- Note a subtlety here -- while a Transformer normally matches - at higher priority against the pattern added to it first, this - will not necessarily be true when a multi-line match is in progress - because one of the complete multi-line patterns may not be completely - loaded in RegexWriter's buffer. For this reason, the Transformer - class is equipped with a way to add a pattern and replacement rule - in three pieces -- a beginning (once this matches, nothing else in - the Transformer can match until the whole pattern matches), an - ending (the whole pattern is a String formed by adding the beginning - and ending), and a ReplaceRule. -
- An illustration of this is given in the this - example. - */ -public class RegexWriter - extends Writer -{ - Replacer repr; - Writer w; - WriterWrap ww; - StringBuffer sb = new StringBuffer(); - PartialBuffer wrap = new PartialBuffer(sb); - int pos, epos; - int interval = 128; - int bufferSize = 2 * 1024; - - public RegexWriter(Transformer t, Writer w) - { - this.w = w; - ww = new WriterWrap(w); - repr = t.getReplacer(); - repr.setBuffer(new StringBufferLike(ww)); - repr.setSource(wrap); - } - - public RegexWriter(Regex r, Writer w) - { - this.w = w; - ww = new WriterWrap(w); - repr = r.getReplacer(); - repr.setBuffer(new StringBufferLike(ww)); - repr.setSource(wrap); - } - - char EOLchar = '\n'; - /** This method no longer serves any purpose. - @deprecated - */ - public char getEOLchar() - { - return EOLchar; - } - - /** This method no longer serves any purpose. - @deprecated - */ - public void setEOLchar(char c) - { - EOLchar = c; - } - - int max_lines = 2; - /** This method no longer serves any purpose. - @deprecated - */ - public int getMaxLines() - { - return max_lines; - } - - /** This method no longer serves any purpose. - @deprecated - */ - public void setMaxLines(int ml) - { - max_lines = ml; - } - - void write() - throws IOException - { - Regex rex = repr.getRegex(); - int eposOld = epos; - if (rex.matchAt(wrap, epos) && !wrap.overRun) - { - while (pos < epos) - { - w.write(sb.charAt(pos++)); - } - int to = rex.matchedTo(); - repr.setPos(to); - repr.apply(rex, rex.getReplaceRule()); - epos = pos = to; - if (epos == eposOld && epos < sb.length()) - { - epos++; - } - } - else if (!wrap.overRun && epos < sb.length()) - { - epos++; - } - while (pos < epos) - { - w.write(sb.charAt(pos++)); - } - if (epos == sb.length()) - { - sb.setLength(1); - pos = epos = 1; - } - else if (pos > bufferSize) - { - for (int i = bufferSize; i < sb.length(); i++) - { - sb.setCharAt(i - bufferSize, sb.charAt(i)); - } - pos -= bufferSize; - epos -= bufferSize; - sb.setLength(sb.length() - bufferSize); - } - } - - public void write(char[] ca, int b, int n) - throws IOException - { - int m = b + n; - for (int i = b; i < m; i++) - { - sb.append(ca[i]); - if (sb.length() % interval == interval - 1) - { - wrap.overRun = false; - while (epos + interval < sb.length() && !wrap.overRun) - { - write(); - } - } - } - } - - public void flush() - throws IOException - { - } - - public void close() - throws IOException - { - wrap.allowOverRun = false; - wrap.overRun = false; - while (epos < sb.length()) - { - write(); - } - write(); - w.close(); - } - - /** The current size of the StringBuffer in use by RegexWriter. */ - public int length() - { - return sb.length(); - } - - /** The character at location i in the StringBuffer. */ - public char charAt(int i) - { - return sb.charAt(i); - } - - /** Set the interval at which regex patterns are checked. */ - public void setInterval(int i) - { - interval = i; - } - - /** Get the interval at which regex matches are checked. */ - public int getInterval() - { - return interval; - } - - /** Get the buffer size. */ - public int getBufferSize() - { - return bufferSize; - } - - /** Set the buffer size. */ - public void setBufferSize(int i) - { - bufferSize = i; - } - - static void test(String re, String inp, int