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+// Copyright 2018 Google LLC.
+//
+// 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.
+//
+
+syntax = "proto3";
+
+package google.api.expr.v1alpha1;
+
+import "google/api/expr/v1alpha1/value.proto";
+
+option cc_enable_arenas = true;
+option go_package = "google.golang.org/genproto/googleapis/api/expr/v1alpha1;expr";
+option java_multiple_files = true;
+option java_outer_classname = "ExplainProto";
+option java_package = "com.google.api.expr.v1alpha1";
+
+// Values of intermediate expressions produced when evaluating expression.
+// Deprecated, use `EvalState` instead.
+message Explain {
+ option deprecated = true;
+
+ // ID and value index of one step.
+ message ExprStep {
+ // ID of corresponding Expr node.
+ int64 id = 1;
+
+ // Index of the value in the values list.
+ int32 value_index = 2;
+ }
+
+ // All of the observed values.
+ //
+ // The field value_index is an index in the values list.
+ // Separating values from steps is needed to remove redundant values.
+ repeated Value values = 1;
+
+ // List of steps.
+ //
+ // Repeated evaluations of the same expression generate new ExprStep
+ // instances. The order of such ExprStep instances matches the order of
+ // elements returned by Comprehension.iter_range.
+ repeated ExprStep expr_steps = 2;
+}