Latex macro in markdown input mangled in latex output

[njbart]

Issue #554 is still unsolved:

With test.txt containing:

\newcommand{\tuple}[1]{\langle #1 \rangle}
\renewcommand{\tuple}[1]{\langle #1 \rangle}
\providecommand{\tuple}[1]{\langle #1 \rangle}

$\tuple{a, b, c}$

and command line: pandoc -t latex test.txt (pandoc 1.10.0.5)

I get:

\providecommand{\tuple}{[}1{]}\{\langle \#1 \rangle\}

$\tuple{a, b, c}$

i.e., newcommand and renewcommand don't even make it into the output, while providecommand does (fine with me, since providecommand is a replacement for both newcommand and renewcommand anyway), but the docs mention newcommand and renewcommand only.

More importantly, [1] is mangled into {[}1{]}, breaking latex.

[kennknowles]

Oh, I was unaware of \providecommand; superb. Perhaps a add that last paragraph to the README?

[njbart]

Actually, it’s more complicated: “LaTeX will not allow you to create a new command that would overwrite an existing one. But there is a special command in case you explicitly want this: \renewcommand. It uses the same syntax as the \newcommand command. In certain cases you might also want to use the \providecommand command. It works like \newcommand, but if the command is already defined, LaTeX will silently ignore the new command.” (https://en.wikibooks.org/wiki/LaTeX/Macros)

So after rechecking, I’m positive we need all three commands.

[njbart]

Thank you: newcommand and renewcommand work as expected now in pandoc 1.10.1.

But could providecommand be added, too?

[jgm]

+++ nickbart1980 [Jan 29 13 04:58 ]:

Thank you: newcommand and renewcommand work as expected now in pandoc
1.10.1.

But could providecommand be added, too?

That will require changes to the texmath library. So yes, eventually.

[jgm]

I opened an issue at jgm/texmath#15 for \providecommand. I'll close this one.

[ziggystar]

I'm using pandoc 1.12.3 and \newcommand{\Par}[1]{\text{Par}(#1)} gets mangled into

\newcommand{\Par}

{[}1{]}\{\text{Par}(\#1)\}

[jgm]

Really? Here's what I'm seeing:

% pandoc --version
Compiled with texmath 0.6.6, highlighting-kate 0.5.6.
Syntax highlighting is supported for the following languages:
    actionscript, ada, apache, asn1, asp, awk, bash, bibtex, boo, c, changelog,
    clojure, cmake, coffee, coldfusion, commonlisp, cpp, cs, css, curry, d,
    diff, djangotemplate, doxygen, doxygenlua, dtd, eiffel, email, erlang,
    fortran, fsharp, gnuassembler, go, haskell, haxe, html, ini, java, javadoc,
    javascript, json, jsp, julia, latex, lex, literatecurry, literatehaskell,
    lua, makefile, mandoc, markdown, matlab, maxima, metafont, mips, modelines,
    modula2, modula3, monobasic, nasm, noweb, objectivec, objectivecpp, ocaml,
    octave, pascal, perl, php, pike, postscript, prolog, python, r,
    relaxngcompact, restructuredtext, rhtml, roff, ruby, rust, scala, scheme,
    sci, sed, sgml, sql, sqlmysql, sqlpostgresql, tcl, texinfo, verilog, vhdl,
    xml, xorg, xslt, xul, yacc, yaml
Default user data directory: /Users/jgm/.pandoc
Copyright (C) 2006-2013 John MacFarlane
Web:  http://johnmacfarlane.net/pandoc
This is free software; see the source for copying conditions.  There is no
warranty, not even for merchantability or fitness for a particular purpose.
% pandoc -t latex
\newcommand{\Par}[1]{\text{Par}(#1)}
^D
\newcommand{\Par}[1]{\text{Par}(#1)}

which looks fine. Can you try exactly the same commands?

+++ ziggystar [Jan 13 14 06:33 ]:

I'm using pandoc 1.12.3 and \newcommand{\Par}[1]{\text{Par}(#1)} gets
mangled into
\newcommand{\Par}

{[}1{]}{\text{Par}(#1)}

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References

1. Latex macro in markdown input mangled in latex output #730 (comment)

[ziggystar]

Today it works, I'm completely puzzled. Thank you.

P.S.: Got it. Depending on how I call pandoc, either cabal or system installation of pandoc is used. So I was using an older version than I thought.

[Rufflewind]

Is it a good idea to expand \providecommand? Pandoc doesn't necessarily have the full context of the LaTeX processor. I sometimes use \providecommand to provide fallbacks if the document class lacks certain commands, but now (as of v2) Pandoc unconditionally expands them, which breaks this particular use case.

[jgm]

\providecommand defines the command only if it's not already defined. So it's inherently conditional, no? If \institute is defined, then the \providecommand has no effect. +++ Phil Ruffwind [Nov 26 17 03:15 ]:

…

Is it a good idea to expand \providecommand? Pandoc doesn't necessarily have the full context of the LaTeX processor. I sometimes use \providecommand to provide fallbacks if the document class lacks certain commands, but now (as of v2) Pandoc unconditionally expands them, which breaks this particular use case. — You are receiving this because you commented. Reply to this email directly, [1]view it on GitHub, or [2]mute the thread. References 1. #730 (comment) 2. https://github.com/notifications/unsubscribe-auth/AAAL5NZgYi7dbZrKj90aXaWUo7Ua2qoSks5s6Ne8gaJpZM4AYzJJ

[Rufflewind]

That assumes Pandoc can correctly detect whether a command is defined, which would require a full-blown TeX processor. Consider:

\providecommand{\wideparen}[1]{fail #1}

$\wideparen{test}$

$ pandoc -s -M fontfamily=fouriernc test.md  -o test.pdf

This (as of v2) outputs “fail test” even though fouriernc defines \wideparen, but if I add -f markdown-latex_macros to suppress Pandoc’s macro expansion, it will produce the correct output (with a parenthesis that stretches across “test”) as it did in v1.

[jgm]

Pandoc's macro resolution isn't foolproof, for the reason you give. Still, in general resolving macros is going to give better results for non-tex output. The key is to use the `-latex-macros` extension when you're going to latex or pdf. +++ Phil Ruffwind [Nov 26 17 15:47 ]:

…

That assumes Pandoc can correctly detect whether a command is defined, which would require a full-blown TeX processor. Consider: \providecommand{\wideparen}[1]{fail #1} $\wideparen{test}$ $ pandoc -s -M fontfamily=fouriernc test.md -o test.pdf This (as of v2) outputs “fail test” even though fouriernc defines \wideparen, but if I add -f markdown-latex_macros to suppress Pandoc’s macro expansion, it will produce the correct output (with a parenthesis that stretches across “test”) as it did in v1. — You are receiving this because you commented. Reply to this email directly, [1]view it on GitHub, or [2]mute the thread. References 1. #730 (comment) 2. https://github.com/notifications/unsubscribe-auth/AAAL5BNebbDEI0f-5RHuvlWP51k-nKQmks5s6YgNgaJpZM4AYzJJ