chore: import upstream snapshot with attribution

paddle/ap/include/graph/node_list.h

@@ -0,0 +1,113 @@
+// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
+//
+// Licensed 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 <list>
+#include <variant>
+#include <vector>
+#include "paddle/ap/include/adt/adt.h"
+#include "paddle/ap/include/graph/tags.h"
+
+namespace ap::graph {
+
+template <typename T>
+struct Node;
+
+template <typename T>
+struct UndefinedTag : public std::monostate {
+  using std::monostate::monostate;
+};
+
+template <typename T>
+struct IndexedTag {
+  T data;
+};
+
+template <typename T>
+struct UnindexedTag {
+  T data;
+};
+
+template <typename T>
+using ValidListTagImpl = std::variant<IndexedTag<T>, UnindexedTag<T>>;
+
+template <typename T>
+struct ValidListTag : public ValidListTagImpl<T> {
+  using ValidListTagImpl<T>::ValidListTagImpl;
+  ADT_DEFINE_VARIANT_METHODS(ValidListTagImpl<T>);
+};
+
+template <typename T>
+using ListTagImpl =
+    std::variant<UndefinedTag<T>, IndexedTag<T>, UnindexedTag<T>>;
+
+template <typename T>
+struct ListTag : public ListTagImpl<T> {
+  using ListTagImpl<T>::ListTagImpl;
+  ADT_DEFINE_VARIANT_METHODS(ListTagImpl<T>);
+};
+
+template <typename T>
+struct NodeList : public ListTag<adt::List<Node<T>>> {
+  using list_type = adt::List<Node<T>>;
+
+  using ListTag<list_type>::ListTag;
+
+  ListTag<std::monostate> type() const {
+    return this->Match(
+        [](const UndefinedTag<list_type>&) -> ListTag<std::monostate> {
+          return UndefinedTag<std::monostate>{};
+        },
+        [](const IndexedTag<list_type>&) -> ListTag<std::monostate> {
+          return IndexedTag<std::monostate>{};
+        },
+        [](const UnindexedTag<list_type>&) -> ListTag<std::monostate> {
+          return UnindexedTag<std::monostate>{};
+        });
+  }
+
+  adt::Result<Node<T>> Sole() const {
+    return this->Match(
+        [](const UndefinedTag<list_type>&) -> adt::Result<Node<T>> {
+          return adt::errors::TypeError{"UndefinedList has no sole data"};
+        },
+        [](const auto& l) -> adt::Result<Node<T>> {
+          ADT_CHECK(l.data->size() == 1);
+          return l.data->at(0);
+        });
+  }
+
+  std::size_t size() const {
+    return this->Match(
+        [](const UndefinedTag<list_type>&) -> std::size_t { return 0; },
+        [](const auto& l) -> std::size_t { return l.data->size(); });
+  }
+
+  template <typename DoEachT>
+  adt::Result<adt::Ok> VisitNodes(const DoEachT& DoEach) const {
+    return this->Match(
+        [](const UndefinedTag<list_type>&) -> adt::Result<adt::Ok> {
+          return adt::Ok{};
+        },
+        [&](const auto& l) -> adt::Result<adt::Ok> {
+          for (const auto& data : *l.data) {
+            ADT_RETURN_IF_ERR(DoEach(data));
+          }
+          return adt::Ok{};
+        });
+  }
+};
+
+}  // namespace ap::graph