HypertextLiteral.jl + CommonMark.jl = 🤯

[fonsp]

I made a combination of HypertextLiteral.jl by @clarkevans and CommonMark.jl, and I think it is really cool!!

DEMO NOTEBOOK

Screenshots

Features

The list of features is really simple to explain: it is everything that CommonMark gives, plus everything that HypertextLiteral gives! This includes:

• CommonMark! Markdown but less glitchy!
• Really flexible interpolation support with infinite nesting and syntax highlighting (since it is a @md(""" macro instead of md""")
• Interpolate Julia objects into <script> to automatically convert to JS literals
• Context-aware HTML escaping
• Automatic quote wrapping for HTML attributes
• Use a Dict or NamedTuple for the style attribute inside an HTML tag

Implementation

Also cool: the code is extremely short!

macro md(expr)
	cm_parser = CommonMark.Parser()
	quote
		result = @htl($expr)
		htl_output = repr(MIME"text/html"(), result)

		$(cm_parser)(htl_output)
	end
end

It is essentially the @htl macro for HypertextLiteral.jl, but the result is passed through a CommonMark parser. This works, because:

• CommonMark allows raw HTML
• HypertextLiteral leaves literal content unchanged, so hello *world* appears exactly

---

Let me know what you think! Perhaps it can be added to this package as a new macro, or we can make a new package.

[MichaelHatherly]

That's awesome. I'm quite surprised that commonmark's HTML handling is actually sufficient to parse htl_output correctly.

[MichaelHatherly]

Regarding including it here, I'd like to remove deps where possible since the eventual end goal is a standard lib. Might be a PlutoUI macro, though whether @md is actually "UI" is debatable I guess...

[fonsp]

That makes sense! I really hope it becomes a stdlib!

I like the idea of including it in PlutoUI. Let's continue testing it to see if there are any unforseen problems, and then release it!

[fonsp]

We will discuss this at the weekly pluto developers call in 1 hour: https://julialang.org/community/#events @MichaelHatherly @jeremiahpslewis feel free to join if you have time!

[MichaelHatherly]

https://github.com/MichaelHatherly/CommonMark.jl/blob/master/src/extensions/interpolation.jl#L121-L152 is the set of extensions that get used in cm"" which is probably what you'd actually want to use in the "real" @mdl macro. It's an internal method so probably don't use it directly, we could export a better named version of that one perhaps.

[fonsp]

Thanks for the pointers! I will add those

[fonsp]

FYI I made https://github.com/JuliaPluto/MarkdownLiteral.jl ! I am still wondering what the best name would be, my favourites are:

• @md (this is not used by any package yet: [1] [2]), but it might be confusingly close to md"""
• @markdown (also not taken) is probably my favourite because it is unintimidating and clear. But it does not capture the HTL magic
• @markdownliteral maybe? Long names are fine because we will eventually use a GUI button
• @mdl is accurate but something abstract to force people to remember

[MichaelHatherly]

Could go with @mdx since the syntax supported is kind of like https://mdxjs.com/ though not quite.

[lukeburns]

This is great, so much easier to interpolate in latex expressions!

[MichaelHatherly]

I'll close this issue now since there isn't much more needed here.