001 package net.sf.cpsolver.ifs.util;
002
003 import java.io.*;
004 import java.util.*;
005
006 /** A class for reading prolog files.
007 *
008 * @version
009 * IFS 1.1 (Iterative Forward Search)<br>
010 * Copyright (C) 2006 Tomáš Müller<br>
011 * <a href="mailto:muller@unitime.org">muller@unitime.org</a><br>
012 * Lazenska 391, 76314 Zlin, Czech Republic<br>
013 * <br>
014 * This library is free software; you can redistribute it and/or
015 * modify it under the terms of the GNU Lesser General Public
016 * License as published by the Free Software Foundation; either
017 * version 2.1 of the License, or (at your option) any later version.
018 * <br><br>
019 * This library is distributed in the hope that it will be useful,
020 * but WITHOUT ANY WARRANTY; without even the implied warranty of
021 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
022 * Lesser General Public License for more details.
023 * <br><br>
024 * You should have received a copy of the GNU Lesser General Public
025 * License along with this library; if not, write to the Free Software
026 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
027 */
028 public class PrologFile implements Iterator {
029 private java.io.BufferedReader iBufferedReader = null;
030 private Term iNextTerm = null;
031
032 public PrologFile(String file) throws java.io.IOException {
033 iBufferedReader = new BufferedReader(new FileReader(file));
034 iNextTerm = (iBufferedReader.ready()?readTerm(new SpecialReader(iBufferedReader)):null);
035 if (iNextTerm==null) iBufferedReader.close(); else iBufferedReader.readLine();
036 }
037
038 /** Reads a prolog file. It returns a set of terms */
039 public static Vector readTermsFromStream(java.io.InputStream is, String term) throws java.io.IOException {
040 BufferedReader br = new BufferedReader(new InputStreamReader(is));
041 Vector ret = new Vector();
042 //int x=0;
043 while (br.ready()) {
044 Term t = readTerm(new SpecialReader(br));
045 //System.out.println(t);
046 //x++;
047 //if (x>10) break;
048 if (t!=null && t.getText()!=null && t.getText().startsWith(term)) {
049 ret.addElement(t);
050 }
051 br.readLine();
052 }
053 br.close();
054 return ret;
055 }
056
057 /** Writes a set of terms. */
058 public static void writeTerms(PrintWriter pw, Vector terms) throws java.io.IOException {
059 for (Enumeration e=terms.elements();e.hasMoreElements();) {
060 Term t = (Term)e.nextElement();
061 writeTerm(pw,t);
062 }
063 }
064
065 /** reads a term */
066 private static Term readTerm( SpecialReader is) throws IOException {
067 StringBuffer text=new StringBuffer();
068 Vector content = null;
069 int i;
070 if ((i = is.read())>=0) {
071 while ((char)i=='%' || (char)i==':') {
072 do {
073 i=is.read();
074 } while (i>=0 && !( i==0x0d || i==0x0a ));
075 i=is.read();
076 if (i>=0 && (i==0x0d || i==0x0a )) i=is.read();
077 }
078 if (i>=0) is.flush((char)i);
079 }
080 char prev = (char)i;
081 if (i>=0) while ((i = is.read())>=0) {
082 char ch = (char)i;
083 if (ch=='\n' || ch=='\r')
084 if (prev=='.') break; else continue;
085 if (ch=='(' || ch=='[') {
086 content = new Vector();
087 content.addElement(readTerm(is));
088 } else if (content==null && (ch==',' || ch==')' || ch==']')) {
089 is.flush(ch);
090 break;
091 } else if (ch==',') content.addElement(readTerm(is));
092 else if (ch==')' || ch==']') break;
093 else text.append(ch);
094 prev = ch;
095 } else return null;
096 Term ret = new Term(text.toString().trim(),content);
097 return ret;
098 }
099
100 /** writes a term */
101 private static void writeTerm( PrintWriter pw, Term t) {
102 pw.println(t.toString()+".");
103 }
104
105
106 public boolean hasNext() {
107 return iNextTerm!=null;
108 }
109
110 public Object next() {
111 Term ret = iNextTerm;
112 try {
113 iNextTerm = (iBufferedReader.ready()?readTerm(new SpecialReader(iBufferedReader)):null);
114 } catch (java.io.IOException x) {
115 iNextTerm = null;
116 }
117 try {
118 if (iNextTerm==null) iBufferedReader.close(); else iBufferedReader.readLine();
119 } catch (java.io.IOException x) {}
120 return ret;
121 }
122
123 public void remove() {
124 }
125
126 /** Flushable reader -- extension of java.io.Reader */
127 private static class SpecialReader {
128 /** reader */
129 private Reader iReader = null;
130 /** flushed characters */
131 private StringBuffer iFlushedChars = new StringBuffer();
132
133 /** constructor */
134 public SpecialReader(Reader r) {
135 iReader = r;
136 }
137
138 /** reads a byte */
139 public int read() throws java.io.IOException {
140 if (iFlushedChars.length()==0) return iReader.read();
141 char ret=iFlushedChars.charAt(0);
142 iFlushedChars.deleteCharAt(0);
143 return ret;
144 }
145
146 /** flush (return to stream) a character */
147 public void flush(char ch) {
148 iFlushedChars.insert(0,ch);
149 }
150 }
151
