Sublime snippet for LaTeX environments with matching and self adjusting comment

enviroment-w-comment.sublime-snippet

<snippet>
	<content><![CDATA[
%==========  ${1/(.+)/\U\1/g}: ${2:Description}  ==========%
\begin{${1:Environment}}
$3
\end{${1:Environment}}
%=============${1/./=/g}=${2/./=/g}============%
]]></content>
	<!-- Optional: Set a tabTrigger to define how to trigger the snippet -->
	<tabTrigger>cenv</tabTrigger>
	<!-- Optional: Set a scope to limit where the snippet will trigger -->
	<scope>text.tex.latex</scope>
	  <!-- Optional: Description to show in the menu -->
    <description>Enviroment with comment</description>
</snippet>

Description

This snippet inserts a LaTeX environment wrapped in a comment where the first part of the comment i automatically filled and capitalized from the environment. The description part must be filled manually.

Example

The snippet is inserted with cenv+tab. When first inserted, the snippet will look like this:

%==========  ENVIRONMENT: Description  ==========%
\begin{Environment}

\end{Environment}
%================================================%

But after filling the Environment placeholder, the snippet will self adjust in with and the first part of the comment is filled and capitalized

%==========  EQUATION: Euler's function  ==========%
\begin{equation}
\phi(q)=\prod_{k=1}\infty(1-q^k)
\end{equation}
%==================================================%