pugixml.hpp

/**
 * pugixml parser - version 0.6
 * --------------------------------------------------------
 * Copyright (C) 2006-2010, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
 * Report bugs and download new versions at http://code.google.com/p/pugixml/
 *
 * This library is distributed under the MIT License. See notice at the end
 * of this file.
 *
 * This work is based on the pugxml parser, which is:
 * Copyright (C) 2003, by Kristen Wegner (kristen@tima.net)
 */

#ifndef HEADER_PUGIXML_HPP
#define HEADER_PUGIXML_HPP

#include "pugiconfig.hpp"

#ifndef PUGIXML_NO_STL
namespace std
{
	struct bidirectional_iterator_tag;

	// Borland C++ compiler has a bug which forces template argument names in forward declarations to be the same as in actual definitions
	template <class _Ty> class allocator;
	template <class _Ty> struct char_traits;
	template <class _Elem, class _Traits> class basic_istream;
	template <class _Elem, class _Traits> class basic_ostream;
	template <class _Elem, class _Traits, class _Ax> class basic_string;

	// Digital Mars compiler has a bug which requires a forward declaration for explicit instantiation (otherwise type selection is messed up later, producing link errors)
	// Also note that we have to declare char_traits as a class here, since it's defined that way
#ifdef __DMC__
	template <> class char_traits<char>;
#endif
}
#endif

// Macro for deprecated features
#ifndef PUGIXML_DEPRECATED
#	define PUGIXML_DEPRECATED(message)
#endif

// No XPath without STL
#ifdef PUGIXML_NO_STL
#	ifndef PUGIXML_NO_XPATH
#		define PUGIXML_NO_XPATH
#	endif
#endif

// Include exception header for XPath
#ifndef PUGIXML_NO_XPATH
#	include <exception>
#endif

// If no API is defined, assume default
#ifndef PUGIXML_API
#   define PUGIXML_API
#endif

// If no API for classes is defined, assume default
#ifndef PUGIXML_CLASS
#   define PUGIXML_CLASS PUGIXML_API
#endif

// If no API for functions is defined, assume default
#ifndef PUGIXML_FUNCTION
#   define PUGIXML_FUNCTION PUGIXML_API
#endif

#include <stddef.h>

// Character interface macros
#ifdef PUGIXML_WCHAR_MODE
#	define PUGIXML_TEXT(t) L ## t

namespace pugi
{
	typedef wchar_t char_t;

#ifndef PUGIXML_NO_STL
	typedef std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> > string_t;
#endif
}
#else
#	define PUGIXML_TEXT(t) t

namespace pugi
{
	typedef char char_t;

#	ifndef PUGIXML_NO_STL
	// gcc3.4 has a bug which prevents string_t instantiation using char_t, so we have to use char type explicitly
	typedef std::basic_string<char, std::char_traits<char>, std::allocator<char> > string_t;
#	endif
}
#endif

// Helpers for inline implementation
namespace pugi
{
	namespace impl
	{
		bool PUGIXML_FUNCTION strequal(const char_t*, const char_t*);
		bool PUGIXML_FUNCTION strequalwild(const char_t*, const char_t*);
	}
}

/// The PugiXML Parser namespace.
namespace pugi
{
	/// Tree node classification.
	enum xml_node_type
	{
		node_null,			///< Undifferentiated entity
		node_document,		///< A document tree's absolute root.
		node_element,		///< E.g. '<...>'
		node_pcdata,		///< E.g. '>...<'
		node_cdata,			///< E.g. '<![CDATA[...]]>'
		node_comment,		///< E.g. '<!--...-->'
		node_pi,			///< E.g. '<?...?>'
		node_declaration	///< E.g. '<?xml ...?>'
	};

	// Parsing options

	/**
	 * Memory block size, used for fast allocator. Memory for DOM tree is allocated in blocks of
	 * memory_block_size + 4.
	 * This value affects size of xml_memory class.
	 */
	const size_t memory_block_size = 32768;