n) - throws Exception - { - StringWriter sw = new StringWriter(); - Regex rex = Regex.perlCode(re); - String res1 = rex.replaceAll(inp); - RegexWriter rw = new RegexWriter(rex, sw); - for (int i = 0; i < inp.length(); i++) - { - rw.write(inp.charAt(i)); - } - rw.close(); - String res2 = sw.toString(); - if (!res1.equals(res2)) - { - System.out.println("nmax=" + n); - System.out.println("re=" + re); - System.out.println("inp=" + inp); - System.out.println("res1=" + res1); - System.out.println("res2=" + res2); - System.exit(255); - } - } - - public static void main(String[] args) - throws Exception - { - for (int n = 1; n <= 1; n++) - { - test("s/x/y/", "-----x123456789", n); - test("s/x/y/", "x123456789", n); - test("s/x/y/", "-----x", n); - test("s/x.*?x/y/", ".xx..x..x...x...x....x....x", n); - test("s/x.*x/[$&]/", "--x........x--xx", n); - test("s/x.*x/[$&]/", "--x........x------", n); - test("s/.$/a/m", "bb\nbbb\nbbbb\nbbbbb\nbbbbbb\nbbbbbbbbbbbb", n); - test("s/.$/a/", "123", n); - test("s/.$/a/", "bb\nbbb\nbbbb\nbbbbb\nbbbbbb\nbb", n); - test("s/^./a/", "bb\nbbb\nbbbb\nbbbbb\nbbbbbb\nbb", n); - test("s/$/a/", "bbb", n); - test("s/^/a/", "bbb", n); - test("s/^/a/", "", n); - test("s{.*}{N}", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", n); - test("s/.{0,7}/y/", "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", n); - test("s/x/$&/", "xxx", n); - } - System.out.println("Success!!!"); - } -} +// +// This software is now distributed according to +// the Lesser Gnu Public License. Please see +// http://www.gnu.org/copyleft/lesser.txt for +// the details. +// -- Happy Computing! +// +package com.stevesoft.pat; + +import java.io.IOException; +import java.io.StringWriter; +import java.io.Writer; + +import com.stevesoft.pat.wrap.WriterWrap; + +/** + * A basic extension of FilterWriter that uses Transformer to make replacements + * in data as it is written out. It attempts to transform a string whenever the + * End-of-Line (EOL) character is written (which is, by default, the carriage + * return '\n'). Only the transformed portion of the line is written out, + * allowing the RegexWriter to wait until a complete pattern is present before + * attempting to write out info. Until a pattern completes, data is stored in a + * StringBuffer -- which can be accessed through the length() and charAt() + * methods of this class. + *
+ * Note a subtlety here -- while a Transformer normally matches at higher + * priority against the pattern added to it first, this will not necessarily be + * true when a multi-line match is in progress because one of the complete + * multi-line patterns may not be completely loaded in RegexWriter's buffer. For + * this reason, the Transformer class is equipped with a way to add a pattern + * and replacement rule in three pieces -- a beginning (once this matches, + * nothing else in the Transformer can match until the whole pattern matches), + * an ending (the whole pattern is a String formed by adding the beginning and + * ending), and a ReplaceRule. + *
+ * An illustration of this is given in the this + * example. + */ +public class RegexWriter extends Writer +{ + Replacer repr; + + Writer w; + + WriterWrap ww; + + StringBuffer sb = new StringBuffer(); + + PartialBuffer wrap = new PartialBuffer(sb); + + int pos, epos; + + int interval = 128; + + int bufferSize = 2 * 1024; + + public RegexWriter(Transformer t, Writer w) + { + this.w = w; + ww = new WriterWrap(w); + repr = t.getReplacer(); + repr.setBuffer(new StringBufferLike(ww)); + repr.setSource(wrap); + } + + public RegexWriter(Regex r, Writer w) + { + this.w = w; + ww = new WriterWrap(w); + repr = r.getReplacer(); + repr.setBuffer(new StringBufferLike(ww)); + repr.setSource(wrap); + } + + char EOLchar = '\n'; + + /** + * This method no longer serves any purpose. + * + * @deprecated + */ + @Deprecated + public char getEOLchar() + { + return EOLchar; + } + + /** + * This method