| // Lucene version compatibility level 4.8.1 |
| using Lucene.Net.Analysis.Util; |
| using Lucene.Net.Util; |
| using System; |
| using System.Collections.Generic; |
| using System.Text.RegularExpressions; |
| |
| namespace Lucene.Net.Analysis.In |
| { |
| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You under the Apache License, Version 2.0 |
| * (the "License"); you may not use this file except in compliance with |
| * the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| /// <summary> |
| /// Normalizes the Unicode representation of text in Indian languages. |
| /// <para> |
| /// Follows guidelines from Unicode 5.2, chapter 6, South Asian Scripts I |
| /// and graphical decompositions from http://ldc.upenn.edu/myl/IndianScriptsUnicode.html |
| /// </para> |
| /// </summary> |
| public class IndicNormalizer |
| { |
| // LUCENENET NOTE: This class was refactored from its Java couterpart, |
| // favoring the .NET Regex class to determine the "Unicode Block" rather than |
| // porting over that part of the Java Character class. |
| // References: |
| // https://msdn.microsoft.com/en-us/library/20bw873z.aspx#SupportedNamedBlocks |
| // http://stackoverflow.com/a/11414800/181087 |
| |
| private class ScriptData |
| { |
| internal readonly Regex block; |
| internal readonly UnicodeBlock flag; |
| internal readonly int @base; |
| internal OpenBitSet decompMask; |
| |
| internal ScriptData(Regex block, UnicodeBlock flag, int @base) |
| { |
| this.block = block; |
| this.flag = flag; |
| this.@base = @base; |
| } |
| } |
| |
| // LUCENENET: scripts moved below declaration of decompositions so it can be populated inline |
| |
| [Flags] |
| internal enum UnicodeBlock |
| { |
| DEVANAGARI = 1, |
| BENGALI = 2, |
| GURMUKHI = 4, |
| GUJARATI = 8, |
| ORIYA = 16, |
| TAMIL = 32, |
| TELUGU = 64, |
| KANNADA = 128, |
| MALAYALAM = 256 |
| } |
| |
| // LUCENENET: static initialization done inline instead of in constructor |
| |
| /// <summary> |
| /// Decompositions according to Unicode 5.2, |
| /// and http://ldc.upenn.edu/myl/IndianScriptsUnicode.html |
| /// <para/> |
| /// Most of these are not handled by unicode normalization anyway. |
| /// <para/> |
| /// The numbers here represent offsets into the respective codepages, |
| /// with -1 representing null and 0xFF representing zero-width joiner. |
| /// <para/> |
| /// the columns are: ch1, ch2, ch3, res, flags |
| /// ch1, ch2, and ch3 are the decomposition |
| /// res is the composition, and flags are the scripts to which it applies. |
| /// </summary> |
| private static readonly int[][] decompositions = new int[][] // LUCENENET: Avoid static constructors (see https://github.com/apache/lucenenet/pull/224#issuecomment-469284006) |
| { |
| /* devanagari, gujarati vowel candra O */ |
| new int[] { 0x05, 0x3E, 0x45, 0x11, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari short O */ |
| new int[] { 0x05, 0x3E, 0x46, 0x12, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari, gujarati letter O */ |
| new int[] { 0x05, 0x3E, 0x47, 0x13, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari letter AI, gujarati letter AU */ |
| new int[] { 0x05, 0x3E, 0x48, 0x14, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari, bengali, gurmukhi, gujarati, oriya AA */ |
