HttpEncoder.cs

//
// 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.Globalization;
using System.IO;
using System.Text;
#if NET_4_0
using System.Web.Configuration;
#endif

namespace SolrNet.Utils {
#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;
            char ch;

            for (int i = 0; i < input.Length; i++) {
                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 ()
		{
			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
#if NET_4_0
		protected internal virtual
#else
        internal static
#endif
 string UrlPathEncode(string value) {
            if (String.IsNullOrEmpty(value))
                return value;

			using (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");

			using (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();
            char ch;
            int len = s.Length;

            for (int i = 0; i < len; i++) {
                switch (s[i]) {
                    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:
                        ch = s[i];
                        if (ch > 159 && ch < 256) {
                            output.Append("&#");
                            output.Append(((int)ch).ToString(CultureInfo.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++)
                switch (s[i]) {
                    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(s[i]);
                        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(CultureInfo.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(CultureInfo.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(CultureInfo.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(CultureInfo.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');
        }
    }
}