libshared: Introduce JSON parser and MessageBuilder.

Based on an earlier piece of source code of mine that parsed JSON into
QObjects, this JSON parser creates a BMessage tree.

Will be used by Stephan in HaikuDepot for communication with the web app.

headers/private/shared/Json.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright 2014, Augustin Cavalier (waddlesplash)
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef JSON_H
+#define JSON_H
+
+#include <Message.h>
+#include <String.h>
+
+namespace BPrivate {
+
+class BJson {
+public:
+			enum JsonObjectType {
+				JSON_TYPE_MAP = '_JTM',
+				JSON_TYPE_ARRAY = '_JTA'
+			};
+
+public:
+	static	status_t			Parse(BMessage& message, const char* JSON);
+	static	status_t			Parse(BMessage& message, BString& JSON);
+
+private:
+	static	BString				_Parser_ParseString(BString& JSON, int32& pos);
+	static	double				_Parser_ParseNumber(BString& JSON, int32& pos);
+	static	bool				_Parser_ParseConstant(BString& JSON, int32& pos,
+													  const char* constant);
+};
+
+} // namespace BPrivate
+
+#endif	// JSON_H

headers/private/shared/MessageBuilder.h

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2014, Augustin Cavalier (waddlesplash)
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef MESSAGE_BUILDER_H
+#define MESSAGE_BUILDER_H
+
+
+#include <Message.h>
+#include <ObjectList.h>
+#include <String.h>
+
+namespace BPrivate {
+
+class BMessageBuilder {
+public:
+								BMessageBuilder(BMessage& message);
+
+			status_t 			PushObject(const char* name);
+			status_t 			PushObject(uint32 name);
+			status_t 			PopObject();
+			
+			uint32				What();
+			void				SetWhat(uint32 what);
+			
+			uint32				CountNames(type_code type = B_ANY_TYPE);
+
+			// Copied from Message.h
+			status_t			AddString(const char* name, const char* string);
+			status_t			AddString(const char* name,
+									const BString& string);
+			status_t			AddInt8(const char* name, int8 value);
+			status_t			AddUInt8(const char* name, uint8 value);
+			status_t			AddInt16(const char* name, int16 value);
+			status_t			AddUInt16(const char* name, uint16 value);
+			status_t			AddInt32(const char* name, int32 value);
+			status_t			AddUInt32(const char* name, uint32 value);
+			status_t			AddInt64(const char* name, int64 value);
+			status_t			AddUInt64(const char* name, uint64 value);
+			status_t			AddBool(const char* name, bool value);
+			status_t			AddFloat(const char* name, float value);
+			status_t			AddDouble(const char* name, double value);
+			status_t			AddPointer(const char* name,
+									const void* pointer);
+
+private:
+			BObjectList<BMessage>	fStack;
+			BObjectList<BString>	fNameStack;
+			BMessage*			fCurrentMessage;
+};
+
+} // namespace BPrivate
+
+#endif	// MESSAGE_BUILDER_H