Regex using Dart lang

Question

I'm building a log parser in dart. How can I use dart regex library to retrieve matching values.

Using this link to check my regex, everything is ok wih the following :

• Regex : (?<suffix>^.*m)(?<time>\d{1,2}:\d{1,2}:\d{1,2},\d{1,3}) (?<level>[^\s]+) (?<message>.*)
• Input : [0m[31m22:25:57,366 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-8) MSC000001: Failed to start service jboss.deployment.unit."bad.war".

Entering these values will give you : suffix, time , level and message

I'm not able to use my regex with the dart library.

Answer 1

When running Dart in a browser, it uses the browser's regex engine, and if it supports named capturing groups they will be supported. If not, they won't. When running your code in Flutter, or standalone Dart, namedGroup works as you'd expect.

Use numbered capturing groups and access them by their indices:

RegExp regExp = new RegExp(r"^(.*m)(\d{1,2}:\d{1,2}:\d{1,2},\d{1,3}) ([^\s]+) (.*)");

See this regex demo

In Dart, try something like this:

RegExp regExp = new RegExp(r"^(.*m)(\d{1,2}:\d{1,2}:\d{1,2},\d{1,3}) ([^\s]+) (.*)");
String s = "[0m[31m22:25:57,366 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-8) MSC000001: Failed to start service jboss.deployment.unit.\"bad.war\"";
Iterable<Match> matches = regExp.allMatches(s);
for (Match match in matches) {
  print("${match.group(1)}\n");
  print("${match.group(2)}\n");
  print("${match.group(3)}\n");
  print("${match.group(4)}\n");
}

See this DartPad demo