Today we’re announcing the public release of RE2/J: a pure-Java implementation of the popular RE2 regular expression library. Although RE2/J is not always faster than java.util.regexp, its running time is always linear in the size of the input. Thus when matching larger inputs, especially against patterns containing a high degree of alternation, RE2/J may be dramatically faster. With a backtrackin
![RE2/J: Linear-time regular-expression matching for Java](https://cdn-ak-scissors.b.st-hatena.com/image/square/b722ab6a8d0eea5af96be1d0582d119630c663bc/height=288;version=1;width=512/https%3A%2F%2Fopensource.google%2Fimages%2Fos-anim-main.gif)