I think the intent is to behave the same way as the Pig "matches" operator (which, unsurprisingly, uses the Java matches method).
RegexExtractAll becomes quite confusing if it means "extract all matched subexpressions of the first match of the expression" (one might expect "all" to refer to all matches of the expression itself). At the very least, the behavior should be documented. On Fri, Feb 3, 2012 at 5:29 PM, Romain Rigaux <[email protected]>wrote: > Hello, > > REGEX_EXTRACT is using Matcher.find() instead of Matcher.matches() and so > does not work with some non greedy regular expression. > > Is it the wanted behavior? > > Thanks, > > Romain > > > http://docs.oracle.com/javase/1.4.2/docs/api/java/util/regex/Matcher.html > > > > - > > The > matches<http://docs.oracle.com/javase/1.4.2/docs/api/java/util/regex/Matcher.html#matches()> > method > attempts to match the entire input sequence against the pattern. > - The > find<http://docs.oracle.com/javase/1.4.2/docs/api/java/util/regex/Matcher.html#find()> > method > scans the input sequence looking for the next subsequence that matches the > pattern. > > > > > System.out.println("Pig's way with m.find()"); > String a = "hdfs://mygrid.com/projects/"; > Matcher m = Pattern.compile("(.+?)/?").matcher(a); > System.out.println(m.find()); > System.out.println(m.group(1)); > System.out.println(m.start()); > System.out.println(m.end()); > > System.out.println("\nm.matches()"); > a = "hdfs://mygrid.com/projects/"; > m = Pattern.compile("(.+?)/?").matcher(a); > System.out.println(m.matches()); > System.out.println(m.group(1)); > System.out.println(m.start()); > System.out.println(m.end()); > > System.out.println("\nREGEX_EXTRACT m.find()"); > Tuple t = TupleFactory.getInstance().newTuple(); > t.append(a); > t.append("(.+?)/?"); > t.append(1); > System.out.println(new TestPigExtractAll().new > REGEX_EXTRACT().exec(t)); > > > Output: > > Pig's way with m.find() > true > h > 0 > 1 > > m.matches() > true > hdfs://mygrid.com/projects > 0 > 27 > > REGEX_EXTRACT m.find() > h > > >
