standard_views.hpp

// SPDX-FileCopyrightText: Intel Corporation
//
// SPDX-License-Identifier: BSD-3-Clause
 
#pragma once
 
#include <dr/detail/index.hpp>
#include <dr/detail/segments_tools.hpp>
#include <dr/sp/distributed_span.hpp>
#include <dr/sp/views/enumerate.hpp>
#include <dr/sp/zip_view.hpp>
#include <dr/views/transform.hpp>
 
namespace dr::sp {
 
namespace views {
 
template <dr::distributed_range R>
auto slice(R &&r, dr::index<> slice_indices) {
  return dr::sp::distributed_span(dr::ranges::segments(std::forward<R>(r)))
      .subspan(slice_indices[0], slice_indices[1] - slice_indices[0]);
}
 
class slice_adaptor_closure {
public:
  slice_adaptor_closure(dr::index<> slice_indices) : idx_(slice_indices) {}
 
  template <rng::random_access_range R> auto operator()(R &&r) const {
    return slice(std::forward<R>(r), idx_);
  }
 
  template <rng::random_access_range R>
  friend auto operator|(R &&r, const slice_adaptor_closure &closure) {
    return closure(std::forward<R>(r));
  }
 
private:
  dr::index<> idx_;
};
 
inline auto slice(dr::index<> slice_indices) {
  return slice_adaptor_closure(slice_indices);
}
 
} // namespace views
 
} // namespace dr::sp