text: /*
   * Copyright 2014 Google Inc. 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.
   */
  
  // independent from idl_parser, since this code is not needed for most clients
  
  #include <unordered_set>
  
  #include "flatbuffers/code_generators.h"
  #include "flatbuffers/flatbuffers.h"
  #include "flatbuffers/idl.h"
  #include "flatbuffers/util.h"
  
  #if defined(FLATBUFFERS_CPP98_STL)
  #  include <cctype>
  #endif  // defined(FLATBUFFERS_CPP98_STL)
  
  namespace flatbuffers {
  
  static TypedFloatConstantGenerator CSharpFloatGen("Double.", "Single.", "NaN",
                                                    "PositiveInfinity",
                                                    "NegativeInfinity");
  static CommentConfig comment_config = {
    nullptr,
    "///",
    nullptr,
  };
  
  namespace csharp {
  class CSharpGenerator : public BaseGenerator {
    struct FieldArrayLength {
      std::string name;
      int length;
    };
  
   public:
    CSharpGenerator(const Parser &parser, const std::string &path,
                    const std::string &file_name)
        : BaseGenerator(parser, path, file_name, parser.opts.cs_global_alias ? "global::" : "", ".", "cs"),
          cur_name_space_(nullptr) {
      // clang-format off
  
      // List of keywords retrieved from here:
      // https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/keywords/
  
      // One per line to ease comparisons to that list are easier
  
      static const char *const keywords[] = {
        "abstract",
        "as",
        "base",
        "bool",
        "break",
        "byte",
        "case",
        "catch",
        "char",
        "checked",
        "class",
        "const",
        "continue",
        "decimal",
        "default",
        "delegate",
        "do",
        "double",
        "else",
        "enum",
        "event",
        "explicit",
        "extern",
        "false",
        "finally",
        "fixed",
        "float",
        "for",
        "foreach",
        "goto",
        "if",
        "implicit",
        "in",
        "int",
        "interface",
        "internal",
        "is",
        "lock",
        "long",
        "namespace",
        "new",
        "null",
        "object",
        "operator",
        "out",
        "override",
        "params",
        "private",
        "protected",
        "public",
        "readonly",
        "ref",
        "return",
        "sbyte",
        "sealed",
        "short",
        "sizeof",
        "stackalloc",
        "static",
        "string",
        "struct",
        "switch",
        "this",
        "throw",
        "true",
        "try",
        "typeof",
        "uint",
        "ulong",
        "unchecked",
        "unsafe",
        "ushort",
        "using",
        "virtual",
        "void",
        "volatile",
        "while",
        nullptr,
        // clang-format on
      };
  
      for (auto kw = keywords; *kw; kw++) keywords_.insert(*kw);
    }
  
    CSharpGenerator &operator=(const CSharpGenerator &);
  
    bool generate() {
      std::string one_file_code;
      cur_name_space_ = parser_.current_namespace_;
  
      for (auto it = parser_.enums_.vec.begin(); it != parser_.enums_.vec.end();
           ++it) {
        std::string enumcode;
        auto &enum_def = **it;
        if (!parser_.opts.one_file) cur_name_space_ = enum_def.defined_namespace;
        GenEnum(enum_def, &enumcode, parser_.opts);
        if (parser_.opts.one_file) {
          one_file_code += enumcode;
        } else {
          if (!SaveType(enum_def.name, *enum_def.defined_namespace, enumcode,
                        false, parser_.opts))
            return false;
        }
      }
  
      for (auto it = parser_.structs_.vec.begin();
           it != parser_.structs_.vec.end(); ++it) {
        std::string declcode;
        auto &struct_def = **it;
        if (!parser_.opts.one_file)
          cur_name_space_ = struct_def.defined_namespace;
        GenStruct(struct_def, &declcode, parser_.opts);
        if (parser_.opts.one_file) {
          one_file_code += declcode;
        } else {
          if (!SaveType(struct_def.name, *struct_def.defined_namespace, declcode,
                        true, parser_.opts))
            return false;
        }
      }
  
      if (parser_.opts.one_file) {
        return SaveType(file_name_, *parser_.current_namespace_, one_file_code,
                        true, parser_.opts);
      }
      return true;
    }
  
   private:
    std::unordered_set<std::string> keywords_;
  
    std::string EscapeKeyword(const std::string &name) const {
      return keywords_.find(name) == keywords_.end() ? name : "@" + name;
    }
  
    std::string Name(const FieldDef &field) const {
      std::string name = MakeCamel(field.name, true);
      return EscapeKeyword(name);
    }
  
    std::string Name(const Definition &def) const {
      return EscapeKeyword(def.name);
    }
  
    std::string NamespacedName(const Definition &def) const {
      return WrapInNameSpace(def.defined_namespace, Name(def));
    }
  
    std::string Name(const EnumVal &ev) const { return EscapeKeyword(ev.name); }
  
    // Save out the generated code for a single class while adding
    // declaration boilerplate.
    bool SaveType(const std::string &defname, const Namespace &ns,
                  const std::string &classcode, bool needs_includes,
                  const IDLOptions &options) const {
      if (!classcode.length()) return true;
  
      std::string code =
          "// <auto-generated>\n"
          "//  " +
          std::string(FlatBuffersGeneratedWarning()) +
          "\n"
          "// </auto-generated>\n\n";
  
      std::string namespace_name = FullNamespace(".", ns);
      if (!namespace_name.empty()) {
        code += "namespace " + namespace_name + "\n{\n\n";
      }
      if (needs_includes) {
        code += "using global::System;\n";
        code += "using global::System.Collections.Generic;\n";
        code += "using global::FlatBuffers;\n\n";
      }
      code += classcode;
      if (!namespace_name.empty()) { code += "\n}\n"; }
      auto filename = NamespaceDir(ns) + defname;
      if (options.one_file) { filename += options.filename_suffix; }
      filename +=
          options.filename_extension.empty() ? ".cs" : options.filename_extension;
      return SaveFile(filename.c_str(), code, false);
    }
  
    const Namespace *CurrentNameSpace() const { return cur_name_space_; }
  
    std::string GenTypeBasic(const Type &type, bool enableLangOverrides) const {
      // clang-format off
      static const char * const csharp_typename[] = {
        #define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, GTYPE, NTYPE, ...) \
          #NTYPE,
          FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
        #undef FLATBUFFERS_TD
      };
      // clang-format on
  
      if (enableLangOverrides) {
        if (IsEnum(type)) return NamespacedName(*type.enum_def);
        if (type.base_type == BASE_TYPE_STRUCT) {
          return "Offset<" + NamespacedName(*type.struct_def) + ">";
        }
      }
  
      return csharp_typename[type.base_type];
    }
  
    inline std::string GenTypeBasic(const Type &type) const {
      return GenTypeBasic(type, true);
    }
  
    std::string GenTypePointer(const Type &type) const {
      switch (type.base_type) {
        case BASE_TYPE_STRING: return "string";
        case BASE_TYPE_VECTOR: return GenTypeGet(type.VectorType());
        case BASE_TYPE_STRUCT: return NamespacedName(*type.struct_def);
        case BASE_TYPE_UNION: return "TTable";
        default: return "Table";
      }
    }
  
    std::string GenTypeGet(const Type &type) const {
      return IsScalar(type.base_type)
                 ? GenTypeBasic(type)
                 : (IsArray(type) ? GenTypeGet(type.VectorType())
                                  : GenTypePointer(type));
    }
  
    std::string GenOffsetType(const StructDef &struct_def) const {
      return "Offset<" + NamespacedName(struct_def) + ">";
    }
  
    std::string GenOffsetConstruct(const StructDef &struct_def,
                                   const std::string &variable_name) const {
      return "new Offset<" + NamespacedName(struct_def) + ">(" + variable_name +
             ")";
    }
  
    // Casts necessary to correctly read serialized data
    std::string DestinationCast(const Type &type) const {
      if (IsSeries(type)) {
        return DestinationCast(type.VectorType());
      } else {
        if (IsEnum(type)) return "(" + NamespacedName(*type.enum_def) + ")";
      }
      return "";
    }
  
    // Cast statements for mutator method parameters.
    // In Java, parameters representing unsigned numbers need to be cast down to
    // their respective type. For example, a long holding an unsigned int value
    // would be cast down to int before being put onto the buffer. In C#, one cast
    // directly cast an Enum to its underlying type, which is essential before
    // putting it onto the buffer.
    std::string SourceCast(const Type &type, const bool isOptional=false) const {
      if (IsSeries(type)) {
        return SourceCast(type.VectorType());
      } else {
        if (IsEnum(type)) return "(" + GenTypeBasic(type, false) + (isOptional ? "?": "") + ")";
      }
      return "";
    }
  
    std::string SourceCastBasic(const Type &type, const bool isOptional) const {
      return IsScalar(type.base_type) ? SourceCast(type, isOptional) : "";
    }
  
    std::string GenEnumDefaultValue(const FieldDef &field) const {
      auto &value = field.value;
      FLATBUFFERS_ASSERT(value.type.enum_def);
      auto &enum_def = *value.type.enum_def;
      auto enum_val = enum_def.FindByValue(value.constant);
      return enum_val ? (NamespacedName(enum_def) + "." + Name(*enum_val))
                      : value.constant;
    }
  
    std::string GenDefaultValue(const FieldDef &field,
                                bool enableLangOverrides) const {
      // If it is an optional scalar field, the default is null
      if (field.IsScalarOptional()) { return "null"; }
  
      auto &value = field.value;
      if (enableLangOverrides) {
        // handles both enum case and vector of enum case
        if (value.type.enum_def != nullptr &&
            value.type.base_type != BASE_TYPE_UNION) {
          return GenEnumDefaultValue(field);
        }
      }
  
      auto longSuffix = "";
      switch (value.type.base_type) {
        case BASE_TYPE_BOOL: return value.constant == "0" ? "false" : "true";
        case BASE_TYPE_ULONG: return value.constant;
        case BASE_TYPE_UINT:
        case BASE_TYPE_LONG: return value.constant + longSuffix;
        default:
          if (IsFloat(value.type.base_type))
            return CSharpFloatGen.GenFloatConstant(field);
          else
            return value.constant;
      }
    }
  
    std::string GenDefaultValue(const FieldDef &field) const {
      return GenDefaultValue(field, true);
    }
  
    std::string GenDefaultValueBasic(const FieldDef &field,
                                     bool enableLangOverrides) const {
      auto &value = field.value;
      if (!IsScalar(value.type.base_type)) {
        if (enableLangOverrides) {
          switch (value.type.base_type) {
            case BASE_TYPE_STRING: return "default(StringOffset)";
            case BASE_TYPE_STRUCT:
              return "default(Offset<" + NamespacedName(*value.type.struct_def) +
                     ">)";
            case BASE_TYPE_VECTOR: return "default(VectorOffset)";
            default: break;
          }
        }
        return "0";
      }
      return GenDefaultValue(field, enableLangOverrides);
    }
  
    std::string GenDefaultValueBasic(const FieldDef &field) const {
      return GenDefaultValueBasic(field, true);
    }
  
    void GenEnum(EnumDef &enum_def, std::string *code_ptr,
                 const IDLOptions &opts) const {
      std::string &code = *code_ptr;
      if (enum_def.generated) return;
  
