Cannot render circumflex

[apjanke]

Copied from rtomayko/ronn#101.

The following Markdown snippet contains a circumflex but it is discarded (or converted to an "=") in the conversion to roff. There does not appear to be a way to render a circumflex.

[~/tmp/ronn-test/render-circumflex]
$ cat test.md                                                                                                                             ✘ 1
# test - render a circumflex

## DESCRIPTION

We are trying to render a circumflex.

y = 2^x

[~/tmp/ronn-test/render-circumflex]
$ ronn test.md
warn: cannot load such file -- ronn. adding /Users/janke/local/repos/ronn-ng/lib to RUBYLIB ...
     roff: ./test
warn: unrecognized inline tag: "sup"
     html: ./test.html                                           +man
[~/tmp/ronn-test/render-circumflex]
$ cat test
.\" generated with Ronn-NG/v0.7.3
.\" http://github.com/apjanke/ronn-ng/tree/0.7.3
.
.TH "TEST" "" "December 2018" "" ""
.
.SH "NAME"
\fBtest\fR \- render a circumflex
.
.SH "DESCRIPTION"
We are trying to render a circumflex\.
.
.P
y = 2
[~/tmp/ronn-test/render-circumflex]
$

[apjanke]

In the HTML section, it renders like this:

<p>y = 2<sup>x</sup></p>

and the warning says warn: unrecognized inline tag: "sup", so I bet it's just dropping the contents of that <sup> tag, which is the missing ^x.

[apjanke]

I added a hacky handling that converts the HTML <sup>...</sup> back to ^(...) in the roff text.

[apjanke]

Re-opening this because I'm not sure I handled it right.

I read through the main Markdown syntax definition, and it doesn't have a "^" for superscript markup. So I'm not sure why it's getting converted as such. Maybe it's an extension in rdiscount or another Markdown library being used?

[apjanke]

Yep, the "^ for superscript" is an RDiscount extension. I've disabled it in the processor by using RDiscount's :strict mode.

Newer versions of RDiscount support a specific :no_superscript option, but that doesn't seem to be available in RDiscount 1.6.8.

[apjanke]

Nope, can't do that. It breaks tests.

[apjanke]

Okay, got a real fix by upgrading to RDiscount 2.x and using the :no_superscript option. Tests still pass this time.