diff --git a/CMakeLists.txt b/CMakeLists.txt
index 6dc73e7a8..e58ead5f6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -81,7 +81,7 @@ if(APPLE)
     "${CMAKE_CXX_FLAGS} -std=c++11 -stdlib=libc++ -Wall -pedantic -Werror -Wextra")
 elseif(CMAKE_COMPILER_IS_GNUCXX)
   set(CMAKE_CXX_FLAGS
-    "${CMAKE_CXX_FLAGS} -std=c++0x -Wall -pedantic -Werror -Wextra -Werror=shadow")
+    "${CMAKE_CXX_FLAGS} -std=c++0x -Wall -pedantic -Werror -Wextra -Werror=shadow -Wunused-result -Werror=unused-result")
 elseif("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang")
   set(CMAKE_CXX_FLAGS
       "${CMAKE_CXX_FLAGS} -std=c++0x -stdlib=libc++ -Wall -pedantic -Werror -Wextra")
diff --git a/include/flatbuffers/flatbuffers.h b/include/flatbuffers/flatbuffers.h
index 569c72b31..b6b84030f 100644
--- a/include/flatbuffers/flatbuffers.h
+++ b/include/flatbuffers/flatbuffers.h
@@ -1187,6 +1187,18 @@ class Table {
   uint8_t data_[1];
 };
 
+// Helper function to test if a field is present, using any of the field
+// enums in the generated code.
+// `table` must be a generated table type. Since this is a template parameter,
+// this is not typechecked to be a subclass of Table, so beware!
+// Note: this function will return false for fields equal to the default
+// value, since they're not stored in the buffer (unless force_defaults was
+// used).
+template<typename T> bool IsFieldPresent(const T *table, voffset_t field) {
+  // Cast, since Table is a private baseclass of any table types.
+  return reinterpret_cast<const Table *>(table)->CheckField(field);
+}
+
 // Utility function for reverse lookups on the EnumNames*() functions
 // (in the generated C++ code)
 // names must be NULL terminated.
diff --git a/include/flatbuffers/idl.h b/include/flatbuffers/idl.h
index 1ed360be1..118a74dd8 100644
--- a/include/flatbuffers/idl.h
+++ b/include/flatbuffers/idl.h
@@ -340,6 +340,46 @@ struct IDLOptions {
       lang(IDLOptions::kJava) {}
 };
 
+// A way to make error propagation less error prone by requiring values to be
+// checked.
+// Once you create a value of this type you must either:
+// - Call Check() on it.
+// - Copy or assign it to another value.
+// Failure to do so leads to an assert.
+// This guarantees that this as return value cannot be ignored.
+class CheckedError {
+ public:
+  explicit CheckedError(bool error)
+    : is_error_(error), has_been_checked_(false) {}
+
+  CheckedError &operator=(const CheckedError &other) {
+    is_error_ = other.is_error_;
+    has_been_checked_ = false;
+    other.has_been_checked_ = true;
+    return *this;
+  }
+
+  CheckedError(const CheckedError &other) {
+    *this = other;  // Use assignment operator.
+  }
+
+  ~CheckedError() { assert(has_been_checked_); }
+
+  bool Check() { has_been_checked_ = true; return is_error_; }
+
+ private:
+  bool is_error_;
+  mutable bool has_been_checked_;
+};
+
+// Additionally, in GCC we can get these errors statically, for additional
+// assurance:
+#ifdef __GNUC__
+#define CHECKED_ERROR CheckedError __attribute__((warn_unused_result))
+#else
+#define CHECKED_ERROR CheckedError
+#endif
+
 class Parser {
  public:
   explicit Parser(const IDLOptions &options = IDLOptions())
@@ -395,44 +435,51 @@ class Parser {
   // See reflection/reflection.fbs
   void Serialize();
 
- private:
-  int64_t ParseHexNum(int nibbles);
-  void Next();
-  bool IsNext(int t);
-  void Expect(int t);
+  CHECKED_ERROR CheckBitsFit(int64_t val, size_t bits);
+
+private:
+  CHECKED_ERROR Error(const std::string &msg);
+  CHECKED_ERROR ParseHexNum(int nibbles, int64_t *val);
+  CHECKED_ERROR Next();
+  bool Is(int t);
+  CHECKED_ERROR Expect(int t);
   std::string TokenToStringId(int t);
   EnumDef *LookupEnum(const std::string &id);
-  void ParseNamespacing(std::string *id, std::string *last);
-  void ParseTypeIdent(Type &type);
-  void ParseType(Type &type);
-  FieldDef &AddField(StructDef &struct_def,
-                     const std::string &name,
-                     const Type &type);
-  void ParseField(StructDef &struct_def);
-  void ParseAnyValue(Value &val, FieldDef *field, size_t parent_fieldn);
-  uoffset_t ParseTable(const StructDef &struct_def, std::string *value);
+  CHECKED_ERROR ParseNamespacing(std::string *id, std::string *last);
+  CHECKED_ERROR ParseTypeIdent(Type &type);
+  CHECKED_ERROR ParseType(Type &type);
+  CHECKED_ERROR AddField(StructDef &struct_def, const std::string &name,
+                         const Type &type, FieldDef **dest);
+  CHECKED_ERROR ParseField(StructDef &struct_def);
+  CHECKED_ERROR ParseAnyValue(Value &val, FieldDef *field, size_t parent_fieldn);
+  CHECKED_ERROR ParseTable(const StructDef &struct_def, std::string *value,
+                           uoffset_t *ovalue);
   void SerializeStruct(const StructDef &struct_def, const Value &val);
   void AddVector(bool sortbysize, int count);
-  uoffset_t ParseVector(const Type &type);
-  void ParseMetaData(Definition &def);
-  bool TryTypedValue(int dtoken, bool check, Value &e, BaseType req);
-  void ParseHash(Value &e, FieldDef* field);
-  void ParseSingleValue(Value &e);
-  int64_t ParseIntegerFromString(Type &type);
+  CHECKED_ERROR ParseVector(const Type &type, uoffset_t *ovalue);
+  CHECKED_ERROR ParseMetaData(Definition &def);
+  CHECKED_ERROR TryTypedValue(int dtoken, bool check, Value &e, BaseType req,
+                              bool *destmatch);
+  CHECKED_ERROR ParseHash(Value &e, FieldDef* field);
+  CHECKED_ERROR ParseSingleValue(Value &e);
+  CHECKED_ERROR ParseIntegerFromString(Type &type, int64_t *result);
   StructDef *LookupCreateStruct(const std::string &name,
                                 bool create_if_new = true,
                                 bool definition = false);
-  EnumDef &ParseEnum(bool is_union);
-  void ParseNamespace();
-  StructDef &StartStruct(const std::string &name);
-  void ParseDecl();
-  void ParseProtoFields(StructDef *struct_def, bool isextend,
-                        bool inside_oneof);
-  void ParseProtoOption();
-  void ParseProtoKey();
-  void ParseProtoDecl();
-  void ParseProtoCurliesOrIdent();
-  Type ParseTypeFromProtoType();
+  CHECKED_ERROR ParseEnum(bool is_union, EnumDef **dest);
+  CHECKED_ERROR ParseNamespace();
+  CHECKED_ERROR StartStruct(const std::string &name, StructDef **dest);
+  CHECKED_ERROR ParseDecl();
+  CHECKED_ERROR ParseProtoFields(StructDef *struct_def, bool isextend,
+                                 bool inside_oneof);
+  CHECKED_ERROR ParseProtoOption();
+  CHECKED_ERROR ParseProtoKey();
+  CHECKED_ERROR ParseProtoDecl();
+  CHECKED_ERROR ParseProtoCurliesOrIdent();
+  CHECKED_ERROR ParseTypeFromProtoType(Type *type);
+
+  CHECKED_ERROR DoParse(const char *_source, const char **include_paths,
+                        const char *source_filename);
 
  public:
   SymbolTable<StructDef> structs_;
@@ -454,7 +501,7 @@ class Parser {
   const char *source_, *cursor_;
   int line_;  // the current line being parsed
   int token_;
-  std::string files_being_parsed_;
+  std::string file_being_parsed_;
 
   std::string attribute_;
   std::vector<std::string> doc_comment_;
diff --git a/src/idl_parser.cpp b/src/idl_parser.cpp
index 9b62075de..6a013c90f 100644
--- a/src/idl_parser.cpp
+++ b/src/idl_parser.cpp
@@ -43,38 +43,68 @@ static_assert(BASE_TYPE_UNION ==
               static_cast<BaseType>(reflection::Union),
               "enums don't match");
 
-static void Error(const std::string &msg) {
-  throw msg;
+#define ECHECK(call) { auto ce = (call); if (ce.Check()) return ce; }
+#define NEXT() ECHECK(Next())
+#define EXPECT(tok) ECHECK(Expect(tok))
+
+CheckedError Parser::Error(const std::string &msg) {
+  error_ = file_being_parsed_.length() ? AbsolutePath(file_being_parsed_) : "";
+  #ifdef _WIN32
+    error_ += "(" + NumToString(line_) + ")";  // MSVC alike
+  #else
+    if (file_being_parsed_.length()) error_ += ":";
+    error_ += NumToString(line_) + ":0";  // gcc alike
+  #endif
+  error_ += ": error: " + msg;
+  return CheckedError(true);
 }
 
+inline CheckedError NoError() { return CheckedError(false); }
+
 // Ensure that integer values we parse fit inside the declared integer type.
-static void CheckBitsFit(int64_t val, size_t bits) {
+CheckedError Parser::CheckBitsFit(int64_t val, size_t bits) {
   // Bits we allow to be used.
   auto mask = static_cast<int64_t>((1ull << bits) - 1);
   if (bits < 64 &&
       (val & ~mask) != 0 &&  // Positive or unsigned.
       (val |  mask) != -1)   // Negative.
-    Error("constant does not fit in a " + NumToString(bits) + "-bit field");
+    return Error("constant does not fit in a " + NumToString(bits) +
+                 "-bit field");
+  return NoError();
 }
 
 // atot: templated version of atoi/atof: convert a string to an instance of T.
-template<typename T> inline T atot(const char *s) {
-  auto val = StringToInt(s);
-  CheckBitsFit(val, sizeof(T) * 8);
-  return (T)val;
+template<typename T> inline CheckedError atot(const char *s, Parser &parser,
+                                              T *val) {
+  int64_t i = StringToInt(s);
+  ECHECK(parser.CheckBitsFit(i, sizeof(T) * 8));
+  *val = (T)i;
+  return NoError();
 }
-template<> inline bool atot<bool>(const char *s) {
-  return 0 != atoi(s);
+template<> inline CheckedError atot<bool>(const char *s, Parser &parser,
+                                          bool *val) {
+  (void)parser;
+  *val = 0 != atoi(s);
+  return NoError();
 }
-template<> inline float atot<float>(const char *s) {
-  return static_cast<float>(strtod(s, nullptr));
+template<> inline CheckedError atot<float>(const char *s, Parser &parser,
+                                           float *val) {
+  (void)parser;
+  *val = static_cast<float>(strtod(s, nullptr));
+  return NoError();
 }
-template<> inline double atot<double>(const char *s) {
-  return strtod(s, nullptr);
+template<> inline CheckedError atot<double>(const char *s, Parser &parser,
+                                            double *val) {
+  (void)parser;
+  *val = strtod(s, nullptr);
+  return NoError();
 }
 
-template<> inline Offset<void> atot<Offset<void>>(const char *s) {
-  return Offset<void>(atoi(s));
+template<> inline CheckedError atot<Offset<void>>(const char *s, Parser &parser,
+                                                  Offset<void> *val) {
+  (void)parser;
+  *val = Offset<void>(atoi(s));
+  return NoError();
 }
 
 std::string Namespace::GetFullyQualifiedName(const std::string &name,
@@ -153,18 +183,18 @@ std::string Parser::TokenToStringId(int t) {
 }
 
 // Parses exactly nibbles worth of hex digits into a number, or error.
-int64_t Parser::ParseHexNum(int nibbles) {
+CheckedError Parser::ParseHexNum(int nibbles, int64_t *val) {
   for (int i = 0; i < nibbles; i++)
     if (!isxdigit(cursor_[i]))
-      Error("escape code must be followed by " + NumToString(nibbles) +
-            " hex digits");
+      return Error("escape code must be followed by " + NumToString(nibbles) +
+                   " hex digits");
   std::string target(cursor_, cursor_ + nibbles);
-  auto val = StringToUInt(target.c_str(), 16);
+  *val = StringToUInt(target.c_str(), 16);
   cursor_ += nibbles;
-  return val;
+  return NoError();
 }
 
