Import several parts of file at once

Question

As a follow up to this Question

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Situation

I would like to create an excerpt from a script that I have TeX'ed as a compendium of the most important statements (theorems & definitions).

I seek to import parts of a file in a way to keep the original numbering (as in the above mentioned question), which is why the MWE imports all, but does not print certain parts.

In order to make the import easier, I would prefer just one (or two) type(s) of tag(s): %<*include> ... %</include> (& %<*exclude> ... %</exclude>). In the file for the shortened version I need a way to go through all tags and display some (while hiding others).

This would mean a lot less work! Is there a way to achieve this by importing with a loop, macro or maybe some other package ?

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QUESTION

Is it possible to have a loop or some macro import all tagged parts of a file while excluding others?

Note: A similar unanswered question does not take into account the numbering and thus different import

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MWE by touhami (slightly altered)

first file (with tags)

\documentclass{amsart}
\usepackage{lipsum}

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}
\newtheorem{example}[theorem]{Example}
\begin{document}
%<*tag>
\lipsum[1]
Here we go
%</tag>
%<*atag> 
\begin{definition}
    some bla bla
\end{definition}
%</atag>
\begin{theorem}
    more bla bla
\end{theorem}
\begin{definition}
    some bla bla
\end{definition}
%<*btag>
\begin{definition}
    some bla bla
\end{definition}
\begin{theorem}
    more bla bla
\end{theorem}
%</btag>
%<*ctag>
\lipsum[1-2]
%</ctag>
%<*dtag>
\begin{lemma}
    more bla bla
\end{lemma}
\begin{theorem}
    more bla bla
\end{theorem}
%</dtag>
%<*etag>
\lipsum[1-2]
\begin{example}
    some bla bla
\end{example}
%</etag>
\begin{theorem}
    more bla bla
\end{theorem}
\end{document}

final file

\documentclass{amsart}
\usepackage{lipsum}

\usepackage{catchfilebetweentags}
\newtoks\temptoken

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\theoremstyle{definition}
\newtheorem{definition}[theorem]{Definition}
\newtheorem{example}[theorem]{Example}
\begin{document}
\lipsum[1]
\CatchFileBetweenTags\temptoken{equ}{tag}% capture part1
\setbox0=\vbox{\the\temptoken}%  skip part1
\CatchFileBetweenTags\temptoken{equ}{atag}% capture part2
\the\temptoken % display part2

\CatchFileBetweenTags\temptoken{equ}{btag}% capture part3
\setbox0=\vbox{\the\temptoken}%  skip part3
\CatchFileBetweenTags\temptoken{equ}{ctag}% capture part4
\setbox0=\vbox{\the\temptoken}%  skip part4

\CatchFileBetweenTags\temptoken{equ}{dtag}% capture part5
\the\temptoken%  display part5
\end{document}

(the odd numbering is intended!)

Answer 1

Here is a solution.

Here we need one tage tag and we use newenvironment mtexclude: this environment does nothing for the original file and for the newfile it save its content to a box \mtbox so the content is skiped.

file.tex (original file)

\documentclass{amsart}
\usepackage{lipsum}

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\theoremstyle{definition}
\newtheorem{definition}{Definition}
\newtheorem{example}{Example}
\newenvironment{mtexclude}{}{}
\begin{document}
First bla bla
%<*tag>
\section{Foo}
\subsection{Foo bar}
I need this
\begin{mtexclude}% begin of part to skiped
\section{Baz}
\subsection{Baz bar}
no need for this
\end{mtexclude}%   end
\section{End}
\subsection{End bar}
and need this \dots 
\begin{mtexclude}% begin of part to skiped
\section{Baz 2}
\subsection{Baz bar 2}
another part to be skiped
\end{mtexclude}%   end
The end
%</tag>
Last bla bla
\end{document}

newfile.tex

\documentclass{amsart}
\usepackage{lipsum}

\usepackage{catchfilebetweentags}
\newtoks\temptoken
\newbox\mtbox
\newenvironment{mtexclude}{\setbox\mtbox\vbox\bgroup}{\egroup}

\newtheorem{theorem}{Theorem}
\newtheorem{lemma}[theorem]{Lemma}
\theoremstyle{definition}
\newtheorem{definition}{Definition}
\newtheorem{example}{Example}

\begin{document}
\lipsum[1]
\CatchFileBetweenTags\temptoken{file}{tag}
\the\temptoken

\end{document}