      // Generate enum definitions of the form:
      // public static (final) int name = value;
      // In Java, we use ints rather than the Enum feature, because we want them
      // to map directly to how they're used in C/C++ and file formats.
      // That, and Java Enums are expensive, and not universally liked.
      GenComment(enum_def.doc_comment, code_ptr, &comment_config);
  
      if (opts.cs_gen_json_serializer && opts.generate_object_based_api) {
        code +=
            "[Newtonsoft.Json.JsonConverter(typeof(Newtonsoft.Json.Converters."
            "StringEnumConverter))]\n";
      }
      // In C# this indicates enumeration values can be treated as bit flags.
      if (enum_def.attributes.Lookup("bit_flags")) {
        code += "[System.FlagsAttribute]\n";
      }
      if (enum_def.attributes.Lookup("private")) {
        code += "internal ";
      } else {
        code += "public ";
      }
      code += "enum " + Name(enum_def);
      code += " : " + GenTypeBasic(enum_def.underlying_type, false);
      code += "\n{\n";
      for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
        auto &ev = **it;
        GenComment(ev.doc_comment, code_ptr, &comment_config, "  ");
        code += "  ";
        code += Name(ev) + " = ";
        code += enum_def.ToString(ev);
        code += ",\n";
      }
      // Close the class
      code += "};\n\n";
  
      if (opts.generate_object_based_api) {
        GenEnum_ObjectAPI(enum_def, code_ptr, opts);
      }
    }
  
    bool HasUnionStringValue(const EnumDef &enum_def) const {
      if (!enum_def.is_union) return false;
      for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
        auto &val = **it;
        if (IsString(val.union_type)) { return true; }
      }
      return false;
    }
  
    // Returns the function name that is able to read a value of the given type.
    std::string GenGetter(const Type &type) const {
      switch (type.base_type) {
        case BASE_TYPE_STRING: return "__p.__string";
        case BASE_TYPE_STRUCT: return "__p.__struct";
        case BASE_TYPE_UNION: return "__p.__union";
        case BASE_TYPE_VECTOR: return GenGetter(type.VectorType());
        case BASE_TYPE_ARRAY: return GenGetter(type.VectorType());
        default: {
          std::string getter = "__p.bb.Get";
          if (type.base_type == BASE_TYPE_BOOL) {
            getter = "0!=" + getter;
          } else if (GenTypeBasic(type, false) != "byte") {
            getter += MakeCamel(GenTypeBasic(type, false));
          }
          return getter;
        }
      }
    }
  
    // Returns the function name that is able to read a value of the given type.
    std::string GenGetterForLookupByKey(flatbuffers::FieldDef *key_field,
                                        const std::string &data_buffer,
                                        const char *num = nullptr) const {
      auto type = key_field->value.type;
      auto dest_mask = "";
      auto dest_cast = DestinationCast(type);
      auto getter = data_buffer + ".Get";
      if (GenTypeBasic(type, false) != "byte") {
        getter += MakeCamel(GenTypeBasic(type, false));
      }
      getter = dest_cast + getter + "(" + GenOffsetGetter(key_field, num) + ")" +
               dest_mask;
      return getter;
    }
  
    // Direct mutation is only allowed for scalar fields.
    // Hence a setter method will only be generated for such fields.
    std::string GenSetter(const Type &type) const {
      if (IsScalar(type.base_type)) {
        std::string setter = "__p.bb.Put";
        if (GenTypeBasic(type, false) != "byte" &&
            type.base_type != BASE_TYPE_BOOL) {
          setter += MakeCamel(GenTypeBasic(type, false));
        }
        return setter;
      } else {
        return "";
      }
    }
  
    // Returns the method name for use with add/put calls.
    std::string GenMethod(const Type &type) const {
      return IsScalar(type.base_type) ? MakeCamel(GenTypeBasic(type, false))
                                      : (IsStruct(type) ? "Struct" : "Offset");
    }
  
    // Recursively generate arguments for a constructor, to deal with nested
    // structs.
    void GenStructArgs(const StructDef &struct_def, std::string *code_ptr,
                       const char *nameprefix, size_t array_count = 0) const {
      std::string &code = *code_ptr;
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        const auto &field_type = field.value.type;
        const auto array_field = IsArray(field_type);
        const auto &type = array_field ? field_type.VectorType() : field_type;
        const auto array_cnt = array_field ? (array_count + 1) : array_count;
        if (IsStruct(type)) {
          // Generate arguments for a struct inside a struct. To ensure names
          // don't clash, and to make it obvious these arguments are constructing
          // a nested struct, prefix the name with the field name.
          GenStructArgs(*field_type.struct_def, code_ptr,
                        (nameprefix + (EscapeKeyword(field.name) + "_")).c_str(),
                        array_cnt);
        } else {
          code += ", ";
          code += GenTypeBasic(type);
          if (field.IsScalarOptional()) { code += "?"; }
          if (array_cnt > 0) {
            code += "[";
            for (size_t i = 1; i < array_cnt; i++) code += ",";
            code += "]";
          }
          code += " ";
          code += nameprefix;
          code += Name(field);
        }
      }
    }
  
    // Recusively generate struct construction statements of the form:
    // builder.putType(name);
    // and insert manual padding.
    void GenStructBody(const StructDef &struct_def, std::string *code_ptr,
                       const char *nameprefix, size_t index = 0,
                       bool in_array = false) const {
      std::string &code = *code_ptr;
      std::string indent((index + 1) * 2, ' ');
      code += indent + "  builder.Prep(";
      code += NumToString(struct_def.minalign) + ", ";
      code += NumToString(struct_def.bytesize) + ");\n";
      for (auto it = struct_def.fields.vec.rbegin();
           it != struct_def.fields.vec.rend(); ++it) {
        auto &field = **it;
        const auto &field_type = field.value.type;
        if (field.padding) {
          code += indent + "  builder.Pad(";
          code += NumToString(field.padding) + ");\n";
        }
        if (IsStruct(field_type)) {
          GenStructBody(*field_type.struct_def, code_ptr,
                        (nameprefix + (field.name + "_")).c_str(), index,
                        in_array);
        } else {
          const auto &type =
              IsArray(field_type) ? field_type.VectorType() : field_type;
          const auto index_var = "_idx" + NumToString(index);
          if (IsArray(field_type)) {
            code += indent + "  for (int " + index_var + " = ";
            code += NumToString(field_type.fixed_length);
            code += "; " + index_var + " > 0; " + index_var + "--) {\n";
            in_array = true;
          }
          if (IsStruct(type)) {
            GenStructBody(*field_type.struct_def, code_ptr,
                          (nameprefix + (field.name + "_")).c_str(), index + 1,
                          in_array);
          } else {
            code += IsArray(field_type) ? "  " : "";
            code += indent + "  builder.Put";
            code += GenMethod(type) + "(";
            code += SourceCast(type);
            auto argname = nameprefix + Name(field);
            code += argname;
            size_t array_cnt = index + (IsArray(field_type) ? 1 : 0);
            if (array_cnt > 0) {
              code += "[";
              for (size_t i = 0; in_array && i < array_cnt; i++) {
                code += "_idx" + NumToString(i) + "-1";
                if (i != (array_cnt - 1)) code += ",";
              }
              code += "]";
            }
            code += ");\n";
          }
          if (IsArray(field_type)) { code += indent + "  }\n"; }
        }
      }
    }
    std::string GenOffsetGetter(flatbuffers::FieldDef *key_field,
                                const char *num = nullptr) const {
      std::string key_offset =
          "Table.__offset(" + NumToString(key_field->value.offset) + ", ";
      if (num) {
        key_offset += num;
        key_offset += ".Value, builder.DataBuffer)";
      } else {
        key_offset += "bb.Length";
        key_offset += " - tableOffset, bb)";
      }
      return key_offset;
    }
  
    std::string GenLookupKeyGetter(flatbuffers::FieldDef *key_field) const {
      std::string key_getter = "      ";
      key_getter += "int tableOffset = Table.";
      key_getter += "__indirect(vectorLocation + 4 * (start + middle)";
      key_getter += ", bb);\n      ";
      if (IsString(key_field->value.type)) {
        key_getter += "int comp = Table.";
        key_getter += "CompareStrings(";
        key_getter += GenOffsetGetter(key_field);
        key_getter += ", byteKey, bb);\n";
      } else {
        auto get_val = GenGetterForLookupByKey(key_field, "bb");
        key_getter += "int comp = " + get_val + ".CompareTo(key);\n";
      }
      return key_getter;
    }
  
    std::string GenKeyGetter(flatbuffers::FieldDef *key_field) const {
      std::string key_getter = "";
      auto data_buffer = "builder.DataBuffer";
      if (IsString(key_field->value.type)) {
        key_getter += "Table.CompareStrings(";
        key_getter += GenOffsetGetter(key_field, "o1") + ", ";
        key_getter += GenOffsetGetter(key_field, "o2") + ", " + data_buffer + ")";
      } else {
        auto field_getter = GenGetterForLookupByKey(key_field, data_buffer, "o1");
        key_getter += field_getter;
        field_getter = GenGetterForLookupByKey(key_field, data_buffer, "o2");
        key_getter += ".CompareTo(" + field_getter + ")";
      }
      return key_getter;
    }
  
    void GenStruct(StructDef &struct_def, std::string *code_ptr,
                   const IDLOptions &opts) const {
      if (struct_def.generated) return;
      std::string &code = *code_ptr;
  
