Scanner - parsing code values using delimiter regex

Question

I'm trying to use a Scanner to read in lines of code from a string of the form "p.addPoint(x,y);"

The regex format I'm after is:

*anything*.addPoint(*spaces or nothing* OR ,*spaces or nothing*

What I've tried so far isn't working: [[.]+\\\\.addPoint(&&[\\\\s]*[,[\\\\s]*]]

Any ideas what I'm doing wrong?

Answer 1

I tested this in Python, but the regexp should be transferable to Java:

>>> regex = '(\w+\.addPoint\(\s*|\s*,\s*|\s*\)\s*)'
>>> re.split(regex, 'poly.addPoint(3, 7)')
['', 'poly.addPoint(', '3', ', ', '7', ')', '']

Your regexp seems seriously malformed. Even if it wasn't, matching infinitely many repetitions of the . wildcard character at the beginning of the string would probably result in huge swaths of text matching that aren't actually relevant/desired.

Edit: Misunderstood the original spec., current regexp should be correct.

Answer 2

Another way:

public class MyPattern {

    private static final Pattern ADD_POINT;
    static {
        String varName = "[\\p{Alnum}_]++";
        String argVal = "([\\p{Alnum}_\\p{Space}]++)";
        String regex = "(" + varName + ")\\.addPoint\\(" + 
                argVal + "," + 
                argVal + "\\);";
        ADD_POINT = Pattern.compile(regex);
        System.out.println("The Pattern is: " + ADD_POINT.pattern());
    }

    public void findIt(String filename) throws FileNotFoundException {
        Scanner s = new Scanner(new FileReader(filename));

        while (s.findWithinHorizon(ADD_POINT, 0) != null) {
            final MatchResult m = s.match();
            System.out.println(m.group(0));
            System.out.println("   arg1=" + m.group(2).trim());
            System.out.println("   arg2=" + m.group(3).trim());
        }
    }

    public static void main(String[] args) throws FileNotFoundException {
        MyPattern p = new MyPattern();
        final String fname = "addPoint.txt";
        p.findIt(fname);
    }

}