php - Java Regexp: UNGREEDY flag

Question

I'd like to port a generic text processing tool, Texy!, from PHP to Java.

This tool does ungreedy matching everywhere, using preg_match_all("/.../U"). So I am looking for a library, which has some UNGREEDY flag.

I know I could use the .*? syntax, but there are really many regular expressions I would have to overwrite, and check them with every updated version.

I've checked

• ORO - seems to be abandoned
• Jakarta Regexp - no support
• java.util.regex - no support

Is there any such library?

Thanks, Ondra

Answer 1

Update: After checking the docs I found the LAZY flag, which is another term for non-greedy. However it only appears to be available in OpenJDK

p = Pattern.compile("your regex here", LAZY);
p.matcher("string to match")

Original deprecated response I honestly don't think there's one.

The whole point of the +? and *? is so that you can choose which sections to do greedily and which ones to do lazily.

Greedy is the default behaviour because that's the most commonly use of + and * in regular expressions. In fact I can't think of a single regex parser that does it the other way around. As in where a modifier is used to make something greedy, and the default is lazy matching.

I know this isn't the answer you're looking for, but, the only way I think you'll be able to make it work is to add the ? to your *'s and +'s. On the upside you can use regular expressions to help determine which ones need to be changed. Or even make the changes for you if all of them need to be changed. Or if you can can describe a pattern that identifies which need to be changed.