      // Generate a struct accessor class, with methods of the form:
      // public type name() { return bb.getType(i + offset); }
      // or for tables of the form:
      // public type name() {
      //   int o = __offset(offset); return o != 0 ? bb.getType(o + i) : default;
      // }
      GenComment(struct_def.doc_comment, code_ptr, &comment_config);
      if (struct_def.attributes.Lookup("private")) {
        code += "internal ";
      } else {
        code += "public ";
      }
      if (struct_def.attributes.Lookup("csharp_partial")) {
        // generate a partial class for this C# struct/table
        code += "partial ";
      }
      code += "struct " + struct_def.name;
      code += " : IFlatbufferObject";
      code += "\n{\n";
      code += "  private ";
      code += struct_def.fixed ? "Struct" : "Table";
      code += " __p;\n";
  
      code += "  public ByteBuffer ByteBuffer { get { return __p.bb; } }\n";
  
      if (!struct_def.fixed) {
        // Generate verson check method.
        // Force compile time error if not using the same version runtime.
        code += "  public static void ValidateVersion() {";
        code += " FlatBufferConstants.";
        code += "FLATBUFFERS_2_0_0(); ";
        code += "}\n";
  
        // Generate a special accessor for the table that when used as the root
        // of a FlatBuffer
        std::string method_name = "GetRootAs" + struct_def.name;
        std::string method_signature =
            "  public static " + struct_def.name + " " + method_name;
  
        // create convenience method that doesn't require an existing object
        code += method_signature + "(ByteBuffer _bb) ";
        code += "{ return " + method_name + "(_bb, new " + struct_def.name +
                "()); }\n";
  
        // create method that allows object reuse
        code +=
            method_signature + "(ByteBuffer _bb, " + struct_def.name + " obj) { ";
        code += "return (obj.__assign(_bb.GetInt(_bb.Position";
        code += ") + _bb.Position";
        code += ", _bb)); }\n";
        if (parser_.root_struct_def_ == &struct_def) {
          if (parser_.file_identifier_.length()) {
            // Check if a buffer has the identifier.
            code += "  public static ";
            code += "bool " + struct_def.name;
            code += "BufferHasIdentifier(ByteBuffer _bb) { return ";
            code += "Table.__has_identifier(_bb, \"";
            code += parser_.file_identifier_;
            code += "\"); }\n";
          }
        }
      }
      // Generate the __init method that sets the field in a pre-existing
      // accessor object. This is to allow object reuse.
      code += "  public void __init(int _i, ByteBuffer _bb) ";
      code += "{ ";
      code += "__p = new ";
      code += struct_def.fixed ? "Struct" : "Table";
      code += "(_i, _bb); ";
      code += "}\n";
      code +=
          "  public " + struct_def.name + " __assign(int _i, ByteBuffer _bb) ";
      code += "{ __init(_i, _bb); return this; }\n\n";
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        if (field.deprecated) continue;
        GenComment(field.doc_comment, code_ptr, &comment_config, "  ");
        std::string type_name = GenTypeGet(field.value.type);
        std::string type_name_dest = GenTypeGet(field.value.type);
        std::string conditional_cast = "";
        std::string optional = "";
        if (!struct_def.fixed &&
            (field.value.type.base_type == BASE_TYPE_STRUCT ||
             field.value.type.base_type == BASE_TYPE_UNION ||
             (IsVector(field.value.type) &&
              (field.value.type.element == BASE_TYPE_STRUCT ||
               field.value.type.element == BASE_TYPE_UNION)))) {
          optional = "?";
          conditional_cast = "(" + type_name_dest + optional + ")";
        }
        if (field.IsScalarOptional()) { optional = "?"; }
        std::string dest_mask = "";
        std::string dest_cast = DestinationCast(field.value.type);
        std::string src_cast = SourceCast(field.value.type);
        std::string field_name_camel = Name(field);
        if (field_name_camel == struct_def.name) { field_name_camel += "_"; }
        std::string method_start =
            "  public " + type_name_dest + optional + " " + field_name_camel;
        std::string obj = "(new " + type_name + "())";
  
        // Most field accessors need to retrieve and test the field offset first,
        // this is the prefix code for that:
        auto offset_prefix =
            IsArray(field.value.type)
                ? " { return "
                : (" { int o = __p.__offset(" + NumToString(field.value.offset) +
                   "); return o != 0 ? ");
        // Generate the accessors that don't do object reuse.
        if (field.value.type.base_type == BASE_TYPE_STRUCT) {
        } else if (IsVector(field.value.type) &&
                   field.value.type.element == BASE_TYPE_STRUCT) {
        } else if (field.value.type.base_type == BASE_TYPE_UNION ||
                   (IsVector(field.value.type) &&
                    field.value.type.VectorType().base_type == BASE_TYPE_UNION)) {
          method_start += "<TTable>";
          type_name = type_name_dest;
        }
        std::string getter = dest_cast + GenGetter(field.value.type);
        code += method_start;
        std::string default_cast = "";
        // only create default casts for c# scalars or vectors of scalars
        if ((IsScalar(field.value.type.base_type) ||
             (IsVector(field.value.type) &&
              IsScalar(field.value.type.element)))) {
          // For scalars, default value will be returned by GetDefaultValue().
          // If the scalar is an enum, GetDefaultValue() returns an actual c# enum
          // that doesn't need to be casted. However, default values for enum
          // elements of vectors are integer literals ("0") and are still casted
          // for clarity.
          // If the scalar is optional and enum, we still need the cast.
          if ((field.value.type.enum_def == nullptr ||
               IsVector(field.value.type)) ||
              (IsEnum(field.value.type) && field.IsScalarOptional())) {
            default_cast = "(" + type_name_dest + optional + ")";
          }
        }
        std::string member_suffix = "; ";
        if (IsScalar(field.value.type.base_type)) {
          code += " { get";
          member_suffix += "} ";
          if (struct_def.fixed) {
            code += " { return " + getter;
            code += "(__p.bb_pos + ";
            code += NumToString(field.value.offset) + ")";
            code += dest_mask;
          } else {
            code += offset_prefix + getter;
            code += "(o + __p.bb_pos)" + dest_mask;
            code += " : " + default_cast;
            code += GenDefaultValue(field);
          }
        } else {
          switch (field.value.type.base_type) {
            case BASE_TYPE_STRUCT:
              code += " { get";
              member_suffix += "} ";
              if (struct_def.fixed) {
                code += " { return " + obj + ".__assign(" + "__p.";
                code += "bb_pos + " + NumToString(field.value.offset) + ", ";
                code += "__p.bb)";
              } else {
                code += offset_prefix + conditional_cast;
                code += obj + ".__assign(";
                code += field.value.type.struct_def->fixed
                            ? "o + __p.bb_pos"
                            : "__p.__indirect(o + __p.bb_pos)";
                code += ", __p.bb) : null";
              }
              break;
            case BASE_TYPE_STRING:
              code += " { get";
              member_suffix += "} ";
              code += offset_prefix + getter + "(o + " + "__p.";
              code += "bb_pos) : null";
              break;
            case BASE_TYPE_ARRAY: FLATBUFFERS_FALLTHROUGH();  // fall thru
            case BASE_TYPE_VECTOR: {
              auto vectortype = field.value.type.VectorType();
              if (vectortype.base_type == BASE_TYPE_UNION) {
                conditional_cast = "(TTable?)";
                getter += "<TTable>";
              }
              code += "(";
              if (vectortype.base_type == BASE_TYPE_STRUCT) {
                getter = obj + ".__assign";
              } else if (vectortype.base_type == BASE_TYPE_UNION) {
              }
              code += "int j)";
              const auto body = offset_prefix + conditional_cast + getter + "(";
              if (vectortype.base_type == BASE_TYPE_UNION) {
                code += " where TTable : struct, IFlatbufferObject" + body;
              } else {
                code += body;
              }
              std::string index = "__p.";
              if (IsArray(field.value.type)) {
                index += "bb_pos + " + NumToString(field.value.offset) + " + ";
              } else {
                index += "__vector(o) + ";
              }
              index += "j * " + NumToString(InlineSize(vectortype));
              if (vectortype.base_type == BASE_TYPE_STRUCT) {
                code += vectortype.struct_def->fixed
                            ? index
                            : "__p.__indirect(" + index + ")";
                code += ", __p.bb";
              } else {
                code += index;
              }
              code += ")" + dest_mask;
              if (!IsArray(field.value.type)) {
                code += " : ";
                code +=
                    field.value.type.element == BASE_TYPE_BOOL
                        ? "false"
                        : (IsScalar(field.value.type.element) ? default_cast + "0"
                                                              : "null");
              }
              if (vectortype.base_type == BASE_TYPE_UNION &&
                  HasUnionStringValue(*vectortype.enum_def)) {
                code += member_suffix;
                code += "}\n";
                code += "  public string " + Name(field) + "AsString(int j)";
                code += offset_prefix + GenGetter(Type(BASE_TYPE_STRING));
                code += "(" + index + ") : null";
              }
              break;
            }
            case BASE_TYPE_UNION:
              code += "() where TTable : struct, IFlatbufferObject";
              code += offset_prefix + "(TTable?)" + getter;
              code += "<TTable>(o + __p.bb_pos) : null";
              if (HasUnionStringValue(*field.value.type.enum_def)) {
                code += member_suffix;
                code += "}\n";
                code += "  public string " + Name(field) + "AsString()";
                code += offset_prefix + GenGetter(Type(BASE_TYPE_STRING));
                code += "(o + __p.bb_pos) : null";
              }
              // As<> accesors for Unions
              // Loop through all the possible union types and generate an As
              // accessor that casts to the correct type.
              for (auto uit = field.value.type.enum_def->Vals().begin();
                   uit != field.value.type.enum_def->Vals().end(); ++uit) {
                auto val = *uit;
                if (val->union_type.base_type == BASE_TYPE_NONE) { continue; }
                auto union_field_type_name = GenTypeGet(val->union_type);
                code += member_suffix + "}\n";
                if (val->union_type.base_type == BASE_TYPE_STRUCT &&
                    val->union_type.struct_def->attributes.Lookup("private")) {
                  code += "  internal ";
                } else {
                  code += "  public ";
                }
                code += union_field_type_name + " ";
                code += field_name_camel + "As" + val->name + "() { return ";
                code += field_name_camel;
                if (IsString(val->union_type)) {
                  code += "AsString()";
                } else {
                  code += "<" + union_field_type_name + ">().Value";
                }
              }
              break;
            default: FLATBUFFERS_ASSERT(0);
          }
        }
        code += member_suffix;
        code += "}\n";
        if (IsVector(field.value.type)) {
          code += "  public int " + Name(field);
          code += "Length";
          code += " { get";
          code += offset_prefix;
          code += "__p.__vector_len(o) : 0; ";
          code += "} ";
          code += "}\n";
          // See if we should generate a by-key accessor.
          if (field.value.type.element == BASE_TYPE_STRUCT &&
              !field.value.type.struct_def->fixed) {
            auto &sd = *field.value.type.struct_def;
            auto &fields = sd.fields.vec;
            for (auto kit = fields.begin(); kit != fields.end(); ++kit) {
              auto &key_field = **kit;
              if (key_field.key) {
                auto qualified_name = NamespacedName(sd);
                code += "  public " + qualified_name + "? ";
                code += Name(field) + "ByKey(";
                code += GenTypeGet(key_field.value.type) + " key)";
                code += offset_prefix;
                code += qualified_name + ".__lookup_by_key(";
                code += "__p.__vector(o), key, ";
                code += "__p.bb) : null; ";
                code += "}\n";
                break;
              }
            }
          }
        }
        // Generate a ByteBuffer accessor for strings & vectors of scalars.
        if ((IsVector(field.value.type) &&
             IsScalar(field.value.type.VectorType().base_type)) ||
            IsString(field.value.type)) {
          code += "#if ENABLE_SPAN_T\n";
          code += "  public Span<" + GenTypeBasic(field.value.type.VectorType()) +
                  "> Get";
          code += Name(field);
          code += "Bytes() { return ";
          code += "__p.__vector_as_span<" +
                  GenTypeBasic(field.value.type.VectorType()) + ">(";
          code += NumToString(field.value.offset);
          code +=
              ", " + NumToString(SizeOf(field.value.type.VectorType().base_type));
          code += "); }\n";
          code += "#else\n";
          code += "  public ArraySegment<byte>? Get";
          code += Name(field);
          code += "Bytes() { return ";
          code += "__p.__vector_as_arraysegment(";
          code += NumToString(field.value.offset);
          code += "); }\n";
          code += "#endif\n";
  
