Cannot create an environment for a table cell

Question

I have an environment whose behavior depends some outer circumstances. In some cases, the environment should act as a table cell (and in other cases it should act as a paragraph). The appropriate \begin{tabular}{...} and \end{tabular} are printed by another macros, which also change their behavior appropriately.

However, I can't define the appropriate environment. The MWE is:

\documentclass{article}
\newenvironment{cell}{}{&}
\begin{document}
\begin{tabular}{lll}
\begin{cell}
    abc
\end{cell}
\end{tabular}
\end{document}

What am I doing wrong and how can I fix it?

The & has to be actually seen by the tabular, and not merely produced by some intermediate macro/environment. Thus, you would need \newenvironment{cell}{}{} and \begin{tabular}{lll} \begin{cell} abc \end{cell}&& \end{tabular} — Steven B. Segletes, Aug 25 '23 at 22:14
basically you can either not use an environment for the cell, or not use \halign/tabular and make your environment produce boxes of known size that you can stack to make an alignment — David Carlisle, Aug 25 '23 at 23:06

score 0 · Answer 1 · answered Aug 26 '23 at 17:37

Using this post: https://tex.stackexchange.com/a/8084/168600 I've found a solution:

\documentclass{article}
\usepackage{environ}
\NewEnviron{cell}{%
  \expandafter\gdef\expandafter\gtemp\expandafter{%
    \BODY\expandafter&
  }%
  \aftergroup\gtemp
}
\begin{document}
\begin{tabular}{l|l|l|l}
\begin{cell}
    abc
\end{cell}
\begin{cell}
    def
\end{cell}
\end{tabular}
\end{document}

Cannot create an environment for a table cell

1 Answers1