How do I use ACCEPT_INCOMPLETE?

[Eli]

I know that I use it as a parameter to find() but how do I get useful information out of the MatchResult methods? I tried it and got these results.

With this test class:

JRegexTest.java
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package net.BeechHaven.Eli.test;
import java.io.InputStreamReader;
import java.io.BufferedReader;
import java.io.IOException;
import jregex.Pattern;
import jregex.Matcher;

public class JRegexTest
{
    public static void main(String[] args) throws IOException
    {
        String regex = args[0];
        Pattern pattern;
        if (args.length > 1) {pattern = new Pattern(args[0],args[1]);}
        else pattern = new Pattern(args[0]);

        String text = new BufferedReader(new InputStreamReader(System.in)).readLine();
        Matcher matcher = pattern.matcher(text);
        System.out.println("Searching \""+matcher.target()+"\" for pattern \""+matcher.pattern().toString()+"\"...");

        while (matcher.find(Matcher.ACCEPT_INCOMPLETE))
        {
            System.out.println("found match \""+matcher.group(0)+"\" of length "+matcher.length()+" between indices "+matcher.start()+" and "+matcher.end());
            System.out.println("prefix|match|suffix = \""+matcher.prefix()+"|"+matcher.group(0)+"|"+matcher.suffix()+"\"");
        }
    }
}
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and this command:
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echo cat | java JRegexTest a.a"
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I get the output:
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found match "null" of length -1 between indices 0 and -1
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followed by a StringIndexOutOfBoundsException