//
// Authors:
//   Patrik Torstensson (Patrik.Torstensson@labs2.com)
//   Wictor Wilén (decode/encode functions) (wictor@ibizkit.se)
//   Tim Coleman (tim@timcoleman.com)
//   Gonzalo Paniagua Javier (gonzalo@ximian.com)

//   Marek Habersack <mhabersack@novell.com>
//
// (C) 2005-2010 Novell, Inc (http://novell.com/)
//

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//
using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Text;
#if NET_4_0 && !MOBILE
using System.Web.Configuration;
#endif

namespace System.Web.Util
{
#if NET_4_0
	public
#endif
	class HttpEncoder
	{
		static char [] hexChars = "0123456789abcdef".ToCharArray ();
		static object entitiesLock = new object ();
		static SortedDictionary <string, char> entities;
#if NET_4_0
		static Lazy <HttpEncoder> defaultEncoder;
		static Lazy <HttpEncoder> currentEncoderLazy;
#else
		static HttpEncoder defaultEncoder;
#endif
		static HttpEncoder currentEncoder;

		static IDictionary <string, char> Entities {
			get {
				lock (entitiesLock) {
					if (entities == null)
						InitEntities ();

					return entities;
				}
			}
		}
		
		public static HttpEncoder Current {
			get {
#if NET_4_0
				if (currentEncoder == null)
					currentEncoder = currentEncoderLazy.Value;
#endif
				return currentEncoder;
			}
#if NET_4_0
			set {
				if (value == null)
					throw new ArgumentNullException ("value");
				currentEncoder = value;
			}
#endif
		}

		public static HttpEncoder Default {
			get {
#if NET_4_0
				return defaultEncoder.Value;
#else
				return defaultEncoder;
#endif
			}
		}

		static HttpEncoder ()
		{
#if NET_4_0
			defaultEncoder = new Lazy <HttpEncoder> (() => new HttpEncoder ());
			currentEncoderLazy = new Lazy <HttpEncoder> (new Func <HttpEncoder> (GetCustomEncoderFromConfig));
#else
			defaultEncoder = new HttpEncoder ();
			currentEncoder = defaultEncoder;
#endif
		}
		
		public HttpEncoder ()
		{
		}
#if NET_4_0	
		protected internal virtual
#else
		internal static
#endif
		void HeaderNameValueEncode (string headerName, string headerValue, out string encodedHeaderName, out string encodedHeaderValue)
		{
			if (String.IsNullOrEmpty (headerName))
				encodedHeaderName = headerName;
			else
				encodedHeaderName = EncodeHeaderString (headerName);

			if (String.IsNullOrEmpty (headerValue))
				encodedHeaderValue = headerValue;
			else
				encodedHeaderValue = EncodeHeaderString (headerValue);
		}

		static void StringBuilderAppend (string s, ref StringBuilder sb)
		{
			if (sb == null)
				sb = new StringBuilder (s);
			else
				sb.Append (s);
		}
		
		static string EncodeHeaderString (string input)
		{
			StringBuilder sb = null;
			
			for (int i = 0; i < input.Length; i++) {
				char ch = input [i];

				if ((ch < 32 && ch != 9) || ch == 127)
					StringBuilderAppend (String.Format ("%{0:x2}", (int)ch), ref sb);
			}

			if (sb != null)
				return sb.ToString ();

			return input;
		}
#if NET_4_0		
		protected internal virtual void HtmlAttributeEncode (string value, TextWriter output)
		{

			if (output == null)
				throw new ArgumentNullException ("output");

			if (String.IsNullOrEmpty (value))
				return;

			output.Write (HtmlAttributeEncode (value));
		}

		protected internal virtual void HtmlDecode (string value, TextWriter output)
		{
			if (output == null)
				throw new ArgumentNullException ("output");

			output.Write (HtmlDecode (value));
		}

		protected internal virtual void HtmlEncode (string value, TextWriter output)
		{
			if (output == null)
				throw new ArgumentNullException ("output");