152 /** Term -- it can contain a text and a content (set of terms) */
153 public static class Term {
154 /** text */
155 private String iText = null;
156 /** content */
157 private Vector iContent = null;
158
159 public boolean equals(Object o) {
160 if (o==null || !(o instanceof Term)) return false;
161 Term t = (Term)o;
162 if (iText==null && t.iText!=null) return false;
163 if (iText!=null && t.iText==null) return false;
164 if (iText!=null && !iText.equals(t.iText)) return false;
165 if (iContent==null && t.iContent!=null) return false;
166 if (iContent!=null && t.iContent==null) return false;
167 if (iContent!=null && !iContent.equals(t.iContent)) return false;
168 return true;
169 }
170
171 /** constructor */
172 public Term(String text) {
173 iText = text;
174 iContent = null;
175 }
176
177 /** constructor */
178 public Term(Vector content) {
179 iText = null;
180 iContent = content;
181 }
182
183 /** constructor */
184 public Term(String text, Vector content) {
185 iText = text;
186 iContent = content;
187 }
188
189 /** constructor */
190 public Term(String text, Term[] content) {
191 iText = text;
192 if (content==null) {
193 iContent = null;
194 } else {
195 iContent = new Vector();
196 for (int i=0;i<content.length;i++)
197 iContent.addElement(content[i]);
198 }
199 }
200
201 /** constructor */
202 public Term(Term[] content) {
203 this(null,content);
204 }
205
206 /** return text */
207 public String getText() {
208 return iText;
209 }
210
211 /** return content */
212 public Vector getContent() {
213 return iContent;
214 }
215
216 /** content size */
217 public int size() {
218 return (iContent==null?-1:iContent.size());
219 }
220
221 /** return text as int */
222 public int toInt() {
223 return Integer.parseInt(iText);
224 }
225
226 /** return text as long */
227 public long toLong() {
228 return Long.parseLong(iText);
229 }
230
231 /** return text as fouble */
232 public double toDouble() {
233 return Double.parseDouble(iText);
234 }
235
236 /** return text as boolean */
237 public boolean toBoolean() {
238 return (toInt()!=0);
239 }
240
241 /** return content as boolean array */
242 public boolean[] toBooleanArray() {
243 if (iContent.size()==1 && iContent.elementAt(0).toString().length()==0) return new boolean[] {};
244 boolean[] ret = new boolean[iContent.size()];
245 for (int i=0;i<ret.length;i++) {
246 ret[i]=elementAt(i).toBoolean();
247 }
248 return ret;
249 }
250
251 /** return content as string array */
252 public String[] toStringArray() {
253 if (iContent.size()==1 && iContent.elementAt(0).toString().length()==0) return new String[] {};
254 String[] ret = new String[iContent.size()];
255 for (int i=0;i<ret.length;i++) {
256 Term t = elementAt(i);
257 ret[i]=(t.getText().length()>0?t.toString():t.elementAt(0).toString());
258 }
259 return ret;
260 }
261
262 /** return content as int array */
263 public int[] toIntArray() {
264 //System.err.println("ToIntArray: "+this);
265 if (iContent.size()==1 && iContent.elementAt(0).toString().length()==0) return new int[] {};
266 int[] ret = new int[iContent.size()];
267 for (int i=0;i<ret.length;i++) {
268 Term t = elementAt(i);
269 ret[i]=(t.getText().length()>0?Integer.parseInt(t.getText()):t.elementAt(0).toInt());
270 //System.err.println(" "+i+" .. "+ret[i]);
271 }
272 return ret;
273 }
274
275 /** idx-th element of content */
276 public Term elementAt(int idx) {
277 try {
278 return (Term)iContent.elementAt(idx);
279 } catch (Exception e) {
280 return null;
281 }
282 }
283
284 /** element of content named name*/
285 public Term element(String name) {
286 try {
287 for (Enumeration i=iContent.elements();i.hasMoreElements();) {
288 Term t = (Term)i.nextElement();
289 if (t.getText()!=null && t.getText().equals(name)) return t;
290 }
291 return null;
292 } catch (Exception e) {
293 return null;
294 }
295 }
296
297 /** index of element of content named name*/
298 public int indexOf(String name) {
299 try {
300 int idx=0;
301 for (Enumeration i=iContent.elements();i.hasMoreElements();) {
302 Term t = (Term)i.nextElement();
303 if (t.getText()!=null && t.getText().equals(name)) return idx;
304 idx++;
305 }
306 return -1;
307 } catch (Exception e) {
308 return -1;
309 }
310 }
311
312 /** string representation of term */
313 public String toString() {
314 boolean isArray = (iText==null || iText.length()==0);
315 StringBuffer sb = new StringBuffer(isArray?"":iText);
316 if (iContent!=null) {
317 sb.append(isArray?"[":"(");
318 for (Enumeration e=iContent.elements();e.hasMoreElements();) {
319 sb.append(e.nextElement().toString());
320 sb.append(e.hasMoreElements()?",":"");
321 }
322 sb.append(isArray?"]":")");
323 }
324 return sb.toString();
325 }
326
327 public Object clone() {
328 return new Term(iText==null?null:new String(iText),iContent==null?iContent:(Vector)iContent.clone());
329 }
330 }
331 }