🤔 Hmmarkdown

Hmmarkdown is a HTML-aware Markdown parser and renderer. Hmmarkdown is as fast as everything else. If you need faster stop using JavaScript.

⚠️ Work in progress! ⚠️

Cons

• Opinionated; limited syntax support
• Unforgiving; no affordance for errors
• Unstable; refactored on a whim

Pros

• Accepts a string or stream (e.g. Response.body)
• Processes some HTML-in-Markdown and Markdown-in-HTML
• Asynchronous plugin and filter architecture
• MIT licensed / zero-dependency

Development

Hmmarkdown is under active development. It is not stable or "production ready" — although I am testing in production (on my website).

Block Syntax

Only the following Markdown syntax is supported for now because it's all I need. If you need alternate or additional syntax use another Markdown library.

Blockquote

> This is a blockquote.
> Blockquotes can have multiple lines.
> <cite>[Some name](https://example.com)</cite>

Lines must start with a > greater-than sign followed by a single space.

Consecutive lines form new paragraphs within the same blockquote.

Heading

# Heading level one
## Level two
### Level three
#### Level four
##### Level five
###### Level six

Line must start with 1–6 # hash characters followed by a single space before the heading.

Horizontal Rule

* * *

Any three asterisks, hyphens, or underscores will render a <hr> element.

Spaces between characters are optional. Spaces around characters are not allowed.

Image

![alternate description](https://example.com/image.jpg)

![alt](%20%28image%29.jpg) — URL spaces and parentheses must be URL encoded.

Alternate text cannot include square brackets ([ or ]).

<img alt="" src="https://example.com/image.jpg">

HTML image tags are passed through the same renderer and filter.

Unordered List

* List item one
    Indented second line
* List item two
* List item three

New lines within an item are indented with exactly four spaces.

Ordered List

1. List item one
    Indented second line
2. List item two
3. List item three

Paragraph

This will become a paragraph.
<div>
  This will also become a paragraph.
</div>

Plain text is wrapped in <p> paragraph tags.

Preformatted

```html
<h1>Hello, World!</h1>
```

Exactly three backticks followed by an optional language name.

Inline Markdown

Anchor

[example link](https://example.com/slug%20%28parentheses%29/)

URL spaces and parentheses must be URI encoded.

Code

Text between `backticks` is wrapped in `<code>`.

Deleted

Text between ~~double tilde~~ is wrapped in `<del>`.

Emphasis

Text between *single asterisk* is wrapped in `<em>`.

Strong

Text between **double asterisk** is wrapped in `<strong>`.

HTML and Inline Markdown

Text content within a subset of HTML tags will have inline Markdown parsed.

<p>These words **are strong**.</p>

Will render:

<p>These words <strong>are strong</strong>.</p>

Inline Markdown with HTML inside is not parsed.

These words **<span>are not strong</span>**.

Will render:

<p>These words **<span>are not strong</span>**.</p>

Void elements and a subset of elements like iframe and video are left untouched and text content within is not parsed.

Nested Markdown blocks are not supported, e.g. lists in blockquotes, lists in lists, etc.

Configuration

Documentation coming soon (maybe lol).

MIT License | Copyright © 2024 David Bushell