ircd::json: Improve value semantics and various fixes.

include/ircd/json/array.h

@@ -60,6 +60,7 @@ struct ircd::json::array
 	using string_view::string_view;
 
 	friend string_view stringify(mutable_buffer &, const array &);
+	friend string_view stringify(mutable_buffer &, const std::vector<json::object> &);
 	friend std::ostream &operator<<(std::ostream &, const array &);
 };
 

include/ircd/json/member.h

@@ -25,16 +25,10 @@
 namespace ircd::json
 {
 	struct member;
-	using members = std::initializer_list<member>;
 
 	size_t serialized(const member *const &begin, const member *const &end);
-	size_t serialized(const members &);
-
 	string_view stringify(mutable_buffer &, const member *const *const &begin, const member *const *const &end);
 	string_view stringify(mutable_buffer &, const member *const &begin, const member *const &end);
-	string_view stringify(mutable_buffer &, const members &);
-
-	string_view stringify(mutable_buffer &, const std::vector<json::object> &);
 }
 
 /// A pair of json::value representing an object member.
@@ -67,6 +61,14 @@ struct ircd::json::member
 	friend std::ostream &operator<<(std::ostream &, const member &);
 };
 
+namespace ircd::json
+{
+	using members = std::initializer_list<member>;
+
+	size_t serialized(const members &);
+	string_view stringify(mutable_buffer &, const members &);
+}
+
 template<class K,
          class V>
 ircd::json::member::member(const K &k,

include/ircd/json/value.h

@@ -49,15 +49,17 @@ struct ircd::json::value
 		const struct array *array;
 	};
 
-	uint64_t len     : 58;
-	enum type type   : 3;
-	uint64_t serial  : 1;
-	uint64_t alloc   : 1;
-	uint64_t floats  : 1;
+	uint64_t len     : 57;      ///< length indicator
+	enum type type   : 3;       ///< json::type indicator
+	uint64_t serial  : 1;       ///< only string* is used. type indicates JSON
+	uint64_t alloc   : 1;       ///< indicates the pointer for type is owned
+	uint64_t floats  : 1;       ///< for NUMBER type, integer or floating
 
   public:
+	bool null() const;
 	bool empty() const;
-	size_t serialized() const;
+	bool undefined() const;
+
 	operator string_view() const;
 	explicit operator double() const;
 	explicit operator int64_t() const;
@@ -65,14 +67,14 @@ struct ircd::json::value
 
 	template<class T> explicit value(const T &specialized);
 	template<size_t N> value(const char (&)[N]);
+	value(const char *const &s);
 	value(const string_view &sv, const enum type &);
 	value(const string_view &sv);
-	value(const char *const &s);
 	value(const index *const &);    // alloc = false
 	value(std::unique_ptr<index>);  // alloc = true
 	value();
 	value(value &&) noexcept;
-	value(const value &) = delete;
+	value(const value &);
 	value &operator=(value &&) noexcept;
 	value &operator=(const value &) = delete;
 	~value() noexcept;
@@ -202,12 +204,22 @@ ircd::json::value::value(const T &t)
 
 template<size_t N>
 ircd::json::value::value(const char (&str)[N])
-:value{string_view{str}}
+:string{str}
+,len{strnlen(str, N)}
+,type{json::type(str, std::nothrow)}
+,serial{true}
+,alloc{false}
+,floats{false}
 {}
 
 inline
 ircd::json::value::value(const char *const &s)
-:value{string_view{s}}
+:string{s}
+,len{strlen(s)}
+,type{json::type(s, std::nothrow)}
+,serial{true}
+,alloc{false}
+,floats{false}
 {}
 
 inline
@@ -228,6 +240,33 @@ noexcept
 	other.alloc = false;
 }
 
+inline
+ircd::json::value::value(const value &other)
+:integer{other.integer}
+,len{other.len}
+,type{other.type}
+,serial{other.serial}
+,alloc{other.alloc}
+,floats{other.floats}
+{
+	switch(type)
+	{
+		case NUMBER:
+			break;
+
+		case LITERAL:
+		case STRING:
+			assert(serial);
+			assert(!alloc);
+			break;
+
+		case OBJECT:
+		case ARRAY:
+			assert(serial);
+			break;
+	}
+}
+
 inline ircd::json::value &
 ircd::json::value::operator=(value &&other)
 noexcept