	/**
	 * Minimal parsing mode. Equivalent to turning all other flags off. This set of flags means
	 * that pugixml does not add pi/cdata sections or comments to DOM tree and does not perform
	 * any conversions for input data, meaning fastest parsing.
	 */
	const unsigned int parse_minimal			= 0x0000;

	/**
	 * This flag determines if processing instructions (nodes with type node_pi; such nodes have the
	 * form of <? target content ?> or <? target ?> in XML) are to be put in DOM tree. If this flag is off,
	 * they are not put in the tree, but are still parsed and checked for correctness.
	 *
	 * The corresponding node in DOM tree will have type node_pi, name "target" and value "content",
	 * if any.
	 *
	 * Note that <?xml ...?> (document declaration) is not considered to be a PI.
	 *
	 * This flag is off by default.
	 */
	const unsigned int parse_pi					= 0x0001;

	/**
	 * This flag determines if comments (nodes with type node_comment; such nodes have the form of
	 * <!-- content --> in XML) are to be put in DOM tree. If this flag is off, they are not put in
	 * the tree, but are still parsed and checked for correctness.
	 *
	 * The corresponding node in DOM tree will have type node_comment, empty name and value "content".
	 *
	 * This flag is off by default.
	 */
	const unsigned int parse_comments			= 0x0002;

	/**
	 * This flag determines if CDATA sections (nodes with type node_cdata; such nodes have the form
	 * of <![CDATA[[content]]> in XML) are to be put in DOM tree. If this flag is off, they are not
	 * put in the tree, but are still parsed and checked for correctness.
	 *
	 * The corresponding node in DOM tree will have type node_cdata, empty name and value "content".
	 *
	 * This flag is on by default.
	 */
	const unsigned int parse_cdata				= 0x0004;

	/**
	 * This flag determines if nodes with PCDATA (regular text) that consist only of whitespace
	 * characters are to be put in DOM tree. Often whitespace-only data is not significant for the
	 * application, and the cost of allocating and storing such nodes (both memory and speed-wise)
	 * can be significant. For example, after parsing XML string "<node> <a/> </node>", <node> element
	 * will have 3 children when parse_ws_pcdata is set (child with type node_pcdata and value=" ",
	 * child with type node_element and name "a", and another child with type node_pcdata and
	 * value=" "), and only 1 child when parse_ws_pcdata is not set.
	 * 
	 * This flag is off by default.
	 */
	const unsigned int parse_ws_pcdata			= 0x0008;

	/**
	 * This flag determines if character and entity references are to be expanded during the parsing
	 * process. Character references are &amp;#...; or &amp;#x...; (... is Unicode numeric representation of
     * character in either decimal (&amp;#...;) or hexadecimal (&amp;#x...;) form), entity references are &amp;...;
     * Note that as pugixml does not handle DTD, the only allowed entities are predefined ones - 
     * &amp;lt;, &amp;gt;, &amp;amp;, &amp;apos; and &amp;quot;. If character/entity reference can not be expanded, it is
     * leaved as is, so you can do additional processing later.
     * Reference expansion is performed in attribute values and PCDATA content.
     *
     * This flag is on by default.
     */
	const unsigned int parse_escapes			= 0x0010;

	/**
	 * This flag determines if EOL handling (that is, replacing sequences 0x0d 0x0a by a single 0x0a
	 * character, and replacing all standalone 0x0d characters by 0x0a) is to be performed on input
	 * data (that is, comments contents, PCDATA/CDATA contents and attribute values).
	 *
	 * This flag is on by default.
	 */
	const unsigned int parse_eol				= 0x0020;
	
 	/**
 	 * This flag determines if attribute value normalization should be performed for all attributes.
 	 * This means, that:
 	 * 1. Whitespace characters (new line, tab and space) are replaced with space (' ')
 	 * 2. Afterwards sequences of spaces are replaced with a single space
 	 * 3. Leading/trailing whitespace characters are trimmed
 	 * 
 	 * This flag is off by default.
 	 */
 	const unsigned int parse_wnorm_attribute	= 0x0040;

