Merge pull request #2564 from BioDataAnalysis/fixing_some_iterator_is…

…sues

Fixing some iterator issues

include/xtensor/xfunctor_view.hpp

@@ -1163,8 +1163,8 @@ namespace xt
  template <layout_type L>
  inline auto xfunctor_applier_base<D>::crbegin() const noexcept
  {
- return xfunctor_iterator<const functor_type, decltype(m_e.template rbegin<L>())>(
- m_e.template rbegin<L>(),
+ return xfunctor_iterator<const functor_type, decltype(m_e.template crbegin<L>())>(
+ m_e.template crbegin<L>(),
  &m_functor
  );
  }
@@ -1178,8 +1178,8 @@ namespace xt
  template <layout_type L>
  inline auto xfunctor_applier_base<D>::crend() const noexcept
  {
- return xfunctor_iterator<const functor_type, decltype(m_e.template rend<L>())>(
- m_e.template rend<L>(),
+ return xfunctor_iterator<const functor_type, decltype(m_e.template crend<L>())>(
+ m_e.template crend<L>(),
  &m_functor
  );
  }

include/xtensor/xiterator.hpp

@@ -604,7 +604,8 @@ namespace xt
  void stepper_tools<layout_type::row_major>::increment_stepper(S& stepper, IT& index, const ST& shape)
  {
  using size_type = typename S::size_type;
- size_type i = index.size();
+ const size_type size = index.size();
+ size_type i = size;
  while (i != 0)
  {
  --i;
@@ -625,7 +626,19 @@ namespace xt
  }
  if (i == 0)
  {
- std::copy(shape.cbegin(), shape.cend(), index.begin());
+ if (size != size_type(0))
+ {
+ std::transform(
+ shape.cbegin(),
+ shape.cend() - 1,
+ index.begin(),
+ [](const auto& v)
+ {
+ return v - 1;
+ }
+ );
+ index[size - 1] = shape[size - 1];
+ }
  stepper.to_end(layout_type::row_major);
  }
  }
@@ -640,8 +653,9 @@ namespace xt
  )
  {
  using size_type = typename S::size_type;
- size_type i = index.size();
- size_type leading_i = index.size() - 1;
+ const size_type size = index.size();
+ const size_type leading_i = size - 1;
+ size_type i = size;
  while (i != 0 && n != 0)
  {
  --i;
@@ -673,7 +687,19 @@ namespace xt
  }
  if (i == 0 && n != 0)
  {
- std::copy(shape.cbegin(), shape.cend(), index.begin());
+ if (size != size_type(0))
+ {
+ std::transform(
+ shape.cbegin(),
+ shape.cend() - 1,
+ index.begin(),
+ [](const auto& v)
+ {
+ return v - 1;
+ }
+ );
+ index[leading_i] = shape[leading_i];
+ }
  stepper.to_end(layout_type::row_major);
  }
  }
@@ -760,7 +786,7 @@ namespace xt
  void stepper_tools<layout_type::column_major>::increment_stepper(S& stepper, IT& index, const ST& shape)
  {
  using size_type = typename S::size_type;
- size_type size = index.size();
+ const size_type size = index.size();
  size_type i = 0;
  while (i != size)
  {
@@ -782,7 +808,19 @@ namespace xt
  }
  if (i == size)
  {
- std::copy(shape.cbegin(), shape.cend(), index.begin());
+ if (size != size_type(0))
+ {
+ std::transform(
+ shape.cbegin() + 1,
+ shape.cend(),
+ index.begin() + 1,
+ [](const auto& v)
+ {
+ return v - 1;
+ }
+ );
+ index[0] = shape[0];
+ }
  stepper.to_end(layout_type::column_major);
  }
  }
@@ -797,9 +835,9 @@ namespace xt
  )
  {
  using size_type = typename S::size_type;
- size_type size = index.size();
+ const size_type size = index.size();
+ const size_type leading_i = 0;
  size_type i = 0;
- size_type leading_i = 0;
  while (i != size && n != 0)
  {
  size_type inc = (i == leading_i) ? n : 1;
@@ -808,7 +846,7 @@ namespace xt
  index[i] += inc;
  stepper.step(i, inc);
  n -= inc;
- if (i != leading_i || index.size() == 1)
+ if (i != leading_i || size == 1)
  {
  i = 0;
  continue;
@@ -832,7 +870,19 @@ namespace xt
  }
  if (i == size && n != 0)
  {
- std::copy(shape.cbegin(), shape.cend(), index.begin());
+ if (size != size_type(0))
+ {
+ std::transform(
+ shape.cbegin() + 1,
+ shape.cend(),
+ index.begin() + 1,
+ [](const auto& v)
+ {
+ return v - 1;
+ }
+ );
+ index[leading_i] = shape[leading_i];
+ }
  stepper.to_end(layout_type::column_major);
  }
  }