-void Parser::Next() {
+CheckedError Parser::Next() {
   doc_comment_.clear();
   bool seen_newline = false;
   attribute_.clear();
@@ -172,20 +202,19 @@ void Parser::Next() {
     char c = *cursor_++;
     token_ = c;
     switch (c) {
-      case '\0': cursor_--; token_ = kTokenEof; return;
+      case '\0': cursor_--; token_ = kTokenEof; return NoError();
       case ' ': case '\r': case '\t': break;
       case '\n': line_++; seen_newline = true; break;
-      case '{': case '}': case '(': case ')': case '[': case ']': return;
-      case ',': case ':': case ';': case '=': return;
+      case '{': case '}': case '(': case ')': case '[': case ']':
+      case ',': case ':': case ';': case '=': return NoError();
       case '.':
-        if(!isdigit(*cursor_)) return;
-        Error("floating point constant can\'t start with \".\"");
-        break;
+        if(!isdigit(*cursor_)) return NoError();
+        return Error("floating point constant can\'t start with \".\"");
       case '\"':
       case '\'':
         while (*cursor_ != c) {
           if (*cursor_ < ' ' && *cursor_ >= 0)
-            Error("illegal character in string constant");
+            return Error("illegal character in string constant");
           if (*cursor_ == '\\') {
             cursor_++;
             switch (*cursor_) {
@@ -200,15 +229,19 @@ void Parser::Next() {
               case '/':  attribute_ += '/';  cursor_++; break;
               case 'x': {  // Not in the JSON standard
                 cursor_++;
-                attribute_ += static_cast<char>(ParseHexNum(2));
+                int64_t val;
+                ECHECK(ParseHexNum(2, &val));
+                attribute_ += static_cast<char>(val);
                 break;
               }
               case 'u': {
                 cursor_++;
-                ToUTF8(static_cast<int>(ParseHexNum(4)), &attribute_);
+                int64_t val;
+                ECHECK(ParseHexNum(4, &val));
+                ToUTF8(static_cast<int>(val), &attribute_);
                 break;
               }
-              default: Error("unknown escape code in string constant"); break;
+              default: return Error("unknown escape code in string constant");
             }
           } else { // printable chars + UTF-8 bytes
             attribute_ += *cursor_++;
@@ -216,14 +249,15 @@ void Parser::Next() {
         }
         cursor_++;
         token_ = kTokenStringConstant;
-        return;
+        return NoError();
       case '/':
         if (*cursor_ == '/') {
           const char *start = ++cursor_;
           while (*cursor_ && *cursor_ != '\n' && *cursor_ != '\r') cursor_++;
           if (*start == '/') {  // documentation comment
             if (cursor_ != source_ && !seen_newline)
-              Error("a documentation comment should be on a line on its own");
+              return Error(
+                    "a documentation comment should be on a line on its own");
             doc_comment_.push_back(std::string(start + 1, cursor_));
           }
           break;
@@ -231,7 +265,7 @@ void Parser::Next() {
           cursor_++;
           // TODO: make nested.
           while (*cursor_ != '*' || cursor_[1] != '/') {
-            if (!*cursor_) Error("end of file in comment");
+            if (!*cursor_) return Error("end of file in comment");
             cursor_++;
           }
           cursor_ += 2;
@@ -251,7 +285,7 @@ void Parser::Next() {
             PTYPE) \
             if (attribute_ == IDLTYPE) { \
               token_ = kToken ## ENUM; \
-              return; \
+              return NoError(); \
             }
             FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
           #undef FLATBUFFERS_TD
@@ -260,28 +294,52 @@ void Parser::Next() {
           if (attribute_ == "true" || attribute_ == "false") {
             attribute_ = NumToString(attribute_ == "true");
             token_ = kTokenIntegerConstant;
-            return;
+            return NoError();
           }
           // Check for declaration keywords:
-          if (attribute_ == "table")     { token_ = kTokenTable;     return; }
-          if (attribute_ == "struct")    { token_ = kTokenStruct;    return; }
-          if (attribute_ == "enum")      { token_ = kTokenEnum;      return; }
-          if (attribute_ == "union")     { token_ = kTokenUnion;     return; }
-          if (attribute_ == "namespace") { token_ = kTokenNameSpace; return; }
-          if (attribute_ == "root_type") { token_ = kTokenRootType;  return; }
-          if (attribute_ == "include")   { token_ = kTokenInclude;   return; }
-          if (attribute_ == "attribute") { token_ = kTokenAttribute; return; }
+          if (attribute_ == "table") {
+            token_ = kTokenTable;
+            return NoError();
+          }
+          if (attribute_ == "struct") {
+            token_ = kTokenStruct;
+            return NoError();
+          }
+          if (attribute_ == "enum") {
+            token_ = kTokenEnum;
+            return NoError();
+          }
+          if (attribute_ == "union") {
+            token_ = kTokenUnion;
+            return NoError();
+          }
+          if (attribute_ == "namespace") {
+            token_ = kTokenNameSpace;
+            return NoError();
+          }
+          if (attribute_ == "root_type") {
+            token_ = kTokenRootType;
+            return NoError();
+          }
+          if (attribute_ == "include") {
+            token_ = kTokenInclude;
+            return NoError();
+          }
+          if (attribute_ == "attribute") {
+            token_ = kTokenAttribute;
+            return NoError();
+          }
           if (attribute_ == "file_identifier") {
             token_ = kTokenFileIdentifier;
-            return;
+            return NoError();
           }
           if (attribute_ == "file_extension") {
             token_ = kTokenFileExtension;
-            return;
+            return NoError();
           }
           // If not, it is a user-defined identifier:
           token_ = kTokenIdentifier;
-          return;
+          return NoError();
         } else if (isdigit(static_cast<unsigned char>(c)) || c == '-') {
           const char *start = cursor_ - 1;
           if (c == '0' && (*cursor_ == 'x' || *cursor_ == 'X')) {
@@ -290,7 +348,7 @@ void Parser::Next() {
               attribute_.append(start + 2, cursor_);
               attribute_ = NumToString(StringToUInt(attribute_.c_str(), 16));
               token_ = kTokenIntegerConstant;
-              return;
+              return NoError();
           }
           while (isdigit(static_cast<unsigned char>(*cursor_))) cursor_++;
           if (*cursor_ == '.' || *cursor_ == 'e' || *cursor_ == 'E') {
@@ -310,56 +368,57 @@ void Parser::Next() {
             token_ = kTokenIntegerConstant;
           }
           attribute_.append(start, cursor_);
-          return;
+          return NoError();
         }
         std::string ch;
         ch = c;
         if (c < ' ' || c > '~') ch = "code: " + NumToString(c);
-        Error("illegal character: " + ch);
-        break;
+        return Error("illegal character: " + ch);
     }
   }
 }
 
-// Check if a given token is next, if so, consume it as well.
-bool Parser::IsNext(int t) {
-  bool isnext = t == token_;
-  if (isnext) Next();
-  return isnext;
+// Check if a given token is next.
+bool Parser::Is(int t) {
+  return t == token_;
 }
 
 // Expect a given token to be next, consume it, or error if not present.
-void Parser::Expect(int t) {
+CheckedError Parser::Expect(int t) {
   if (t != token_) {
-    Error("expecting: " + TokenToString(t) + " instead got: " +
-          TokenToStringId(token_));
+    return Error("expecting: " + TokenToString(t) + " instead got: " +
+                 TokenToStringId(token_));
   }
-  Next();
+  NEXT();
+  return NoError();
 }
 
-void Parser::ParseNamespacing(std::string *id, std::string *last) {
-  while (IsNext('.')) {
+CheckedError Parser::ParseNamespacing(std::string *id, std::string *last) {
+  while (Is('.')) {
+    NEXT();
     *id += ".";
     *id += attribute_;
     if (last) *last = attribute_;
-    Expect(kTokenIdentifier);
+    EXPECT(kTokenIdentifier);
   }
+  return NoError();
 }
 
 EnumDef *Parser::LookupEnum(const std::string &id) {
   // Search thru parent namespaces.
   for (int components = static_cast<int>(namespaces_.back()->components.size());
        components >= 0; components--) {
-    auto ed = enums_.Lookup(namespaces_.back()->GetFullyQualifiedName(id, components));
+    auto ed = enums_.Lookup(
+                namespaces_.back()->GetFullyQualifiedName(id, components));
     if (ed) return ed;
   }
   return nullptr;
 }
 
-void Parser::ParseTypeIdent(Type &type) {
+CheckedError Parser::ParseTypeIdent(Type &type) {
   std::string id = attribute_;
-  Expect(kTokenIdentifier);
-  ParseNamespacing(&id, nullptr);
+  EXPECT(kTokenIdentifier);
+  ECHECK(ParseNamespacing(&id, nullptr));
   auto enum_def = LookupEnum(id);
   if (enum_def) {
     type = enum_def->underlying_type;
@@ -368,41 +427,45 @@ void Parser::ParseTypeIdent(Type &type) {
     type.base_type = BASE_TYPE_STRUCT;
     type.struct_def = LookupCreateStruct(id);
   }
+  return NoError();
 }
 
 // Parse any IDL type.
-void Parser::ParseType(Type &type) {
+CheckedError Parser::ParseType(Type &type) {
   if (token_ >= kTokenBOOL && token_ <= kTokenSTRING) {
     type.base_type = static_cast<BaseType>(token_ - kTokenNONE);
-    Next();
+    NEXT();
   } else {
     if (token_ == kTokenIdentifier) {
-      ParseTypeIdent(type);
+      ECHECK(ParseTypeIdent(type));
     } else if (token_ == '[') {
-      Next();
+      NEXT();
       Type subtype;
-      ParseType(subtype);
+      ECHECK(ParseType(subtype));
       if (subtype.base_type == BASE_TYPE_VECTOR) {
         // We could support this, but it will complicate things, and it's
         // easier to work around with a struct around the inner vector.
-        Error("nested vector types not supported (wrap in table first).");
+        return Error(
+              "nested vector types not supported (wrap in table first).");
       }
       if (subtype.base_type == BASE_TYPE_UNION) {
         // We could support this if we stored a struct of 2 elements per
         // union element.
-        Error("vector of union types not supported (wrap in table first).");
+        return Error(
+              "vector of union types not supported (wrap in table first).");
       }
       type = Type(BASE_TYPE_VECTOR, subtype.struct_def, subtype.enum_def);
       type.element = subtype.base_type;
-      Expect(']');
+      EXPECT(']');
     } else {
-      Error("illegal type syntax");
+      return Error("illegal type syntax");
     }
   }
+  return NoError();
 }
 
-FieldDef &Parser::AddField(StructDef &struct_def, const std::string &name,
-                           const Type &type) {
+CheckedError Parser::AddField(StructDef &struct_def, const std::string &name,
+                              const Type &type, FieldDef **dest) {
   auto &field = *new FieldDef();
   field.value.offset =
     FieldIndexToOffset(static_cast<voffset_t>(struct_def.fields.vec.size()));
@@ -420,36 +483,38 @@ FieldDef &Parser::AddField(StructDef &struct_def, const std::string &name,
     struct_def.bytesize += size;
   }
   if (struct_def.fields.Add(name, &field))
-    Error("field already exists: " + name);
-  return field;
+    return Error("field already exists: " + name);
+  *dest = &field;
+  return NoError();
 }
 
-void Parser::ParseField(StructDef &struct_def) {
+CheckedError Parser::ParseField(StructDef &struct_def) {
   std::string name = attribute_;
   std::vector<std::string> dc = doc_comment_;
-  Expect(kTokenIdentifier);
-  Expect(':');
+  EXPECT(kTokenIdentifier);
+  EXPECT(':');
   Type type;
-  ParseType(type);
+  ECHECK(ParseType(type));
 
   if (struct_def.fixed && !IsScalar(type.base_type) && !IsStruct(type))
-    Error("structs_ may contain only scalar or struct fields");
+    return Error("structs_ may contain only scalar or struct fields");
 
   FieldDef *typefield = nullptr;
   if (type.base_type == BASE_TYPE_UNION) {
     // For union fields, add a second auto-generated field to hold the type,
     // with _type appended as the name.
-    typefield = &AddField(struct_def, name + "_type",
-                          type.enum_def->underlying_type);
+    ECHECK(AddField(struct_def, name + "_type", type.enum_def->underlying_type,
+                    &typefield));
   }
 
-  auto &field = AddField(struct_def, name, type);
+  FieldDef *field;
+  ECHECK(AddField(struct_def, name, type, &field));
 
   if (token_ == '=') {
-    Next();
+    NEXT();
     if (!IsScalar(type.base_type))
-      Error("default values currently only supported for scalars");
-    ParseSingleValue(field.value);
+      return Error("default values currently only supported for scalars");
+    ECHECK(ParseSingleValue(field->value));
   }
 
   if (type.enum_def &&
@@ -457,59 +522,62 @@ void Parser::ParseField(StructDef &struct_def) {
       !struct_def.fixed &&
       !type.enum_def->attributes.Lookup("bit_flags") &&
       !type.enum_def->ReverseLookup(static_cast<int>(
-                         StringToInt(field.value.constant.c_str()))))
-    Error("enum " + type.enum_def->name +
+                         StringToInt(field->value.constant.c_str()))))
+    return Error("enum " + type.enum_def->name +
           " does not have a declaration for this field\'s default of " +
-          field.value.constant);
+          field->value.constant);
 
