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+#pragma clang system_header
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you under the Apache License, Version 2.0 (the
+// "License"); you may not use this file except in compliance
+// with the License.  You may obtain a copy of the License at
+//
+//   http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing,
+// software distributed under the License is distributed on an
+// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+// KIND, either express or implied.  See the License for the
+// specific language governing permissions and limitations
+// under the License.
+
+#pragma once
+
+#include <cstdint>
+#include <functional>
+#include <iosfwd>
+#include <memory>
+
+#include "arrow/array/array_base.h"
+#include "arrow/array/array_nested.h"
+#include "arrow/result.h"
+#include "arrow/status.h"
+#include "arrow/type.h"
+#include "arrow/util/visibility.h"
+
+namespace arrow20 {
+
+/// \brief Compare two arrays, returning an edit script which expresses the difference
+/// between them
+///
+/// An edit script is an array of struct(insert: bool, run_length: int64_t).
+/// Each element of "insert" determines whether an element was inserted into (true)
+/// or deleted from (false) base. Each insertion or deletion is followed by a run of
+/// elements which are unchanged from base to target; the length of this run is stored
+/// in "run_length". (Note that the edit script begins and ends with a run of shared
+/// elements but both fields of the struct must have the same length. To accommodate this
+/// the first element of "insert" should be ignored.)
+///
+/// For example for base "hlloo" and target "hello", the edit script would be
+/// [
+///   {"insert": false, "run_length": 1}, // leading run of length 1 ("h")
+///   {"insert": true, "run_length": 3}, // insert("e") then a run of length 3 ("llo")
+///   {"insert": false, "run_length": 0} // delete("o") then an empty run
+/// ]
+///
+/// Diffing arrays containing nulls is not currently supported.
+///
+/// \param[in] base baseline for comparison
+/// \param[in] target an array of identical type to base whose elements differ from base's
+/// \param[in] pool memory to store the result will be allocated from this memory pool
+/// \return an edit script array which can be applied to base to produce target
+ARROW_EXPORT
+Result<std::shared_ptr<StructArray>> Diff(const Array& base, const Array& target,
+                                          MemoryPool* pool = default_memory_pool());
+
+/// \brief visitor interface for easy traversal of an edit script
+///
+/// visitor will be called for each hunk of insertions and deletions.
+ARROW_EXPORT Status VisitEditScript(
+    const Array& edits,
+    const std::function<Status(int64_t delete_begin, int64_t delete_end,
+                               int64_t insert_begin, int64_t insert_end)>& visitor);
+
+/// \brief return a function which will format an edit script in unified
+/// diff format to os, given base and target arrays of type
+ARROW_EXPORT Result<
+    std::function<Status(const Array& edits, const Array& base, const Array& target)>>
+MakeUnifiedDiffFormatter(const DataType& type, std::ostream* os);
+
+}  // namespace arrow20