			output.Write (HtmlEncode (value));
		}

		protected internal virtual byte[] UrlEncode (byte[] bytes, int offset, int count)
		{
			return UrlEncodeToBytes (bytes, offset, count);
		}

		static HttpEncoder GetCustomEncoderFromConfig ()
		{
#if MOBILE
			return defaultEncoder.Value;
#else
			var cfg = HttpRuntime.Section;
			string typeName = cfg.EncoderType;

			if (String.Compare (typeName, "System.Web.Util.HttpEncoder", StringComparison.OrdinalIgnoreCase) == 0)
				return Default;
			
			Type t = Type.GetType (typeName, false);
			if (t == null)
				throw new ConfigurationErrorsException (String.Format ("Could not load type '{0}'.", typeName));
			
			if (!typeof (HttpEncoder).IsAssignableFrom (t))
				throw new ConfigurationErrorsException (
					String.Format ("'{0}' is not allowed here because it does not extend class 'System.Web.Util.HttpEncoder'.", typeName)
				);

			return Activator.CreateInstance (t, false) as HttpEncoder;
#endif
		}
#endif
#if NET_4_0
		protected internal virtual
#else
		internal static
#endif
		string UrlPathEncode (string value)
		{
			if (String.IsNullOrEmpty (value))
				return value;

			MemoryStream result = new MemoryStream ();
			int length = value.Length;
			for (int i = 0; i < length; i++)
				UrlPathEncodeChar (value [i], result);
			
			return Encoding.ASCII.GetString (result.ToArray ());
		}
		
		internal static byte[] UrlEncodeToBytes (byte[] bytes, int offset, int count)
		{
			if (bytes == null)
				throw new ArgumentNullException ("bytes");
			
			int blen = bytes.Length;
			if (blen == 0)
				return new byte [0];
			
			if (offset < 0 || offset >= blen)
				throw new ArgumentOutOfRangeException("offset");

			if (count < 0 || count > blen - offset)
				throw new ArgumentOutOfRangeException("count");

			MemoryStream result = new MemoryStream (count);
			int end = offset + count;
			for (int i = offset; i < end; i++)
				UrlEncodeChar ((char)bytes [i], result, false);

			return result.ToArray();
		}
		
		internal static string HtmlEncode (string s) 
		{
			if (s == null)
				return null;

			if (s.Length == 0)
				return String.Empty;
			
			bool needEncode = false;
			for (int i = 0; i < s.Length; i++) {
				char c = s [i];
				if (c == '&' || c == '"' || c == '<' || c == '>' || c > 159
#if NET_4_0
				    || c == '\''
#endif
				) {
					needEncode = true;
					break;
				}
			}

			if (!needEncode)
				return s;

			StringBuilder output = new StringBuilder ();
			int len = s.Length;
			
			for (int i = 0; i < len; i++) {
				char ch = s [i];
				switch (ch) {
					case '&' :
						output.Append ("&amp;");
						break;
					case '>' : 
						output.Append ("&gt;");
						break;
					case '<' :
						output.Append ("&lt;");
						break;
					case '"' :
						output.Append ("&quot;");
						break;
#if NET_4_0
					case '\'':
						output.Append ("&#39;");
						break;
#endif
					case '\uff1c':
						output.Append ("&#65308;");
						break;

					case '\uff1e':
						output.Append ("&#65310;");
						break;
						
					default:
						if (ch > 159 && ch < 256) {
							output.Append ("&#");
							output.Append (((int) ch).ToString (Helpers.InvariantCulture));
							output.Append (";");
						} else
							output.Append (ch);
						break;
				}	
			}
			
			return output.ToString ();			
		}
		
		internal static string HtmlAttributeEncode (string s) 
		{
#if NET_4_0
			if (String.IsNullOrEmpty (s))
				return String.Empty;
#else
			if (s == null) 
				return null;
			
			if (s.Length == 0)
				return String.Empty;
#endif			
			bool needEncode = false;
			for (int i = 0; i < s.Length; i++) {
				char c = s [i];
				if (c == '&' || c == '"' || c == '<'
#if NET_4_0
				    || c == '\''
#endif
				) {
					needEncode = true;
					break;
				}
			}

			if (!needEncode)
				return s;

