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copied!<p>No, you can't do this. If you look at the definition of the Parser used when you convert a regex to a Parser, it throws away all context and just returns the full matched string:</p> <p><a href="http://lampsvn.epfl.ch/trac/scala/browser/scala/tags/R_2_7_7_final/src/library/scala/util/parsing/combinator/RegexParsers.scala?view=markup#L55" rel="nofollow noreferrer">http://lampsvn.epfl.ch/trac/scala/browser/scala/tags/R_2_7_7_final/src/library/scala/util/parsing/combinator/RegexParsers.scala?view=markup#L55</a></p> <p>You have a couple of other options, though:</p> <ul> <li>break up your parser into several smaller parsers (for the tokens you actually want to extract)</li> <li>define a custom parser that extracts the values you want and returns a domain object instead of a string</li> </ul> <p>The first would look like</p> <pre><code>val separator = "-" | "/" val year = ("""\d{4}"""r) <~ separator val month = ("""\d\d"""r) <~ separator val day = """\d\d"""r val date = ((year?) ~ (month?) ~ day) map { case year ~ month ~ day => (year.getOrElse("2009"), month.getOrElse("11"), day) } </code></pre> <p>The <code><~</code> means "require these two tokens together, but only give me the result of the first one.</p> <p>The <code>~</code> means "require these two tokens together and tie them together in a pattern-matchable ~ object.</p> <p>The <code>?</code> means that the parser is optional and will return an Option.</p> <p>The <code>.getOrElse</code> bit provides a default value for when the parser didn't define a value.</p>

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