-  field.doc_comment = dc;
-  ParseMetaData(field);
-  field.deprecated = field.attributes.Lookup("deprecated") != nullptr;
-  auto hash_name = field.attributes.Lookup("hash");
+  field->doc_comment = dc;
+  ECHECK(ParseMetaData(*field));
+  field->deprecated = field->attributes.Lookup("deprecated") != nullptr;
+  auto hash_name = field->attributes.Lookup("hash");
   if (hash_name) {
     switch (type.base_type) {
       case BASE_TYPE_INT:
       case BASE_TYPE_UINT: {
         if (FindHashFunction32(hash_name->constant.c_str()) == nullptr)
-          Error("Unknown hashing algorithm for 32 bit types: " +
+          return Error("Unknown hashing algorithm for 32 bit types: " +
                 hash_name->constant);
         break;
       }
       case BASE_TYPE_LONG:
       case BASE_TYPE_ULONG: {
         if (FindHashFunction64(hash_name->constant.c_str()) == nullptr)
-          Error("Unknown hashing algorithm for 64 bit types: " +
+          return Error("Unknown hashing algorithm for 64 bit types: " +
                 hash_name->constant);
         break;
       }
       default:
-        Error("only int, uint, long and ulong data types support hashing.");
+        return Error(
+              "only int, uint, long and ulong data types support hashing.");
     }
   }
-  if (field.deprecated && struct_def.fixed)
-    Error("can't deprecate fields in a struct");
-  field.required = field.attributes.Lookup("required") != nullptr;
-  if (field.required && (struct_def.fixed ||
-                         IsScalar(field.value.type.base_type)))
-    Error("only non-scalar fields in tables may be 'required'");
-  field.key = field.attributes.Lookup("key") != nullptr;
-  if (field.key) {
+  if (field->deprecated && struct_def.fixed)
+    return Error("can't deprecate fields in a struct");
+  field->required = field->attributes.Lookup("required") != nullptr;
+  if (field->required && (struct_def.fixed ||
+                         IsScalar(field->value.type.base_type)))
+    return Error("only non-scalar fields in tables may be 'required'");
+  field->key = field->attributes.Lookup("key") != nullptr;
+  if (field->key) {
     if (struct_def.has_key)
-      Error("only one field may be set as 'key'");
+      return Error("only one field may be set as 'key'");
     struct_def.has_key = true;
-    if (!IsScalar(field.value.type.base_type)) {
-      field.required = true;
-      if (field.value.type.base_type != BASE_TYPE_STRING)
-        Error("'key' field must be string or scalar type");
+    if (!IsScalar(field->value.type.base_type)) {
+      field->required = true;
+      if (field->value.type.base_type != BASE_TYPE_STRING)
+        return Error("'key' field must be string or scalar type");
     }
   }
-  auto nested = field.attributes.Lookup("nested_flatbuffer");
+  auto nested = field->attributes.Lookup("nested_flatbuffer");
   if (nested) {
     if (nested->type.base_type != BASE_TYPE_STRING)
-      Error("nested_flatbuffer attribute must be a string (the root type)");
-    if (field.value.type.base_type != BASE_TYPE_VECTOR ||
-        field.value.type.element != BASE_TYPE_UCHAR)
-      Error("nested_flatbuffer attribute may only apply to a vector of ubyte");
+      return Error(
+            "nested_flatbuffer attribute must be a string (the root type)");
+    if (field->value.type.base_type != BASE_TYPE_VECTOR ||
+        field->value.type.element != BASE_TYPE_UCHAR)
+      return Error(
+            "nested_flatbuffer attribute may only apply to a vector of ubyte");
     // This will cause an error if the root type of the nested flatbuffer
     // wasn't defined elsewhere.
     LookupCreateStruct(nested->constant);
@@ -518,7 +586,7 @@ void Parser::ParseField(StructDef &struct_def) {
   if (typefield) {
     // If this field is a union, and it has a manually assigned id,
     // the automatically added type field should have an id as well (of N - 1).
-    auto attr = field.attributes.Lookup("id");
+    auto attr = field->attributes.Lookup("id");
     if (attr) {
       auto id = atoi(attr->constant.c_str());
       auto val = new Value();
@@ -528,35 +596,41 @@ void Parser::ParseField(StructDef &struct_def) {
     }
   }
 
-  Expect(';');
+  EXPECT(';');
+  return NoError();
 }
 
-void Parser::ParseAnyValue(Value &val, FieldDef *field, size_t parent_fieldn) {
+CheckedError Parser::ParseAnyValue(Value &val, FieldDef *field,
+                                   size_t parent_fieldn) {
   switch (val.type.base_type) {
     case BASE_TYPE_UNION: {
       assert(field);
       if (!parent_fieldn ||
           field_stack_.back().second->value.type.base_type != BASE_TYPE_UTYPE)
-        Error("missing type field before this union value: " + field->name);
-      auto enum_idx = atot<unsigned char>(
-                                    field_stack_.back().first.constant.c_str());
+        return Error("missing type field before this union value: " +
+                     field->name);
+      uint8_t enum_idx;
+      ECHECK(atot(field_stack_.back().first.constant.c_str(), *this,
+                  &enum_idx));
       auto enum_val = val.type.enum_def->ReverseLookup(enum_idx);
-      if (!enum_val) Error("illegal type id for: " + field->name);
-      ParseTable(*enum_val->struct_def, &val.constant);
+      if (!enum_val) return Error("illegal type id for: " + field->name);
+      ECHECK(ParseTable(*enum_val->struct_def, &val.constant, nullptr));
       break;
     }
     case BASE_TYPE_STRUCT:
-      ParseTable(*val.type.struct_def, &val.constant);
+      ECHECK(ParseTable(*val.type.struct_def, &val.constant, nullptr));
       break;
     case BASE_TYPE_STRING: {
       auto s = attribute_;
-      Expect(kTokenStringConstant);
+      EXPECT(kTokenStringConstant);
       val.constant = NumToString(builder_.CreateString(s).o);
       break;
     }
     case BASE_TYPE_VECTOR: {
-      Expect('[');
-      val.constant = NumToString(ParseVector(val.type.VectorType()));
+      EXPECT('[');
+      uoffset_t off;
+      ECHECK(ParseVector(val.type.VectorType(), &off));
+      val.constant = NumToString(off);
       break;
     }
     case BASE_TYPE_INT:
@@ -565,16 +639,17 @@ void Parser::ParseAnyValue(Value &val, FieldDef *field, size_t parent_fieldn) {
     case BASE_TYPE_ULONG: {
       if (field && field->attributes.Lookup("hash") &&
           (token_ == kTokenIdentifier || token_ == kTokenStringConstant)) {
-        ParseHash(val, field);
+        ECHECK(ParseHash(val, field));
       } else {
-        ParseSingleValue(val);
+        ECHECK(ParseSingleValue(val));
       }
       break;
     }
     default:
-      ParseSingleValue(val);
+      ECHECK(ParseSingleValue(val));
       break;
   }
+  return NoError();
 }
 
 void Parser::SerializeStruct(const StructDef &struct_def, const Value &val) {
@@ -585,35 +660,39 @@ void Parser::SerializeStruct(const StructDef &struct_def, const Value &val) {
   builder_.AddStructOffset(val.offset, builder_.GetSize());
 }
 
-uoffset_t Parser::ParseTable(const StructDef &struct_def, std::string *value) {
-  Expect('{');
+CheckedError Parser::ParseTable(const StructDef &struct_def, std::string *value,
+                                uoffset_t *ovalue) {
+  EXPECT('{');
   size_t fieldn = 0;
   for (;;) {
-    if ((!opts.strict_json || !fieldn) && IsNext('}')) break;
+    if ((!opts.strict_json || !fieldn) && Is('}')) { NEXT(); break; }
     std::string name = attribute_;
-    if (!IsNext(kTokenStringConstant))
-      Expect(opts.strict_json ? kTokenStringConstant : kTokenIdentifier);
+    if (Is(kTokenStringConstant)) {
+      NEXT();
+    } else {
+      EXPECT(opts.strict_json ? kTokenStringConstant : kTokenIdentifier);
+    }
     auto field = struct_def.fields.Lookup(name);
-    if (!field) Error("unknown field: " + name);
-    Expect(':');
+    if (!field) return Error("unknown field: " + name);
+    EXPECT(':');
     Value val = field->value;
-    ParseAnyValue(val, field, fieldn);
+    ECHECK(ParseAnyValue(val, field, fieldn));
     size_t i = field_stack_.size();
     // Hardcoded insertion-sort with error-check.
     // If fields are specified in order, then this loop exits immediately.
     for (; i > field_stack_.size() - fieldn; i--) {
       auto existing_field = field_stack_[i - 1].second;
       if (existing_field == field)
-        Error("field set more than once: " + field->name);
+        return Error("field set more than once: " + field->name);
       if (existing_field->value.offset < field->value.offset) break;
     }
     field_stack_.insert(field_stack_.begin() + i, std::make_pair(val, field));
     fieldn++;
-    if (IsNext('}')) break;
-    Expect(',');
+    if (Is('}')) { NEXT(); break; }
+    EXPECT(',');
   }
   if (struct_def.fixed && fieldn != struct_def.fields.vec.size())
-    Error("struct: wrong number of initializers: " + struct_def.name);
+    return Error("struct: wrong number of initializers: " + struct_def.name);
 
   auto start = struct_def.fixed
                  ? builder_.StartStruct(struct_def.minalign)
@@ -627,18 +706,22 @@ uoffset_t Parser::ParseTable(const StructDef &struct_def, std::string *value) {
              it != field_stack_.rbegin() + fieldn; ++it) {
       auto &field_value = it->first;
       auto field = it->second;
-      if (!struct_def.sortbysize || size == SizeOf(field_value.type.base_type)) {
+      if (!struct_def.sortbysize ||
+          size == SizeOf(field_value.type.base_type)) {
         switch (field_value.type.base_type) {
           #define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, GTYPE, NTYPE, \
             PTYPE) \
             case BASE_TYPE_ ## ENUM: \
               builder_.Pad(field->padding); \
               if (struct_def.fixed) { \
-                builder_.PushElement(atot<CTYPE>(field_value.constant.c_str())); \
+                CTYPE val; \
+                ECHECK(atot(field_value.constant.c_str(), *this, &val)); \
+                builder_.PushElement(val); \
               } else { \
-                builder_.AddElement(field_value.offset, \
-                             atot<CTYPE>(       field_value.constant.c_str()), \
-                             atot<CTYPE>(field->value.constant.c_str())); \
+                CTYPE val, valdef; \
+                ECHECK(atot(field_value.constant.c_str(), *this, &val)); \
+                ECHECK(atot(field->value.constant.c_str(), *this, &valdef)); \
+                builder_.AddElement(field_value.offset, val, valdef); \
               } \
               break;
             FLATBUFFERS_GEN_TYPES_SCALAR(FLATBUFFERS_TD);
@@ -650,8 +733,9 @@ uoffset_t Parser::ParseTable(const StructDef &struct_def, std::string *value) {
               if (IsStruct(field->value.type)) { \
                 SerializeStruct(*field->value.type.struct_def, field_value); \
               } else { \
-                builder_.AddOffset(field_value.offset, \
-                  atot<CTYPE>(field_value.constant.c_str())); \
+                CTYPE val; \
+                ECHECK(atot(field_value.constant.c_str(), *this, &val)); \
+                builder_.AddOffset(field_value.offset, val); \
               } \
               break;
             FLATBUFFERS_GEN_TYPES_POINTER(FLATBUFFERS_TD);
@@ -672,27 +756,27 @@ uoffset_t Parser::ParseTable(const StructDef &struct_def, std::string *value) {
           reinterpret_cast<const char *>(builder_.GetCurrentBufferPointer()),
           struct_def.bytesize);
     builder_.PopBytes(struct_def.bytesize);
-    return 0xFFFFFFFF;  // Value not used by the caller.
+    assert(!ovalue);
   } else {
-    auto off = builder_.EndTable(
-      start,
-      static_cast<voffset_t>(struct_def.fields.vec.size()));
-    if (value) *value = NumToString(off);
-    return off;
+    auto val = builder_.EndTable(start,
+                          static_cast<voffset_t>(struct_def.fields.vec.size()));
+    if (ovalue) *ovalue = val;
+    if (value) *value = NumToString(val);
   }
+  return NoError();
 }
 
-uoffset_t Parser::ParseVector(const Type &type) {
+CheckedError Parser::ParseVector(const Type &type, uoffset_t *ovalue) {
   int count = 0;
   for (;;) {
-    if ((!opts.strict_json || !count) && IsNext(']')) break;
+    if ((!opts.strict_json || !count) && Is(']')) { NEXT(); break; }
     Value val;
     val.type = type;
-    ParseAnyValue(val, nullptr, 0);
+    ECHECK(ParseAnyValue(val, nullptr, 0));
     field_stack_.push_back(std::make_pair(val, nullptr));
     count++;
-    if (IsNext(']')) break;
-    Expect(',');
+    if (Is(']')) { NEXT(); break; }
+    EXPECT(',');
   }
 
   builder_.StartVector(count * InlineSize(type) / InlineAlignment(type),
@@ -704,7 +788,11 @@ uoffset_t Parser::ParseVector(const Type &type) {
       #define FLATBUFFERS_TD(ENUM, IDLTYPE, CTYPE, JTYPE, GTYPE, NTYPE, PTYPE) \
         case BASE_TYPE_ ## ENUM: \
           if (IsStruct(val.type)) SerializeStruct(*val.type.struct_def, val); \
-          else builder_.PushElement(atot<CTYPE>(val.constant.c_str())); \
+          else { \
+             CTYPE elem; \
+             ECHECK(atot(val.constant.c_str(), *this, &elem)); \
+             builder_.PushElement(elem); \
+          } \
           break;
         FLATBUFFERS_GEN_TYPES(FLATBUFFERS_TD)
       #undef FLATBUFFERS_TD
@@ -713,51 +801,55 @@ uoffset_t Parser::ParseVector(const Type &type) {
   }
 
   builder_.ClearOffsets();
-  return builder_.EndVector(count);
+  *ovalue = builder_.EndVector(count);
+  return NoError();
 }
 