			StringBuilder output = new StringBuilder ();
			int len = s.Length;

			for (int i = 0; i < len; i++) {
				char ch = s [i];
				switch (ch) {
					case '&' : 
						output.Append ("&amp;");
						break;
					case '"' :
						output.Append ("&quot;");
						break;
					case '<':
						output.Append ("&lt;");
						break;
#if NET_4_0
					case '\'':
						output.Append ("&#39;");
						break;
#endif
					default:
						output.Append (ch);
						break;
				}
			}

			return output.ToString();
		}
		
		internal static string HtmlDecode (string s)
		{
			if (s == null)
				return null;

			if (s.Length == 0)
				return String.Empty;
			
			if (s.IndexOf ('&') == -1)
				return s;
#if NET_4_0
			StringBuilder rawEntity = new StringBuilder ();
#endif
			StringBuilder entity = new StringBuilder ();
			StringBuilder output = new StringBuilder ();
			int len = s.Length;
			// 0 -> nothing,
			// 1 -> right after '&'
			// 2 -> between '&' and ';' but no '#'
			// 3 -> '#' found after '&' and getting numbers
			int state = 0;
			int number = 0;
			bool is_hex_value = false;
			bool have_trailing_digits = false;
	
			for (int i = 0; i < len; i++) {
				char c = s [i];
				if (state == 0) {
					if (c == '&') {
						entity.Append (c);
#if NET_4_0
						rawEntity.Append (c);
#endif
						state = 1;
					} else {
						output.Append (c);
					}
					continue;
				}

				if (c == '&') {
					state = 1;
					if (have_trailing_digits) {
						entity.Append (number.ToString (Helpers.InvariantCulture));
						have_trailing_digits = false;
					}

					output.Append (entity.ToString ());
					entity.Length = 0;
					entity.Append ('&');
					continue;
				}

				if (state == 1) {
					if (c == ';') {
						state = 0;
						output.Append (entity.ToString ());
						output.Append (c);
						entity.Length = 0;
					} else {
						number = 0;
						is_hex_value = false;
						if (c != '#') {
							state = 2;
						} else {
							state = 3;
						}
						entity.Append (c);
#if NET_4_0
						rawEntity.Append (c);
#endif
					}
				} else if (state == 2) {
					entity.Append (c);
					if (c == ';') {
						string key = entity.ToString ();
						if (key.Length > 1 && Entities.ContainsKey (key.Substring (1, key.Length - 2)))
							key = Entities [key.Substring (1, key.Length - 2)].ToString ();

						output.Append (key);
						state = 0;
						entity.Length = 0;
#if NET_4_0
						rawEntity.Length = 0;
#endif
					}
				} else if (state == 3) {
					if (c == ';') {
#if NET_4_0
						if (number == 0)
							output.Append (rawEntity.ToString () + ";");
						else
#endif
						if (number > 65535) {
							output.Append ("&#");
							output.Append (number.ToString (Helpers.InvariantCulture));
							output.Append (";");
						} else {
							output.Append ((char) number);
						}
						state = 0;
						entity.Length = 0;
#if NET_4_0
						rawEntity.Length = 0;
#endif
						have_trailing_digits = false;
					} else if (is_hex_value &&  Uri.IsHexDigit(c)) {
						number = number * 16 + Uri.FromHex(c);
						have_trailing_digits = true;
#if NET_4_0
						rawEntity.Append (c);
#endif
					} else if (Char.IsDigit (c)) {
						number = number * 10 + ((int) c - '0');
						have_trailing_digits = true;
#if NET_4_0
						rawEntity.Append (c);
#endif
					} else if (number == 0 && (c == 'x' || c == 'X')) {
						is_hex_value = true;
#if NET_4_0
						rawEntity.Append (c);
#endif
					} else {
						state = 2;
						if (have_trailing_digits) {
							entity.Append (number.ToString (Helpers.InvariantCulture));
							have_trailing_digits = false;
						}
						entity.Append (c);
					}
				}
			}

