrayHandleScalarFunctor()));
+
+  std::cout << "  Trying scalar dynamic array." << std::endl;
+  vtkm::cont::DynamicArrayHandle dynamicArray = concreteArray;
+  TRY_TRANSFORM(transform(dynamicArray, ArrayHandleScalarFunctor()));
+
+  std::cout << "  Trying with unusual (string) dynamic array." << std::endl;
+  dynamicArray = vtkm::cont::ArrayHandle<std::string>();
+  TRY_TRANSFORM(transform(dynamicArray.ResetTypeList(TypeListTagString()),
+                          ArrayHandleStringFunctor()));
+}
+
+void TestFunctionTransform()
+{
+  std::cout << "Testing transforms in FunctionInterface." << std::endl;
+
+  vtkm::cont::ArrayHandle<vtkm::Scalar> scalarArray;
+  vtkm::cont::ArrayHandle<std::string> stringArray;
+
+  std::cout << "  Trying basic functor call w/o transform (make sure it works)."
+            << std::endl;
+  TRY_TRANSFORM(FunctionInterfaceFunctor()(
+                  vtkm::internal::make_FunctionInterface<void>(scalarArray,
+                                                               scalarArray,
+                                                               stringArray)));
+
+  std::cout << "  Trying dynamic cast" << std::endl;
+  TRY_TRANSFORM(
+        vtkm::internal::make_FunctionInterface<void>(
+          scalarArray,
+          vtkm::cont::DynamicArrayHandle(scalarArray),
+          vtkm::cont::DynamicArrayHandle(stringArray).ResetTypeList(TypeListTagString()))
+        .DynamicTransformCont(vtkm::cont::internal::DynamicTransform(),
+                              FunctionInterfaceFunctor()));
+}
+
+void TestDynamicTransform()
+{
+  TestBasicTransform();
+  TestFunctionTransform();
+}
+
+} // anonymous namespace
+
+int UnitTestDynamicTransform(int, char *[])
+{
+  return vtkm::cont::testing::Testing::Run(TestDynamicTransform);
+}

vtkm/internal/FunctionInterface.h

@@ -583,9 +583,9 @@ public:
   ///   template<typename InputType, typename ContinueFunctor>
   ///   VTKM_CONT_EXPORT
   ///   void operator()(const InputType &input,
-  ///                   const ContinueFunctor &continue) const
+  ///                   const ContinueFunctor &continueFunc) const
   ///   {
-  ///     continue(input);
+  ///     continueFunc(input);
   ///   }
   ///
   ///   template<typename ContinueFunctor>