From 4efd593626487f939b2296cabf5aed53ffc8d01a Mon Sep 17 00:00:00 2001
From: =?utf8?q?=EB=B0=95=EC=A2=85=ED=98=84/=EB=8F=99=EC=9E=91=EC=A0=9C?=
 =?utf8?q?=EC=96=B4Lab=28SR=29/Senior=20Engineer/=EC=82=BC=EC=84=B1?=
 =?utf8?q?=EC=A0=84=EC=9E=90?= <jh1302.park@samsung.com>
Date: Mon, 9 Apr 2018 09:30:41 +0900
Subject: [PATCH] Introduce nnfw::util::tensor::Zipper (#495)

This commit introduces Zipper class and related helper methods.

Signed-off-by: Jonghyun Park <jh1302.park@samsung.com>
---
 include/util/tensor/Zipper.h       | 56 ++++++++++++++++++++++++++++++++++++++
 tools/nnapi_test/src/nnapi_test.cc |  6 ++--
 2 files changed, 59 insertions(+), 3 deletions(-)
 create mode 100644 include/util/tensor/Zipper.h

diff --git a/include/util/tensor/Zipper.h b/include/util/tensor/Zipper.h
new file mode 100644
index 0000000..d0e0c46
--- /dev/null
+++ b/include/util/tensor/Zipper.h
@@ -0,0 +1,56 @@
+#ifndef __NNFW_UTIL_TENSOR_ZIPPER_H__
+#define __NNFW_UTIL_TENSOR_ZIPPER_H__
+
+#include "util/tensor/Index.h"
+#include "util/tensor/IndexIterator.h"
+#include "util/tensor/Reader.h"
+
+namespace nnfw
+{
+namespace util
+{
+namespace tensor
+{
+
+template <typename T> class Zipper
+{
+public:
+  Zipper(const Shape &shape, const Reader<T> &lhs, const Reader<T> &rhs)
+    : _shape{shape}, _lhs{lhs}, _rhs{rhs}
+  {
+    // DO NOTHING
+  }
+
+public:
+  template <typename Callable> void zip(Callable cb) const
+  {
+    iterate(_shape) << [this, &cb] (const Index &index)
+    {
+      cb(index, _lhs.at(index), _rhs.at(index));
+    };
+  }
+
+private:
+  const Shape &_shape;
+  const Reader<T> &_lhs;
+  const Reader<T> &_rhs;
+};
+
+template<typename T, typename Callable>
+const Zipper<T> &operator<<(const Zipper<T> &zipper, Callable cb)
+{
+  zipper.zip(cb);
+  return zipper;
+}
+
+template<typename T>
+Zipper<T> zip(const Shape &shape, const Reader<T> &lhs, const Reader<T> &rhs)
+{
+  return Zipper<T>{shape, lhs, rhs};
+}
+
+} // namespace tensor
+} // namespace util
+} // namespace nnfw
+
+#endif // __NNFW_UTIL_TENSOR_ZIPPER_H__
diff --git a/tools/nnapi_test/src/nnapi_test.cc b/tools/nnapi_test/src/nnapi_test.cc
index ae8ed05..c5c7d9d 100644
--- a/tools/nnapi_test/src/nnapi_test.cc
+++ b/tools/nnapi_test/src/nnapi_test.cc
@@ -4,6 +4,7 @@
 #include "util/environment.h"
 #include "util/fp32.h"
 #include "util/tensor/IndexIterator.h"
+#include "util/tensor/Zipper.h"
 #include "support/tflite/TensorView.h"
 #include "support/tflite/interp/FlatBufferBuilder.h"
 
@@ -117,10 +118,9 @@ TfLiteTensorComparator::compare(const nnfw::support::tflite::TensorView<float> &
 
   assert(expected.shape() == obtained.shape());
 
-  nnfw::util::tensor::iterate(expected.shape()) << [&] (const nnfw::util::tensor::Index &index)
+  nnfw::util::tensor::zip(expected.shape(), expected, obtained) <<
+    [&] (const nnfw::util::tensor::Index &index, float expected_value, float obtained_value)
   {
-    const auto expected_value = expected.at(index);
-    const auto obtained_value = obtained.at(index);
     const auto relative_diff = nnfw::util::fp32::relative_diff(expected_value, obtained_value);
 
     if (!_compare_fn(expected_value, obtained_value))
-- 
2.7.4