			if (entity.Length > 0) {
				output.Append (entity.ToString ());
			} else if (have_trailing_digits) {
				output.Append (number.ToString (Helpers.InvariantCulture));
			}
			return output.ToString ();
		}

		internal static bool NotEncoded (char c)
		{
			return (c == '!' || c == '(' || c == ')' || c == '*' || c == '-' || c == '.' || c == '_'
#if !NET_4_0
				|| c == '\''
#endif
			);
		}
		
		internal static void UrlEncodeChar (char c, Stream result, bool isUnicode) {
			if (c > 255) {
				//FIXME: what happens when there is an internal error?
				//if (!isUnicode)
				//	throw new ArgumentOutOfRangeException ("c", c, "c must be less than 256");
				int idx;
				int i = (int) c;

				result.WriteByte ((byte)'%');
				result.WriteByte ((byte)'u');
				idx = i >> 12;
				result.WriteByte ((byte)hexChars [idx]);
				idx = (i >> 8) & 0x0F;
				result.WriteByte ((byte)hexChars [idx]);
				idx = (i >> 4) & 0x0F;
				result.WriteByte ((byte)hexChars [idx]);
				idx = i & 0x0F;
				result.WriteByte ((byte)hexChars [idx]);
				return;
			}
			
			if (c > ' ' && NotEncoded (c)) {
				result.WriteByte ((byte)c);
				return;
			}
			if (c==' ') {
				result.WriteByte ((byte)'+');
				return;
			}
			if (	(c < '0') ||
				(c < 'A' && c > '9') ||
				(c > 'Z' && c < 'a') ||
				(c > 'z')) {
				if (isUnicode && c > 127) {
					result.WriteByte ((byte)'%');
					result.WriteByte ((byte)'u');
					result.WriteByte ((byte)'0');
					result.WriteByte ((byte)'0');
				}
				else
					result.WriteByte ((byte)'%');
				
				int idx = ((int) c) >> 4;
				result.WriteByte ((byte)hexChars [idx]);
				idx = ((int) c) & 0x0F;
				result.WriteByte ((byte)hexChars [idx]);
			}
			else
				result.WriteByte ((byte)c);
		}

		internal static void UrlPathEncodeChar (char c, Stream result)
		{
			if (c < 33 || c > 126) {
				byte [] bIn = Encoding.UTF8.GetBytes (c.ToString ());
				for (int i = 0; i < bIn.Length; i++) {
					result.WriteByte ((byte) '%');
					int idx = ((int) bIn [i]) >> 4;
					result.WriteByte ((byte) hexChars [idx]);
					idx = ((int) bIn [i]) & 0x0F;
					result.WriteByte ((byte) hexChars [idx]);
				}
			}
			else if (c == ' ') {
				result.WriteByte ((byte) '%');
				result.WriteByte ((byte) '2');
				result.WriteByte ((byte) '0');
			}
			else
				result.WriteByte ((byte) c);
		}
		
		static void InitEntities ()
		{
			// Build the hash table of HTML entity references.  This list comes
			// from the HTML 4.01 W3C recommendation.
			entities = new SortedDictionary <string, char> (StringComparer.Ordinal);
			
