RegEx Capturing Groups with Sublime

Parentheses in regular expression (RegEx) can be used for grouping expression.

Within the same expression you can backreference the group using the following:

\<GROUP_POSITION>

<GROUP_POSITION> is the quantitative location of the group from left to right starting from 1.

On the replace field, it follows the <GROUP_POSITION> but instead of using backslash (i.e. \) use dollar sign (i.e. $) to precedes it.

Note: if your group exceeds a single digit use ${<nn>} (e.g. ${10}) notation.

Example

<?xml version="1.0"?>
<fruits>
 <a>apple</a>
 <b></b>
 <c>cashew</c>
 <d></d>
</fruits>

From the XML above find all the empty elements and add an attribute empty that is set to true.