How to extract parts of (La)TeX document?

How to extract parts of (La)TeX document?

• I want to run queries against LaTeX documents like these: get list of all equations, even if one declares \def\be{\begin{equation}} and uses it; get list of all arguments of some command (e. g. \marginpar), where it has been used in document (again, even if one declares \def\m\marginpar and calls this macro); get the theorem with given counter value. The task seems to require full compiling of all macros, but I want to get arguments in not expanded form --- that is not as blocks and glue, but as user's input (if possible). How can I do such things? Update: ideally, I want to use "semantic markup" to mark parts of documents and generate different views of them. Assume I have smth like this: \beginBlock{calculus} \beginBlock{content} ... lectures... \endBlock \beginBlock{exam} ... problems... \beginBlock{comments} ... comments about criteria and how to evaluate typical mistakes... \endBlock \endBlock[exam] \endBlock[calculus] and similar for linear algebra in other file; I want to generate a report with sections for calculus and linear algebra, containing only exam problems, e. g.

• Answer:

  Let's look at \marginpar. You want to redefine this command to save its arguments in some list to be printed, say, at end document. One has to look the definition of \marginpar, discovering that it's not a command with arguments and it performs a rather complicated series of tasks. So we can't simply add some action to it without examining in detail the macro that are used. A good strategy is to gather the arguments and then put them back for the original \marginpar. \makeatletter \let\saved@marginpar\marginpar \renewcommand\marginpar[2][]{% \if\relax\detokenize{#1}\relax \let\saved@mp@optional\@empty \else \def\saved@mp@optional{[#1]}% \fi \def\saved@mp@mandatory{{#2}}% \saved@mp@add{\saved@mp@print{#1}{#2}}% \expandafter\expandafter\expandafter\saved@marginpar \expandafter\saved@mp@optional\saved@mp@mandatory} \newtoks\saved@mp@toks \def\saved@mp@add#1{\global\saved@mp@toks=\expandafter{\the\saved@mp@toks#1}} \def\printmarginpars{\the\saved@mp@toks} \def\saved@mp@print#1#2{\par\noindent Marginpar\\ Optional: #1\\ Mandatory: #2\par\medskip} \makeatother If you say, after this code, \newcommand{\mpx}{\marginpar} then it will work the same. What do the macro do? \marginpar is redefined to have an optional and a mandatory argument, after having saved a copy of the original command. If the optional argument is empty, then we define \saved@mp@optional to be \@empty, otherwise we define it to expand to the optional argument in brackets. Similarly, we define \saved@mp@mandatory to expand to the mandatory argument in braces. We add the contents of the arguments to the token list we have allocated. We put back the arguments after \saved@marginpar, so LaTeX will do its usual work as if nothing had happened. Example \documentclass{article} \makeatletter \let\saved@marginpar\marginpar \renewcommand\marginpar[2][]{% \if\relax\detokenize{#1}\relax \let\saved@mp@optional\@empty \else \def\saved@mp@optional{[#1]}% \fi \def\saved@mp@mandatory{{#2}}% \saved@mp@add{\saved@mp@print{#1}{#2}}% \expandafter\expandafter\expandafter\saved@marginpar \expandafter\saved@mp@optional\saved@mp@mandatory} \newtoks\saved@mp@toks \def\saved@mp@add#1{\global\saved@mp@toks=\expandafter{\the\saved@mp@toks#1}} \def\printmarginpars{\the\saved@mp@toks} \def\saved@mp@print#1#2{\par\noindent Marginpar\\ Optional: #1\\ Mandatory: #2\par\medskip} \makeatother \newcommand{\mpx}{\marginpar} \begin{document} a\marginpar{xxx} b\mpx[yyy]{zzz} \printmarginpars \end{document}