			entities.Add ("nbsp", '\u00A0');
			entities.Add ("iexcl", '\u00A1');
			entities.Add ("cent", '\u00A2');
			entities.Add ("pound", '\u00A3');
			entities.Add ("curren", '\u00A4');
			entities.Add ("yen", '\u00A5');
			entities.Add ("brvbar", '\u00A6');
			entities.Add ("sect", '\u00A7');
			entities.Add ("uml", '\u00A8');
			entities.Add ("copy", '\u00A9');
			entities.Add ("ordf", '\u00AA');
			entities.Add ("laquo", '\u00AB');
			entities.Add ("not", '\u00AC');
			entities.Add ("shy", '\u00AD');
			entities.Add ("reg", '\u00AE');
			entities.Add ("macr", '\u00AF');
			entities.Add ("deg", '\u00B0');
			entities.Add ("plusmn", '\u00B1');
			entities.Add ("sup2", '\u00B2');
			entities.Add ("sup3", '\u00B3');
			entities.Add ("acute", '\u00B4');
			entities.Add ("micro", '\u00B5');
			entities.Add ("para", '\u00B6');
			entities.Add ("middot", '\u00B7');
			entities.Add ("cedil", '\u00B8');
			entities.Add ("sup1", '\u00B9');
			entities.Add ("ordm", '\u00BA');
			entities.Add ("raquo", '\u00BB');
			entities.Add ("frac14", '\u00BC');
			entities.Add ("frac12", '\u00BD');
			entities.Add ("frac34", '\u00BE');
			entities.Add ("iquest", '\u00BF');
			entities.Add ("Agrave", '\u00C0');
			entities.Add ("Aacute", '\u00C1');
			entities.Add ("Acirc", '\u00C2');
			entities.Add ("Atilde", '\u00C3');
			entities.Add ("Auml", '\u00C4');
			entities.Add ("Aring", '\u00C5');
			entities.Add ("AElig", '\u00C6');
			entities.Add ("Ccedil", '\u00C7');
			entities.Add ("Egrave", '\u00C8');
			entities.Add ("Eacute", '\u00C9');
			entities.Add ("Ecirc", '\u00CA');
			entities.Add ("Euml", '\u00CB');
			entities.Add ("Igrave", '\u00CC');
			entities.Add ("Iacute", '\u00CD');
			entities.Add ("Icirc", '\u00CE');
			entities.Add ("Iuml", '\u00CF');
			entities.Add ("ETH", '\u00D0');
			entities.Add ("Ntilde", '\u00D1');
			entities.Add ("Ograve", '\u00D2');
			entities.Add ("Oacute", '\u00D3');
			entities.Add ("Ocirc", '\u00D4');
			entities.Add ("Otilde", '\u00D5');
			entities.Add ("Ouml", '\u00D6');
			entities.Add ("times", '\u00D7');
			entities.Add ("Oslash", '\u00D8');
			entities.Add ("Ugrave", '\u00D9');
			entities.Add ("Uacute", '\u00DA');
			entities.Add ("Ucirc", '\u00DB');
			entities.Add ("Uuml", '\u00DC');
			entities.Add ("Yacute", '\u00DD');
			entities.Add ("THORN", '\u00DE');
			entities.Add ("szlig", '\u00DF');
			entities.Add ("agrave", '\u00E0');
			entities.Add ("aacute", '\u00E1');
			entities.Add ("acirc", '\u00E2');
			entities.Add ("atilde", '\u00E3');
			entities.Add ("auml", '\u00E4');
			entities.Add ("aring", '\u00E5');
			entities.Add ("aelig", '\u00E6');
			entities.Add ("ccedil", '\u00E7');
			entities.Add ("egrave", '\u00E8');
			entities.Add ("eacute", '\u00E9');
			entities.Add ("ecirc", '\u00EA');
			entities.Add ("euml", '\u00EB');
			entities.Add ("igrave", '\u00EC');
			entities.Add ("iacute", '\u00ED');
			entities.Add ("icirc", '\u00EE');
			entities.Add ("iuml", '\u00EF');
			entities.Add ("eth", '\u00F0');
			entities.Add ("ntilde", '\u00F1');
			entities.Add ("ograve", '\u00F2');