-void Parser::ParseMetaData(Definition &def) {
-  if (IsNext('(')) {
+CheckedError Parser::ParseMetaData(Definition &def) {
+  if (Is('(')) {
+    NEXT();
     for (;;) {
       auto name = attribute_;
-      Expect(kTokenIdentifier);
+      EXPECT(kTokenIdentifier);
       if (known_attributes_.find(name) == known_attributes_.end())
-        Error("user define attributes must be declared before use: " + name);
+        return Error("user define attributes must be declared before use: " +
+                     name);
       auto e = new Value();
       def.attributes.Add(name, e);
-      if (IsNext(':')) {
-        ParseSingleValue(*e);
+      if (Is(':')) {
+        NEXT();
+        ECHECK(ParseSingleValue(*e));
       }
-      if (IsNext(')')) break;
-      Expect(',');
+      if (Is(')')) { NEXT(); break; }
+      EXPECT(',');
     }
   }
+  return NoError();
 }
 
-bool Parser::TryTypedValue(int dtoken,
-                           bool check,
-                           Value &e,
-                           BaseType req) {
+CheckedError Parser::TryTypedValue(int dtoken, bool check, Value &e,
+                                   BaseType req, bool *destmatch) {
   bool match = dtoken == token_;
   if (match) {
+    *destmatch = true;
     e.constant = attribute_;
     if (!check) {
       if (e.type.base_type == BASE_TYPE_NONE) {
         e.type.base_type = req;
       } else {
-        Error(std::string("type mismatch: expecting: ") +
-              kTypeNames[e.type.base_type] +
-              ", found: " +
-              kTypeNames[req]);
+        return Error(std::string("type mismatch: expecting: ") +
+                     kTypeNames[e.type.base_type] +
+                     ", found: " +
+                     kTypeNames[req]);
       }
     }
-    Next();
+    NEXT();
   }
-  return match;
+  return NoError();
 }
 
-int64_t Parser::ParseIntegerFromString(Type &type) {
-  int64_t result = 0;
+CheckedError Parser::ParseIntegerFromString(Type &type, int64_t *result) {
+  *result = 0;
   // Parse one or more enum identifiers, separated by spaces.
   const char *next = attribute_.c_str();
   do {
@@ -773,29 +865,30 @@ int64_t Parser::ParseIntegerFromString(Type &type) {
     if (type.enum_def) {  // The field has an enum type
       auto enum_val = type.enum_def->vals.Lookup(word);
       if (!enum_val)
-        Error("unknown enum value: " + word +
+        return Error("unknown enum value: " + word +
               ", for enum: " + type.enum_def->name);
-      result |= enum_val->value;
+      *result |= enum_val->value;
     } else {  // No enum type, probably integral field.
       if (!IsInteger(type.base_type))
-        Error("not a valid value for this field: " + word);
+        return Error("not a valid value for this field: " + word);
       // TODO: could check if its a valid number constant here.
       const char *dot = strrchr(word.c_str(), '.');
-      if (!dot) Error("enum values need to be qualified by an enum type");
+      if (!dot)
+        return Error("enum values need to be qualified by an enum type");
       std::string enum_def_str(word.c_str(), dot);
       std::string enum_val_str(dot + 1, word.c_str() + word.length());
       auto enum_def = LookupEnum(enum_def_str);
-      if (!enum_def) Error("unknown enum: " + enum_def_str);
+      if (!enum_def) return Error("unknown enum: " + enum_def_str);
       auto enum_val = enum_def->vals.Lookup(enum_val_str);
-      if (!enum_val) Error("unknown enum value: " + enum_val_str);
-      result |= enum_val->value;
+      if (!enum_val) return Error("unknown enum value: " + enum_val_str);
+      *result |= enum_val->value;
     }
   } while(*next);
-  return result;
+  return NoError();
 }
 
 
-void Parser::ParseHash(Value &e, FieldDef* field) {
+CheckedError Parser::ParseHash(Value &e, FieldDef* field) {
   assert(field);
   Value *hash_name = field->attributes.Lookup("hash");
   switch (e.type.base_type) {
@@ -816,31 +909,41 @@ void Parser::ParseHash(Value &e, FieldDef* field) {
     default:
       assert(0);
   }
-  Next();
+  NEXT();
+  return NoError();
 }
 
-void Parser::ParseSingleValue(Value &e) {
+CheckedError Parser::ParseSingleValue(Value &e) {
   // First check if this could be a string/identifier enum value:
   if (e.type.base_type != BASE_TYPE_STRING &&
       e.type.base_type != BASE_TYPE_NONE &&
       (token_ == kTokenIdentifier || token_ == kTokenStringConstant)) {
-      e.constant = NumToString(ParseIntegerFromString(e.type));
-      Next();
-  } else if (TryTypedValue(kTokenIntegerConstant,
-                    IsScalar(e.type.base_type),
-                    e,
-                    BASE_TYPE_INT) ||
-      TryTypedValue(kTokenFloatConstant,
-                    IsFloat(e.type.base_type),
-                    e,
-                    BASE_TYPE_FLOAT) ||
-      TryTypedValue(kTokenStringConstant,
-                    e.type.base_type == BASE_TYPE_STRING,
-                    e,
-                    BASE_TYPE_STRING)) {
+    int64_t val;
+    ECHECK(ParseIntegerFromString(e.type, &val));
+    e.constant = NumToString(val);
+    NEXT();
   } else {
-    Error("cannot parse value starting with: " + TokenToStringId(token_));
+    bool match = false;
+    ECHECK(TryTypedValue(kTokenIntegerConstant,
+                         IsScalar(e.type.base_type),
+                         e,
+                         BASE_TYPE_INT,
+                         &match));
+    ECHECK(TryTypedValue(kTokenFloatConstant,
+                         IsFloat(e.type.base_type),
+                         e,
+                         BASE_TYPE_FLOAT,
+                         &match));
+    ECHECK(TryTypedValue(kTokenStringConstant,
+                         e.type.base_type == BASE_TYPE_STRING,
+                         e,
+                         BASE_TYPE_STRING,
+                         &match));
+    if (!match)
+      return Error("cannot parse value starting with: " +
+                   TokenToStringId(token_));
   }
+  return NoError();
 }
 
 StructDef *Parser::LookupCreateStruct(const std::string &name,
@@ -885,20 +988,20 @@ StructDef *Parser::LookupCreateStruct(const std::string &name,
   return struct_def;
 }
 
-EnumDef &Parser::ParseEnum(bool is_union) {
+CheckedError Parser::ParseEnum(bool is_union, EnumDef **dest) {
   std::vector<std::string> enum_comment = doc_comment_;
-  Next();
+  NEXT();
   std::string enum_name = attribute_;
-  Expect(kTokenIdentifier);
+  EXPECT(kTokenIdentifier);
   auto &enum_def = *new EnumDef();
   enum_def.name = enum_name;
-  enum_def.file = files_being_parsed_;
+  enum_def.file = file_being_parsed_;
   enum_def.doc_comment = enum_comment;
   enum_def.is_union = is_union;
   enum_def.defined_namespace = namespaces_.back();
   if (enums_.Add(namespaces_.back()->GetFullyQualifiedName(enum_name),
                  &enum_def))
-    Error("enum already exists: " + enum_name);
+    return Error("enum already exists: " + enum_name);
   if (is_union) {
     enum_def.underlying_type.base_type = BASE_TYPE_UTYPE;
     enum_def.underlying_type.enum_def = &enum_def;
@@ -908,107 +1011,119 @@ EnumDef &Parser::ParseEnum(bool is_union) {
     } else {
       // Give specialized error message, since this type spec used to
       // be optional in the first FlatBuffers release.
-      if (!IsNext(':')) Error("must specify the underlying integer type for this"
-                              " enum (e.g. \': short\', which was the default).");
+      if (!Is(':')) {
+        return Error("must specify the underlying integer type for this"
+              " enum (e.g. \': short\', which was the default).");
+      } else {
+        NEXT();
+      }
       // Specify the integer type underlying this enum.
-      ParseType(enum_def.underlying_type);
+      ECHECK(ParseType(enum_def.underlying_type));
       if (!IsInteger(enum_def.underlying_type.base_type))
-        Error("underlying enum type must be integral");
+        return Error("underlying enum type must be integral");
     }
     // Make this type refer back to the enum it was derived from.
     enum_def.underlying_type.enum_def = &enum_def;
   }
-  ParseMetaData(enum_def);
-  Expect('{');
+  ECHECK(ParseMetaData(enum_def));
+  EXPECT('{');
   if (is_union) enum_def.vals.Add("NONE", new EnumVal("NONE", 0));
-  do {
+  for (;;) {
     if (opts.proto_mode && attribute_ == "option") {
-      ParseProtoOption();
+      ECHECK(ParseProtoOption());
     } else {
       auto value_name = attribute_;
       auto full_name = value_name;
       std::vector<std::string> value_comment = doc_comment_;
-      Expect(kTokenIdentifier);
-      if (is_union) ParseNamespacing(&full_name, &value_name);
+      EXPECT(kTokenIdentifier);
+      if (is_union) ECHECK(ParseNamespacing(&full_name, &value_name));
       auto prevsize = enum_def.vals.vec.size();
       auto value = enum_def.vals.vec.size()
         ? enum_def.vals.vec.back()->value + 1
         : 0;
       auto &ev = *new EnumVal(value_name, value);
       if (enum_def.vals.Add(value_name, &ev))
-        Error("enum value already exists: " + value_name);
+        return Error("enum value already exists: " + value_name);
       ev.doc_comment = value_comment;
       if (is_union) {
         ev.struct_def = LookupCreateStruct(full_name);
       }
-      if (IsNext('=')) {
+      if (Is('=')) {
+        NEXT();
         ev.value = atoi(attribute_.c_str());
-        Expect(kTokenIntegerConstant);
+        EXPECT(kTokenIntegerConstant);
         if (!opts.proto_mode && prevsize &&
             enum_def.vals.vec[prevsize - 1]->value >= ev.value)
-          Error("enum values must be specified in ascending order");
+          return Error("enum values must be specified in ascending order");
       }
-      if (opts.proto_mode && IsNext('[')) {
+      if (opts.proto_mode && Is('[')) {
+        NEXT();
         // ignore attributes on enums.
-        while (token_ != ']') Next();
-        Next();
+        while (token_ != ']') NEXT();
+        NEXT();
       }
     }
-  } while (IsNext(opts.proto_mode ? ';' : ',') && token_ != '}');
-  Expect('}');
+    if (!Is(opts.proto_mode ? ';' : ',')) break;
+    NEXT();
+    if (Is('}')) break;
+  }
+  EXPECT('}');
   if (enum_def.attributes.Lookup("bit_flags")) {
     for (auto it = enum_def.vals.vec.begin(); it != enum_def.vals.vec.end();
          ++it) {
       if (static_cast<size_t>((*it)->value) >=
            SizeOf(enum_def.underlying_type.base_type) * 8)
-        Error("bit flag out of range of underlying integral type");
+        return Error("bit flag out of range of underlying integral type");
       (*it)->value = 1LL << (*it)->value;
     }
   }
-  return enum_def;
+  if (dest) *dest = &enum_def;
+  return NoError();
 }
 
-StructDef &Parser::StartStruct(const std::string &name) {
+CheckedError Parser::StartStruct(const std::string &name, StructDef **dest) {
   auto &struct_def = *LookupCreateStruct(name, true, true);
-  if (!struct_def.predecl) Error("datatype already exists: " + name);
+  if (!struct_def.predecl) return Error("datatype already exists: " + name);
   struct_def.predecl = false;
   struct_def.name = name;
-  struct_def.file = files_being_parsed_;
+  struct_def.file = file_being_parsed_;
   // Move this struct to the back of the vector just in case it was predeclared,
   // to preserve declaration order.
   *remove(structs_.vec.begin(), structs_.vec.end(), &struct_def) = &struct_def;
-  return struct_def;
+  *dest = &struct_def;
+  return NoError();
 }
 
