Merge commit '36bca61764984ff5395653cf8377ec5daa71b709' as 'libs/protobuf'

libs/protobuf/csharp/src/Google.Protobuf/JsonToken.cs

@@ -0,0 +1,141 @@
+#region Copyright notice and license
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#endregion
+
+using System;
+
+namespace Google.Protobuf
+{
+    internal sealed class JsonToken : IEquatable<JsonToken>
+    {
+        internal static JsonToken Null { get; } = new JsonToken(TokenType.Null);
+        internal static JsonToken False { get; } = new JsonToken(TokenType.False);
+        internal static JsonToken True { get; } = new JsonToken(TokenType.True);
+        internal static JsonToken StartObject { get; } = new JsonToken(TokenType.StartObject);
+        internal static JsonToken EndObject { get; } = new JsonToken(TokenType.EndObject);
+        internal static JsonToken StartArray { get; } = new JsonToken(TokenType.StartArray);
+        internal static JsonToken EndArray { get; } = new JsonToken(TokenType.EndArray);
+        internal static JsonToken EndDocument { get; } = new JsonToken(TokenType.EndDocument);
+
+        internal static JsonToken Name(string name)
+        {
+            return new JsonToken(TokenType.Name, stringValue: name);
+        }
+
+        internal static JsonToken Value(string value)
+        {
+            return new JsonToken(TokenType.StringValue, stringValue: value);
+        }
+
+        internal static JsonToken Value(double value)
+        {
+            return new JsonToken(TokenType.Number, numberValue: value);
+        }
+
+        internal enum TokenType
+        {
+            Null,
+            False,
+            True,
+            StringValue,
+            Number,
+            Name,
+            StartObject,
+            EndObject,
+            StartArray,
+            EndArray,
+            EndDocument
+        }
+
+        // A value is a string, number, array, object, null, true or false
+        // Arrays and objects have start/end
+        // A document consists of a value
+        // Objects are name/value sequences.
+
+        private readonly TokenType type;
+        private readonly string stringValue;
+        private readonly double numberValue;
+
+        internal TokenType Type => type;
+        internal string StringValue => stringValue;
+        internal double NumberValue => numberValue;
+
+        private JsonToken(TokenType type, string stringValue = null, double numberValue = 0)
+        {
+            this.type = type;
+            this.stringValue = stringValue;
+            this.numberValue = numberValue;
+        }
+
+        public override bool Equals(object obj) => Equals(obj as JsonToken);
+
+        public override int GetHashCode()
+        {
+            unchecked
+            {
+                int hash = 17;
+                hash = hash * 31 + (int) type;
+                hash = hash * 31 + stringValue == null ? 0 : stringValue.GetHashCode();
+                hash = hash * 31 + numberValue.GetHashCode();
+                return hash;
+            }
+        }
+
+        public override string ToString()
+        {
+            return type switch
+            {
+                TokenType.Null => "null",
+                TokenType.True => "true",
+                TokenType.False => "false",
+                TokenType.Name => $"name ({stringValue})",
+                TokenType.StringValue => $"value ({stringValue})",
+                TokenType.Number => $"number ({numberValue})",
+                TokenType.StartObject => "start-object",
+                TokenType.EndObject => "end-object",
+                TokenType.StartArray => "start-array",
+                TokenType.EndArray => "end-array",
+                TokenType.EndDocument => "end-document",
+                _ => throw new InvalidOperationException($"Token is of unknown type {type}"),
+            };
+        }
+
+        public bool Equals(JsonToken other)
+        {
+            if (other is null)
+            {
+                return false;
+            }
+            // Note use of other.numberValue.Equals rather than ==, so that NaN compares appropriately.
+            return other.type == type && other.stringValue == stringValue && other.numberValue.Equals(numberValue);
+        }
+    }
+}