| using J2N.IO; |
| using System.Collections.Generic; |
| using System.IO; |
| using System.Text; |
| |
| /* |
| Egothor Software License version 1.00 |
| Copyright (C) 1997-2004 Leo Galambos. |
| Copyright (C) 2002-2004 "Egothor developers" |
| on behalf of the Egothor Project. |
| All rights reserved. |
| |
| This software is copyrighted by the "Egothor developers". If this |
| license applies to a single file or document, the "Egothor developers" |
| are the people or entities mentioned as copyright holders in that file |
| or document. If this license applies to the Egothor project as a |
| whole, the copyright holders are the people or entities mentioned in |
| the file CREDITS. This file can be found in the same location as this |
| license in the distribution. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are |
| met: |
| 1. Redistributions of source code must retain the above copyright |
| notice, the list of contributors, this list of conditions, and the |
| following disclaimer. |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, the list of contributors, this list of conditions, and the |
| disclaimer that follows these conditions in the documentation |
| and/or other materials provided with the distribution. |
| 3. The name "Egothor" must not be used to endorse or promote products |
| derived from this software without prior written permission. For |
| written permission, please contact Leo.G@seznam.cz |
| 4. Products derived from this software may not be called "Egothor", |
| nor may "Egothor" appear in their name, without prior written |
| permission from Leo.G@seznam.cz. |
| |
| In addition, we request that you include in the end-user documentation |
| provided with the redistribution and/or in the software itself an |
| acknowledgement equivalent to the following: |
| "This product includes software developed by the Egothor Project. |
| http://egothor.sf.net/" |
| |
| THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED |
| WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF |
| MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. |
| IN NO EVENT SHALL THE EGOTHOR PROJECT OR ITS CONTRIBUTORS BE LIABLE |
| FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR |
| BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, |
| WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE |
| OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN |
| IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| This software consists of voluntary contributions made by many |
| individuals on behalf of the Egothor Project and was originally |
| created by Leo Galambos (Leo.G@seznam.cz). |
| */ |
| |
| namespace Egothor.Stemmer |
| { |
| /// <summary> |
| /// The <see cref="MultiTrie"/> is a <see cref="Trie"/> of <see cref="Trie"/>s. It stores words and their associated patch |
| /// commands. The <see cref="MultiTrie"/> handles patch commands individually (each command by |
| /// itself). |
| /// </summary> |
| public class MultiTrie : Trie |
| { |
| internal static char EOM = '*'; |
| internal static string EOM_NODE = "" + EOM; |
| |
| protected List<Trie> m_tries = new List<Trie>(); |
| |
| private readonly int BY = 1; // LUCENENET: marked readonly |
| |
| /// <summary> |
| /// Constructor for the <see cref="MultiTrie"/> object. |
| /// </summary> |
| /// <param name="is">the input stream</param> |
| /// <exception cref="IOException">if an I/O error occurs</exception> |
| public MultiTrie(IDataInput @is) |
| : base(false) |
| { |
| forward = @is.ReadBoolean(); |
| BY = @is.ReadInt32(); |
| for (int i = @is.ReadInt32(); i > 0; i--) |
| { |
| m_tries.Add(new Trie(@is)); |
| } |
| } |
| |
| /// <summary> |
| /// Constructor for the <see cref="MultiTrie"/> object |
| /// </summary> |
| /// <param name="forward">set to <c>true</c> if the elements should be read left to right</param> |
| public MultiTrie(bool forward) |
| : base(forward) |
| { |
| } |
| |
| /// <summary> |
| /// Return the element that is stored in a cell associated with the given key. |
| /// </summary> |
| /// <param name="key">the key to the cell holding the desired element</param> |
| /// <returns>the element</returns> |
| public override string GetFully(string key) |
| { |
| StringBuilder result = new StringBuilder(m_tries.Count * 2); |
| for (int i = 0; i < m_tries.Count; i++) |
| { |
| string r = m_tries[i].GetFully(key); |
| if (r == null || (r.Length == 1 && r[0] == EOM)) |
| { |
| return result.ToString(); |
| } |
| result.Append(r); |
| } |
| return result.ToString(); |
| } |
| |
| /// <summary> |
| /// Return the element that is stored as last on a path belonging to the given |
| /// key. |
| /// </summary> |
| /// <param name="key">the key associated with the desired element</param> |
| /// <returns>the element that is stored as last on a path</returns> |
| public override string GetLastOnPath(string key) |
| { |
| StringBuilder result = new StringBuilder(m_tries.Count * 2); |
| for (int i = 0; i < m_tries.Count; i++) |
| { |
| string r = m_tries[i].GetLastOnPath(key); |
| if (r == null || (r.Length == 1 && r[0] == EOM)) |
| { |
| return result.ToString(); |
| } |
| result.Append(r); |
| } |
| return result.ToString(); |
| } |
| |
| /// <summary> |
| /// Write this data structure to the given output stream. |
| /// </summary> |
| /// <param name="os">the output stream</param> |
| /// <exception cref="IOException">if an I/O error occurs</exception> |
| public override void Store(IDataOutput os) |
| { |
| os.WriteBoolean(forward); |
| os.WriteInt32(BY); |
| os.WriteInt32(m_tries.Count); |
| foreach (Trie trie in m_tries) |
| trie.Store(os); |
| } |
| |
| /// <summary> |
| /// Add an element to this structure consisting of the given key and patch |
| /// command. |
| /// <para> |
| /// This method will return without executing if the <paramref name="cmd"/> |
| /// parameter's length is 0. |
| /// </para> |
| /// </summary> |
| /// <param name="key">the key</param> |
| /// <param name="cmd">the patch command</param> |
| public override void Add(string key, string cmd) |
| { |
| if (cmd.Length == 0) |
| { |
| return; |
| } |
| int levels = cmd.Length / BY; |
| while (levels >= m_tries.Count) |
| { |
| m_tries.Add(new Trie(forward)); |
| } |
| for (int i = 0; i < levels; i++) |
| { |
| m_tries[i].Add(key, cmd.Substring(BY * i, BY)); |
| } |
| m_tries[levels].Add(key, EOM_NODE); |
| } |
| |
| /// <summary> |
| /// Remove empty rows from the given <see cref="Trie"/> and return the newly reduced <see cref="Trie"/>. |
| /// </summary> |
| /// <param name="by">the <see cref="Trie"/> to reduce</param> |
| /// <returns>the newly reduced Trie</returns> |
| public override Trie Reduce(Reduce by) |
| { |
| List<Trie> h = new List<Trie>(); |
| foreach (Trie trie in m_tries) |
| h.Add(trie.Reduce(by)); |
| |
| MultiTrie m = new MultiTrie(forward); |
| m.m_tries = h; |
| return m; |
| } |
| |
| /// <summary> |
| /// Print the given prefix and the position(s) in the Trie where it appears. |
| /// </summary> |
| /// <param name="out"></param> |
| /// <param name="prefix">the desired prefix</param> |
| public override void PrintInfo(TextWriter @out, string prefix) |
| { |
| int c = 0; |
| foreach (Trie trie in m_tries) |
| trie.PrintInfo(@out, prefix + "[" + (++c) + "] "); |
| } |
| } |
| } |