-void Parser::ParseDecl() {
+CheckedError Parser::ParseDecl() {
   std::vector<std::string> dc = doc_comment_;
-  bool fixed = IsNext(kTokenStruct);
-  if (!fixed) Expect(kTokenTable);
+  bool fixed = Is(kTokenStruct);
+  if (fixed) NEXT() else EXPECT(kTokenTable);
   std::string name = attribute_;
-  Expect(kTokenIdentifier);
-  auto &struct_def = StartStruct(name);
-  struct_def.doc_comment = dc;
-  struct_def.fixed = fixed;
-  ParseMetaData(struct_def);
-  struct_def.sortbysize =
-    struct_def.attributes.Lookup("original_order") == nullptr && !fixed;
-  Expect('{');
-  while (token_ != '}') ParseField(struct_def);
-  auto force_align = struct_def.attributes.Lookup("force_align");
+  EXPECT(kTokenIdentifier);
+  StructDef *struct_def;
+  ECHECK(StartStruct(name, &struct_def));
+  struct_def->doc_comment = dc;
+  struct_def->fixed = fixed;
+  ECHECK(ParseMetaData(*struct_def));
+  struct_def->sortbysize =
+    struct_def->attributes.Lookup("original_order") == nullptr && !fixed;
+  EXPECT('{');
+  while (token_ != '}') ECHECK(ParseField(*struct_def));
+  auto force_align = struct_def->attributes.Lookup("force_align");
   if (fixed && force_align) {
     auto align = static_cast<size_t>(atoi(force_align->constant.c_str()));
     if (force_align->type.base_type != BASE_TYPE_INT ||
-        align < struct_def.minalign ||
+        align < struct_def->minalign ||
         align > 16 ||
         align & (align - 1))
-      Error("force_align must be a power of two integer ranging from the"
+      return Error("force_align must be a power of two integer ranging from the"
             "struct\'s natural alignment to 16");
-    struct_def.minalign = align;
+    struct_def->minalign = align;
   }
-  struct_def.PadLastField(struct_def.minalign);
+  struct_def->PadLastField(struct_def->minalign);
   // Check if this is a table that has manual id assignments
-  auto &fields = struct_def.fields.vec;
-  if (!struct_def.fixed && fields.size()) {
+  auto &fields = struct_def->fields.vec;
+  if (!struct_def->fixed && fields.size()) {
     size_t num_id_fields = 0;
     for (auto it = fields.begin(); it != fields.end(); ++it) {
       if ((*it)->attributes.Lookup("id")) num_id_fields++;
@@ -1017,7 +1132,8 @@ void Parser::ParseDecl() {
     if (num_id_fields) {
       // Then all fields must have them.
       if (num_id_fields != fields.size())
-        Error("either all fields or no fields must have an 'id' attribute");
+        return Error(
+              "either all fields or no fields must have an 'id' attribute");
       // Simply sort by id, then the fields are the same as if no ids had
       // been specified.
       std::sort(fields.begin(), fields.end(),
@@ -1029,7 +1145,7 @@ void Parser::ParseDecl() {
       // Verify we have a contiguous set, and reassign vtable offsets.
       for (int i = 0; i < static_cast<int>(fields.size()); i++) {
         if (i != atoi(fields[i]->attributes.Lookup("id")->constant.c_str()))
-          Error("field id\'s must be consecutive from 0, id " +
+          return Error("field id\'s must be consecutive from 0, id " +
                 NumToString(i) + " missing or set twice");
         fields[i]->value.offset = FieldIndexToOffset(static_cast<voffset_t>(i));
       }
@@ -1039,30 +1155,32 @@ void Parser::ParseDecl() {
   // This is not an ideal situation, but should occur very infrequently,
   // and allows us to keep using very readable names for type & length fields
   // without inducing compile errors.
-  auto CheckClash = [&fields, &struct_def](const char *suffix,
-                                           BaseType basetype) {
+  auto CheckClash = [&fields, &struct_def, this](const char *suffix,
+                                            BaseType basetype) -> CheckedError {
     auto len = strlen(suffix);
     for (auto it = fields.begin(); it != fields.end(); ++it) {
       auto &fname = (*it)->name;
       if (fname.length() > len &&
           fname.compare(fname.length() - len, len, suffix) == 0 &&
           (*it)->value.type.base_type != BASE_TYPE_UTYPE) {
-        auto field = struct_def.fields.Lookup(
+        auto field = struct_def->fields.Lookup(
                        fname.substr(0, fname.length() - len));
         if (field && field->value.type.base_type == basetype)
-          Error("Field " + fname +
+          return Error("Field " + fname +
                 " would clash with generated functions for field " +
                 field->name);
       }
     }
+    return NoError();
   };
-  CheckClash("_type", BASE_TYPE_UNION);
-  CheckClash("Type", BASE_TYPE_UNION);
-  CheckClash("_length", BASE_TYPE_VECTOR);
-  CheckClash("Length", BASE_TYPE_VECTOR);
-  CheckClash("_byte_vector", BASE_TYPE_STRING);
-  CheckClash("ByteVector", BASE_TYPE_STRING);
-  Expect('}');
+  ECHECK(CheckClash("_type", BASE_TYPE_UNION));
+  ECHECK(CheckClash("Type", BASE_TYPE_UNION));
+  ECHECK(CheckClash("_length", BASE_TYPE_VECTOR));
+  ECHECK(CheckClash("Length", BASE_TYPE_VECTOR));
+  ECHECK(CheckClash("_byte_vector", BASE_TYPE_STRING));
+  ECHECK(CheckClash("ByteVector", BASE_TYPE_STRING));
+  EXPECT('}');
+  return NoError();
 }
 
 bool Parser::SetRootType(const char *name) {
@@ -1087,44 +1205,46 @@ void Parser::MarkGenerated() {
   }
 }
 
-void Parser::ParseNamespace() {
-  Next();
+CheckedError Parser::ParseNamespace() {
+  NEXT();
   auto ns = new Namespace();
   namespaces_.push_back(ns);
   if (token_ != ';') {
     for (;;) {
       ns->components.push_back(attribute_);
-      Expect(kTokenIdentifier);
-      if (!IsNext('.')) break;
+      EXPECT(kTokenIdentifier);
+      if (Is('.')) NEXT() else break;
     }
   }
-  Expect(';');
+  EXPECT(';');
+  return NoError();
 }
 
 // Best effort parsing of .proto declarations, with the aim to turn them
 // in the closest corresponding FlatBuffer equivalent.
 // We parse everything as identifiers instead of keywords, since we don't
 // want protobuf keywords to become invalid identifiers in FlatBuffers.
-void Parser::ParseProtoDecl() {
+CheckedError Parser::ParseProtoDecl() {
   bool isextend = attribute_ == "extend";
   if (attribute_ == "package") {
     // These are identical in syntax to FlatBuffer's namespace decl.
-    ParseNamespace();
+    ECHECK(ParseNamespace());
   } else if (attribute_ == "message" || isextend) {
     std::vector<std::string> struct_comment = doc_comment_;
-    Next();
+    NEXT();
     StructDef *struct_def = nullptr;
     if (isextend) {
-      IsNext('.');  // qualified names may start with a . ?
+      if (Is('.')) NEXT();  // qualified names may start with a . ?
       auto id = attribute_;
-      Expect(kTokenIdentifier);
-      ParseNamespacing(&id, nullptr);
+      EXPECT(kTokenIdentifier);
+      ECHECK(ParseNamespacing(&id, nullptr));
       struct_def = LookupCreateStruct(id, false);
-      if (!struct_def) Error("cannot extend unknown message type: " + id);
+      if (!struct_def)
+        return Error("cannot extend unknown message type: " + id);
     } else {
       std::string name = attribute_;
-      Expect(kTokenIdentifier);
-      struct_def = &StartStruct(name);
+      EXPECT(kTokenIdentifier);
+      ECHECK(StartStruct(name, &struct_def));
       // Since message definitions can be nested, we create a new namespace.
       auto ns = new Namespace();
       // Copy of current namespace.
@@ -1134,7 +1254,7 @@ void Parser::ParseProtoDecl() {
       namespaces_.push_back(ns);
     }
     struct_def->doc_comment = struct_comment;
-    ParseProtoFields(struct_def, isextend, false);
+    ECHECK(ParseProtoFields(struct_def, isextend, false));
     if (!isextend) {
       // We have to remove the nested namespace, but we can't just throw it
       // away, so put it at the beginning of the vector.
@@ -1142,13 +1262,14 @@ void Parser::ParseProtoDecl() {
       namespaces_.pop_back();
       namespaces_.insert(namespaces_.begin(), ns);
     }
-    IsNext(';');
+    if (Is(';')) NEXT();
   } else if (attribute_ == "enum") {
     // These are almost the same, just with different terminator:
-    auto &enum_def = ParseEnum(false);
-    IsNext(';');
+    EnumDef *enum_def;
+    ECHECK(ParseEnum(false, &enum_def));
+    if (Is(';')) NEXT();
     // Protobuf allows them to be specified in any order, so sort afterwards.
-    auto &v = enum_def.vals.vec;
+    auto &v = enum_def->vals.vec;
     std::sort(v.begin(), v.end(), [](const EnumVal *a, const EnumVal *b) {
       return a->value < b->value;
     });
@@ -1158,46 +1279,48 @@ void Parser::ParseProtoDecl() {
       else ++it;
     }
   } else if (attribute_ == "syntax") {  // Skip these.
-    Next();
-    Expect('=');
-    Expect(kTokenStringConstant);
-    Expect(';');
+    NEXT();
+    EXPECT('=');
+    EXPECT(kTokenStringConstant);
+    EXPECT(';');
   } else if (attribute_ == "option") {  // Skip these.
-    ParseProtoOption();
-    Expect(';');
+    ECHECK(ParseProtoOption());
+    EXPECT(';');
   } else if (attribute_ == "service") {  // Skip these.
-    Next();
-    Expect(kTokenIdentifier);
-    ParseProtoCurliesOrIdent();
+    NEXT();
+    EXPECT(kTokenIdentifier);
+    ECHECK(ParseProtoCurliesOrIdent());
   } else {
-    Error("don\'t know how to parse .proto declaration starting with " +
+    return Error("don\'t know how to parse .proto declaration starting with " +
           TokenToStringId(token_));
   }
+  return NoError();
 }
 
-void Parser::ParseProtoFields(StructDef *struct_def, bool isextend,
-                              bool inside_oneof) {
-  Expect('{');
+CheckedError Parser::ParseProtoFields(StructDef *struct_def, bool isextend,
+                                      bool inside_oneof) {
+  EXPECT('{');
   while (token_ != '}') {
     if (attribute_ == "message" || attribute_ == "extend" ||
         attribute_ == "enum") {
       // Nested declarations.
-      ParseProtoDecl();
+      ECHECK(ParseProtoDecl());
     } else if (attribute_ == "extensions") {  // Skip these.
-      Next();
-      Expect(kTokenIntegerConstant);
-      if (IsNext(kTokenIdentifier)) {  // to
-        Next();  // num
+      NEXT();
+      EXPECT(kTokenIntegerConstant);
+      if (Is(kTokenIdentifier)) {
+        NEXT();  // to
+        NEXT();  // num
       }
-      Expect(';');
+      EXPECT(';');
     } else if (attribute_ == "option") {  // Skip these.
-      ParseProtoOption();
-      Expect(';');
+      ECHECK(ParseProtoOption());
+      EXPECT(';');
     } else if (attribute_ == "reserved") {  // Skip these.
-      Next();
-      Expect(kTokenIntegerConstant);
-      while (IsNext(',')) Expect(kTokenIntegerConstant);
-      Expect(';');
+      NEXT();
+      EXPECT(kTokenIntegerConstant);
+      while (Is(',')) { NEXT(); EXPECT(kTokenIntegerConstant); }
+      EXPECT(';');
     } else {
       std::vector<std::string> field_comment = doc_comment_;
       // Parse the qualifier.
@@ -1207,16 +1330,16 @@ void Parser::ParseProtoFields(StructDef *struct_def, bool isextend,
       if (!inside_oneof) {
         if (attribute_ == "optional") {
           // This is the default.
-          Expect(kTokenIdentifier);
+          EXPECT(kTokenIdentifier);
         } else if (attribute_ == "required") {
           required = true;
-          Expect(kTokenIdentifier);
+          EXPECT(kTokenIdentifier);
         } else if (attribute_ == "repeated") {
           repeated = true;
-          Expect(kTokenIdentifier);
+          EXPECT(kTokenIdentifier);
         } else if (attribute_ == "oneof") {
           oneof = true;
-          Expect(kTokenIdentifier);
+          EXPECT(kTokenIdentifier);
         } else {
           // can't error, proto3 allows decls without any of the above.
         }
@@ -1224,12 +1347,12 @@ void Parser::ParseProtoFields(StructDef *struct_def, bool isextend,
       StructDef *anonymous_struct = nullptr;
       Type type;
       if (attribute_ == "group" || oneof) {
-        if (!oneof) Expect(kTokenIdentifier);
+        if (!oneof) EXPECT(kTokenIdentifier);
         auto name = "Anonymous" + NumToString(anonymous_counter++);
-        anonymous_struct = &StartStruct(name);
+        ECHECK(StartStruct(name, &anonymous_struct));
         type = Type(BASE_TYPE_STRUCT, anonymous_struct);
       } else {
-        type = ParseTypeFromProtoType();
+        ECHECK(ParseTypeFromProtoType(&type));
       }
       // Repeated elements get mapped to a vector.
       if (repeated) {
@@ -1238,93 +1361,100 @@ void Parser::ParseProtoFields(StructDef *struct_def, bool isextend,
       }
       std::string name = attribute_;
       // Protos may use our keywords "attribute" & "namespace" as an identifier.
-      if (IsNext(kTokenAttribute) || IsNext(kTokenNameSpace)) {
+      if (Is(kTokenAttribute) || Is(kTokenNameSpace)) {
+        NEXT();
         // TODO: simpler to just not make these keywords?
         name += "_";  // Have to make it not a keyword.
       } else {
-        Expect(kTokenIdentifier);
+        EXPECT(kTokenIdentifier);
       }
       if (!oneof) {
         // Parse the field id. Since we're just translating schemas, not
         // any kind of binary compatibility, we can safely ignore these, and
         // assign our own.
-        Expect('=');
-        Expect(kTokenIntegerConstant);
+        EXPECT('=');
+        EXPECT(kTokenIntegerConstant);
       }
-      FieldDef *existing_field = nullptr;
+      FieldDef *field = nullptr;
       if (isextend) {
         // We allow a field to be re-defined when extending.
         // TODO: are there situations where that is problematic?
-        existing_field = struct_def->fields.Lookup(name);
+        field = struct_def->fields.Lookup(name);
       }
-      auto &field = existing_field
-                    ? *existing_field
-                    : AddField(*struct_def, name, type);
-      field.doc_comment = field_comment;
-      if (!IsScalar(type.base_type)) field.required = required;
+      if (!field) ECHECK(AddField(*struct_def, name, type, &field));
+      field->doc_comment = field_comment;
+      if (!IsScalar(type.base_type)) field->required = required;
       // See if there's a default specified.
-      if (IsNext('[')) {
-        do {
+      if (Is('[')) {
+        NEXT();
+        for (;;) {
           auto key = attribute_;
-          ParseProtoKey();
-          Expect('=');
+          ECHECK(ParseProtoKey());
+          EXPECT('=');
           auto val = attribute_;
-          ParseProtoCurliesOrIdent();
+          ECHECK(ParseProtoCurliesOrIdent());
           if (key == "default") {
             // Temp: skip non-numeric defaults (enums).
             auto numeric = strpbrk(val.c_str(), "0123456789-+.");
             if (IsScalar(type.base_type) && numeric == val.c_str())
-              field.value.constant = val;
+              field->value.constant = val;
           } else if (key == "deprecated") {
-            field.deprecated = val == "true";
+            field->deprecated = val == "true";
           }
-        } while (IsNext(','));
-        Expect(']');
+          if (!Is(',')) break;
+          NEXT();
+        }
+        EXPECT(']');
       }
       if (anonymous_struct) {
-        ParseProtoFields(anonymous_struct, false, oneof);
-        IsNext(';');
+        ECHECK(ParseProtoFields(anonymous_struct, false, oneof));
+        if (Is(';')) NEXT();
       } else {
-        Expect(';');
+        EXPECT(';');
       }
     }
   }
-  Next();
+  NEXT();
+  return NoError();
 }
 
