myst-spec

MyST Spec

:warning: The MyST AST specification is still in dev; any structures or features present in the JSON schema may change at any time without notice.

MyST (Markedly Structured Text) is designed to create publication-quality, computational documents written entirely in Markdown. The main use case driving the development and design of MyST is JupyterBook, which creates educational online textbooks and tutorials with Jupyter Notebooks and narrative content written in MyST.

MyST is a superset of CommonMark (a standard form of Markdown) and allows you to directly create “directives” and “roles” as extension points in the language. These extensions points are influenced by ReStructured Text (RST) and Sphinx -- pulling on the nomenclature and introducing additional standards where appropriate. directives are block-level extension points, like callout panels, tabs, figures or embedded charts; and roles are inline extension points, for components like references, citations, or inline math.

```{directive} Argument
The *content* of a directive can have {role}`with content`
```

Goals

myst-spec is designed to standardize implementations and extensions to MyST, with the goal of making the MyST ecosystem as rich and interoperable as possible. The spec formalizes three formats:

1. the MyST markup syntax, to ensure MyST works as expected across languages and implementations;
2. the MyST abstract syntax tree (AST), to promote an ecosystem of transformations and exports to diverse formats (e.g. latex/word/html/docutils/etc.); and
3. suggested semantic HTML output and CSS class structure, to promote web-accessibility and interoperability of themes.

The myst-spec will be improved overtime through enhancement proposals which can be submitted by our multi-stakeholder community. [IN PROGRESS]

MyST Spec

This repository introduces tests to cover the MyST Spec. These tests cover three target formats: myst, mdast, and html. An simple example test case (in yaml) for a header looks like:

cases:
  - title: CommonMark headers
    myst: |-
      # Heading!
    mdast:
      type: root
      children:
        - type: heading
          depth: 1
          children:
            - type: text
              value: Heading!
    html: |-
      <h1>Heading!</h1>

[TBD: Do we include latex here, maybe?]

Markdown Abstract Syntax Tree, mdast

Markdown AST, or mdast, is an intermediate format that builds upon the existing mdast spec, which is used throughout the unifiedjs Javascript community with hundreds of existing transformations, utilities and serializers. mdast is simple, with a type defining the node optional properties on the node and optional children (a leaf node has a value).

Beyond CommonMark and GitHub Flavoured Markdown, MyST introduces new directives and roles (like admonitions, citations, equations) following existing standards where they are defined. mdast is serializable to JSON or YAML, and can be effectively shared between projects, languages and implementations. The output of this repository is a versioned JSON file that can be used in implementations of MyST.

Structure of the Repository

schema/
|- myst.schema.json          // root schema definition
|- myst.md                   // docs
|- schema.spec.ts            // test for validating all examples against the schema
|- unist/
|  |- unist.schema.json      // unist base types
|  |- unist.md               // docs
|  |- unist.yml              // example mdast structures
|- commonmark/
|  |- commonmark.schema.json // commonmark mdast types
|  |- commonmark.md          // docs
|  |- commonmark.yml         // simple commonmark examples
|  |- cmark_spec_0.30.yml    // commonmark spec examples
...
|- roles/                    // future myst features
|  |- roles.schema.json
|  ...
|- directives/
|  |- directives.schema.json
|  ...

Relation to other markup languages, frameworks

[TODO]

• CommonMark
• GitHub Flavored Markdown
• Pandoc
• Unified
• Markdown-It