The following testcase used to capture groups, it doesn't capture anymore.

var semver = "\\s*[v=]*\\s*([0-9]+)" // major
           + "\\.([0-9]+)" // minor
           + "\\.([0-9]+)" // patch
           + "(-[0-9]+-?)?" // build
           + "([a-zA-Z-+][a-zA-Z0-9-\.:]*)?" // tag
  , exprComparator = "^((<|>)?=?)\s*("+semver+")$|^$";
  var validComparator = new RegExp("^"+exprComparator+"$");
  
  // Matches should be: >=0.6.0-,>=,>,0.6.0-,0,6,0,,-
  print("Matches " + ">=0.6.0-".match(validComparator));