 	/**
 	 * This flag determines if attribute value normalization should be performed for all attributes.
 	 * This means, that whitespace characters (new line, tab and space) are replaced with space (' ').
 	 * Note, that the actions performed while this flag is on are also performed if parse_wnorm_attribute
 	 * is on, so this flag has no effect if parse_wnorm_attribute flag is set.
 	 * 
 	 * This flag is on by default.
 	 */
 	const unsigned int parse_wconv_attribute	= 0x0080;
	
	/**
	 * This flag determines if XML document declaration (this node has the form of <?xml ... ?> in XML)
	 * are to be put in DOM tree. If this flag is off, it is not put in the tree, but is still parsed
	 * and checked for correctness.
	 *
	 * The corresponding node in DOM tree will have type node_declaration, name "xml" and attributes,
	 * if any.
	 *
	 * This flag is off by default.
	 */
	const unsigned int parse_declaration		= 0x0100;

	/**
     * This is the default set of flags. It includes parsing CDATA sections (comments/PIs are not
     * parsed), performing character and entity reference expansion, replacing whitespace characters
     * with spaces in attribute values and performing EOL handling. Note, that PCDATA sections
     * consisting only of whitespace characters are not parsed (by default) for performance reasons.
     */
	const unsigned int parse_default			= parse_cdata | parse_escapes | parse_wconv_attribute | parse_eol;

	/**
	 * These flags determine the encoding of input data for XML document. Default mode is encoding_auto,
	 * which means that document encoding is autodetected from BOM and necessary encoding conversions are
	 * applied. You can override this mode by using any of the specific encodings.
	 */
	enum encoding_t
	{
		encoding_auto,      //!< Auto-detect input encoding using BOM or </<? detection; use UTF8 if BOM is not found
		encoding_utf8,      //!< UTF8 encoding
		encoding_utf16_le,  //!< Little-endian UTF16
		encoding_utf16_be,  //!< Big-endian UTF16
		encoding_utf16,     //!< UTF16 with native endianness
		encoding_utf32_le,  //!< Little-endian UTF32
		encoding_utf32_be,  //!< Big-endian UTF32
		encoding_utf32,     //!< UTF32 with native endianness
		encoding_wchar      //!< The same encoding wchar_t has (either UTF16 or UTF32)
	};

	// Formatting flags
	
	/**
	 * Indent the nodes that are written to output stream with as many indentation strings as deep
	 * the node is in DOM tree.
	 *
	 * This flag is on by default.
	 */
	const unsigned int format_indent	= 0x01;
	
	/**
	 * This flag determines if encoding-specific BOM is to be written to output stream.
	 *
	 * This flag is off by default.
	 */
	const unsigned int format_write_bom = 0x02;

	PUGIXML_DEPRECATED("Use format_write_bom instead") const unsigned int format_write_bom_utf8 = format_write_bom;
	
	/**
	 * If this flag is on, no indentation is performed and no line breaks are written to output file.
	 * This means that the data is written to output stream as is.
	 *
	 * This flag is off by default.
	 */
	const unsigned int format_raw		= 0x04;
	
	/**
	 * If this flag is on, no default XML declaration is written to output file.
	 * This means that there will be no XML declaration in output stream unless there was one in XML document
	 * (i.e. if it was parsed with parse_declaration flag).
	 *
	 * This flag is off by default.
	 */
	const unsigned int format_no_declaration = 0x08;

	/**
	 * This is the default set of formatting flags. It includes indenting nodes depending on their
	 * depth in DOM tree.
	 */
	const unsigned int format_default	= format_indent;
		
	// Forward declarations
	struct xml_attribute_struct;
	struct xml_node_struct;

	class xml_allocator;

	class xml_node_iterator;
	class xml_attribute_iterator;

	class xml_tree_walker;
	
	class xml_node;

	#ifndef PUGIXML_NO_XPATH
	class xpath_node;
	class xpath_node_set;
	class xpath_ast_node;
	class xpath_allocator;
	