          // For direct blockcopying the data into a typed array
          code += "  public ";
          code += GenTypeBasic(field.value.type.VectorType());
          code += "[] Get";
          code += Name(field);
          code += "Array() { ";
          if (IsEnum(field.value.type.VectorType())) {
            // Since __vector_as_array does not work for enum types,
            // fill array using an explicit loop.
            code += "int o = __p.__offset(";
            code += NumToString(field.value.offset);
            code += "); if (o == 0) return null; int p = ";
            code += "__p.__vector(o); int l = ";
            code += "__p.__vector_len(o); ";
            code += GenTypeBasic(field.value.type.VectorType());
            code += "[] a = new ";
            code += GenTypeBasic(field.value.type.VectorType());
            code += "[l]; for (int i = 0; i < l; i++) { a[i] = " + getter;
            code += "(p + i * ";
            code += NumToString(InlineSize(field.value.type.VectorType()));
            code += "); } return a;";
          } else {
            code += "return ";
            code += "__p.__vector_as_array<";
            code += GenTypeBasic(field.value.type.VectorType());
            code += ">(";
            code += NumToString(field.value.offset);
            code += ");";
          }
          code += " }\n";
        }
        // generate object accessors if is nested_flatbuffer
        if (field.nested_flatbuffer) {
          auto nested_type_name = NamespacedName(*field.nested_flatbuffer);
          auto nested_method_name =
              Name(field) + "As" + field.nested_flatbuffer->name;
          auto get_nested_method_name = nested_method_name;
          get_nested_method_name = "Get" + nested_method_name;
          conditional_cast = "(" + nested_type_name + "?)";
          obj = "(new " + nested_type_name + "())";
          code += "  public " + nested_type_name + "? ";
          code += get_nested_method_name + "(";
          code += ") { int o = __p.__offset(";
          code += NumToString(field.value.offset) + "); ";
          code += "return o != 0 ? " + conditional_cast + obj + ".__assign(";
          code += "__p.";
          code += "__indirect(__p.__vector(o)), ";
          code += "__p.bb) : null; }\n";
        }
        // Generate mutators for scalar fields or vectors of scalars.
        if (parser_.opts.mutable_buffer) {
          auto is_series = (IsSeries(field.value.type));
          const auto &underlying_type =
              is_series ? field.value.type.VectorType() : field.value.type;
          // Boolean parameters have to be explicitly converted to byte
          // representation.
          auto setter_parameter =
              underlying_type.base_type == BASE_TYPE_BOOL
                  ? "(byte)(" + EscapeKeyword(field.name) + " ? 1 : 0)"
                  : EscapeKeyword(field.name);
          auto mutator_prefix = MakeCamel("mutate", true);
          // A vector mutator also needs the index of the vector element it should
          // mutate.
          auto mutator_params = (is_series ? "(int j, " : "(") +
                                GenTypeGet(underlying_type) + " " +
                                EscapeKeyword(field.name) + ") { ";
          auto setter_index =
              is_series
                  ? "__p." +
                        (IsArray(field.value.type)
                             ? "bb_pos + " + NumToString(field.value.offset)
                             : "__vector(o)") +
                        +" + j * " + NumToString(InlineSize(underlying_type))
                  : (struct_def.fixed
                         ? "__p.bb_pos + " + NumToString(field.value.offset)
                         : "o + __p.bb_pos");
          if (IsScalar(underlying_type.base_type) && !IsUnion(field.value.type)) {
            code += "  public ";
            code += struct_def.fixed ? "void " : "bool ";
            code += mutator_prefix + Name(field);
            code += mutator_params;
            if (struct_def.fixed) {
              code += GenSetter(underlying_type) + "(" + setter_index + ", ";
              code += src_cast + setter_parameter + "); }\n";
            } else {
              code += "int o = __p.__offset(";
              code += NumToString(field.value.offset) + ");";
              code += " if (o != 0) { " + GenSetter(underlying_type);
              code += "(" + setter_index + ", " + src_cast + setter_parameter +
                      "); return true; } else { return false; } }\n";
            }
          }
        }
        if (parser_.opts.java_primitive_has_method &&
            IsScalar(field.value.type.base_type) && !struct_def.fixed) {
          auto vt_offset_constant = "  public static final int VT_" +
                                    MakeScreamingCamel(field.name) + " = " +
                                    NumToString(field.value.offset) + ";";
  
          code += vt_offset_constant;
          code += "\n";
        }
      }
      code += "\n";
      auto struct_has_create = false;
      std::set<flatbuffers::FieldDef *> field_has_create_set;
      flatbuffers::FieldDef *key_field = nullptr;
      if (struct_def.fixed) {
        struct_has_create = true;
        // create a struct constructor function
        code += "  public static " + GenOffsetType(struct_def) + " ";
        code += "Create";
        code += struct_def.name + "(FlatBufferBuilder builder";
        GenStructArgs(struct_def, code_ptr, "");
        code += ") {\n";
        GenStructBody(struct_def, code_ptr, "");
        code += "    return ";
        code += GenOffsetConstruct(struct_def, "builder.Offset");
        code += ";\n  }\n";
      } else {
        // Generate a method that creates a table in one go. This is only possible
        // when the table has no struct fields, since those have to be created
        // inline, and there's no way to do so in Java.
        bool has_no_struct_fields = true;
        int num_fields = 0;
        for (auto it = struct_def.fields.vec.begin();
             it != struct_def.fields.vec.end(); ++it) {
          auto &field = **it;
          if (field.deprecated) continue;
          if (IsStruct(field.value.type)) {
            has_no_struct_fields = false;
          } else {
            num_fields++;
          }
        }
        // JVM specifications restrict default constructor params to be < 255.
        // Longs and doubles take up 2 units, so we set the limit to be < 127.
        if ((has_no_struct_fields || opts.generate_object_based_api) &&
            num_fields && num_fields < 127) {
          struct_has_create = true;
          // Generate a table constructor of the form:
          // public static int createName(FlatBufferBuilder builder, args...)
          code += "  public static " + GenOffsetType(struct_def) + " ";
          code += "Create" + struct_def.name;
          code += "(FlatBufferBuilder builder";
          for (auto it = struct_def.fields.vec.begin();
               it != struct_def.fields.vec.end(); ++it) {
            auto &field = **it;
            if (field.deprecated) continue;
            code += ",\n      ";
            if (IsStruct(field.value.type) && opts.generate_object_based_api) {
              code += WrapInNameSpace(
                  field.value.type.struct_def->defined_namespace,
                  GenTypeName_ObjectAPI(field.value.type.struct_def->name, opts));
              code += " ";
              code += EscapeKeyword(field.name);
              code += " = null";
            } else {
              code += GenTypeBasic(field.value.type);
              if (field.IsScalarOptional()) { code += "?"; }
              code += " ";
              code += EscapeKeyword(field.name);
              if (!IsScalar(field.value.type.base_type)) code += "Offset";
  
              code += " = ";
              code += GenDefaultValueBasic(field);
            }
          }
          code += ") {\n    builder.";
          code += "StartTable(";
          code += NumToString(struct_def.fields.vec.size()) + ");\n";
          for (size_t size = struct_def.sortbysize ? sizeof(largest_scalar_t) : 1;
               size; size /= 2) {
            for (auto it = struct_def.fields.vec.rbegin();
                 it != struct_def.fields.vec.rend(); ++it) {
              auto &field = **it;
              if (!field.deprecated &&
                  (!struct_def.sortbysize ||
                   size == SizeOf(field.value.type.base_type))) {
                code += "    " + struct_def.name + ".";
                code += "Add";
                code += Name(field) + "(builder, ";
                if (IsStruct(field.value.type) &&
                    opts.generate_object_based_api) {
                  code += GenTypePointer(field.value.type) + ".Pack(builder, " +
                          EscapeKeyword(field.name) + ")";
                } else {
                  code += EscapeKeyword(field.name);
                  if (!IsScalar(field.value.type.base_type)) code += "Offset";
                }
  
