chore: import upstream snapshot with attribution

paddle/ap/include/axpr/function_method_class.h

@@ -0,0 +1,61 @@
+// 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 "paddle/ap/include/axpr/anf_expr_helper.h"
+#include "paddle/ap/include/axpr/anf_expr_util.h"
+#include "paddle/ap/include/axpr/function.h"
+#include "paddle/ap/include/axpr/method_class.h"
+#include "paddle/ap/include/axpr/serializable_value.h"
+
+namespace ap::axpr {
+
+template <typename ValueT>
+struct MethodClassImpl<ValueT, Function<SerializableValue>>
+    : public EmptyMethodClass<ValueT> {
+  using Self = Function<SerializableValue>;
+
+  adt::Result<ValueT> ToString(const Self& function) {
+    const auto& lambda = function->lambda;
+    const auto& anf_expr = ConvertCoreExprToAnfExpr(lambda);
+    ADT_LET_CONST_REF(anf_atomic, anf_expr.template TryGet<Atomic<AnfExpr>>());
+    ADT_LET_CONST_REF(anf_lambda,
+                      anf_atomic.template TryGet<Lambda<AnfExpr>>());
+    AnfExprHelper anf_expr_helper;
+    ADT_LET_CONST_REF(anf_expr_str,
+                      anf_expr_helper.FunctionToString(anf_lambda));
+    return anf_expr_str;
+  }
+
+  adt::Result<ValueT> Hash(const Self& function) {
+    ADT_LET_CONST_REF(hash_value, function->GetHashValue());
+    return hash_value;
+  }
+
+  adt::Result<ValueT> GetAttr(const Self& self, const ValueT& attr_name_val) {
+    ADT_LET_CONST_REF(attr_name, TryGetImpl<std::string>(attr_name_val));
+    if (attr_name == "__function__") {
+      return self;
+    }
+    return adt::errors::AttributeError{
+        std::string() + "function has not attribute '" + attr_name + "'."};
+  }
+};
+
+template <typename ValueT>
+struct MethodClassImpl<ValueT, TypeImpl<Function<SerializableValue>>>
+    : public EmptyMethodClass<ValueT> {};
+
+}  // namespace ap::axpr