	/// XPath query return type classification
	enum xpath_type_t
	{
		xpath_type_none,      ///< Unknown type (query failed to compile)
		xpath_type_node_set,  ///< Node set (xpath_node_set)
		xpath_type_number,    ///< Number
		xpath_type_string,    ///< String
		xpath_type_boolean    ///< Boolean
	};

	/**
	 * A class that holds compiled XPath query and allows to evaluate query result
	 */
	class PUGIXML_CLASS xpath_query
	{
	private:
		// Noncopyable semantics
		xpath_query(const xpath_query&);
		xpath_query& operator=(const xpath_query&);

		xpath_allocator* m_alloc;
		xpath_ast_node* m_root;

		void compile(const char_t* query);

	public:
		/**
		 * Ctor from string with XPath expression.
		 * Throws xpath_exception on compilation error, std::bad_alloc on out of memory error.
		 *
		 * \param query - string with XPath expression
		 */
		explicit xpath_query(const char_t* query);

		/**
		 * Dtor
		 */
		~xpath_query();

		/**
		 * Get query expression return type
		 *
		 * \return expression return type
		 **/
		xpath_type_t return_type() const;
		
		/**
		 * Evaluate expression as boolean value for the context node \a n.
		 * If expression does not directly evaluate to boolean, the expression result is converted
		 * as through boolean() XPath function call.
		 * Throws std::bad_alloc on out of memory error.
		 *
		 * \param n - context node
		 * \return evaluation result
		 */
		bool evaluate_boolean(const xml_node& n) const;
		
		/**
		 * Evaluate expression as double value for the context node \a n.
		 * If expression does not directly evaluate to double, the expression result is converted
		 * as through number() XPath function call.
		 * Throws std::bad_alloc on out of memory error.
		 *
		 * \param n - context node
		 * \return evaluation result
		 */
		double evaluate_number(const xml_node& n) const;
		
		/**
		 * Evaluate expression as string value for the context node \a n.
		 * If expression does not directly evaluate to string, the expression result is converted
		 * as through string() XPath function call.
		 * Throws std::bad_alloc on out of memory error.
		 *
		 * \param n - context node
		 * \return evaluation result
		 */
		string_t evaluate_string(const xml_node& n) const;
		
		/**
		 * Evaluate expression as node set for the context node \a n.
		 * If expression does not directly evaluate to node set, throws xpath_exception.
		 * Throws std::bad_alloc on out of memory error.
		 *
		 * \param n - context node
		 * \return evaluation result
		 */
		xpath_node_set evaluate_node_set(const xml_node& n) const;
	};
	#endif
	
	/**
	 * Abstract writer class
	 * \see xml_node::print
	 */
	class PUGIXML_CLASS xml_writer
	{
	public:
		/**
		 * Virtual dtor
		 */
		virtual ~xml_writer() {}

		/**
		 * Write memory chunk into stream/file/whatever
		 *
		 * \param data - data pointer
		 * \param size - data size
		 */
		virtual void write(const void* data, size_t size) = 0;
	};

	/** xml_writer implementation for FILE*
	 * \see xml_writer
	 */
	class PUGIXML_CLASS xml_writer_file: public xml_writer
	{
	public:
		/**
		 * Construct writer instance
		 *
		 * \param file - this is FILE* object, void* is used to avoid header dependencies on stdio
		 */
		xml_writer_file(void* file);

		virtual void write(const void* data, size_t size);

	private:
		void* file;
	};

	#ifndef PUGIXML_NO_STL
	/** xml_writer implementation for streams
	 * \see xml_writer
	 */
	class PUGIXML_CLASS xml_writer_stream: public xml_writer
	{
	public:
		/**
		 * Construct writer instance
		 *
		 * \param stream - output stream object
		 */
		xml_writer_stream(std::basic_ostream<char, std::char_traits<char> >& stream);