                code += ");\n";
              }
            }
          }
          code += "    return " + struct_def.name + ".";
          code += "End" + struct_def.name;
          code += "(builder);\n  }\n\n";
        }
        // Generate a set of static methods that allow table construction,
        // of the form:
        // public static void addName(FlatBufferBuilder builder, short name)
        // { builder.addShort(id, name, default); }
        // Unlike the Create function, these always work.
        code += "  public static void Start";
        code += struct_def.name;
        code += "(FlatBufferBuilder builder) { builder.";
        code += "StartTable(";
        code += NumToString(struct_def.fields.vec.size()) + "); }\n";
        for (auto it = struct_def.fields.vec.begin();
             it != struct_def.fields.vec.end(); ++it) {
          auto &field = **it;
          if (field.deprecated) continue;
          if (field.key) key_field = &field;
          code += "  public static void Add";
          code += Name(field);
          code += "(FlatBufferBuilder builder, ";
          code += GenTypeBasic(field.value.type);
          auto argname = MakeCamel(field.name, false);
          if (!IsScalar(field.value.type.base_type)) argname += "Offset";
          if (field.IsScalarOptional()) { code += "?"; }
          code += " " + EscapeKeyword(argname) + ") { builder.Add";
          code += GenMethod(field.value.type) + "(";
          code += NumToString(it - struct_def.fields.vec.begin()) + ", ";
          code += SourceCastBasic(field.value.type, field.IsScalarOptional());
          code += EscapeKeyword(argname);
          if (!IsScalar(field.value.type.base_type) &&
              field.value.type.base_type != BASE_TYPE_UNION) {
            code += ".Value";
          }
          if (!field.IsScalarOptional()) {
            // When the scalar is optional, use the builder method that doesn't
            // supply a default value. Otherwise, we to continue to use the
            // default value method.
            code += ", ";
            code += GenDefaultValue(field, false);
          }
          code += "); }\n";
          if (IsVector(field.value.type)) {
            auto vector_type = field.value.type.VectorType();
            auto alignment = InlineAlignment(vector_type);
            auto elem_size = InlineSize(vector_type);
            if (!IsStruct(vector_type)) {
              field_has_create_set.insert(&field);
              code += "  public static VectorOffset ";
              code += "Create";
              code += Name(field);
              code += "Vector(FlatBufferBuilder builder, ";
              code += GenTypeBasic(vector_type) + "[] data) ";
              code += "{ builder.StartVector(";
              code += NumToString(elem_size);
              code += ", data.Length, ";
              code += NumToString(alignment);
              code += "); for (int i = data.";
              code += "Length - 1; i >= 0; i--) builder.";
              code += "Add";
              code += GenMethod(vector_type);
              code += "(";
              // At the moment there is no support of the type Vector with optional enum, 
              // e.g. if we have enum type SomeEnum there is no way to define `SomeEmum?[] enums` in FlatBuffer schema, so isOptional = false
              code += SourceCastBasic(vector_type, false);
              code += "data[i]";
              if (vector_type.base_type == BASE_TYPE_STRUCT ||
                  IsString(vector_type))
                code += ".Value";
              code += "); return ";
              code += "builder.EndVector(); }\n";
  
              code += "  public static VectorOffset ";
              code += "Create";
              code += Name(field);
              code += "VectorBlock(FlatBufferBuilder builder, ";
              code += GenTypeBasic(vector_type) + "[] data) ";
              code += "{ builder.StartVector(";
              code += NumToString(elem_size);
              code += ", data.Length, ";
              code += NumToString(alignment);
              code += "); builder.Add(data); return builder.EndVector(); }\n";
            }
            // Generate a method to start a vector, data to be added manually
            // after.
            code += "  public static void Start";
            code += Name(field);
            code += "Vector(FlatBufferBuilder builder, int numElems) ";
            code += "{ builder.StartVector(";
            code += NumToString(elem_size);
            code += ", numElems, " + NumToString(alignment);
            code += "); }\n";
          }
        }
        code += "  public static " + GenOffsetType(struct_def) + " ";
        code += "End" + struct_def.name;
        code += "(FlatBufferBuilder builder) {\n    int o = builder.";
        code += "EndTable();\n";
        for (auto it = struct_def.fields.vec.begin();
             it != struct_def.fields.vec.end(); ++it) {
          auto &field = **it;
          if (!field.deprecated && field.IsRequired()) {
            code += "    builder.Required(o, ";
            code += NumToString(field.value.offset);
            code += ");  // " + field.name + "\n";
          }
        }
        code += "    return " + GenOffsetConstruct(struct_def, "o") + ";\n  }\n";
        if (parser_.root_struct_def_ == &struct_def) {
          std::string size_prefix[] = { "", "SizePrefixed" };
          for (int i = 0; i < 2; ++i) {
            code += "  public static void ";
            code += "Finish" + size_prefix[i] + struct_def.name;
            code +=
                "Buffer(FlatBufferBuilder builder, " + GenOffsetType(struct_def);
            code += " offset) {";
            code += " builder.Finish" + size_prefix[i] + "(offset";
            code += ".Value";
  
            if (parser_.file_identifier_.length())
              code += ", \"" + parser_.file_identifier_ + "\"";
            code += "); }\n";
          }
        }
      }
      // Only generate key compare function for table,
      // because `key_field` is not set for struct
      if (struct_def.has_key && !struct_def.fixed) {
        FLATBUFFERS_ASSERT(key_field);
        code += "\n  public static VectorOffset ";
        code += "CreateSortedVectorOf" + struct_def.name;
        code += "(FlatBufferBuilder builder, ";
        code += "Offset<" + struct_def.name + ">";
        code += "[] offsets) {\n";
        code += "    Array.Sort(offsets, (Offset<" + struct_def.name +
                "> o1, Offset<" + struct_def.name + "> o2) => " +
                GenKeyGetter(key_field);
        code += ");\n";
        code += "    return builder.CreateVectorOfTables(offsets);\n  }\n";
  
        code += "\n  public static " + struct_def.name + "?";
        code += " __lookup_by_key(";
        code += "int vectorLocation, ";
        code += GenTypeGet(key_field->value.type);
        code += " key, ByteBuffer bb) {\n";
        if (IsString(key_field->value.type)) {
          code += "    byte[] byteKey = ";
          code += "System.Text.Encoding.UTF8.GetBytes(key);\n";
        }
        code += "    int span = ";
        code += "bb.GetInt(vectorLocation - 4);\n";
        code += "    int start = 0;\n";
        code += "    while (span != 0) {\n";
        code += "      int middle = span / 2;\n";
        code += GenLookupKeyGetter(key_field);
        code += "      if (comp > 0) {\n";
        code += "        span = middle;\n";
        code += "      } else if (comp < 0) {\n";
        code += "        middle++;\n";
        code += "        start += middle;\n";
        code += "        span -= middle;\n";
        code += "      } else {\n";
        code += "        return ";
        code += "new " + struct_def.name + "()";
        code += ".__assign(tableOffset, bb);\n";
        code += "      }\n    }\n";
        code += "    return null;\n";
        code += "  }\n";
      }
  
      if (opts.generate_object_based_api) {
        GenPackUnPack_ObjectAPI(struct_def, code_ptr, opts, struct_has_create,
                                field_has_create_set);
      }
      code += "}\n\n";
  
      if (opts.generate_object_based_api) {
        GenStruct_ObjectAPI(struct_def, code_ptr, opts);
      }
    }
  
    void GenVectorAccessObject(StructDef &struct_def,
                               std::string *code_ptr) const {
      auto &code = *code_ptr;
      // Generate a vector of structs accessor class.
      code += "\n";
      code += "  ";
      if (!struct_def.attributes.Lookup("private")) code += "public ";
      code += "static struct Vector : BaseVector\n{\n";
  
      // Generate the __assign method that sets the field in a pre-existing
      // accessor object. This is to allow object reuse.
      std::string method_indent = "    ";
      code += method_indent + "public Vector ";
      code += "__assign(int _vector, int _element_size, ByteBuffer _bb) { ";
      code += "__reset(_vector, _element_size, _bb); return this; }\n\n";
  
      auto type_name = struct_def.name;
      auto method_start = method_indent + "public " + type_name + " Get";
      // Generate the accessors that don't do object reuse.
      code += method_start + "(int j) { return Get";
      code += "(new " + type_name + "(), j); }\n";
      code += method_start + "(" + type_name + " obj, int j) { ";
      code += " return obj.__assign(";
      code += struct_def.fixed ? "__p.__element(j)"
                               : "__p.__indirect(__p.__element(j), bb)";
      code += ", __p.bb); }\n";
      // See if we should generate a by-key accessor.
      if (!struct_def.fixed) {
        auto &fields = struct_def.fields.vec;
        for (auto kit = fields.begin(); kit != fields.end(); ++kit) {
          auto &key_field = **kit;
          if (key_field.key) {
            auto nullable_annotation =
                parser_.opts.gen_nullable ? "@Nullable " : "";
            code += method_indent + nullable_annotation;
            code += "public " + type_name + "? ";
            code += "GetByKey(";
            code += GenTypeGet(key_field.value.type) + " key) { ";
            code += " return __lookup_by_key(null, ";
            code += "__p.__vector(), key, ";
            code += "__p.bb); ";
            code += "}\n";
            code += method_indent + nullable_annotation;
            code += "public " + type_name + "?" + " ";
            code += "GetByKey(";
            code += type_name + "? obj, ";
            code += GenTypeGet(key_field.value.type) + " key) { ";
            code += " return __lookup_by_key(obj, ";
            code += "__p.__vector(), key, ";
            code += "__p.bb); ";
            code += "}\n";
            break;
          }
        }
      }
      code += "  }\n";
    }
  
