Thanks for the help folks.
I don't understand why this would be an issue with the latex reader- that's a comment about me, not pandoc! - so I apologise for the laborious pace of this question...

If I change the test document to:

$ cat test.md
... \ae robe

that's three periods then the ligature

and look at the native format:

$ pandoc -S -f markdown -t native test.md > test.native

[Para [Str "\8230",Space,RawInline (Format "tex") "\\ae ",Str "robe"]]

so the three periods are converted to the correct ellipsis character, and the ligature is parsed to a RawInline

then outputting latex from this native representation:

$ pandoc -S -f native -t latex test.native

\ldots{} \ae robe

so Str "\8230" is converted to \dots, and the ligature is done from RawInline

converting the same native to html:

$ pandoc -S -f native -t html test.native
<p>… robe </p>

the Str"\8230" is printed as the single ellipsis character, and the RawInline is dropped.

It seems as if the md reader can parse three periods to an ellipsis character, but doesn't have a representation of the ligature that would work in both HTML and LaTex - thought it would work in LuaLaTeX/XeTex if it outputted the ligature character (e.g. Str"\8230").

Might it work if the ligature was recognised as something like:

Ligature(ae) was generated in the native format, which could then be converted by whatever writer produced the output format?

again, thanks for your patience and help

Chris

On Tuesday, 22 September 2015 06:55:14 UTC+10, John MacFarlane wrote:
Ideally pandoc's latex reader would recognize \ae and

convert it to the proper character, so feel free to put
an issue on the bug tracker about this.

+++ 'Jason Seeley' via pandoc-discuss [Sep 21 15 07:50 ]:
> Hello,
> Ligatures like \ae are specific to the LaTeX (and thus PDF) writer, so
> they don't work in any other formats. Pandoc just passes it through
> unchanged. For HTML output, you can use an entity: `Æ` or
> `æ`, for upper case or lower case. Another option is to use the
> unicode character directly (how you do this depends on your system and
> text editor; in Windows hold Alt and type 0230 on the number pad; in
> vim type CTRL-K a e; use a character-map app, etc.) This should work
> for most output formats. It'll work with LaTeX if you use XeLaTeX or
> LuaLaTeX, as those allow unicode input.
> Jason
> On Monday, September 21, 2015 at 5:57:37 AM UTC-5, Chris Wright wrote:
>
> I want to publish a document with an \ae ligature to html and to pdf.
> The latex form "\ae robic" converts to the appropriate form and
> displays properly in pdf, but the html just drops the ligature.
>
> Simple test case:
>
> chriswri$ cat > test.txt
>
> \ae robic
>
> chriswri$ more test.txt
>
> \ae robic
>
> chriswri$ pandoc -t native test.txt
>
> [Para [RawInline (Format "tex") "\\ae ",Str "robic"]]
>
> chriswri$ pandoc -t html test.txt
>
> <p>robic</p>
>
> What's the best way around this - write a filter? finding some docs
> that will help? (I've found that ... is automatically converted to an
> ellipsis - so \dots isn't necessary).
>
> with thanks
>
> Chris
>
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