| new int[] { 0x05, 0x3E, -1, 0x06, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.BENGALI | (int)UnicodeBlock.GURMUKHI | (int)UnicodeBlock.GUJARATI | (int)UnicodeBlock.ORIYA }, |
| /* devanagari letter candra A */ |
| new int[] { 0x05, 0x45, -1, 0x72, (int)UnicodeBlock.DEVANAGARI }, |
| /* gujarati vowel candra E */ |
| new int[] { 0x05, 0x45, -1, 0x0D, (int)UnicodeBlock.GUJARATI }, |
| /* devanagari letter short A */ |
| new int[] { 0x05, 0x46, -1, 0x04, (int)UnicodeBlock.DEVANAGARI }, |
| /* gujarati letter E */ |
| new int[] { 0x05, 0x47, -1, 0x0F, (int)UnicodeBlock.GUJARATI }, |
| /* gurmukhi, gujarati letter AI */ |
| new int[] { 0x05, 0x48, -1, 0x10, (int)UnicodeBlock.GURMUKHI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari, gujarati vowel candra O */ |
| new int[] { 0x05, 0x49, -1, 0x11, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari short O */ |
| new int[] { 0x05, 0x4A, -1, 0x12, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari, gujarati letter O */ |
| new int[] { 0x05, 0x4B, -1, 0x13, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari letter AI, gurmukhi letter AU, gujarati letter AU */ |
| new int[] { 0x05, 0x4C, -1, 0x14, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GURMUKHI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari, gujarati vowel candra O */ |
| new int[] { 0x06, 0x45, -1, 0x11, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari short O */ |
| new int[] { 0x06, 0x46, -1, 0x12, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari, gujarati letter O */ |
| new int[] { 0x06, 0x47, -1, 0x13, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari letter AI, gujarati letter AU */ |
| new int[] { 0x06, 0x48, -1, 0x14, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* malayalam letter II */ |
| new int[] { 0x07, 0x57, -1, 0x08, (int)UnicodeBlock.MALAYALAM }, |
| /* devanagari letter UU */ |
| new int[] { 0x09, 0x41, -1, 0x0A, (int)UnicodeBlock.DEVANAGARI }, |
| /* tamil, malayalam letter UU (some styles) */ |
| new int[] { 0x09, 0x57, -1, 0x0A, (int)UnicodeBlock.TAMIL | (int)UnicodeBlock.MALAYALAM }, |
| /* malayalam letter AI */ |
| new int[] { 0x0E, 0x46, -1, 0x10, (int)UnicodeBlock.MALAYALAM }, |
| /* devanagari candra E */ |
| new int[] { 0x0F, 0x45, -1, 0x0D, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari short E */ |
| new int[] { 0x0F, 0x46, -1, 0x0E, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari AI */ |
| new int[] { 0x0F, 0x47, -1, 0x10, (int)UnicodeBlock.DEVANAGARI }, |
| /* oriya AI */ |
| new int[] { 0x0F, 0x57, -1, 0x10, (int)UnicodeBlock.ORIYA }, |
| /* malayalam letter OO */ |
| new int[] { 0x12, 0x3E, -1, 0x13, (int)UnicodeBlock.MALAYALAM }, |
| /* telugu, kannada letter AU */ |
| new int[] { 0x12, 0x4C, -1, 0x14, (int)UnicodeBlock.TELUGU | (int)UnicodeBlock.KANNADA }, |
| /* telugu letter OO */ |
| new int[] { 0x12, 0x55, -1, 0x13, (int)UnicodeBlock.TELUGU }, |
| /* tamil, malayalam letter AU */ |
| new int[] { 0x12, 0x57, -1, 0x14, (int)UnicodeBlock.TAMIL | (int)UnicodeBlock.MALAYALAM }, |
| /* oriya letter AU */ |
| new int[] { 0x13, 0x57, -1, 0x14, (int)UnicodeBlock.ORIYA }, |
| /* devanagari qa */ |
| new int[] { 0x15, 0x3C, -1, 0x58, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari, gurmukhi khha */ |
