* add a Make* expression type builder to allow the

  construction of generic expressions working
  for both dense and sparse matrix. A nicer solution
  would be to use CwiseBinaryOp for any kind of matrix.
  To this end we either need to change the overall design
  so that the base class(es) depends on the kind of matrix,
  or we could add a template parameter to each expression
  type (e.g., int Kind = ei_traits<MatrixType>::Kind)
  allowing to specialize each expression for each kind of matrix.
* Extend AutoDiffScalar to work with sparse vector expression
  for the derivatives.

4 files changed, 111 insertions, 0 deletions

diff --git a/Eigen/Core b/Eigen/Core
index c8fcb1c09..3dce6422f 100644
--- a/Eigen/Core
+++ b/Eigen/Core
@@ -200,6 +200,7 @@ namespace Eigen {
 #include "src/Core/products/TriangularMatrixMatrix.h"
 #include "src/Core/products/TriangularSolverMatrix.h"
 #include "src/Core/BandMatrix.h"
+#include "src/Core/ExpressionMaker.h"
 
 } // namespace Eigen
 
diff --git a/Eigen/Sparse b/Eigen/Sparse
index a8888daa3..96bd61419 100644
--- a/Eigen/Sparse
+++ b/Eigen/Sparse
@@ -110,6 +110,7 @@ namespace Eigen {
 #include "src/Sparse/SparseLLT.h"
 #include "src/Sparse/SparseLDLT.h"
 #include "src/Sparse/SparseLU.h"
+#include "src/Sparse/SparseExpressionMaker.h"
 
 #ifdef EIGEN_CHOLMOD_SUPPORT
 # include "src/Sparse/CholmodSupport.h"
diff --git a/Eigen/src/Core/ExpressionMaker.h b/Eigen/src/Core/ExpressionMaker.h
new file mode 100644
index 000000000..1d265b63c
--- /dev/null
+++ b/Eigen/src/Core/ExpressionMaker.h
@@ -0,0 +1,61 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009 Gael Guennebaud <g.gael@free.fr>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_EXPRESSIONMAKER_H
+#define EIGEN_EXPRESSIONMAKER_H
+
+// computes the shape of a matrix from its traits flag
+template<typename XprType> struct ei_shape_of
+{
+  enum { ret = ei_traits<XprType>::Flags&SparseBit ? IsSparse : IsDense };
+};
+
+
+// Since the Sparse module is completely separated from the Core module, there is
+// no way to write the type of a generic expression working for both dense and sparse
+// matrix. Unless we change the overall design, here is a workaround.
+// There is an example in unsuported/Eigen/src/AutoDiff/AutoDiffScalar.
+
+template<typename XprType, int Shape = ei_shape_of<XprType>::ret>
+struct MakeNestByValue
+{
+  typedef NestByValue<XprType> Type;
+};
+
+template<typename Func, typename XprType, int Shape = ei_shape_of<XprType>::ret>
+struct MakeCwiseUnaryOp
+{
+  typedef CwiseUnaryOp<Func,XprType> Type;
+};
+
+template<typename Func, typename A, typename B, int Shape = ei_shape_of<A>::ret>
+struct MakeCwiseBinaryOp
+{
+  typedef CwiseBinaryOp<Func,A,B> Type;
+};
+
+// TODO complete the list
+
+
+#endif // EIGEN_EXPRESSIONMAKER_H
diff --git a/Eigen/src/Sparse/SparseExpressionMaker.h b/Eigen/src/Sparse/SparseExpressionMaker.h
new file mode 100644
index 000000000..1fdcbb1f2
--- /dev/null
+++ b/Eigen/src/Sparse/SparseExpressionMaker.h
@@ -0,0 +1,48 @@
+// This file is part of Eigen, a lightweight C++ template library
+// for linear algebra.
+//
+// Copyright (C) 2009 Gael Guennebaud <g.gael@free.fr>
+//
+// Eigen is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; either
+// version 3 of the License, or (at your option) any later version.
+//
+// Alternatively, you can redistribute it and/or
+// modify it under the terms of the GNU General Public License as
+// published by the Free Software Foundation; either version 2 of
+// the License, or (at your option) any later version.
+//
+// Eigen is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+// FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License or the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License and a copy of the GNU General Public License along with
+// Eigen. If not, see <http://www.gnu.org/licenses/>.
+
+#ifndef EIGEN_SPARSE_EXPRESSIONMAKER_H
+#define EIGEN_SPARSE_EXPRESSIONMAKER_H
+
+template<typename XprType>
+struct MakeNestByValue<XprType,IsSparse>
+{
+  typedef SparseNestByValue<XprType> Type;
+};
+
+template<typename Func, typename XprType>
+struct MakeCwiseUnaryOp<Func,XprType,IsSparse>
+{
+  typedef SparseCwiseUnaryOp<Func,XprType> Type;
+};
+
+template<typename Func, typename A, typename B>
+struct MakeCwiseBinaryOp<Func,A,B,IsSparse>
+{
+  typedef SparseCwiseBinaryOp<Func,A,B> Type;
+};
+
+// TODO complete the list
+
+#endif // EIGEN_SPARSE_EXPRESSIONMAKER_H