Re: regex capability

From:
markspace <-@.>
Newsgroups:
comp.lang.java.programmer
Date:
Tue, 05 Apr 2011 10:07:21 -0700
Message-ID:
<infi8i$gfu$1@dont-email.me>
On 4/5/2011 6:33 AM, Robert Klemme wrote:

On Apr 5, 2:35 am, markspace<-@.> wrote:

Why re-invent the wheel?


In this case I just wanted to demonstrate the strategy to first check
overall validity of the input and extract the interesting part and
then ripping that interesting part apart. Whether a Scanner or
another Matcher is used for the second step wasn't that important to
me. Also, the thread is called "regex capability". :-)


Fair enough. :)

But, of course, your approach using the Scanner is perfectly
compatible with the two step strategy as Patricia also pointed
out. :-)


Don't forget too that Scanner can do other things besides use
delimiters. It has methods like skip() and findInLine() that ignore
delimiters and could be used to build a simple parser. You can also
change the delimiters on the fly to extract different sections of text.

A simple change to my example above:

public class ScannerTest {
     public static void main(String[] args) {
         StringReader in = new StringReader(
                 "Support DDR2 100/200/300/400 DDR2 SDRAM");

         Scanner scanner = new Scanner(in);
         scanner.findInLine( "Support DDR2" );
         scanner.useDelimiter( "[ /]+" );
         while( scanner.hasNextInt() ) {
             System.out.println( scanner.nextInt() );
         }
     }
}

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