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// Copyright 2017 Daniel Parker
// Distributed under the Boost license, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
// See https://github.com/danielaparker/jsoncons for latest version
#ifndef JSONCONS_JSONMERGEPATCH_JSONMERGEPATCH_HPP
#define JSONCONS_JSONMERGEPATCH_JSONMERGEPATCH_HPP
#include <string>
#include <vector>
#include <memory>
#include <algorithm> // std::min
#include <utility> // std::move
#include <jsoncons/json.hpp>
namespace jsoncons {
namespace mergepatch {
template <class Json>
Json from_diff(const Json& source, const Json& target)
{
if (!source.is_object() || !target.is_object())
{
return target;
}
Json result(json_object_arg);
for (const auto& member : source.object_range())
{
auto it = target.find(member.key());
if (it != target.object_range().end())
{
if (member.value() != it->value())
{
result.try_emplace(member.key(), from_diff(member.value(), it->value()));
}
}
else
{
result.try_emplace(member.key(), Json::null());
}
}
for (const auto& member : target.object_range())
{
auto it = source.find(member.key());
if (it == source.object_range().end())
{
result.try_emplace(member.key(), member.value());
}
}
return result;
}
namespace detail {
template <class Json>
Json apply_merge_patch_(Json& target, const Json& patch)
{
if (patch.is_object())
{
if (!target.is_object())
{
target = Json(json_object_arg);
}
for (auto& member : patch.object_range())
{
auto it = target.find(member.key());
if (it != target.object_range().end())
{
Json item = it->value();
target.erase(it);
if (!member.value().is_null())
{
target.try_emplace(member.key(), apply_merge_patch_(item, member.value()));
}
}
else if (!member.value().is_null())
{
Json item(json_object_arg);
target.try_emplace(member.key(), apply_merge_patch_(item, member.value()));
}
}
return target;
}
else
{
return patch;
}
}
} // namespace detail
template <class Json>
void apply_merge_patch(Json& target, const Json& patch)
{
target = detail::apply_merge_patch_(target, patch);
}
} // namespace mergepatch
} // namespace jsoncons
#endif
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