overline and bar are mixed up in pandoc 2.9.1.1

[pianzuo]

I don't know whether or not this is a bug. I use pandoc 2.9.1.1.
This is a very simple demo latex:
\documentclass{article}
\begin{document}
This is overline: $\overline{ABC}$.

This is bar: $\bar{ABC}$.
\end{document}
The correct result looks like this:

But if I run convert it to MS word by command:
pandoc demo.tex -o demo.docx
I get:

All files are in the attached zip file.demo.zip

[jgm]

texmath does distinguish these in parsing, but the distinction apparently gets collapsed when rendering to OMML.

 %     texmath -t native
\overline{ABC} \bar{ABC}
[EOver False (EGrouped [EIdentifier "A",EIdentifier "B",EIdentifier "C"]) (ESymbol TOver "\175"),EOver False (EGrouped [EIdentifier "A",EIdentifier "B",EIdentifier "C"]) (ESymbol Accent "\8254")]

[pianzuo]

Oh, thx. Is this will be handled in the next version of pandoc? or next version of texmath?

[pianzuo]

I have tried it texmath demo [here](https://johnmacfarlane.net/texmath.html. LaTeX convert to MathML and then convert back works fine.

[jgm]

Yes - texmath's tex parsing and MathML rendering do distinguish these things. But its OMML rendering (Word equation) does not.

[pianzuo]

I think word equation also distinguish these things. This is a example:

The first one is input as \overline(A)[sp]\overline(B)[sp]\overline(C)[sp] under math mode. [sp] means press space key. The second one is input as A\bar[sp]B\bar[sp]C\bar[sp] under math mode.

Example files:
demo2.docx

[pianzuo]

I unzip demo2.docx as a zip. Then the first A looks like:
<m:bar>
<m:barPr>
<m:pos m:val="top"/>
<m:ctrlPr>
<w:rPr>
<w:rFonts w:ascii="Cambria Math" w:hAnsi="Cambria Math"/>
<w:i/>
</w:rPr>
</m:ctrlPr>
</m:barPr>
<m:e>
<m:r>
<w:rPr>
<w:rFonts w:ascii="Cambria Math" w:hAnsi="Cambria Math" w:hint="eastAsia"/>
</w:rPr>
<m:t>A</m:t>
</m:r>
</m:e>
</m:bar>

The second A looks like
<m:acc>
<m:accPr>
<m:chr m:val="̅"/>
<m:ctrlPr>
<w:rPr>
<w:rFonts w:ascii="Cambria Math" w:hAnsi="Cambria Math"/>
<w:i/>
</w:rPr>
</m:ctrlPr>
</m:accPr>
<m:e>
<m:r>
<w:rPr>
<w:rFonts w:ascii="Cambria Math" w:hAnsi="Cambria Math" w:hint="eastAsia"/>
</w:rPr>
<m:t>A</m:t>
</m:r>
<m:ctrlPr>
<w:rPr>
<w:rFonts w:ascii="Cambria Math" w:hAnsi="Cambria Math" w:hint="eastAsia"/>
<w:i/>
</w:rPr>
</m:ctrlPr>
</m:e>
</m:acc>

[pianzuo]

Then I convert demo2.docx to demo2.tex, they are mixed up.
(\overline{A}\overline{B}\overline{C}) v.s.
(\overline{A}\overline{B}\overline{C})

I put demo2.tex in here. demo2.zip

[pianzuo]

So I think there maybe some problem with the translation between mathml and word.

[jgm]

texmath doesn't go via a MathML intermediary. It uses a Haskell data structure. But yes, the problem lies there, in the translation from our equation structure to omml.

[jgm]

Thank you for the xml samples, which show the output we should be getting.

[jgm]

To recap, overline is parsed as

EOver False XXX (ESymbol TOver "\175")

and bar as

EOver False XXX (ESymbol Accent "\8254")

We want to use m:bar in the first case and m:acc in the second.

[pianzuo]

thx for reply.

[jgm]

With this patch

diff --git a/src/Text/TeXMath/Writers/OMML.hs b/src/Text/TeXMath/Writers/OMML.hs
index 342d95fa..23a7b555 100644
--- a/src/Text/TeXMath/Writers/OMML.hs
+++ b/src/Text/TeXMath/Writers/OMML.hs
@@ -221,11 +221,11 @@ showExp props e =
      | n > 1.8               -> [str props "\x2001\x2001"]
      | otherwise             -> [str props "\x200B"]
        -- this is how the xslt sheet handles all spaces
-   EUnder _ x (ESymbol _ (T.unpack -> [c])) | isBarChar c ->
+   EUnder _ x (ESymbol TUnder t) | T.all isBarChar t ->
                        [mnode "bar" [ mnode "barPr" $
                                         mnodeA "pos" "bot" ()
                                     , mnode "e" $ showExp props x ]]
-   EOver _ x (ESymbol _ (T.unpack -> [c])) | isBarChar c ->
+   EOver _ x (ESymbol TOver t) | T.all isBarChar t ->
                        [mnode "bar" [ mnode "barPr" $
                                         mnodeA "pos" "top" ()
                                     , mnode "e" $ showExp props x ]]

we get the following output:

% stack exec texmath -- -t tex -t omml
\bar{AB} \overline{AB}
<m:oMathPara>
  <m:oMathParaPr>
    <m:jc m:val="center" />
  </m:oMathParaPr>
  <m:oMath>
    <m:acc>
      <m:accPr>
        <m:chr m:val="‾" />
      </m:accPr>
      <m:e>
        <m:r>
          <m:t>A</m:t>
        </m:r>
        <m:r>
          <m:t>B</m:t>
        </m:r>
      </m:e>
    </m:acc>
    <m:bar>
      <m:barPr>
        <m:pos m:val="top" />
      </m:barPr>
      <m:e>
        <m:r>
          <m:t>A</m:t>
        </m:r>
        <m:r>
          <m:t>B</m:t>
        </m:r>
      </m:e>
    </m:bar>
  </m:oMath>
</m:oMathPara>

which looks right I think. However, this induces a number of failures in our automated tests, which I'll need to go through and look at before committing.