include/ircd/m/error.h

@@ -37,6 +37,7 @@ struct ircd::m::error
 	template<class... args> error(const string_view &errcode, const char *const &fmt, args&&...);
 	error(const http::code &, const json::object &object = {});
 	error(const http::code &, const json::index &idx);
+	error(const http::code &, const json::iov &);
 	error(const http::code &);
 	error(std::string = {});
 

ircd/json.cc

@@ -963,7 +963,7 @@ const
 			if(serial)
 				return std::string(string_view(*this));
 			else
-				return std::string(*object);
+				return json::string(*object);
 
 		case ARRAY:
 			if(serial)
@@ -991,9 +991,16 @@ const
 		case STRING:
 			return unquote(string_view{string, len});
 
+		case NUMBER:
+			if(serial)
+				return string_view{string, len};
+			else if(floats)
+				return byte_view<string_view>{floating};
+			else
+				return byte_view<string_view>{integer};
+
 		case ARRAY:
 		case OBJECT:
-		case NUMBER:
 		case LITERAL:
 			if(serial)
 				return string_view{string, len};
@@ -1013,6 +1020,7 @@ const
 			return likely(!floats)? integer : floating;
 
 		case STRING:
+			assert(serial);
 			return lex_cast<int64_t>(string_view(*this));
 
 		case ARRAY:
@@ -1033,6 +1041,7 @@ const
 			return likely(floats)? floating : integer;
 
 		case STRING:
+			assert(serial);
 			return lex_cast<double>(string_view(*this));
 
 		case ARRAY:
@@ -1044,6 +1053,36 @@ const
 	throw type_error("value type[%d] is not a float", int(type));
 }
 
+bool
+ircd::json::value::undefined()
+const
+{
+	switch(type)
+	{
+		case NUMBER:
+			return false;
+
+		case STRING:
+			return string == nullptr;
+
+		case OBJECT:
+			return serial? string == nullptr:
+			       object? object->empty():
+			               true;
+
+		case ARRAY:
+			return serial? string == nullptr:
+			       array?  array == nullptr:
+			               true;
+
+		case LITERAL:
+			return serial? string == nullptr:
+			               true;
+	};
+
+	throw type_error("deciding if a type[%u] is undefined is undefined", int(type));
+}
+
 bool
 ircd::json::value::empty()
 const
@@ -1054,32 +1093,56 @@ const
 		case STRING:   return !len;
 		case OBJECT:   return serial? !len : object? object->empty() : true;
 		case ARRAY:    return serial? !len : array? false : true;            //TODO: XXX arr
-		case LITERAL:  return !len;
+		case LITERAL:  return serial? !len : true;
 	};
 
 	throw type_error("deciding if a type[%u] is empty is undefined", int(type));
 }
 
-size_t
-ircd::json::serialized(const value &value)
-{
-	return value.serialized();
-}
-
-size_t
-ircd::json::value::serialized()
+bool
+ircd::json::value::null()
 const
 {
 	switch(type)
 	{
-		case NUMBER:   return lex_cast(integer).size();
-		case STRING:   return 1 + len + 1;
-		case OBJECT:   return serial? len : object->serialized();
-		case ARRAY:    return serial? len : 2;
-		case LITERAL:  return len;
+		case NUMBER:
+			return floats?  !(floating > 0.0 || floating < 0.0):
+			                bool(integer);
+
+		case STRING:
+			return string == nullptr;
+
+		case OBJECT:
+			return serial? string == nullptr:
+			       object? object->empty():
+			               true;
+
+		case ARRAY:
+			return serial? string == nullptr:
+			       array?  array == nullptr:
+			               true;
+
+		case LITERAL:
+			return serial? string == nullptr:
+			               true;
 	};
 
-	throw type_error("deciding the size of a type[%u] is undefined", int(type));
+	throw type_error("deciding if a type[%u] is null is undefined", int(type));
+}
+
+size_t
+ircd::json::serialized(const value &v)
+{
+	switch(v.type)
+	{
+		case NUMBER:   return lex_cast(v.integer).size();
+		case STRING:   return 1 + v.len + 1;
+		case OBJECT:   return v.serial? v.len : serialized(*v.object);
+		case ARRAY:    return v.serial? v.len : 2;
+		case LITERAL:  return v.len;
+	};
+
+	throw type_error("deciding the size of a type[%u] is undefined", int(v.type));
 }
 
 std::ostream &