| new int[] { 0x16, 0x3C, -1, 0x59, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GURMUKHI }, |
| /* devanagari, gurmukhi ghha */ |
| new int[] { 0x17, 0x3C, -1, 0x5A, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GURMUKHI }, |
| /* devanagari, gurmukhi za */ |
| new int[] { 0x1C, 0x3C, -1, 0x5B, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GURMUKHI }, |
| /* devanagari dddha, bengali, oriya rra */ |
| new int[] { 0x21, 0x3C, -1, 0x5C, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.BENGALI | (int)UnicodeBlock.ORIYA }, |
| /* devanagari, bengali, oriya rha */ |
| new int[] { 0x22, 0x3C, -1, 0x5D, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.BENGALI | (int)UnicodeBlock.ORIYA }, |
| /* malayalam chillu nn */ |
| new int[] { 0x23, 0x4D, 0xFF, 0x7A, (int)UnicodeBlock.MALAYALAM }, |
| /* bengali khanda ta */ |
| new int[] { 0x24, 0x4D, 0xFF, 0x4E, (int)UnicodeBlock.BENGALI }, |
| /* devanagari nnna */ |
| new int[] { 0x28, 0x3C, -1, 0x29, (int)UnicodeBlock.DEVANAGARI }, |
| /* malayalam chillu n */ |
| new int[] { 0x28, 0x4D, 0xFF, 0x7B, (int)UnicodeBlock.MALAYALAM }, |
| /* devanagari, gurmukhi fa */ |
| new int[] { 0x2B, 0x3C, -1, 0x5E, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GURMUKHI }, |
| /* devanagari, bengali yya */ |
| new int[] { 0x2F, 0x3C, -1, 0x5F, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.BENGALI }, |
| /* telugu letter vocalic R */ |
| new int[] { 0x2C, 0x41, 0x41, 0x0B, (int)UnicodeBlock.TELUGU }, |
| /* devanagari rra */ |
| new int[] { 0x30, 0x3C, -1, 0x31, (int)UnicodeBlock.DEVANAGARI }, |
| /* malayalam chillu rr */ |
| new int[] { 0x30, 0x4D, 0xFF, 0x7C, (int)UnicodeBlock.MALAYALAM }, |
| /* malayalam chillu l */ |
| new int[] { 0x32, 0x4D, 0xFF, 0x7D, (int)UnicodeBlock.MALAYALAM }, |
| /* devanagari llla */ |
| new int[] { 0x33, 0x3C, -1, 0x34, (int)UnicodeBlock.DEVANAGARI }, |
| /* malayalam chillu ll */ |
| new int[] { 0x33, 0x4D, 0xFF, 0x7E, (int)UnicodeBlock.MALAYALAM }, |
| /* telugu letter MA */ |
| new int[] { 0x35, 0x41, -1, 0x2E, (int)UnicodeBlock.TELUGU }, |
| /* devanagari, gujarati vowel sign candra O */ |
| new int[] { 0x3E, 0x45, -1, 0x49, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari vowel sign short O */ |
| new int[] { 0x3E, 0x46, -1, 0x4A, (int)UnicodeBlock.DEVANAGARI }, |
| /* devanagari, gujarati vowel sign O */ |
| new int[] { 0x3E, 0x47, -1, 0x4B, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* devanagari, gujarati vowel sign AU */ |
| new int[] { 0x3E, 0x48, -1, 0x4C, (int)UnicodeBlock.DEVANAGARI | (int)UnicodeBlock.GUJARATI }, |
| /* kannada vowel sign II */ |
| new int[] { 0x3F, 0x55, -1, 0x40, (int)UnicodeBlock.KANNADA }, |
| /* gurmukhi vowel sign UU (when stacking) */ |
| new int[] { 0x41, 0x41, -1, 0x42, (int)UnicodeBlock.GURMUKHI }, |
| /* tamil, malayalam vowel sign O */ |
| new int[] { 0x46, 0x3E, -1, 0x4A, (int)UnicodeBlock.TAMIL | (int)UnicodeBlock.MALAYALAM }, |
| /* kannada vowel sign OO */ |
| new int[] { 0x46, 0x42, 0x55, 0x4B, (int)UnicodeBlock.KANNADA }, |
| /* kannada vowel sign O */ |
| new int[] { 0x46, 0x42, -1, 0x4A, (int)UnicodeBlock.KANNADA }, |
| /* malayalam vowel sign AI (if reordered twice) */ |
| new int[] { 0x46, 0x46, -1, 0x48, (int)UnicodeBlock.MALAYALAM }, |
| /* telugu, kannada vowel sign EE */ |
| new int[] { 0x46, 0x55, -1, 0x47, (int)UnicodeBlock.TELUGU | (int)UnicodeBlock.KANNADA }, |
