Add italics and bold highlights to escape characters

[marshallward]

As discussed in #39 , italic and bold escape characters (e.g. *foo\*bar*) are not styled within inlines.

It would be good to work out a way to apply the appropriate style to the characters

[adrian5]

This also trips up highlighting in the following section for me, i.e.

**abc.\***    # offending syntax


Subheading    # not highlighted
----------

.. note::    # not highlighted

    We are `not highlighted <https://example.com>`_.


Next subheading    # I am highlighted!
---------------

Anything here and beyond is highlighted!

[marshallward]

Confirmed, we need to intervene when delimiter is more than one character.

Best I can tell, all the subsequent problems are due to it trying to treat \** as a single escape character.

[marshallward]

The latest commit (0cfea2f) should resolve the double star delimiter problem. Still looking into adding italic/bold to the escape string though.

[marshallward]

For the record, this is touching an older problem related to highlights. When defining highlights, we currently link to existing standard highlights, since it's a safer way to match the expectation of colorscheme designers. The two exceptions are italic and bold, where we do not assign a color on default.

We do optionally assign a color by using a control flag, which hard-codes the color to a terminal color code. This is not usually a good idea, since it can clash with colorschemes, but the setting is rather buried and I may be the only person using it.

But now we want to make a special character both italic and give it the Special color. We could just force it to some color and hope for the best, but I am guessing that there's a better solution here. Currently I don't know what that would look like.

[marshallward]

I've tested the examples here and they all appear to be highlighted correctly now. if there's no objection then I'll close this issue.

[marshallward]

Sorry just realized that the goal was to add italics and bold fonts to the escape characters, even if the problems raised here have been resolved. I'll re-open this for now.