-void Parser::ParseProtoKey() {
+CheckedError Parser::ParseProtoKey() {
   if (token_ == '(') {
-    Next();
+    NEXT();
     // Skip "(a.b)" style custom attributes.
-    while (token_ == '.' || token_ == kTokenIdentifier) Next();
-    Expect(')');
-    while (IsNext('.')) Expect(kTokenIdentifier);
+    while (token_ == '.' || token_ == kTokenIdentifier) NEXT();
+    EXPECT(')');
+    while (Is('.')) { NEXT(); EXPECT(kTokenIdentifier); }
   } else {
-    Expect(kTokenIdentifier);
+    EXPECT(kTokenIdentifier);
   }
+  return NoError();
 }
 
-void Parser::ParseProtoCurliesOrIdent() {
-  if (IsNext('{')) {
+CheckedError Parser::ParseProtoCurliesOrIdent() {
+  if (Is('{')) {
+    NEXT();
     for (int nesting = 1; nesting; ) {
       if (token_ == '{') nesting++;
       else if (token_ == '}') nesting--;
-      Next();
+      NEXT();
     }
   } else {
-    Next();  // Any single token.
+    NEXT();  // Any single token.
   }
+  return NoError();
 }
 
-void Parser::ParseProtoOption() {
-  Next();
-  ParseProtoKey();
-  Expect('=');
-  ParseProtoCurliesOrIdent();
+CheckedError Parser::ParseProtoOption() {
+  NEXT();
+  ECHECK(ParseProtoKey());
+  EXPECT('=');
+  ECHECK(ParseProtoCurliesOrIdent());
+  return NoError();
 }
 
 // Parse a protobuf type, and map it to the corresponding FlatBuffer one.
-Type Parser::ParseTypeFromProtoType() {
+CheckedError Parser::ParseTypeFromProtoType(Type *type) {
   struct type_lookup { const char *proto_type; BaseType fb_type; };
   static type_lookup lookup[] = {
     { "float", BASE_TYPE_FLOAT },  { "double", BASE_TYPE_DOUBLE },
@@ -1338,22 +1468,26 @@ Type Parser::ParseTypeFromProtoType() {
     { "bytes", BASE_TYPE_STRING },
     { nullptr, BASE_TYPE_NONE }
   };
-  Type type;
   for (auto tl = lookup; tl->proto_type; tl++) {
     if (attribute_ == tl->proto_type) {
-      type.base_type = tl->fb_type;
-      Next();
-      return type;
+      type->base_type = tl->fb_type;
+      NEXT();
+      return NoError();
     }
   }
-  IsNext('.');  // qualified names may start with a . ?
-  ParseTypeIdent(type);
-  return type;
+  if (Is('.')) NEXT();  // qualified names may start with a . ?
+  ECHECK(ParseTypeIdent(*type));
+  return NoError();
 }
 
 bool Parser::Parse(const char *source, const char **include_paths,
                    const char *source_filename) {
-  files_being_parsed_ = source_filename ? source_filename : "";
+  return !DoParse(source, include_paths, source_filename).Check();
+}
+
+CheckedError Parser::DoParse(const char *source, const char **include_paths,
+                             const char *source_filename) {
+  file_being_parsed_ = source_filename ? source_filename : "";
   if (source_filename &&
       included_files_.find(source_filename) == included_files_.end()) {
     included_files_[source_filename] = true;
@@ -1369,141 +1503,130 @@ bool Parser::Parse(const char *source, const char **include_paths,
   builder_.Clear();
   // Start with a blank namespace just in case this file doesn't have one.
   namespaces_.push_back(new Namespace());
-  try {
-    Next();
-    // Includes must come before type declarations:
-    for (;;) {
-      // Parse pre-include proto statements if any:
-      if (opts.proto_mode  &&
-          (attribute_ == "option" || attribute_ == "syntax" ||
-           attribute_ == "package")) {
-          ParseProtoDecl();
-      } else if (IsNext(kTokenInclude) ||
-                 (opts.proto_mode &&
-                  attribute_ == "import" &&
-                  IsNext(kTokenIdentifier))) {
-        if (opts.proto_mode && attribute_ == "public") Next();
-        auto name = attribute_;
-        Expect(kTokenStringConstant);
-        // Look for the file in include_paths.
-        std::string filepath;
-        for (auto paths = include_paths; paths && *paths; paths++) {
-          filepath = flatbuffers::ConCatPathFileName(*paths, name);
-          if(FileExists(filepath.c_str())) break;
-        }
-        if (filepath.empty())
-          Error("unable to locate include file: " + name);
-        if (source_filename)
-          files_included_per_file_[source_filename].insert(filepath);
-        if (included_files_.find(filepath) == included_files_.end()) {
-          // We found an include file that we have not parsed yet.
-          // Load it and parse it.
-          std::string contents;
-          if (!LoadFile(filepath.c_str(), true, &contents))
-            Error("unable to load include file: " + name);
-          if (!Parse(contents.c_str(), include_paths, filepath.c_str())) {
-            // Any errors, we're done.
-            return false;
-          }
-          // We generally do not want to output code for any included files:
-          if (!opts.generate_all) MarkGenerated();
-          // This is the easiest way to continue this file after an include:
-          // instead of saving and restoring all the state, we simply start the
-          // file anew. This will cause it to encounter the same include statement
-          // again, but this time it will skip it, because it was entered into
-          // included_files_.
-          // This is recursive, but only go as deep as the number of include
-          // statements.
-          return Parse(source, include_paths, source_filename);
-        }
-        Expect(';');
-      } else {
-        break;
+  NEXT();
+  // Includes must come before type declarations:
+  for (;;) {
+    // Parse pre-include proto statements if any:
+    if (opts.proto_mode &&
+        (attribute_ == "option" || attribute_ == "syntax" ||
+         attribute_ == "package")) {
+        ECHECK(ParseProtoDecl());
+    } else if (Is(kTokenInclude) ||
+               (opts.proto_mode &&
+                attribute_ == "import" &&
+                Is(kTokenIdentifier))) {
+      NEXT();
+      if (opts.proto_mode && attribute_ == "public") NEXT();
+      auto name = attribute_;
+      EXPECT(kTokenStringConstant);
+      // Look for the file in include_paths.
+      std::string filepath;
+      for (auto paths = include_paths; paths && *paths; paths++) {
+        filepath = flatbuffers::ConCatPathFileName(*paths, name);
+        if(FileExists(filepath.c_str())) break;
       }
-    }
-    // Now parse all other kinds of declarations:
-    while (token_ != kTokenEof) {
-      if (opts.proto_mode) {
-        ParseProtoDecl();
-      } else if (token_ == kTokenNameSpace) {
-        ParseNamespace();
-      } else if (token_ == '{') {
-        if (!root_struct_def_) Error("no root type set to parse json with");
-        if (builder_.GetSize()) {
-          Error("cannot have more than one json object in a file");
-        }
-        builder_.Finish(Offset<Table>(ParseTable(*root_struct_def_, nullptr)),
-          file_identifier_.length() ? file_identifier_.c_str() : nullptr);
-      } else if (token_ == kTokenEnum) {
-        ParseEnum(false);
-      } else if (token_ == kTokenUnion) {
-        ParseEnum(true);
-      } else if (token_ == kTokenRootType) {
-        Next();
-        auto root_type = attribute_;
-        Expect(kTokenIdentifier);
-        ParseNamespacing(&root_type, nullptr);
-        if (!SetRootType(root_type.c_str()))
-          Error("unknown root type: " + root_type);
-        if (root_struct_def_->fixed)
-          Error("root type must be a table");
-        Expect(';');
-      } else if (token_ == kTokenFileIdentifier) {
-        Next();
-        file_identifier_ = attribute_;
-        Expect(kTokenStringConstant);
-        if (file_identifier_.length() !=
-            FlatBufferBuilder::kFileIdentifierLength)
-          Error("file_identifier must be exactly " +
-                NumToString(FlatBufferBuilder::kFileIdentifierLength) +
-                " characters");
-        Expect(';');
-      } else if (token_ == kTokenFileExtension) {
-        Next();
-        file_extension_ = attribute_;
-        Expect(kTokenStringConstant);
-        Expect(';');
-      } else if(token_ == kTokenInclude) {
-        Error("includes must come before declarations");
-      } else if(token_ == kTokenAttribute) {
-        Next();
-        auto name = attribute_;
-        Expect(kTokenStringConstant);
-        Expect(';');
-        known_attributes_.insert(name);
-      } else {
-        ParseDecl();
+      if (filepath.empty())
+        return Error("unable to locate include file: " + name);
+      if (source_filename)
+        files_included_per_file_[source_filename].insert(filepath);
+      if (included_files_.find(filepath) == included_files_.end()) {
+        // We found an include file that we have not parsed yet.
+        // Load it and parse it.
+        std::string contents;
+        if (!LoadFile(filepath.c_str(), true, &contents))
+          return Error("unable to load include file: " + name);
+        ECHECK(DoParse(contents.c_str(), include_paths, filepath.c_str()));
+        // We generally do not want to output code for any included files:
+        if (!opts.generate_all) MarkGenerated();
+        // This is the easiest way to continue this file after an include:
+        // instead of saving and restoring all the state, we simply start the
+        // file anew. This will cause it to encounter the same include
+        // statement again, but this time it will skip it, because it was
+        // entered into included_files_.
+        // This is recursive, but only go as deep as the number of include
+        // statements.
+        return DoParse(source, include_paths, source_filename);
       }
+      EXPECT(';');
+    } else {
+      break;
     }
-    for (auto it = structs_.vec.begin(); it != structs_.vec.end(); ++it) {
-      if ((*it)->predecl) {
-        Error("type referenced but not defined: " + (*it)->name);
-      }
-    }
-    for (auto it = enums_.vec.begin(); it != enums_.vec.end(); ++it) {
-      auto &enum_def = **it;
-      if (enum_def.is_union) {
-        for (auto val_it = enum_def.vals.vec.begin();
-             val_it != enum_def.vals.vec.end();
-             ++val_it) {
-          auto &val = **val_it;
-          if (val.struct_def && val.struct_def->fixed)
-            Error("only tables can be union elements: " + val.name);
-        }
-      }
-    }
-  } catch (const std::string &msg) {
-    error_ = source_filename ? AbsolutePath(source_filename) : "";
-    #ifdef _WIN32
-      error_ += "(" + NumToString(line_) + ")";  // MSVC alike
-    #else
-      if (source_filename) error_ += ":";
-      error_ += NumToString(line_) + ":0";  // gcc alike
-    #endif
-    error_ += ": error: " + msg;
-    return false;
   }
-  return true;
+  // Now parse all other kinds of declarations:
+  while (token_ != kTokenEof) {
+    if (opts.proto_mode) {
+      ECHECK(ParseProtoDecl());
+    } else if (token_ == kTokenNameSpace) {
+      ECHECK(ParseNamespace());
+    } else if (token_ == '{') {
+      if (!root_struct_def_)
+        return Error("no root type set to parse json with");
+      if (builder_.GetSize()) {
+        return Error("cannot have more than one json object in a file");
+      }
+      uoffset_t toff;
+      ECHECK(ParseTable(*root_struct_def_, nullptr, &toff));
+      builder_.Finish(Offset<Table>(toff),
+                file_identifier_.length() ? file_identifier_.c_str() : nullptr);
+    } else if (token_ == kTokenEnum) {
+      ECHECK(ParseEnum(false, nullptr));
+    } else if (token_ == kTokenUnion) {
+      ECHECK(ParseEnum(true, nullptr));
+    } else if (token_ == kTokenRootType) {
+      NEXT();
+      auto root_type = attribute_;
+      EXPECT(kTokenIdentifier);
+      ECHECK(ParseNamespacing(&root_type, nullptr));
+      if (!SetRootType(root_type.c_str()))
+        return Error("unknown root type: " + root_type);
+      if (root_struct_def_->fixed)
+        return Error("root type must be a table");
+      EXPECT(';');
+    } else if (token_ == kTokenFileIdentifier) {
+      NEXT();
+      file_identifier_ = attribute_;
+      EXPECT(kTokenStringConstant);
+      if (file_identifier_.length() !=
+          FlatBufferBuilder::kFileIdentifierLength)
+        return Error("file_identifier must be exactly " +
+              NumToString(FlatBufferBuilder::kFileIdentifierLength) +
+              " characters");
+      EXPECT(';');
+    } else if (token_ == kTokenFileExtension) {
+      NEXT();
+      file_extension_ = attribute_;
+      EXPECT(kTokenStringConstant);
+      EXPECT(';');
+    } else if(token_ == kTokenInclude) {
+      return Error("includes must come before declarations");
+    } else if(token_ == kTokenAttribute) {
+      NEXT();
+      auto name = attribute_;
+      EXPECT(kTokenStringConstant);
+      EXPECT(';');
+      known_attributes_.insert(name);
+    } else {
+      ECHECK(ParseDecl());
+    }
+  }
+  for (auto it = structs_.vec.begin(); it != structs_.vec.end(); ++it) {
+    if ((*it)->predecl) {
+      return Error("type referenced but not defined: " + (*it)->name);
+    }
+  }
+  for (auto it = enums_.vec.begin(); it != enums_.vec.end(); ++it) {
+    auto &enum_def = **it;
+    if (enum_def.is_union) {
+      for (auto val_it = enum_def.vals.vec.begin();
+           val_it != enum_def.vals.vec.end();
+           ++val_it) {
+        auto &val = **val_it;
+        if (val.struct_def && val.struct_def->fixed)
+          return Error("only tables can be union elements: " + val.name);
+      }
+    }
+  }
+  return NoError();
 }
 
