001 // This file is part of the Attempto Java Packages. 002 // Copyright 2008-2009, Attempto Group, University of Zurich (see http://attempto.ifi.uzh.ch). 003 // 004 // The Attempto Java Packages is free software: you can redistribute it and/or modify it under the 005 // terms of the GNU Lesser General Public License as published by the Free Software Foundation, 006 // either version 3 of the License, or (at your option) any later version. 007 // 008 // The Attempto Java Packages is distributed in the hope that it will be useful, but WITHOUT ANY 009 // WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 010 // PURPOSE. See the GNU Lesser General Public License for more details. 011 // 012 // You should have received a copy of the GNU Lesser General Public License along with the Attempto 013 // Java Packages. If not, see http://www.gnu.org/licenses/. 014 015 package ch.uzh.ifi.attempto.ape; 016 017 import jpl.Atom; 018 import jpl.Compound; 019 import jpl.JPL; 020 import jpl.Query; 021 import jpl.Term; 022 import jpl.Util; 023 import jpl.Variable; 024 025 /** 026 * This class provides an interface to the SWI Prolog executable of the Attempto Parsing Engine (APE). 027 * Note that you need the file "ape.exe" (which can be compiled from the Attempto APE distribution) and that 028 * SWI Prolog needs to be installed. 029 * Furthermore, you have to make sure that the JPL libraries of SWI Prolog are in the java library path. 030 * This can be achieved by a Java VM argument which looks like this (for Mac OS X): 031 * 032 * <blockquote><code>-Djava.library.path=/opt/local/lib/swipl-5.6.45/lib/i386-darwin8.10.1</code></blockquote> 033 * 034 * It is very likely that the path is different on your machine. Just look for the directory that contains 035 * the file or symbolic link <em>libjpl.jnilib</em> (under Mac OS X), <em>libjpl.dll</em> (under Windows), or 036 * <em>libjpl.so</em> (under Unix). 037 * 038 * If you get the error message 039 * 040 * <blockquote><code>java.lang.UnsatisfiedLinkError: no jpl in java.library.path</code></blockquote> 041 * 042 * then this is a strong indication that the SWI Prolog JPL libraries are not found. 043 * 044 * 045 * @author Tobias Kuhn 046 */ 047 public class APELocal extends ACEParser { 048 049 private static APELocal apeLocal; 050 051 /** 052 * Creates a new parser object. You can create at most one such object per JVM. If you 053 * try to create more than one such object or if you called the init method before 054 * then a runtime exception is thrown. 055 * 056 * @param prologCommand The command to run the SWI Prolog interpreter. 057 * On Windows this is usually "plcon", on Linux "pl", and on Mac "swipl". 058 * @param apeExeFile The path (with filename) of the file "ape.exe". 059 */ 060 public APELocal(String prologCommand, String apeExeFile) { 061 if (apeLocal != null) { 062 throw new RuntimeException("Only one APELocal object can be created."); 063 } 064 JPL.init(new String[] {prologCommand, "-x", apeExeFile, "-g", "true", "--nosignals"}); 065 // A problem was reported that might be solved by using the --nosignals option. 066 // Otherwise, it seems to have no effect in our case. 067 apeLocal = this; 068 } 069 070 /** 071 * Returns the singleton APELocal instance. Null is returned if the APELocal instance has not yet 072 * been initialized by the constructor or the init method. 073 * 074 * @return The singleton APELocal instance. 075 */ 076 public static APELocal getInstance() { 077 return apeLocal; 078 } 079 080 /** 081 * Initializes the APELocal singleton instance. This method can be called at most once. 082 * If you call it twice or if you called the constructor before then a runtime exception 083 * is thrown. 084 * 085 * @param prologCommand The command to run the SWI Prolog interpreter. 086 * On Windows this is usually "plcon", on Linux "pl", and on Mac "swipl". 087 * @param apeExeFile The path (with filename) of the file "ape.exe". 088 */ 089 public static void init(String prologCommand, String apeExeFile) { 090 new APELocal(prologCommand, apeExeFile); 091 } 092 093 /** 094 * Checks whether the singleton instance has already been initialized. 095 * 096 * @return true if the singleton instance has been initialized. 097 */ 098 public static boolean isInitialized() { 099 return apeLocal != null; 100 } 101 102 public synchronized String getSoloOutput(String text, Lexicon lexicon, OutputType outputType) throws ACEParserException { 103 clearMessages(); 104 String ulextext = ""; 105 if (lexicon != null) { 106 ulextext = ",ulextext=" + PrologUtils.escape(lexicon.toString()); 107 } 108 Term input = Util.textToTerm("[text=" + PrologUtils.escape(text) + ulextext + ",solo=" + outputType.toString().toLowerCase() + getOptions() + "]"); 109 Query q = new Query("get_ape_results", new Term[] {input, new Variable("Result")}); 110 Atom result = (Atom) q.oneSolution().get("Result"); 111 String s = result.name(); 112 113 return checkForErrors(s); 114 } 115 116 public synchronized ACEParserResult getMultiOutput(String text, Lexicon lexicon, OutputType... outputTypes) { 117 clearMessages(); 118 String outputs = ""; 119 for (OutputType t : outputTypes) { 120 outputs += ",c" + t.toString().toLowerCase() + "=on"; 121 } 122 String ulextext = ""; 123 if (lexicon != null) { 124 ulextext = ",ulextext=" + PrologUtils.escape(lexicon.toString()); 125 } 126 Term input = Util.textToTerm("[text=" + PrologUtils.escape(text) + ulextext + outputs + getOptions() + "]"); 127 Query q = new Query("get_ape_results", new Term[] {input, new Variable("Result")}); 128 Atom result = (Atom) q.oneSolution().get("Result"); 129 return new ACEParserResult(result.name()); 130 } 131 132 /** 133 * Loads the lexicon by adding all lexicon entries of the lexicon. Note that these lexicon entries 134 * are automatically discarded the first time you call getSoloOutput or getMultiOutput with a lexicon 135 * parameter that is not null. 136 * 137 * @param lexicon The lexicon to be loaded. 138 * @see #addLexiconEntry 139 * @see #discardLexicon 140 */ 141 public synchronized void addLexicon(Lexicon lexicon) { 142 clearMessages(); 143 Query q = new Query(new Compound("add_lexicon_entries", new Term[] { Util.textToTerm(lexicon.toList()) })); 144 q.oneSolution(); 145 } 146 147 /** 148 * Adds a new lexicon entry. Note that this lexicon entry is automatically discarded the first time 149 * you call getSoloOutput or getMultiOutput with a lexicon parameter that is not null. 150 * 151 * @param lexiconEntry The lexicon entry to be added. 152 * @see #addLexicon 153 * @see #discardLexicon 154 */ 155 public synchronized void addLexiconEntry(LexiconEntry lexiconEntry) { 156 clearMessages(); 157 Query q = new Query(new Compound("add_lexicon_entry", new Term[] { Util.textToTerm(lexiconEntry.toString()) }) ); 158 q.oneSolution(); 159 } 160 161 /** 162 * Discards the dynamically added lexicon entries. Note that the lexicon entries that are complied into 163 * the SWI Prolog executable are not affected by this operation. 164 * 165 * @see #addLexiconEntry 166 * @see #addLexicon 167 */ 168 public synchronized void discardLexicon() { 169 clearMessages(); 170 Query q = new Query("discard_ulex"); 171 q.oneSolution(); 172 } 173 174 private void clearMessages() { 175 Query q = new Query("clear_messages"); 176 q.oneSolution(); 177 } 178 }