no longer serves any purpose. + * + * @deprecated + */ + @Deprecated + public void setEOLchar(char c) + { + EOLchar = c; + } + + int max_lines = 2; + + /** + * This method no longer serves any purpose. + * + * @deprecated + */ + @Deprecated + public int getMaxLines() + { + return max_lines; + } + + /** + * This method no longer serves any purpose. + * + * @deprecated + */ + @Deprecated + public void setMaxLines(int ml) + { + max_lines = ml; + } + + void write() throws IOException + { + Regex rex = repr.getRegex(); + int eposOld = epos; + if (rex.matchAt(wrap, epos) && !wrap.overRun) + { + while (pos < epos) + { + w.write(sb.charAt(pos++)); + } + int to = rex.matchedTo(); + repr.setPos(to); + repr.apply(rex, rex.getReplaceRule()); + epos = pos = to; + if (epos == eposOld && epos < sb.length()) + { + epos++; + } + } + else if (!wrap.overRun && epos < sb.length()) + { + epos++; + } + while (pos < epos) + { + w.write(sb.charAt(pos++)); + } + if (epos == sb.length()) + { + sb.setLength(1); + pos = epos = 1; + } + else if (pos > bufferSize) + { + for (int i = bufferSize; i < sb.length(); i++) + { + sb.setCharAt(i - bufferSize, sb.charAt(i)); + } + pos -= bufferSize; + epos -= bufferSize; + sb.setLength(sb.length() - bufferSize); + } + } + + public void write(char[] ca, int b, int n) throws IOException + { + int m = b + n; + for (int i = b; i < m; i++) + { + sb.append(ca[i]); + if (sb.length() % interval == interval - 1) + { + wrap.overRun = false; + while (epos + interval < sb.length() && !wrap.overRun) + { + write(); + } + } + } + } + + public void flush() throws IOException + { + } + + public void close() throws IOException + { + wrap.allowOverRun = false; + wrap.overRun = false; + while (epos < sb.length()) + { + write(); + } + write(); + w.close(); + } + + /** The current size of the StringBuffer in use by RegexWriter. */ + public int length() + { + return sb.length(); + } + + /** The character at location i in the StringBuffer. */ + public char charAt(int i) + { + return sb.charAt(i); + } + + /** Set the interval at which regex patterns are checked. */ + public void setInterval(int i) + { + interval = i; + } + + /** Get the interval at which regex matches are checked. */ + public int getInterval() + { + return interval; + } + + /** Get the buffer size. */ + public int getBufferSize() + { + return bufferSize; + } + + /** Set the buffer size. */ + public void setBufferSize(int i) + { + bufferSize = i; + } + + static void test(String re, String inp, int n) throws Exception + { + StringWriter sw = new StringWriter(); + Regex rex = Regex.perlCode(re); + String res1 = rex.replaceAll(inp); + RegexWriter rw = new RegexWriter(rex, sw); + for (int i = 0; i < inp.length(); i++) + { + rw.write(inp.charAt(i)); + } + rw.close(); + String res2 = sw.toString(); + if (!res1.equals(res2)) + { + System.out.println("nmax=" + n); + System.out.println("re=" + re); + System.out.println("inp=" + inp); + System.out.println("res1=" + res1); + System.out.println("res2=" + res2); + System.exit(255); + } + } + + public static void main(String[] args) throws Exception + { + for (int n = 1; n <= 1; n++) + { + test("s/x/y/", "-----x123456789", n); + test("s/x/y/", "x123456789", n); + test("s/x/y/", "-----x", n); + test("s/x.*?x/y/", ".xx..x..x...x...x....x....x", n); + test("s/x.*x/[$&]/", "--x........x--xx", n); + test("s/x.*x/[$&]/", "--x........x------", n); + test("s/.$/a/m", "bb\nbbb\nbbbb\nbbbbb\nbbbbbb\nbbbbbbbbbbbb", n); + test("s/.$/a/", "123", n); + test("s/.$/a/", "bb\nbbb\nbbbb\nbbbbb\nbbbbbb\nbb", n); + test("s/^./a/", "bb\nbbb\nbbbb\nbbbbb\nbbbbbb\nbb", n); + test("s/$/a/", "bbb", n); + test("s/^/a/", "bbb", n); + test("s/^/a/", "", n); + test("s{.*}{N}", "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx", n); + test("s/.{0,7}/y/", "AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA", n); + test("s/x/$&/", "xxx", n); + } + System.out.println("Success!!!"); + } +}