include/xtensor/xstrided_view.hpp

@@ -155,6 +155,8 @@ namespace xt
  using storage_type = typename base_type::storage_type;
  using linear_iterator = typename storage_type::iterator;
  using const_linear_iterator = typename storage_type::const_iterator;
+ using reverse_linear_iterator = std::reverse_iterator<linear_iterator>;
+ using const_reverse_linear_iterator = std::reverse_iterator<const_linear_iterator>;
 
  using iterable_base = select_iterable_base_t<L, xexpression_type::static_layout, self_type>;
  using inner_shape_type = typename base_type::inner_shape_type;
@@ -217,9 +219,18 @@ namespace xt
 
  linear_iterator linear_begin();
  linear_iterator linear_end();
+ const_linear_iterator linear_begin() const;
+ const_linear_iterator linear_end() const;
  const_linear_iterator linear_cbegin() const;
  const_linear_iterator linear_cend() const;
 
+ reverse_linear_iterator linear_rbegin();
+ reverse_linear_iterator linear_rend();
+ const_reverse_linear_iterator linear_rbegin() const;
+ const_reverse_linear_iterator linear_rend() const;
+ const_reverse_linear_iterator linear_crbegin() const;
+ const_reverse_linear_iterator linear_crend() const;
+
  template <class ST, class STEP = stepper>
  disable_indexed_stepper_t<STEP> stepper_begin(const ST& shape);
  template <class ST, class STEP = stepper>
@@ -485,6 +496,18 @@ namespace xt
  return this->storage().begin() + static_cast<std::ptrdiff_t>(data_offset() + size());
  }
 
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_begin() const -> const_linear_iterator
+ {
+ return this->linear_cbegin();
+ }
+
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_end() const -> const_linear_iterator
+ {
+ return this->linear_cend();
+ }
+
  template <class CT, class S, layout_type L, class FST>
  inline auto xstrided_view<CT, S, L, FST>::linear_cbegin() const -> const_linear_iterator
  {
@@ -497,6 +520,42 @@ namespace xt
  return this->storage().cbegin() + static_cast<std::ptrdiff_t>(data_offset() + size());
  }
 
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_rbegin() -> reverse_linear_iterator
+ {
+ return reverse_linear_iterator(this->linear_begin());
+ }
+
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_rend() -> reverse_linear_iterator
+ {
+ return reverse_linear_iterator(this->linear_end());
+ }
+
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_rbegin() const -> const_reverse_linear_iterator
+ {
+ return this->linear_crbegin();
+ }
+
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_rend() const -> const_reverse_linear_iterator
+ {
+ return this->linear_crend();
+ }
+
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_crbegin() const -> const_reverse_linear_iterator
+ {
+ return const_reverse_linear_iterator(this->linear_cbegin());
+ }
+
+ template <class CT, class S, layout_type L, class FST>
+ inline auto xstrided_view<CT, S, L, FST>::linear_crend() const -> const_reverse_linear_iterator
+ {
+ return const_reverse_linear_iterator(this->linear_cend());
+ }
+
  /***************
  * stepper api *
  ***************/