    void GenEnum_ObjectAPI(EnumDef &enum_def, std::string *code_ptr,
                           const IDLOptions &opts) const {
      auto &code = *code_ptr;
      if (enum_def.generated) return;
      if (!enum_def.is_union) return;
      if (enum_def.attributes.Lookup("private")) {
        code += "internal ";
      } else {
        code += "public ";
      }
      auto union_name = enum_def.name + "Union";
      code += "class " + union_name + " {\n";
      // Type
      code += "  public " + enum_def.name + " Type { get; set; }\n";
      // Value
      code += "  public object Value { get; set; }\n";
      code += "\n";
      // Constructor
      code += "  public " + union_name + "() {\n";
      code += "    this.Type = " + enum_def.name + "." +
              enum_def.Vals()[0]->name + ";\n";
      code += "    this.Value = null;\n";
      code += "  }\n\n";
      // As<T>
      code += "  public T As<T>() where T : class { return this.Value as T; }\n";
      // As, From
      for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
        auto &ev = **it;
        if (ev.union_type.base_type == BASE_TYPE_NONE) continue;
        auto type_name = GenTypeGet_ObjectAPI(ev.union_type, opts);
        std::string accessibility =
            (ev.union_type.base_type == BASE_TYPE_STRUCT &&
             ev.union_type.struct_def->attributes.Lookup("private"))
                ? "internal"
                : "public";
        // As
        code += "  " + accessibility + " " + type_name + " As" + ev.name +
                "() { return this.As<" + type_name + ">(); }\n";
        // From
        auto lower_ev_name = ev.name;
        std::transform(lower_ev_name.begin(), lower_ev_name.end(),
                       lower_ev_name.begin(), CharToLower);
        code += "  " + accessibility + " static " + union_name + " From" +
                ev.name + "(" + type_name + " _" + lower_ev_name +
                ") { return new " + union_name + "{ Type = " + Name(enum_def) +
                "." + Name(ev) + ", Value = _" + lower_ev_name + " }; }\n";
      }
      code += "\n";
      // Pack()
      code += "  public static int Pack(FlatBuffers.FlatBufferBuilder builder, " +
              union_name + " _o) {\n";
      code += "    switch (_o.Type) {\n";
      for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end(); ++it) {
        auto &ev = **it;
        if (ev.union_type.base_type == BASE_TYPE_NONE) {
          code += "      default: return 0;\n";
        } else {
          code += "      case " + Name(enum_def) + "." + Name(ev) + ": return ";
          if (IsString(ev.union_type)) {
            code += "builder.CreateString(_o.As" + ev.name + "()).Value;\n";
          } else {
            code += GenTypeGet(ev.union_type) + ".Pack(builder, _o.As" + ev.name +
                    "()).Value;\n";
          }
        }
      }
      code += "    }\n";
      code += "  }\n";
      code += "}\n\n";
      // JsonConverter
      if (opts.cs_gen_json_serializer) {
        if (enum_def.attributes.Lookup("private")) {
          code += "internal ";
        } else {
          code += "public ";
        }
        code += "class " + union_name +
                "_JsonConverter : Newtonsoft.Json.JsonConverter {\n";
        code += "  public override bool CanConvert(System.Type objectType) {\n";
        code += "    return objectType == typeof(" + union_name +
                ") || objectType == typeof(System.Collections.Generic.List<" +
                union_name + ">);\n";
        code += "  }\n";
        code +=
            "  public override void WriteJson(Newtonsoft.Json.JsonWriter writer, "
            "object value, "
            "Newtonsoft.Json.JsonSerializer serializer) {\n";
        code += "    var _olist = value as System.Collections.Generic.List<" +
                union_name + ">;\n";
        code += "    if (_olist != null) {\n";
        code += "      writer.WriteStartArray();\n";
        code +=
            "      foreach (var _o in _olist) { this.WriteJson(writer, _o, "
            "serializer); }\n";
        code += "      writer.WriteEndArray();\n";
        code += "    } else {\n";
        code += "      this.WriteJson(writer, value as " + union_name +
                ", serializer);\n";
        code += "    }\n";
        code += "  }\n";
        code += "  public void WriteJson(Newtonsoft.Json.JsonWriter writer, " +
                union_name +
                " _o, "
                "Newtonsoft.Json.JsonSerializer serializer) {\n";
        code += "    if (_o == null) return;\n";
        code += "    serializer.Serialize(writer, _o.Value);\n";
        code += "  }\n";
        code +=
            "  public override object ReadJson(Newtonsoft.Json.JsonReader "
            "reader, "
            "System.Type objectType, "
            "object existingValue, Newtonsoft.Json.JsonSerializer serializer) "
            "{\n";
        code +=
            "    var _olist = existingValue as System.Collections.Generic.List<" +
            union_name + ">;\n";
        code += "    if (_olist != null) {\n";
        code += "      for (var _j = 0; _j < _olist.Count; ++_j) {\n";
        code += "        reader.Read();\n";
        code +=
            "        _olist[_j] = this.ReadJson(reader, _olist[_j], "
            "serializer);\n";
        code += "      }\n";
        code += "      reader.Read();\n";
        code += "      return _olist;\n";
        code += "    } else {\n";
        code += "      return this.ReadJson(reader, existingValue as " +
                union_name + ", serializer);\n";
        code += "    }\n";
        code += "  }\n";
        code += "  public " + union_name +
                " ReadJson(Newtonsoft.Json.JsonReader reader, " + union_name +
                " _o, Newtonsoft.Json.JsonSerializer serializer) {\n";
        code += "    if (_o == null) return null;\n";
        code += "    switch (_o.Type) {\n";
        for (auto it = enum_def.Vals().begin(); it != enum_def.Vals().end();
             ++it) {
          auto &ev = **it;
          if (ev.union_type.base_type == BASE_TYPE_NONE) {
            code += "      default: break;\n";
          } else {
            auto type_name = GenTypeGet_ObjectAPI(ev.union_type, opts);
            code += "      case " + Name(enum_def) + "." + Name(ev) +
                    ": _o.Value = serializer.Deserialize<" + type_name +
                    ">(reader); break;\n";
          }
        }
        code += "    }\n";
        code += "    return _o;\n";
        code += "  }\n";
        code += "}\n\n";
      }
    }
  
    std::string GenTypeName_ObjectAPI(const std::string &name,
                                      const IDLOptions &opts) const {
      return opts.object_prefix + name + opts.object_suffix;
    }
  
    void GenUnionUnPack_ObjectAPI(const EnumDef &enum_def, std::string *code_ptr,
                                  const std::string &camel_name,
                                  bool is_vector) const {
      auto &code = *code_ptr;
      std::string varialbe_name = "_o." + camel_name;
      std::string type_suffix = "";
      std::string func_suffix = "()";
      std::string indent = "    ";
      if (is_vector) {
        varialbe_name = "_o_" + camel_name;
        type_suffix = "(_j)";
        func_suffix = "(_j)";
        indent = "      ";
      }
      if (is_vector) {
        code += indent + "var " + varialbe_name + " = new ";
      } else {
        code += indent + varialbe_name + " = new ";
      }
      code += NamespacedName(enum_def) + "Union();\n";
      code += indent + varialbe_name + ".Type = this." + camel_name + "Type" +
              type_suffix + ";\n";
      code +=
          indent + "switch (this." + camel_name + "Type" + type_suffix + ") {\n";
      for (auto eit = enum_def.Vals().begin(); eit != enum_def.Vals().end();
           ++eit) {
        auto &ev = **eit;
        if (ev.union_type.base_type == BASE_TYPE_NONE) {
          code += indent + "  default: break;\n";
        } else {
          code += indent + "  case " + NamespacedName(enum_def) + "." + ev.name +
                  ":\n";
          code += indent + "    " + varialbe_name + ".Value = this." + camel_name;
          if (IsString(ev.union_type)) {
            code += "AsString" + func_suffix + ";\n";
          } else {
            code += "<" + GenTypeGet(ev.union_type) + ">" + func_suffix;
            code += ".HasValue ? this." + camel_name;
            code += "<" + GenTypeGet(ev.union_type) + ">" + func_suffix +
                    ".Value.UnPack() : null;\n";
          }
          code += indent + "    break;\n";
        }
      }
      code += indent + "}\n";
      if (is_vector) {
        code += indent + "_o." + camel_name + ".Add(" + varialbe_name + ");\n";
      }
    }
  