			entities.Add ("oacute", '\u00F3');
			entities.Add ("ocirc", '\u00F4');
			entities.Add ("otilde", '\u00F5');
			entities.Add ("ouml", '\u00F6');
			entities.Add ("divide", '\u00F7');
			entities.Add ("oslash", '\u00F8');
			entities.Add ("ugrave", '\u00F9');
			entities.Add ("uacute", '\u00FA');
			entities.Add ("ucirc", '\u00FB');
			entities.Add ("uuml", '\u00FC');
			entities.Add ("yacute", '\u00FD');
			entities.Add ("thorn", '\u00FE');
			entities.Add ("yuml", '\u00FF');
			entities.Add ("fnof", '\u0192');
			entities.Add ("Alpha", '\u0391');
			entities.Add ("Beta", '\u0392');
			entities.Add ("Gamma", '\u0393');
			entities.Add ("Delta", '\u0394');
			entities.Add ("Epsilon", '\u0395');
			entities.Add ("Zeta", '\u0396');
			entities.Add ("Eta", '\u0397');
			entities.Add ("Theta", '\u0398');
			entities.Add ("Iota", '\u0399');
			entities.Add ("Kappa", '\u039A');
			entities.Add ("Lambda", '\u039B');
			entities.Add ("Mu", '\u039C');
			entities.Add ("Nu", '\u039D');
			entities.Add ("Xi", '\u039E');
			entities.Add ("Omicron", '\u039F');
			entities.Add ("Pi", '\u03A0');
			entities.Add ("Rho", '\u03A1');
			entities.Add ("Sigma", '\u03A3');
			entities.Add ("Tau", '\u03A4');
			entities.Add ("Upsilon", '\u03A5');
			entities.Add ("Phi", '\u03A6');
			entities.Add ("Chi", '\u03A7');
			entities.Add ("Psi", '\u03A8');
			entities.Add ("Omega", '\u03A9');
			entities.Add ("alpha", '\u03B1');
			entities.Add ("beta", '\u03B2');
			entities.Add ("gamma", '\u03B3');
			entities.Add ("delta", '\u03B4');
			entities.Add ("epsilon", '\u03B5');
			entities.Add ("zeta", '\u03B6');
			entities.Add ("eta", '\u03B7');
			entities.Add ("theta", '\u03B8');
			entities.Add ("iota", '\u03B9');
			entities.Add ("kappa", '\u03BA');
			entities.Add ("lambda", '\u03BB');
			entities.Add ("mu", '\u03BC');
			entities.Add ("nu", '\u03BD');
			entities.Add ("xi", '\u03BE');
			entities.Add ("omicron", '\u03BF');
			entities.Add ("pi", '\u03C0');
			entities.Add ("rho", '\u03C1');
			entities.Add ("sigmaf", '\u03C2');
			entities.Add ("sigma", '\u03C3');
			entities.Add ("tau", '\u03C4');
			entities.Add ("upsilon", '\u03C5');
			entities.Add ("phi", '\u03C6');
			entities.Add ("chi", '\u03C7');
			entities.Add ("psi", '\u03C8');
			entities.Add ("omega", '\u03C9');
			entities.Add ("thetasym", '\u03D1');
			entities.Add ("upsih", '\u03D2');
			entities.Add ("piv", '\u03D6');
			entities.Add ("bull", '\u2022');
			entities.Add ("hellip", '\u2026');
			entities.Add ("prime", '\u2032');
			entities.Add ("Prime", '\u2033');
			entities.Add ("oline", '\u203E');
			entities.Add ("frasl", '\u2044');
			entities.Add ("weierp", '\u2118');
			entities.Add ("image", '\u2111');
			entities.Add ("real", '\u211C');
			entities.Add ("trade", '\u2122');
			entities.Add ("alefsym", '\u2135');
			entities.Add ("larr", '\u2190');
			entities.Add ("uarr", '\u2191');
			entities.Add ("rarr", '\u2192');
			entities.Add ("darr", '\u2193');
			entities.Add ("harr", '\u2194');
			entities.Add ("crarr", '\u21B5');
			entities.Add ("lArr", '\u21D0');
			entities.Add ("uArr", '\u21D1');
