Putting custom environment (using environ package) start and ends in commands

Question

I was trying to write an environment using the environ package. The new environment can be defined without any problem. For some personal reasons, I want to put the start and end of environments to some macros.

See this MWE:

\documentclass{article}

\usepackage{environ}

\makeatletter
\NewEnviron{workpl@n}{\BODY}[\relax]

% The following will not pose any problem
% \newenvironment{workpl@n}{\relax}{\relax}

\def\beginworkplan{\begin{workpl@n}}
\def\endworkplan{\end{workpl@n}}
\makeatother

\begin{document}

% Does not work
% \beginworkplan

\makeatletter
% Works 
\begin{workpl@n}

Plan

% Works 
\end{workpl@n}

% Does not work
% \endworkplan
\makeatother

\end{document}

Strangely, \beginworkplan, \endworkplan command pair fails with the message:

! LaTeX Error: \begin{workpl@n} on input line 14 ended by \end{document}.

However, if the environment is started and finished directly (using \begin{workpl@n} and \end{workpl@n}), it also works.

Moreover, if a new environment is defined using the basic \newenvironment command, putting the start and end of environments to\beginworkplan and \endworkplan does not pose any problem at all.

I need to use \NewEnviron since I have the necessity to collect the environment body.

Answer 1

Note that an environment defined with \NewEnviron has to see \end in order to determine the extent of the body.

However, you don't need environ for your purpose, but I surely cannot recommend doing things this way.

\documentclass{article}

\long\def\beginworkplan#1\endworkplan{%
  whatever with #1% #1 here is the same as \BODY with \NewEnviron
}

\begin{document}

\beginworkplan
Plan
\endworkplan
\makeatother

\end{document}