mdast-util-substitute

mdast utilities for inline substitution (:sub[INITIAL]{REPLACEMENT}).

Inline substitution enables progressive disclosure — show brief content initially, reveal full content on activation. This package provides the mdast utilities; for a complete solution, use remark-substitute.

Install

npm install mdast-util-substitute

Usage

import { fromMarkdown } from 'mdast-util-from-markdown'
import { toMarkdown } from 'mdast-util-to-markdown'
import { sub } from 'micromark-extension-substitute'
import { subFromMarkdown, subToMarkdown } from 'mdast-util-substitute'

// Parse
const tree = fromMarkdown(':sub[initial]{replacement}', {
  extensions: [sub()],
  mdastExtensions: [subFromMarkdown()]
})

// Stringify
const md = toMarkdown(tree, {
  extensions: [subToMarkdown()]
})

AST

Sub

interface Sub extends Parent {
  type: 'sub'
  children: PhrasingContent[]      // Empty at this layer
  data: {
    replacement: PhrasingContent[] // Empty at this layer
    rawInitial: string             // Raw INITIAL text (escapes processed)
    rawReplacement: string         // Raw REPLACEMENT text (escapes processed)
  }
}

At the mdast-util layer, raw content is stored in rawInitial and rawReplacement. The children and replacement arrays are populated later by remark-substitute, which re-parses the raw content as inline Markdown.

Escaping

When serializing to markdown:

• Unbalanced ] in INITIAL is escaped as \]
• Unbalanced } in REPLACEMENT is escaped as \}
• Balanced brackets/braces don't need escaping

License

MIT