			entities.Add ("rArr", '\u21D2');
			entities.Add ("dArr", '\u21D3');
			entities.Add ("hArr", '\u21D4');
			entities.Add ("forall", '\u2200');
			entities.Add ("part", '\u2202');
			entities.Add ("exist", '\u2203');
			entities.Add ("empty", '\u2205');
			entities.Add ("nabla", '\u2207');
			entities.Add ("isin", '\u2208');
			entities.Add ("notin", '\u2209');
			entities.Add ("ni", '\u220B');
			entities.Add ("prod", '\u220F');
			entities.Add ("sum", '\u2211');
			entities.Add ("minus", '\u2212');
			entities.Add ("lowast", '\u2217');
			entities.Add ("radic", '\u221A');
			entities.Add ("prop", '\u221D');
			entities.Add ("infin", '\u221E');
			entities.Add ("ang", '\u2220');
			entities.Add ("and", '\u2227');
			entities.Add ("or", '\u2228');
			entities.Add ("cap", '\u2229');
			entities.Add ("cup", '\u222A');
			entities.Add ("int", '\u222B');
			entities.Add ("there4", '\u2234');
			entities.Add ("sim", '\u223C');
			entities.Add ("cong", '\u2245');
			entities.Add ("asymp", '\u2248');
			entities.Add ("ne", '\u2260');
			entities.Add ("equiv", '\u2261');
			entities.Add ("le", '\u2264');
			entities.Add ("ge", '\u2265');
			entities.Add ("sub", '\u2282');
			entities.Add ("sup", '\u2283');
			entities.Add ("nsub", '\u2284');
			entities.Add ("sube", '\u2286');
			entities.Add ("supe", '\u2287');
			entities.Add ("oplus", '\u2295');
			entities.Add ("otimes", '\u2297');
			entities.Add ("perp", '\u22A5');
			entities.Add ("sdot", '\u22C5');
			entities.Add ("lceil", '\u2308');
			entities.Add ("rceil", '\u2309');
			entities.Add ("lfloor", '\u230A');
			entities.Add ("rfloor", '\u230B');
			entities.Add ("lang", '\u2329');
			entities.Add ("rang", '\u232A');
			entities.Add ("loz", '\u25CA');
			entities.Add ("spades", '\u2660');
			entities.Add ("clubs", '\u2663');
			entities.Add ("hearts", '\u2665');
			entities.Add ("diams", '\u2666');
			entities.Add ("quot", '\u0022');
			entities.Add ("amp", '\u0026');
			entities.Add ("lt", '\u003C');
			entities.Add ("gt", '\u003E');
			entities.Add ("OElig", '\u0152');
			entities.Add ("oelig", '\u0153');
			entities.Add ("Scaron", '\u0160');
			entities.Add ("scaron", '\u0161');
			entities.Add ("Yuml", '\u0178');
			entities.Add ("circ", '\u02C6');
			entities.Add ("tilde", '\u02DC');
			entities.Add ("ensp", '\u2002');
			entities.Add ("emsp", '\u2003');
			entities.Add ("thinsp", '\u2009');
			entities.Add ("zwnj", '\u200C');
			entities.Add ("zwj", '\u200D');
			entities.Add ("lrm", '\u200E');
			entities.Add ("rlm", '\u200F');
			entities.Add ("ndash", '\u2013');
			entities.Add ("mdash", '\u2014');
			entities.Add ("lsquo", '\u2018');
			entities.Add ("rsquo", '\u2019');
			entities.Add ("sbquo", '\u201A');
			entities.Add ("ldquo", '\u201C');
			entities.Add ("rdquo", '\u201D');
			entities.Add ("bdquo", '\u201E');
			entities.Add ("dagger", '\u2020');
			entities.Add ("Dagger", '\u2021');
			entities.Add ("permil", '\u2030');
			entities.Add ("lsaquo", '\u2039');
			entities.Add ("rsaquo", '\u203A');
			entities.Add ("euro", '\u20AC');
		}
	}
}