		/**
		 * Construct writer instance
		 *
		 * \param stream - output stream object
		 */
		xml_writer_stream(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream);

		virtual void write(const void* data, size_t size);

	private:
		std::basic_ostream<char, std::char_traits<char> >* narrow_stream;
		std::basic_ostream<wchar_t, std::char_traits<wchar_t> >* wide_stream;
	};
	#endif

	/**
	 * A light-weight wrapper for manipulating attributes in DOM tree.
	 * Note: xml_attribute does not allocate any memory for the attribute it wraps; it only wraps a
	 * pointer to existing attribute.
	 */
	class PUGIXML_CLASS xml_attribute
	{
		friend class xml_attribute_iterator;
		friend class xml_node;

	private:
		xml_attribute_struct* _attr;
	
    	/// \internal Safe bool type
#ifdef __MWERKS__
    	typedef bool (xml_attribute::*unspecified_bool_type)() const;
#else
    	typedef xml_attribute_struct* xml_attribute::*unspecified_bool_type;
#endif

		/// \internal Initializing ctor
		explicit xml_attribute(xml_attribute_struct* attr);

	public:
		/**
		 * Default ctor. Constructs an empty attribute.
		 */
		xml_attribute();
		
	public:
    	/**
    	 * Safe bool conversion.
    	 * Allows xml_node to be used in a context where boolean variable is expected, such as 'if (node)'.
    	 */
    	operator unspecified_bool_type() const;

    	// Borland C++ workaround
    	bool operator!() const;

		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator==(const xml_attribute& r) const;
		
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator!=(const xml_attribute& r) const;
		
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator<(const xml_attribute& r) const;
		
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator>(const xml_attribute& r) const;
		
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator<=(const xml_attribute& r) const;
		
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator>=(const xml_attribute& r) const;

	public:
    	/**
    	 * Get next attribute in attribute list of node that contains the attribute.
    	 *
    	 * \return next attribute, if any; empty attribute otherwise
    	 */
    	xml_attribute next_attribute() const;

    	/**
    	 * Get previous attribute in attribute list of node that contains the attribute.
    	 *
    	 * \return previous attribute, if any; empty attribute otherwise
    	 */
    	xml_attribute previous_attribute() const;

		/**
		 * Cast attribute value as int.
		 *
		 * \return attribute value as int, or 0 if conversion did not succeed or attribute is empty
		 */
		int as_int() const;

		/**
		 * Cast attribute value as unsigned int.
		 *
		 * \return attribute value as unsigned int, or 0 if conversion did not succeed or attribute is empty
		 * \note values out of non-negative int range (usually [0, 2^31-1]) get clamped to range boundaries
		 */
		unsigned int as_uint() const;

		/**
		 * Cast attribute value as double.
		 *
		 * \return attribute value as double, or 0.0 if conversion did not succeed or attribute is empty
		 */
		double as_double() const;
	
		/**
		 * Cast attribute value as float.
		 *
		 * \return attribute value as float, or 0.0f if conversion did not succeed or attribute is empty
		 */
		float as_float() const;

		/**
		 * Cast attribute value as bool. Returns true for attributes with values that start with '1',
		 * 't', 'T', 'y', 'Y', returns false for other attributes.
		 *
		 * \return attribute value as bool, or false if conversion did not succeed or attribute is empty
		 */
		bool as_bool() const;

		/// \internal Document order or 0 if not set
		unsigned int document_order() const;

	public:
		/**
         * Set attribute value to \a rhs.
         *
         * \param rhs - new attribute value
         * \return self
         */
		xml_attribute& operator=(const char_t* rhs);
	
		/**
         * Set attribute value to \a rhs.
         *
         * \param rhs - new attribute value
         * \return self
         */
		xml_attribute& operator=(int rhs);
	
		/**
         * Set attribute value to \a rhs.
         *
         * \param rhs - new attribute value
         * \return self
         */
		xml_attribute& operator=(unsigned int rhs);

		/**
         * Set attribute value to \a rhs.
         *
         * \param rhs - new attribute value
         * \return self
         */
		xml_attribute& operator=(double rhs);
		