    void GenPackUnPack_ObjectAPI(
        StructDef &struct_def, std::string *code_ptr, const IDLOptions &opts,
        bool struct_has_create,
        const std::set<FieldDef *> &field_has_create) const {
      auto &code = *code_ptr;
      auto struct_name = GenTypeName_ObjectAPI(struct_def.name, opts);
      // UnPack()
      code += "  public " + struct_name + " UnPack() {\n";
      code += "    var _o = new " + struct_name + "();\n";
      code += "    this.UnPackTo(_o);\n";
      code += "    return _o;\n";
      code += "  }\n";
      // UnPackTo()
      code += "  public void UnPackTo(" + struct_name + " _o) {\n";
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        if (field.deprecated) continue;
        auto camel_name = Name(field);
        auto start = "    _o." + camel_name + " = ";
        switch (field.value.type.base_type) {
          case BASE_TYPE_STRUCT: {
            auto fixed = struct_def.fixed && field.value.type.struct_def->fixed;
            if (fixed) {
              code += start + "this." + camel_name + ".UnPack();\n";
            } else {
              code += start + "this." + camel_name + ".HasValue ? this." +
                      camel_name + ".Value.UnPack() : null;\n";
            }
            break;
          }
          case BASE_TYPE_ARRAY: {
            auto type_name = GenTypeGet_ObjectAPI(field.value.type, opts);
            auto length_str = NumToString(field.value.type.fixed_length);
            auto unpack_method = field.value.type.struct_def == nullptr
                                     ? ""
                                     : field.value.type.struct_def->fixed
                                           ? ".UnPack()"
                                           : "?.UnPack()";
            code += start + "new " + type_name.substr(0, type_name.length() - 1) +
                    length_str + "];\n";
            code += "    for (var _j = 0; _j < " + length_str + "; ++_j) { _o." +
                    camel_name + "[_j] = this." + camel_name + "(_j)" +
                    unpack_method + "; }\n";
            break;
          }
          case BASE_TYPE_VECTOR:
            if (field.value.type.element == BASE_TYPE_UNION) {
              code += start + "new " +
                      GenTypeGet_ObjectAPI(field.value.type, opts) + "();\n";
              code += "    for (var _j = 0; _j < this." + camel_name +
                      "Length; ++_j) {\n";
              GenUnionUnPack_ObjectAPI(*field.value.type.enum_def, code_ptr,
                                       camel_name, true);
              code += "    }\n";
            } else if (field.value.type.element != BASE_TYPE_UTYPE) {
              auto fixed = field.value.type.struct_def == nullptr;
              code += start + "new " +
                      GenTypeGet_ObjectAPI(field.value.type, opts) + "();\n";
              code += "    for (var _j = 0; _j < this." + camel_name +
                      "Length; ++_j) {";
              code += "_o." + camel_name + ".Add(";
              if (fixed) {
                code += "this." + camel_name + "(_j)";
              } else {
                code += "this." + camel_name + "(_j).HasValue ? this." +
                        camel_name + "(_j).Value.UnPack() : null";
              }
              code += ");}\n";
            }
            break;
          case BASE_TYPE_UTYPE: break;
          case BASE_TYPE_UNION: {
            GenUnionUnPack_ObjectAPI(*field.value.type.enum_def, code_ptr,
                                     camel_name, false);
            break;
          }
          default: {
            code += start + "this." + camel_name + ";\n";
            break;
          }
        }
      }
      code += "  }\n";
      // Pack()
      code += "  public static " + GenOffsetType(struct_def) +
              " Pack(FlatBufferBuilder builder, " + struct_name + " _o) {\n";
      code += "    if (_o == null) return default(" + GenOffsetType(struct_def) +
              ");\n";
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        if (field.deprecated) continue;
        auto camel_name = Name(field);
        // pre
        switch (field.value.type.base_type) {
          case BASE_TYPE_STRUCT: {
            if (!field.value.type.struct_def->fixed) {
              code += "    var _" + field.name + " = _o." + camel_name +
                      " == null ? default(" +
                      GenOffsetType(*field.value.type.struct_def) +
                      ") : " + GenTypeGet(field.value.type) +
                      ".Pack(builder, _o." + camel_name + ");\n";
            } else if (struct_def.fixed && struct_has_create) {
              std::vector<FieldArrayLength> array_lengths;
              FieldArrayLength tmp_array_length = {
                field.name,
                field.value.type.fixed_length,
              };
              array_lengths.push_back(tmp_array_length);
              GenStructPackDecl_ObjectAPI(*field.value.type.struct_def, code_ptr,
                                          array_lengths);
            }
            break;
          }
          case BASE_TYPE_STRING: {
            std::string create_string =
                field.shared ? "CreateSharedString" : "CreateString";
            code += "    var _" + field.name + " = _o." + camel_name +
                    " == null ? default(StringOffset) : "
                    "builder." +
                    create_string + "(_o." + camel_name + ");\n";
            break;
          }
          case BASE_TYPE_VECTOR: {
            if (field_has_create.find(&field) != field_has_create.end()) {
              auto property_name = camel_name;
              auto gen_for_loop = true;
              std::string array_name = "__" + field.name;
              std::string array_type = "";
              std::string to_array = "";
              switch (field.value.type.element) {
                case BASE_TYPE_STRING: {
                  std::string create_string =
                      field.shared ? "CreateSharedString" : "CreateString";
                  array_type = "StringOffset";
                  to_array += "builder." + create_string + "(_o." +
                              property_name + "[_j])";
                  break;
                }
                case BASE_TYPE_STRUCT:
                  array_type = "Offset<" + GenTypeGet(field.value.type) + ">";
                  to_array = GenTypeGet(field.value.type) + ".Pack(builder, _o." +
                             property_name + "[_j])";
                  break;
                case BASE_TYPE_UTYPE:
                  property_name = camel_name.substr(0, camel_name.size() - 4);
                  array_type = NamespacedName(*field.value.type.enum_def);
                  to_array = "_o." + property_name + "[_j].Type";
                  break;
                case BASE_TYPE_UNION:
                  array_type = "int";
                  to_array = NamespacedName(*field.value.type.enum_def) +
                             "Union.Pack(builder,  _o." + property_name + "[_j])";
                  break;
                default: gen_for_loop = false; break;
              }
              code += "    var _" + field.name + " = default(VectorOffset);\n";
              code += "    if (_o." + property_name + " != null) {\n";
              if (gen_for_loop) {
                code += "      var " + array_name + " = new " + array_type +
                        "[_o." + property_name + ".Count];\n";
                code += "      for (var _j = 0; _j < " + array_name +
                        ".Length; ++_j) { ";
                code += array_name + "[_j] = " + to_array + "; }\n";
              } else {
                code += "      var " + array_name + " = _o." + property_name +
                        ".ToArray();\n";
              }
              code += "      _" + field.name + " = Create" + camel_name +
                      "Vector(builder, " + array_name + ");\n";
              code += "    }\n";
            } else {
              auto pack_method =
                  field.value.type.struct_def == nullptr
                      ? "builder.Add" + GenMethod(field.value.type.VectorType()) +
                            "(_o." + camel_name + "[_j]);"
                      : GenTypeGet(field.value.type) + ".Pack(builder, _o." +
                            camel_name + "[_j]);";
              code += "    var _" + field.name + " = default(VectorOffset);\n";
              code += "    if (_o." + camel_name + " != null) {\n";
              code += "      Start" + camel_name + "Vector(builder, _o." +
                      camel_name + ".Count);\n";
              code += "      for (var _j = _o." + camel_name +
                      ".Count - 1; _j >= 0; --_j) { " + pack_method + " }\n";
              code += "      _" + field.name + " = builder.EndVector();\n";
              code += "    }\n";
            }
            break;
          }
          case BASE_TYPE_ARRAY: {
            if (field.value.type.struct_def != nullptr) {
              std::vector<FieldArrayLength> array_lengths;
              FieldArrayLength tmp_array_length = {
                field.name,
                field.value.type.fixed_length,
              };
              array_lengths.push_back(tmp_array_length);
              GenStructPackDecl_ObjectAPI(*field.value.type.struct_def, code_ptr,
                                          array_lengths);
            } else {
              code += "    var _" + field.name + " = _o." + camel_name + ";\n";
            }
            break;
          }
          case BASE_TYPE_UNION: {
            code += "    var _" + field.name + "_type = _o." + camel_name +
                    " == null ? " + NamespacedName(*field.value.type.enum_def) +
                    ".NONE : " + "_o." + camel_name + ".Type;\n";
            code +=
                "    var _" + field.name + " = _o." + camel_name +
                " == null ? 0 : " + GenTypeGet_ObjectAPI(field.value.type, opts) +
                ".Pack(builder, _o." + camel_name + ");\n";
            break;
          }
          default: break;
        }
      }
      if (struct_has_create) {
        // Create
        code += "    return Create" + struct_def.name + "(\n";
        code += "      builder";
        for (auto it = struct_def.fields.vec.begin();
             it != struct_def.fields.vec.end(); ++it) {
          auto &field = **it;
          if (field.deprecated) continue;
          auto camel_name = Name(field);
          switch (field.value.type.base_type) {
            case BASE_TYPE_STRUCT: {
              if (struct_def.fixed) {
                GenStructPackCall_ObjectAPI(*field.value.type.struct_def,
                                            code_ptr,
                                            "      _" + field.name + "_");
              } else {
                code += ",\n";
                if (field.value.type.struct_def->fixed) {
                  if (opts.generate_object_based_api)
                    code += "      _o." + camel_name;
                  else
                    code += "      " + GenTypeGet(field.value.type) +
                            ".Pack(builder, _o." + camel_name + ")";
                } else {
                  code += "      _" + field.name;
                }
              }
              break;
            }
            case BASE_TYPE_ARRAY: {
              if (field.value.type.struct_def != nullptr) {
                GenStructPackCall_ObjectAPI(*field.value.type.struct_def,
                                            code_ptr,
                                            "      _" + field.name + "_");
              } else {
                code += ",\n";
                code += "      _" + field.name;
              }
              break;
            }
            case BASE_TYPE_UNION: FLATBUFFERS_FALLTHROUGH();   // fall thru
            case BASE_TYPE_UTYPE: FLATBUFFERS_FALLTHROUGH();   // fall thru
            case BASE_TYPE_STRING: FLATBUFFERS_FALLTHROUGH();  // fall thru
            case BASE_TYPE_VECTOR: {
              code += ",\n";
              code += "      _" + field.name;
              break;
            }
            default:  // scalar
              code += ",\n";
              code += "      _o." + camel_name;
              break;
          }
        }
        code += ");\n";
      } else {
        // Start, End
        code += "    Start" + struct_def.name + "(builder);\n";
        for (auto it = struct_def.fields.vec.begin();
             it != struct_def.fields.vec.end(); ++it) {
          auto &field = **it;
          if (field.deprecated) continue;
          auto camel_name = Name(field);
          switch (field.value.type.base_type) {
            case BASE_TYPE_STRUCT: {
              if (field.value.type.struct_def->fixed) {
                code += "    Add" + camel_name + "(builder, " +
                        GenTypeGet(field.value.type) + ".Pack(builder, _o." +
                        camel_name + "));\n";
              } else {
                code +=
                    "    Add" + camel_name + "(builder, _" + field.name + ");\n";
              }
              break;
            }
            case BASE_TYPE_STRING: FLATBUFFERS_FALLTHROUGH();  // fall thru
            case BASE_TYPE_ARRAY: FLATBUFFERS_FALLTHROUGH();   // fall thru
            case BASE_TYPE_VECTOR: {
              code +=
                  "    Add" + camel_name + "(builder, _" + field.name + ");\n";
              break;
            }
            case BASE_TYPE_UTYPE: break;
            case BASE_TYPE_UNION: {
              code += "    Add" + camel_name + "Type(builder, _" + field.name +
                      "_type);\n";
              code +=
                  "    Add" + camel_name + "(builder, _" + field.name + ");\n";
              break;
            }
            // scalar
            default: {
              code +=
                  "    Add" + camel_name + "(builder, _o." + camel_name + ");\n";
              break;
            }
          }
        }
        code += "    return End" + struct_def.name + "(builder);\n";
      }
      code += "  }\n";
    }
  