| /* telugu, kannada vowel sign AI */ |
| new int[] { 0x46, 0x56, -1, 0x48, (int)UnicodeBlock.TELUGU | (int)UnicodeBlock.KANNADA }, |
| /* tamil, malayalam vowel sign AU */ |
| new int[] { 0x46, 0x57, -1, 0x4C, (int)UnicodeBlock.TAMIL | (int)UnicodeBlock.MALAYALAM }, |
| /* bengali, oriya vowel sign O, tamil, malayalam vowel sign OO */ |
| new int[] { 0x47, 0x3E, -1, 0x4B, (int)UnicodeBlock.BENGALI | (int)UnicodeBlock.ORIYA | (int)UnicodeBlock.TAMIL | (int)UnicodeBlock.MALAYALAM }, |
| /* bengali, oriya vowel sign AU */ |
| new int[] { 0x47, 0x57, -1, 0x4C, (int)UnicodeBlock.BENGALI | (int)UnicodeBlock.ORIYA }, |
| /* kannada vowel sign OO */ |
| new int[] { 0x4A, 0x55, -1, 0x4B, (int)UnicodeBlock.KANNADA }, |
| /* gurmukhi letter I */ |
| new int[] { 0x72, 0x3F, -1, 0x07, (int)UnicodeBlock.GURMUKHI }, |
| /* gurmukhi letter II */ |
| new int[] { 0x72, 0x40, -1, 0x08, (int)UnicodeBlock.GURMUKHI }, |
| /* gurmukhi letter EE */ |
| new int[] { 0x72, 0x47, -1, 0x0F, (int)UnicodeBlock.GURMUKHI }, |
| /* gurmukhi letter U */ |
| new int[] { 0x73, 0x41, -1, 0x09, (int)UnicodeBlock.GURMUKHI }, |
| /* gurmukhi letter UU */ |
| new int[] { 0x73, 0x42, -1, 0x0A, (int)UnicodeBlock.GURMUKHI }, |
| /* gurmukhi letter OO */ |
| new int[] { 0x73, 0x4B, -1, 0x13, (int)UnicodeBlock.GURMUKHI } |
| }; |
| |
| private static readonly IList<ScriptData> scripts = LoadScripts(); // LUCENENET: Avoid static constructors (see https://github.com/apache/lucenenet/pull/224#issuecomment-469284006) |
| |
| private static IList<ScriptData> LoadScripts() |
| { |
| IList<ScriptData> result = new List<ScriptData>(capacity: 9) |
| { |
| new ScriptData(new Regex(@"\p{IsDevanagari}", RegexOptions.Compiled), UnicodeBlock.DEVANAGARI, 0x0900), |
| new ScriptData(new Regex(@"\p{IsBengali}", RegexOptions.Compiled), UnicodeBlock.BENGALI, 0x0980), |
| new ScriptData(new Regex(@"\p{IsGurmukhi}", RegexOptions.Compiled), UnicodeBlock.GURMUKHI, 0x0A00), |
| new ScriptData(new Regex(@"\p{IsGujarati}", RegexOptions.Compiled), UnicodeBlock.GUJARATI, 0x0A80), |
| new ScriptData(new Regex(@"\p{IsOriya}", RegexOptions.Compiled), UnicodeBlock.ORIYA, 0x0B00), |
| new ScriptData(new Regex(@"\p{IsTamil}", RegexOptions.Compiled), UnicodeBlock.TAMIL, 0x0B80), |
| new ScriptData(new Regex(@"\p{IsTelugu}", RegexOptions.Compiled), UnicodeBlock.TELUGU, 0x0C00), |
| new ScriptData(new Regex(@"\p{IsKannada}", RegexOptions.Compiled), UnicodeBlock.KANNADA, 0x0C80), |
| new ScriptData(new Regex(@"\p{IsMalayalam}", RegexOptions.Compiled), UnicodeBlock.MALAYALAM, 0x0D00), |
| }; |
| |
| foreach (ScriptData sd in result) |
| { |
| sd.decompMask = new OpenBitSet(0x7F); |
| for (int i = 0; i < decompositions.Length; i++) |
| { |
| int ch = decompositions[i][0]; |
| int flags = decompositions[i][4]; |
| if ((flags & (int)sd.flag) != 0) |
| { |
| sd.decompMask.Set(ch); |
| } |
| } |
| } |
| |
| return result; |
| } |
| |
| /// <summary> |
| /// Normalizes input text, and returns the new length. |
| /// The length will always be less than or equal to the existing length. |
| /// </summary> |
| /// <param name="text"> input text </param> |
| /// <param name="len"> valid length </param> |
| /// <returns> normalized length </returns> |
| public virtual int Normalize(char[] text, int len) |