		/**
         * Set attribute value to either 'true' or 'false' (depends on whether \a rhs is true or false).
         *
         * \param rhs - new attribute value
         * \return self
         */
		xml_attribute& operator=(bool rhs);

		/**
		 * Set attribute name to \a rhs.
		 *
		 * \param rhs - new attribute name
		 * \return success flag (call fails if attribute is empty or there is not enough memory)
		 */
		bool set_name(const char_t* rhs);
		
		/**
		 * Set attribute value to \a rhs.
		 *
		 * \param rhs - new attribute value
		 * \return success flag (call fails if attribute is empty or there is not enough memory)
		 */
		bool set_value(const char_t* rhs);

		/**
		 * Set attribute value to \a rhs.
		 *
		 * \param rhs - new attribute value
		 * \return success flag (call fails if attribute is empty or there is not enough memory)
		 */
		bool set_value(int rhs);

		/**
		 * Set attribute value to \a rhs.
		 *
		 * \param rhs - new attribute value
		 * \return success flag (call fails if attribute is empty or there is not enough memory)
		 */
		bool set_value(unsigned int rhs);

		/**
		 * Set attribute value to \a rhs.
		 *
		 * \param rhs - new attribute value
		 * \return success flag (call fails if attribute is empty or there is not enough memory)
		 */
		bool set_value(double rhs);

		/**
		 * Set attribute value to either 'true' or 'false' (depends on whether \a rhs is true or false).
		 *
		 * \param rhs - new attribute value
		 * \return success flag (call fails if attribute is empty or there is not enough memory)
		 */
		bool set_value(bool rhs);

	public:
		/**
		 * Check if attribute is empty.
		 *
		 * \return true if attribute is empty, false otherwise
		 */
		bool empty() const;

	public:
		/**
		 * Get attribute name.
		 *
		 * \return attribute name, or "" if attribute is empty
		 */
		const char_t* name() const;

		/**
		 * Get attribute value.
		 *
		 * \return attribute value, or "" if attribute is empty
		 */
		const char_t* value() const;
	};

#ifdef __BORLANDC__
	// Borland C++ workaround
	bool PUGIXML_FUNCTION operator&&(const xml_attribute& lhs, bool rhs);
	bool PUGIXML_FUNCTION operator||(const xml_attribute& lhs, bool rhs);
#endif

	/**
	 * A light-weight wrapper for manipulating nodes in DOM tree.
	 * Note: xml_node does not allocate any memory for the node it wraps; it only wraps a pointer to
	 * existing node.
	 */
	class PUGIXML_CLASS xml_node
	{
		friend class xml_node_iterator;

	protected:
		xml_node_struct* _root;

    	/// \internal Safe bool type
#ifdef __MWERKS__
    	typedef bool (xml_node::*unspecified_bool_type)() const;
#else
    	typedef xml_node_struct* xml_node::*unspecified_bool_type;
#endif

		/// \internal Initializing ctor
		explicit xml_node(xml_node_struct* p);

		/// \internal Precompute document order (valid only for document node)
		void precompute_document_order_impl();

		/// \internal Get allocator
		xml_allocator& get_allocator() const;

	public:
		/**
		 * Default ctor. Constructs an empty node.
		 */
		xml_node();

	public:
    	/**
    	 * Safe bool conversion.
    	 * Allows xml_node to be used in a context where boolean variable is expected, such as 'if (node)'.
    	 */
		operator unspecified_bool_type() const;

		// Borland C++ workaround
		bool operator!() const;
	
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator==(const xml_node& r) const;

		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator!=(const xml_node& r) const;

		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator<(const xml_node& r) const;

		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator>(const xml_node& r) const;

		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator<=(const xml_node& r) const;
		
		/**
		 * Compare wrapped pointer to the attribute to the pointer that is wrapped by \a r.
		 *
		 * \param r - value to compare to
		 * \return comparison result
		 */
		bool operator>=(const xml_node& r) const;

	public:
		/**
		 * Node iterator type (for child nodes).
		 * \see xml_node_iterator
		 */
		typedef xml_node_iterator iterator;