 std::set<std::string> Parser::GetIncludedFilesRecursive(
diff --git a/src/reflection.cpp b/src/reflection.cpp
index 35ae16feb..ab39e1e20 100644
--- a/src/reflection.cpp
+++ b/src/reflection.cpp
@@ -287,14 +287,17 @@ void SetString(const reflection::Schema &schema, const std::string &val,
                       const String *str, std::vector<uint8_t> *flatbuf,
                       const reflection::Object *root_table) {
   auto delta = static_cast<int>(val.size()) - static_cast<int>(str->Length());
-  auto start = static_cast<uoffset_t>(reinterpret_cast<const uint8_t *>(str) -
-                                      flatbuf->data() +
-                                      sizeof(uoffset_t));
+  auto str_start = static_cast<uoffset_t>(
+                     reinterpret_cast<const uint8_t *>(str) - flatbuf->data());
+  auto start = str_start + sizeof(uoffset_t);
   if (delta) {
     // Clear the old string, since we don't want parts of it remaining.
     memset(flatbuf->data() + start, 0, str->Length());
     // Different size, we must expand (or contract).
     ResizeContext(schema, start, delta, flatbuf, root_table);
+    // Set the new length.
+    WriteScalar(flatbuf->data() + str_start,
+                static_cast<uoffset_t>(val.size()));
   }
   // Copy new data. Safe because we created the right amount of space.
   memcpy(flatbuf->data() + start, val.c_str(), val.size() + 1);
diff --git a/tests/generate_code.bat b/tests/generate_code.bat
index 75ac1433e..00b16d900 100644
--- a/tests/generate_code.bat
+++ b/tests/generate_code.bat
@@ -1,2 +1,17 @@
-..\flatc.exe -c -j -n -g -b -p --php -s --gen-mutable --no-includes monster_test.fbs monsterdata_test.json
-..\flatc.exe -b --schema monster_test.fbs
+:: Copyright 2015 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.
+
+..\flatc.exe --cpp --java --csharp --go --binary --python --js --php --gen-mutable --no-includes monster_test.fbs monsterdata_test.json
+..\flatc.exe --cpp --java --csharp --go --binary --python --js --php --gen-mutable -o namespace_test namespace_test\namespace_test1.fbs namespace_test\namespace_test2.fbs
+..\flatc.exe --binary --schema monster_test.fbs
diff --git a/tests/generate_code.sh b/tests/generate_code.sh
index 91661f30d..712da6c77 100644
--- a/tests/generate_code.sh
+++ b/tests/generate_code.sh
@@ -1,2 +1,20 @@
+#!/bin/bash
+
+# Copyright 2015 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.
+
 ../flatc --cpp --java --csharp --go --binary --python --js --php --gen-mutable --no-includes monster_test.fbs monsterdata_test.json
+../flatc --cpp --java --csharp --go --binary --python --js --php --gen-mutable -o namespace_test namespace_test/namespace_test1.fbs namespace_test/namespace_test2.fbs
 ../flatc --binary --schema monster_test.fbs
+
diff --git a/tests/namespace_test/NamespaceA/NamespaceB/EnumInNestedNS.py b/tests/namespace_test/NamespaceA/NamespaceB/EnumInNestedNS.py
new file mode 100644
index 000000000..5de5be804
--- /dev/null
+++ b/tests/namespace_test/NamespaceA/NamespaceB/EnumInNestedNS.py
@@ -0,0 +1,9 @@
+# automatically generated, do not modify
+
+# namespace: NamespaceB
+
+class EnumInNestedNS(object):
+    A = 0
+    B = 1
+    C = 2
+
diff --git a/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.cs b/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.cs
index 9eb853c74..7317f2410 100644
--- a/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.cs
+++ b/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.cs
@@ -3,6 +3,7 @@
 namespace NamespaceA.NamespaceB
 {
 
+using System;
 using FlatBuffers;
 
 public sealed class StructInNestedNS : Struct {
diff --git a/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.py b/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.py
new file mode 100644
index 000000000..ae3f94024
--- /dev/null
+++ b/tests/namespace_test/NamespaceA/NamespaceB/StructInNestedNS.py
@@ -0,0 +1,23 @@
+# automatically generated, do not modify
+
+# namespace: NamespaceB
+
+import flatbuffers
+
+class StructInNestedNS(object):
+    __slots__ = ['_tab']
+
+    # StructInNestedNS
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # StructInNestedNS
+    def A(self): return self._tab.Get(flatbuffers.number_types.Int32Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(0))
+    # StructInNestedNS
+    def B(self): return self._tab.Get(flatbuffers.number_types.Int32Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(4))
+
+def CreateStructInNestedNS(builder, a, b):
+    builder.Prep(4, 8)
+    builder.PrependInt32(b)
+    builder.PrependInt32(a)
+    return builder.Offset()
diff --git a/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.cs b/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.cs
index e04bc7cb2..dec8da9ee 100644
--- a/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.cs
+++ b/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.cs
@@ -3,6 +3,7 @@
 namespace NamespaceA.NamespaceB
 {
 
+using System;
 using FlatBuffers;
 
 public sealed class TableInNestedNS : Table {
diff --git a/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.py b/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.py
new file mode 100644
index 000000000..834103bfe
--- /dev/null
+++ b/tests/namespace_test/NamespaceA/NamespaceB/TableInNestedNS.py
@@ -0,0 +1,23 @@
+# automatically generated, do not modify
+
+# namespace: NamespaceB
+
+import flatbuffers
+
+class TableInNestedNS(object):
+    __slots__ = ['_tab']
+
+    # TableInNestedNS
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # TableInNestedNS
+    def Foo(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Int32Flags, o + self._tab.Pos)
+        return 0
+
+def TableInNestedNSStart(builder): builder.StartObject(1)
+def TableInNestedNSAddFoo(builder, foo): builder.PrependInt32Slot(0, foo, 0)
+def TableInNestedNSEnd(builder): return builder.EndObject()
diff --git a/tests/namespace_test/NamespaceA/NamespaceB/__init__.py b/tests/namespace_test/NamespaceA/NamespaceB/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/namespace_test/NamespaceA/TableInFirstNS.cs b/tests/namespace_test/NamespaceA/TableInFirstNS.cs
index a82b83cc1..21a12cf59 100644
--- a/tests/namespace_test/NamespaceA/TableInFirstNS.cs
+++ b/tests/namespace_test/NamespaceA/TableInFirstNS.cs
@@ -3,6 +3,7 @@
 namespace NamespaceA
 {
 
+using System;
 using FlatBuffers;
 
 public sealed class TableInFirstNS : Table {
diff --git a/tests/namespace_test/NamespaceA/TableInFirstNS.py b/tests/namespace_test/NamespaceA/TableInFirstNS.py
new file mode 100644
index 000000000..eb09014ce
--- /dev/null
+++ b/tests/namespace_test/NamespaceA/TableInFirstNS.py
@@ -0,0 +1,47 @@
+# automatically generated, do not modify
+
+# namespace: NamespaceA
+
+import flatbuffers
+
+class TableInFirstNS(object):
+    __slots__ = ['_tab']
+
+    # TableInFirstNS
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # TableInFirstNS
+    def FooTable(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(4))
+        if o != 0:
+            x = self._tab.Indirect(o + self._tab.Pos)
+            from .TableInNestedNS import TableInNestedNS
+            obj = TableInNestedNS()
+            obj.Init(self._tab.Bytes, x)
+            return obj
+        return None
+
+    # TableInFirstNS
+    def FooEnum(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(6))
+        if o != 0:
+            return self._tab.Get(flatbuffers.number_types.Int8Flags, o + self._tab.Pos)
+        return 0
+
+    # TableInFirstNS
+    def FooStruct(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(8))
+        if o != 0:
+            x = o + self._tab.Pos
+            from .StructInNestedNS import StructInNestedNS
+            obj = StructInNestedNS()
+            obj.Init(self._tab.Bytes, x)
+            return obj
+        return None
+
+def TableInFirstNSStart(builder): builder.StartObject(3)
+def TableInFirstNSAddFooTable(builder, fooTable): builder.PrependUOffsetTRelativeSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(fooTable), 0)
+def TableInFirstNSAddFooEnum(builder, fooEnum): builder.PrependInt8Slot(1, fooEnum, 0)
+def TableInFirstNSAddFooStruct(builder, fooStruct): builder.PrependStructSlot(2, flatbuffers.number_types.UOffsetTFlags.py_type(fooStruct), 0)
+def TableInFirstNSEnd(builder): return builder.EndObject()
diff --git a/tests/namespace_test/NamespaceA/__init__.py b/tests/namespace_test/NamespaceA/__init__.py
new file mode 100644
index 000000000..e69de29bb
diff --git a/tests/namespace_test/namespace_test1_generated.h b/tests/namespace_test/namespace_test1_generated.h
index 3c5b9c4b8..29f8e1229 100644
--- a/tests/namespace_test/namespace_test1_generated.h
+++ b/tests/namespace_test/namespace_test1_generated.h
@@ -42,11 +42,14 @@ MANUALLY_ALIGNED_STRUCT(4) StructInNestedNS FLATBUFFERS_FINAL_CLASS {
 STRUCT_END(StructInNestedNS, 8);
 
 struct TableInNestedNS FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
-  int32_t foo() const { return GetField<int32_t>(4, 0); }
-  bool mutate_foo(int32_t _foo) { return SetField(4, _foo); }
+  enum {
+    VT_FOO = 4,
+  };
+  int32_t foo() const { return GetField<int32_t>(VT_FOO, 0); }
+  bool mutate_foo(int32_t _foo) { return SetField(VT_FOO, _foo); }
   bool Verify(flatbuffers::Verifier &verifier) const {
     return VerifyTableStart(verifier) &&
-           VerifyField<int32_t>(verifier, 4 /* foo */) &&
+           VerifyField<int32_t>(verifier, VT_FOO) &&
            verifier.EndTable();
   }
 };
@@ -54,7 +57,7 @@ struct TableInNestedNS FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
 struct TableInNestedNSBuilder {
   flatbuffers::FlatBufferBuilder &fbb_;
   flatbuffers::uoffset_t start_;
-  void add_foo(int32_t foo) { fbb_.AddElement<int32_t>(4, foo, 0); }
+  void add_foo(int32_t foo) { fbb_.AddElement<int32_t>(TableInNestedNS::VT_FOO, foo, 0); }
   TableInNestedNSBuilder(flatbuffers::FlatBufferBuilder &_fbb) : fbb_(_fbb) { start_ = fbb_.StartTable(); }
   TableInNestedNSBuilder &operator=(const TableInNestedNSBuilder &);
   flatbuffers::Offset<TableInNestedNS> Finish() {
diff --git a/tests/namespace_test/namespace_test1_generated.js b/tests/namespace_test/namespace_test1_generated.js
new file mode 100644
index 000000000..769b523e3
--- /dev/null
+++ b/tests/namespace_test/namespace_test1_generated.js
@@ -0,0 +1,143 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+/**
+ * @const
+*/
+var NamespaceA = NamespaceA || {};
+
+/**
+ * @const
+*/
+NamespaceA.NamespaceB = NamespaceA.NamespaceB || {};
+
+/**
+ * @enum
+ */
+NamespaceA.NamespaceB.EnumInNestedNS = {
+  A: 0,
+  B: 1,
+  C: 2
+};
+
+/**
+ * @constructor
+ */
+NamespaceA.NamespaceB.TableInNestedNS = function() {
+  /**
+   * @type {flatbuffers.ByteBuffer}
+   */
+  this.bb = null;
+
+  /**
+   * @type {number}
+   */
+  this.bb_pos = 0;
+};
+
+/**
+ * @param {number} i
+ * @param {flatbuffers.ByteBuffer} bb
+ * @returns {NamespaceA.NamespaceB.TableInNestedNS}
+ */
+NamespaceA.NamespaceB.TableInNestedNS.prototype.__init = function(i, bb) {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+};
+
+/**
+ * @param {flatbuffers.ByteBuffer} bb
+ * @param {NamespaceA.NamespaceB.TableInNestedNS=} obj
+ * @returns {NamespaceA.NamespaceB.TableInNestedNS}
+ */
+NamespaceA.NamespaceB.TableInNestedNS.getRootAsTableInNestedNS = function(bb, obj) {
+  return (obj || new NamespaceA.NamespaceB.TableInNestedNS).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+};
+
+/**
+ * @returns {number}
+ */
+NamespaceA.NamespaceB.TableInNestedNS.prototype.foo = function() {
+  var offset = this.bb.__offset(this.bb_pos, 4);
+  return offset ? this.bb.readInt32(this.bb_pos + offset) : 0;
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ */
+NamespaceA.NamespaceB.TableInNestedNS.startTableInNestedNS = function(builder) {
+  builder.startObject(1);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {number} foo
+ */
+NamespaceA.NamespaceB.TableInNestedNS.addFoo = function(builder, foo) {
+  builder.addFieldInt32(0, foo, 0);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @returns {flatbuffers.Offset}
+ */
+NamespaceA.NamespaceB.TableInNestedNS.endTableInNestedNS = function(builder) {
+  var offset = builder.endObject();
+  return offset;
+};
+
+/**
+ * @constructor
+ */
+NamespaceA.NamespaceB.StructInNestedNS = function() {
+  /**
+   * @type {flatbuffers.ByteBuffer}
+   */
+  this.bb = null;
+
+  /**
+   * @type {number}
+   */
+  this.bb_pos = 0;
+};
+
+/**
+ * @param {number} i
+ * @param {flatbuffers.ByteBuffer} bb
+ * @returns {NamespaceA.NamespaceB.StructInNestedNS}
+ */
+NamespaceA.NamespaceB.StructInNestedNS.prototype.__init = function(i, bb) {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+};
+
+/**
+ * @returns {number}
+ */
+NamespaceA.NamespaceB.StructInNestedNS.prototype.a = function() {
+  return this.bb.readInt32(this.bb_pos);
+};
+
+/**
+ * @returns {number}
+ */
+NamespaceA.NamespaceB.StructInNestedNS.prototype.b = function() {
+  return this.bb.readInt32(this.bb_pos + 4);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {number} a
+ * @param {number} b
+ * @returns {flatbuffers.Offset}
+ */
+NamespaceA.NamespaceB.StructInNestedNS.createStructInNestedNS = function(builder, a, b) {
+  builder.prep(4, 8);
+  builder.writeInt32(b);
+  builder.writeInt32(a);
+  return builder.offset();
+};
+
+// Exports for Node.js and RequireJS
+this.NamespaceA = NamespaceA;
diff --git a/tests/namespace_test/namespace_test2_generated.h b/tests/namespace_test/namespace_test2_generated.h
index 0395824ac..f60986a61 100644
--- a/tests/namespace_test/namespace_test2_generated.h
+++ b/tests/namespace_test/namespace_test2_generated.h
@@ -5,6 +5,8 @@
 
