--- /dev/null
+/*
+ * gnu/regexp/REFilterReader.java
+ * Copyright (C) 2001 Lee Sau Dan
+ * Based on gnu.regexp.REFilterInputStream by Wes Biggs
+ *
+ * This library is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation; either version 2.1 of the License, or
+ * (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+package gnu.regexp;
+import java.io.FilterReader;
+import java.io.Reader;
+
+/**
+ * Replaces instances of a given RE with replacement text.
+ *
+ * @author <A HREF="http://www.csis.hku.hk/~sdlee/">Lee Sau Dan</A>
+ * @since gnu.regexp 1.1.0
+ */
+
+public class REFilterReader extends FilterReader {
+
+ private RE expr;
+ private String replace;
+ private String buffer;
+ private int bufpos;
+ private int offset;
+ private CharIndexedReader stream;
+
+ /**
+ * Creates an REFilterReader. When reading from this stream,
+ * occurrences of patterns matching the supplied regular expression
+ * will be replaced with the supplied replacement text (the
+ * metacharacters $0 through $9 may be used to refer to the full
+ * match or subexpression matches.
+ *
+ * @param stream The Reader to be filtered.
+ * @param expr The regular expression to search for.
+ * @param replace The text pattern to replace matches with.
+ */
+ public REFilterReader(Reader stream, RE expr, String replace) {
+ super(stream);
+ this.stream = new CharIndexedReader(stream,0);
+ this.expr = expr;
+ this.replace = replace;
+ }
+
+ /**
+ * Reads the next character from the stream per the general contract of
+ * Reader.read(). Returns -1 on error or end of stream.
+ */
+ public int read() {
+ // If we have buffered replace data, use it.
+ if ((buffer != null) && (bufpos < buffer.length())) {
+ return (int) buffer.charAt(bufpos++);
+ }
+
+ // check if input is at a valid position
+ if (!stream.isValid()) return -1;
+
+ REMatch mymatch = new REMatch(expr.getNumSubs(),offset,0);
+ if (expr.match(stream,mymatch)) {
+ mymatch.end[0] = mymatch.index;
+ mymatch.finish(stream);
+ stream.move(mymatch.toString().length());
+ offset += mymatch.toString().length();
+ buffer = mymatch.substituteInto(replace);
+ bufpos = 1;
+
+ if (buffer.length() > 0) {
+ return buffer.charAt(0);
+ }
+ }
+ char ch = stream.charAt(0);
+ if (ch == CharIndexed.OUT_OF_BOUNDS) return -1;
+ stream.move(1);
+ offset++;
+ return ch;
+ }
+
+ /**
+ * Returns false. REFilterReader does not support mark() and
+ * reset() methods.
+ */
+ public boolean markSupported() {
+ return false;
+ }
+
+ /** Reads from the stream into the provided array. */
+ public int read(char[] b, int off, int len) {
+ int i;
+ int ok = 0;
+ while (len-- > 0) {
+ i = read();
+ if (i == -1) return (ok == 0) ? -1 : ok;
+ b[off++] = (char) i;
+ ok++;
+ }
+ return ok;
+ }
+
+ /** Reads from the stream into the provided array. */
+ public int read(char[] b) {
+ return read(b,0,b.length);
+ }
+}