		/**
		 * Node iterator type (for child nodes).
		 * \see xml_attribute_iterator
		 */
		typedef xml_attribute_iterator attribute_iterator;

		/**
		 * Access the begin iterator for this node's collection of child nodes.
		 *
		 * \return iterator that points to the first child node, or past-the-end iterator if node is empty or has no children
		 */
		iterator begin() const;
	
		/**
		 * Access the end iterator for this node's collection of child nodes.
		 *
		 * \return past-the-end iterator for child list
		 */
		iterator end() const;
	
		/**
		 * Access the begin iterator for this node's collection of attributes.
		 *
		 * \return iterator that points to the first attribute, or past-the-end iterator if node is empty or has no attributes
		 */
		attribute_iterator attributes_begin() const;
	
		/**
		 * Access the end iterator for this node's collection of attributes.
		 *
		 * \return past-the-end iterator for attribute list
		 */
		attribute_iterator attributes_end() const;

	public:
		/**
		 * Check if node is empty.
		 *
		 * \return true if node is empty, false otherwise
		 */
		bool empty() const;

	public:
		/**
		 * Get node type
		 *
		 * \return node type; node_null for empty nodes
		 */
		xml_node_type type() const;

		/**
		 * Get node name (element name for element nodes, PI target for PI)
		 *
		 * \return node name, if any; "" otherwise
		 */
		const char_t* name() const;

		/**
		 * Get node value (comment/PI/PCDATA/CDATA contents, depending on node type)
		 *
		 * \return node value, if any; "" otherwise
		 */
		const char_t* value() const;
	
		/**
		 * Get child with the specified name
		 *
		 * \param name - child name
		 * \return child with the specified name, if any; empty node otherwise
		 */
		xml_node child(const char_t* name) const;

		/**
		 * Get child with the name that matches specified pattern
		 *
		 * \param name - child name pattern
		 * \return child with the name that matches pattern, if any; empty node otherwise
		 */
		xml_node child_w(const char_t* name) const;

		/**
		 * Get attribute with the specified name
		 *
		 * \param name - attribute name
		 * \return attribute with the specified name, if any; empty attribute otherwise
		 */
		xml_attribute attribute(const char_t* name) const;

		/**
		 * Get attribute with the name that matches specified pattern
		 *
		 * \param name - attribute name pattern
		 * \return attribute with the name that matches pattern, if any; empty attribute otherwise
		 */
		xml_attribute attribute_w(const char_t* name) const;

		/**
		 * Get first of following sibling nodes with the specified name
		 *
		 * \param name - sibling name
		 * \return node with the specified name, if any; empty node otherwise
		 */
		xml_node next_sibling(const char_t* name) const;

		/**
		 * Get first of the following sibling nodes with the name that matches specified pattern
		 *
		 * \param name - sibling name pattern
		 * \return node with the name that matches pattern, if any; empty node otherwise
		 */
		xml_node next_sibling_w(const char_t* name) const;

		/**
		 * Get following sibling
		 *
		 * \return following sibling node, if any; empty node otherwise
		 */
		xml_node next_sibling() const;

		/**
		 * Get first of preceding sibling nodes with the specified name
		 *
		 * \param name - sibling name
		 * \return node with the specified name, if any; empty node otherwise
		 */
		xml_node previous_sibling(const char_t* name) const;

		/**
		 * Get first of the preceding sibling nodes with the name that matches specified pattern
		 *
		 * \param name - sibling name pattern
		 * \return node with the name that matches pattern, if any; empty node otherwise
		 */
		xml_node previous_sibling_w(const char_t* name) const;

		/**
		 * Get preceding sibling
		 *
		 * \return preceding sibling node, if any; empty node otherwise
		 */
		xml_node previous_sibling() const;

		/**
		 * Get parent node
		 *
		 * \return parent node if any; empty node otherwise
		 */
		xml_node parent() const;