 #include "flatbuffers/flatbuffers.h"
 
+#include "namespace_test1_generated.h"
+
 namespace NamespaceA {
 namespace NamespaceB {
 struct TableInNestedNS;
@@ -17,18 +19,23 @@ namespace NamespaceA {
 struct TableInFirstNS;
 
 struct TableInFirstNS FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
-  const NamespaceA::NamespaceB::TableInNestedNS *foo_table() const { return GetPointer<const NamespaceA::NamespaceB::TableInNestedNS *>(4); }
-  NamespaceA::NamespaceB::TableInNestedNS *mutable_foo_table() { return GetPointer<NamespaceA::NamespaceB::TableInNestedNS *>(4); }
-  NamespaceA::NamespaceB::EnumInNestedNS foo_enum() const { return static_cast<NamespaceA::NamespaceB::EnumInNestedNS>(GetField<int8_t>(6, 0)); }
-  bool mutate_foo_enum(NamespaceA::NamespaceB::EnumInNestedNS _foo_enum) { return SetField(6, static_cast<int8_t>(_foo_enum)); }
-  const NamespaceA::NamespaceB::StructInNestedNS *foo_struct() const { return GetStruct<const NamespaceA::NamespaceB::StructInNestedNS *>(8); }
-  NamespaceA::NamespaceB::StructInNestedNS *mutable_foo_struct() { return GetStruct<NamespaceA::NamespaceB::StructInNestedNS *>(8); }
+  enum {
+    VT_FOO_TABLE = 4,
+    VT_FOO_ENUM = 6,
+    VT_FOO_STRUCT = 8,
+  };
+  const NamespaceA::NamespaceB::TableInNestedNS *foo_table() const { return GetPointer<const NamespaceA::NamespaceB::TableInNestedNS *>(VT_FOO_TABLE); }
+  NamespaceA::NamespaceB::TableInNestedNS *mutable_foo_table() { return GetPointer<NamespaceA::NamespaceB::TableInNestedNS *>(VT_FOO_TABLE); }
+  NamespaceA::NamespaceB::EnumInNestedNS foo_enum() const { return static_cast<NamespaceA::NamespaceB::EnumInNestedNS>(GetField<int8_t>(VT_FOO_ENUM, 0)); }
+  bool mutate_foo_enum(NamespaceA::NamespaceB::EnumInNestedNS _foo_enum) { return SetField(VT_FOO_ENUM, static_cast<int8_t>(_foo_enum)); }
+  const NamespaceA::NamespaceB::StructInNestedNS *foo_struct() const { return GetStruct<const NamespaceA::NamespaceB::StructInNestedNS *>(VT_FOO_STRUCT); }
+  NamespaceA::NamespaceB::StructInNestedNS *mutable_foo_struct() { return GetStruct<NamespaceA::NamespaceB::StructInNestedNS *>(VT_FOO_STRUCT); }
   bool Verify(flatbuffers::Verifier &verifier) const {
     return VerifyTableStart(verifier) &&
-           VerifyField<flatbuffers::uoffset_t>(verifier, 4 /* foo_table */) &&
+           VerifyField<flatbuffers::uoffset_t>(verifier, VT_FOO_TABLE) &&
            verifier.VerifyTable(foo_table()) &&
-           VerifyField<int8_t>(verifier, 6 /* foo_enum */) &&
-           VerifyField<NamespaceA::NamespaceB::StructInNestedNS>(verifier, 8 /* foo_struct */) &&
+           VerifyField<int8_t>(verifier, VT_FOO_ENUM) &&
+           VerifyField<NamespaceA::NamespaceB::StructInNestedNS>(verifier, VT_FOO_STRUCT) &&
            verifier.EndTable();
   }
 };
@@ -36,9 +43,9 @@ struct TableInFirstNS FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
 struct TableInFirstNSBuilder {
   flatbuffers::FlatBufferBuilder &fbb_;
   flatbuffers::uoffset_t start_;
-  void add_foo_table(flatbuffers::Offset<NamespaceA::NamespaceB::TableInNestedNS> foo_table) { fbb_.AddOffset(4, foo_table); }
-  void add_foo_enum(NamespaceA::NamespaceB::EnumInNestedNS foo_enum) { fbb_.AddElement<int8_t>(6, static_cast<int8_t>(foo_enum), 0); }
-  void add_foo_struct(const NamespaceA::NamespaceB::StructInNestedNS *foo_struct) { fbb_.AddStruct(8, foo_struct); }
+  void add_foo_table(flatbuffers::Offset<NamespaceA::NamespaceB::TableInNestedNS> foo_table) { fbb_.AddOffset(TableInFirstNS::VT_FOO_TABLE, foo_table); }
+  void add_foo_enum(NamespaceA::NamespaceB::EnumInNestedNS foo_enum) { fbb_.AddElement<int8_t>(TableInFirstNS::VT_FOO_ENUM, static_cast<int8_t>(foo_enum), 0); }
+  void add_foo_struct(const NamespaceA::NamespaceB::StructInNestedNS *foo_struct) { fbb_.AddStruct(TableInFirstNS::VT_FOO_STRUCT, foo_struct); }
   TableInFirstNSBuilder(flatbuffers::FlatBufferBuilder &_fbb) : fbb_(_fbb) { start_ = fbb_.StartTable(); }
   TableInFirstNSBuilder &operator=(const TableInFirstNSBuilder &);
   flatbuffers::Offset<TableInFirstNS> Finish() {
diff --git a/tests/namespace_test/namespace_test2_generated.js b/tests/namespace_test/namespace_test2_generated.js
new file mode 100644
index 000000000..e99d77573
--- /dev/null
+++ b/tests/namespace_test/namespace_test2_generated.js
@@ -0,0 +1,115 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+/**
+ * @const
+*/
+var NamespaceA = NamespaceA || {};
+
+/**
+ * @const
+*/
+NamespaceA.NamespaceB = NamespaceA.NamespaceB || {};
+
+/**
+ * @constructor
+ */
+NamespaceA.TableInFirstNS = function() {
+  /**
+   * @type {flatbuffers.ByteBuffer}
+   */
+  this.bb = null;
+
+  /**
+   * @type {number}
+   */
+  this.bb_pos = 0;
+};
+
+/**
+ * @param {number} i
+ * @param {flatbuffers.ByteBuffer} bb
+ * @returns {NamespaceA.TableInFirstNS}
+ */
+NamespaceA.TableInFirstNS.prototype.__init = function(i, bb) {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+};
+
+/**
+ * @param {flatbuffers.ByteBuffer} bb
+ * @param {NamespaceA.TableInFirstNS=} obj
+ * @returns {NamespaceA.TableInFirstNS}
+ */
+NamespaceA.TableInFirstNS.getRootAsTableInFirstNS = function(bb, obj) {
+  return (obj || new NamespaceA.TableInFirstNS).__init(bb.readInt32(bb.position()) + bb.position(), bb);
+};
+
+/**
+ * @param {NamespaceA.NamespaceB.TableInNestedNS=} obj
+ * @returns {NamespaceA.NamespaceB.TableInNestedNS}
+ */
+NamespaceA.TableInFirstNS.prototype.fooTable = function(obj) {
+  var offset = this.bb.__offset(this.bb_pos, 4);
+  return offset ? (obj || new NamespaceA.NamespaceB.TableInNestedNS).__init(this.bb.__indirect(this.bb_pos + offset), this.bb) : null;
+};
+
+/**
+ * @returns {NamespaceA.NamespaceB.EnumInNestedNS}
+ */
+NamespaceA.TableInFirstNS.prototype.fooEnum = function() {
+  var offset = this.bb.__offset(this.bb_pos, 6);
+  return offset ? /** @type {NamespaceA.NamespaceB.EnumInNestedNS} */ (this.bb.readInt8(this.bb_pos + offset)) : NamespaceA.NamespaceB.EnumInNestedNS.A;
+};
+
+/**
+ * @param {NamespaceA.NamespaceB.StructInNestedNS=} obj
+ * @returns {NamespaceA.NamespaceB.StructInNestedNS}
+ */
+NamespaceA.TableInFirstNS.prototype.fooStruct = function(obj) {
+  var offset = this.bb.__offset(this.bb_pos, 8);
+  return offset ? (obj || new NamespaceA.NamespaceB.StructInNestedNS).__init(this.bb_pos + offset, this.bb) : null;
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ */
+NamespaceA.TableInFirstNS.startTableInFirstNS = function(builder) {
+  builder.startObject(3);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {flatbuffers.Offset} fooTableOffset
+ */
+NamespaceA.TableInFirstNS.addFooTable = function(builder, fooTableOffset) {
+  builder.addFieldOffset(0, fooTableOffset, 0);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {NamespaceA.NamespaceB.EnumInNestedNS} fooEnum
+ */
+NamespaceA.TableInFirstNS.addFooEnum = function(builder, fooEnum) {
+  builder.addFieldInt8(1, fooEnum, NamespaceA.NamespaceB.EnumInNestedNS.A);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {flatbuffers.Offset} fooStructOffset
+ */
+NamespaceA.TableInFirstNS.addFooStruct = function(builder, fooStructOffset) {
+  builder.addFieldStruct(2, fooStructOffset, 0);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @returns {flatbuffers.Offset}
+ */
+NamespaceA.TableInFirstNS.endTableInFirstNS = function(builder) {
+  var offset = builder.endObject();
+  return offset;
+};
+
+// Exports for Node.js and RequireJS
+this.NamespaceA = NamespaceA;
diff --git a/tests/test.cpp b/tests/test.cpp
index be364d407..d009438ea 100644
--- a/tests/test.cpp
+++ b/tests/test.cpp
@@ -21,6 +21,8 @@
 #include "flatbuffers/util.h"
 
 #include "monster_test_generated.h"
+#include "namespace_test/namespace_test1_generated.h"
+#include "namespace_test/namespace_test2_generated.h"
 
 #include <random>
 
@@ -219,6 +221,10 @@ void AccessFlatBufferTest(const uint8_t *flatbuf, size_t length) {
   for (auto it = tests->begin(); it != tests->end(); ++it) {
     TEST_EQ(it->a() == 10 || it->a() == 30, true);  // Just testing iterators.
   }
+
+  // Checking for presence of fields:
+  TEST_EQ(flatbuffers::IsFieldPresent(monster, Monster::VT_HP), true);
+  TEST_EQ(flatbuffers::IsFieldPresent(monster, Monster::VT_MANA), false);
 }
 
 // Change a FlatBuffer in-place, after it has been constructed.
@@ -398,6 +404,11 @@ void ReflectionTest(uint8_t *flatbuf, size_t length) {
   rtestarrayofstring->MutateOffset(2, string_ptr);
   TEST_EQ_STR(rtestarrayofstring->Get(0)->c_str(), "bob");
   TEST_EQ_STR(rtestarrayofstring->Get(2)->c_str(), "hank");
+  // Test integrity of all resize operations above.
+  flatbuffers::Verifier resize_verifier(
+        reinterpret_cast<const uint8_t *>(resizingbuf.data()),
+        resizingbuf.size());
+  TEST_EQ(VerifyMonsterBuffer(resize_verifier), true);
   // As an additional test, also set it on the name field.
   // Note: unlike the name change above, this just overwrites the offset,
   // rather than changing the string in-place.