    void GenStructPackDecl_ObjectAPI(
        const StructDef &struct_def, std::string *code_ptr,
        std::vector<FieldArrayLength> &array_lengths) const {
      auto &code = *code_ptr;
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        auto is_array = IsArray(field.value.type);
        const auto &field_type =
            is_array ? field.value.type.VectorType() : field.value.type;
        FieldArrayLength tmp_array_length = {
          field.name,
          field_type.fixed_length,
        };
        array_lengths.push_back(tmp_array_length);
        if (field_type.struct_def != nullptr) {
          GenStructPackDecl_ObjectAPI(*field_type.struct_def, code_ptr,
                                      array_lengths);
        } else {
          std::vector<FieldArrayLength> array_only_lengths;
          for (size_t i = 0; i < array_lengths.size(); ++i) {
            if (array_lengths[i].length > 0) {
              array_only_lengths.push_back(array_lengths[i]);
            }
          }
          std::string name;
          for (size_t i = 0; i < array_lengths.size(); ++i) {
            name += "_" + array_lengths[i].name;
          }
          code += "    var " + name + " = ";
          if (array_only_lengths.size() > 0) {
            code += "new " + GenTypeBasic(field_type) + "[";
            for (size_t i = 0; i < array_only_lengths.size(); ++i) {
              if (i != 0) { code += ","; }
              code += NumToString(array_only_lengths[i].length);
            }
            code += "];\n";
            code += "    ";
            // initialize array
            for (size_t i = 0; i < array_only_lengths.size(); ++i) {
              auto idx = "idx" + NumToString(i);
              code += "for (var " + idx + " = 0; " + idx + " < " +
                      NumToString(array_only_lengths[i].length) + "; ++" + idx +
                      ") {";
            }
            for (size_t i = 0; i < array_only_lengths.size(); ++i) {
              auto idx = "idx" + NumToString(i);
              if (i == 0) {
                code += name + "[" + idx;
              } else {
                code += "," + idx;
              }
            }
            code += "] = _o";
            for (size_t i = 0, j = 0; i < array_lengths.size(); ++i) {
              code += "." + MakeCamel(array_lengths[i].name, true);
              if (array_lengths[i].length <= 0) continue;
              code += "[idx" + NumToString(j++) + "]";
            }
            code += ";";
            for (size_t i = 0; i < array_only_lengths.size(); ++i) {
              code += "}";
            }
          } else {
            code += "_o";
            for (size_t i = 0; i < array_lengths.size(); ++i) {
              code += "." + MakeCamel(array_lengths[i].name, true);
            }
            code += ";";
          }
          code += "\n";
        }
        array_lengths.pop_back();
      }
    }
  
    void GenStructPackCall_ObjectAPI(const StructDef &struct_def,
                                     std::string *code_ptr,
                                     std::string prefix) const {
      auto &code = *code_ptr;
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        const auto &field_type = field.value.type;
        if (field_type.struct_def != nullptr) {
          GenStructPackCall_ObjectAPI(*field_type.struct_def, code_ptr,
                                      prefix + field.name + "_");
        } else {
          code += ",\n";
          code += prefix + field.name;
        }
      }
    }
  
    std::string GenTypeGet_ObjectAPI(flatbuffers::Type type,
                                     const IDLOptions &opts) const {
      auto type_name = GenTypeGet(type);
      // Replace to ObjectBaseAPI Type Name
      switch (type.base_type) {
        case BASE_TYPE_STRUCT: FLATBUFFERS_FALLTHROUGH();  // fall thru
        case BASE_TYPE_ARRAY: FLATBUFFERS_FALLTHROUGH();   // fall thru
        case BASE_TYPE_VECTOR: {
          if (type.struct_def != nullptr) {
            auto type_name_length = type.struct_def->name.length();
            auto new_type_name =
                GenTypeName_ObjectAPI(type.struct_def->name, opts);
            type_name.replace(type_name.length() - type_name_length,
                              type_name_length, new_type_name);
          } else if (type.element == BASE_TYPE_UNION) {
            type_name = NamespacedName(*type.enum_def) + "Union";
          }
          break;
        }
  
        case BASE_TYPE_UNION: {
          type_name = NamespacedName(*type.enum_def) + "Union";
          break;
        }
        default: break;
      }
  
      switch (type.base_type) {
        case BASE_TYPE_ARRAY: {
          type_name = type_name + "[]";
          break;
        }
        case BASE_TYPE_VECTOR: {
          type_name = "List<" + type_name + ">";
          break;
        }
        default: break;
      }
      return type_name;
    }
  
    void GenStruct_ObjectAPI(StructDef &struct_def, std::string *code_ptr,
                             const IDLOptions &opts) const {
      auto &code = *code_ptr;
      if (struct_def.attributes.Lookup("private")) {
        code += "internal ";
      } else {
        code += "public ";
      }
      if (struct_def.attributes.Lookup("csharp_partial")) {
        // generate a partial class for this C# struct/table
        code += "partial ";
      }
      auto class_name = GenTypeName_ObjectAPI(struct_def.name, opts);
      code += "class " + class_name;
      code += "\n{\n";
      // Generate Properties
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        if (field.deprecated) continue;
        if (field.value.type.base_type == BASE_TYPE_UTYPE) continue;
        if (field.value.type.element == BASE_TYPE_UTYPE) continue;
        auto type_name = GenTypeGet_ObjectAPI(field.value.type, opts);
        if (field.IsScalarOptional()) type_name += "?";
        auto camel_name = Name(field);
        if (opts.cs_gen_json_serializer) {
          if (IsUnion(field.value.type)) {
            auto utype_name = NamespacedName(*field.value.type.enum_def);
            code +=
                "  [Newtonsoft.Json.JsonProperty(\"" + field.name + "_type\")]\n";
            if (IsVector(field.value.type)) {
              code += "  private " + utype_name + "[] " + camel_name + "Type {\n";
              code += "    get {\n";
              code += "      if (this." + camel_name + " == null) return null;\n";
              code += "      var _o = new " + utype_name + "[this." + camel_name +
                      ".Count];\n";
              code +=
                  "      for (var _j = 0; _j < _o.Length; ++_j) { _o[_j] = "
                  "this." +
                  camel_name + "[_j].Type; }\n";
              code += "      return _o;\n";
              code += "    }\n";
              code += "    set {\n";
              code += "      this." + camel_name + " = new List<" + utype_name +
                      "Union>();\n";
              code += "      for (var _j = 0; _j < value.Length; ++_j) {\n";
              code += "        var _o = new " + utype_name + "Union();\n";
              code += "        _o.Type = value[_j];\n";
              code += "        this." + camel_name + ".Add(_o);\n";
              code += "      }\n";
              code += "    }\n";
              code += "  }\n";
            } else {
              code += "  private " + utype_name + " " + camel_name + "Type {\n";
              code += "    get {\n";
              code += "      return this." + camel_name + " != null ? this." +
                      camel_name + ".Type : " + utype_name + ".NONE;\n";
              code += "    }\n";
              code += "    set {\n";
              code += "      this." + camel_name + " = new " + utype_name +
                      "Union();\n";
              code += "      this." + camel_name + ".Type = value;\n";
              code += "    }\n";
              code += "  }\n";
            }
          }
          code += "  [Newtonsoft.Json.JsonProperty(\"" + field.name + "\")]\n";
          if (IsUnion(field.value.type)) {
            auto union_name =
                (IsVector(field.value.type))
                    ? GenTypeGet_ObjectAPI(field.value.type.VectorType(), opts)
                    : type_name;
            code += "  [Newtonsoft.Json.JsonConverter(typeof(" + union_name +
                    "_JsonConverter))]\n";
          }
          if (field.attributes.Lookup("hash")) {
            code += "  [Newtonsoft.Json.JsonIgnore()]\n";
          }
        }
        code += "  public " + type_name + " " + camel_name + " { get; set; }\n";
      }
      // Generate Constructor
      code += "\n";
      code += "  public " + class_name + "() {\n";
      for (auto it = struct_def.fields.vec.begin();
           it != struct_def.fields.vec.end(); ++it) {
        auto &field = **it;
        if (field.deprecated) continue;
        if (field.value.type.base_type == BASE_TYPE_UTYPE) continue;
        if (field.value.type.element == BASE_TYPE_UTYPE) continue;
        code += "    this." + Name(field) + " = ";
        auto type_name = GenTypeGet_ObjectAPI(field.value.type, opts);
        if (IsScalar(field.value.type.base_type)) {
          code += GenDefaultValue(field) + ";\n";
        } else {
          switch (field.value.type.base_type) {
            case BASE_TYPE_STRUCT: {
              if (IsStruct(field.value.type)) {
                code += "new " + type_name + "();\n";
              } else {
                code += "null;\n";
              }
              break;
            }
            case BASE_TYPE_ARRAY: {
              code += "new " + type_name.substr(0, type_name.length() - 1) +
                      NumToString(field.value.type.fixed_length) + "];\n";
              break;
            }
            default: {
              code += "null;\n";
              break;
            }
          }
        }
      }
      code += "  }\n";
      // Generate Serialization
      if (opts.cs_gen_json_serializer &&
          parser_.root_struct_def_ == &struct_def) {
        code += "\n";
        code += "  public static " + class_name +
                " DeserializeFromJson(string jsonText) {\n";
        code += "    return Newtonsoft.Json.JsonConvert.DeserializeObject<" +
                class_name + ">(jsonText);\n";
        code += "  }\n";
        code += "  public string SerializeToJson() {\n";
        code +=
            "    return Newtonsoft.Json.JsonConvert.SerializeObject(this, "
            "Newtonsoft.Json.Formatting.Indented);\n";
        code += "  }\n";
      }
      if (parser_.root_struct_def_ == &struct_def) {
        code += "  public static " + class_name +
                " DeserializeFromBinary(byte[] fbBuffer) {\n";
        code += "    return " + struct_def.name + ".GetRootAs" + struct_def.name +
                "(new ByteBuffer(fbBuffer)).UnPack();\n";
        code += "  }\n";
        code += "  public byte[] SerializeToBinary() {\n";
        code += "    var fbb = new FlatBufferBuilder(0x10000);\n";
        code += "    " + struct_def.name + ".Finish" + struct_def.name +
                "Buffer(fbb, " + struct_def.name + ".Pack(fbb, this));\n";
        code += "    return fbb.DataBuffer.ToSizedArray();\n";
        code += "  }\n";
      }
      code += "}\n\n";
    }
  
    // This tracks the current namespace used to determine if a type need to be
    // prefixed by its namespace
    const Namespace *cur_name_space_;
  };
  }  // namespace csharp
  
  bool GenerateCSharp(const Parser &parser, const std::string &path,
                      const std::string &file_name) {
    csharp::CSharpGenerator generator(parser, path, file_name);
    return generator.generate();
  }
  
  }  // namespace flatbuffers
  