| { |
| for (int i = 0; i < len; i++) |
| { |
| Regex block; |
| if ((block = GetBlockForChar(text[i], out ScriptData sd)) != unknownScript) |
| { |
| int ch = text[i] - sd.@base; |
| if (sd.decompMask.Get(ch)) |
| { |
| len = Compose(ch, block, sd, text, i, len); |
| } |
| } |
| } |
| return len; |
| } |
| |
| /// <summary> |
| /// Compose into standard form any compositions in the decompositions table. |
| /// </summary> |
| private static int Compose(int ch0, Regex block0, ScriptData sd, char[] text, int pos, int len) // LUCENENET: CA1822: Mark members as static |
| { |
| if (pos + 1 >= len) // need at least 2 chars! |
| { |
| return len; |
| } |
| |
| int ch1 = text[pos + 1] - sd.@base; |
| var block1 = GetBlockForChar(text[pos + 1], out _); |
| if (block1 != block0) // needs to be the same writing system |
| { |
| return len; |
| } |
| |
| int ch2 = -1; |
| |
| if (pos + 2 < len) |
| { |
| ch2 = text[pos + 2] - sd.@base; |
| var block2 = GetBlockForChar(text[pos + 2], out _); |
| if (text[pos + 2] == '\u200D') // ZWJ |
| { |
| ch2 = 0xFF; |
| } |
| else if (block2 != block1) // still allow a 2-char match |
| { |
| ch2 = -1; |
| } |
| } |
| |
| for (int i = 0; i < decompositions.Length; i++) |
| { |
| if (decompositions[i][0] == ch0 && (decompositions[i][4] & (int)sd.flag) != 0) |
| { |
| if (decompositions[i][1] == ch1 && (decompositions[i][2] < 0 || decompositions[i][2] == ch2)) |
| { |
| text[pos] = (char)(sd.@base + decompositions[i][3]); |
| len = StemmerUtil.Delete(text, pos + 1, len); |
| if (decompositions[i][2] >= 0) |
| { |
| len = StemmerUtil.Delete(text, pos + 1, len); |
| } |
| return len; |
| } |
| } |
| } |
| |
| return len; |
| } |
| |
| // LUCENENET: Never matches - we just use this as a placeholder |
| private static readonly Regex unknownScript = new Regex(@"[^\S\s]", RegexOptions.Compiled); |
| [ThreadStatic] |
| private static ScriptData previousScriptData; |
| |
| /// <summary> |
| /// LUCENENET: Returns the unicode block for the specified character. Caches the |
| /// last script and script data used on the current thread to optimize performance |
| /// when not switching between scripts. |
| /// </summary> |
| private static Regex GetBlockForChar(char c, out ScriptData scriptData) // LUCENENET: CA1822: Mark members as static |
| { |
| string charAsString = c.ToString(); |
| // Store reference locally to avoid threading issues |
| ScriptData previousScriptDataLocal = previousScriptData; |
| Regex previousScript = previousScriptDataLocal?.block; |
| |
| // Optimize to try the most recent script first. |
| if (previousScript?.IsMatch(charAsString) ?? false) |
| { |
| scriptData = previousScriptDataLocal; |
| return previousScript; |
| } |
| |
| return GetBlockForCharSlow(previousScript, charAsString, out scriptData); |
| |
| static Regex GetBlockForCharSlow(Regex previousScript, string charAsString, out ScriptData scriptData) |
| { |
| foreach (var script in scripts) |
| { |
| Regex block = script.block; |
| if (block != previousScript && block.IsMatch(charAsString)) |
| { |
| previousScriptData = script; |
| scriptData = script; |
| return block; |
| } |
| } |
| |
| scriptData = null; |
| // return a regex that never matches, nor is in our scripts dictionary |
| return unknownScript; |
| } |
| } |
| } |
| } |
