mdast-util-to-nlcst

mdast utility to transform to nlcst.

Contents

• What is this?
• When should I use this?
• Install
• Use
• API
  • toNlcst(tree, file, Parser[, options])
  • Options
  • ParserConstructor
  • ParserInstance
• Types
• Compatibility
• Security
• Related
• Contribute
• License

What is this?

This package is a utility that takes an mdast (markdown) syntax tree as input and turns it into nlcst (natural language).

When should I use this?

This project is useful when you want to deal with ASTs and inspect the natural language inside markdown. Unfortunately, there is no way yet to apply changes to the nlcst back into mdast.

The hast utility hast-util-to-nlcst does the same but uses an HTML tree as input.

The remark plugin remark-retext wraps this utility to do the same at a higher-level (easier) abstraction.

Install

This package is ESM only. In Node.js (version 16+), install with npm:

npm install mdast-util-to-nlcst

In Deno with esm.sh:

import {toNlcst} from 'https://esm.sh/mdast-util-to-nlcst@7'

In browsers with esm.sh:

<script type="module">
  import {toNlcst} from 'https://esm.sh/mdast-util-to-nlcst@7?bundle'
</script>

Use

Say we have the following example.md:

Some *foo*sball.

…and next to it a module example.js:

import {fromMarkdown} from 'mdast-util-from-markdown'
import {toNlcst} from 'mdast-util-to-nlcst'
import {ParseEnglish} from 'parse-english'
import {read} from 'to-vfile'
import {inspect} from 'unist-util-inspect'

const file = await read('example.md')
const mdast = fromMarkdown(file)
const nlcst = toNlcst(mdast, file, ParseEnglish)

console.log(inspect(nlcst))

Yields:

RootNode[1] (1:1-1:17, 0-16)
└─0 ParagraphNode[1] (1:1-1:17, 0-16)
    └─0 SentenceNode[4] (1:1-1:17, 0-16)
        ├─0 WordNode[1] (1:1-1:5, 0-4)
        │   └─0 TextNode "Some" (1:1-1:5, 0-4)
        ├─1 WhiteSpaceNode " " (1:5-1:6, 4-5)
        ├─2 WordNode[2] (1:7-1:16, 6-15)
        │   ├─0 TextNode "foo" (1:7-1:10, 6-9)
        │   └─1 TextNode "sball" (1:11-1:16, 10-15)
        └─3 PunctuationNode "." (1:16-1:17, 15-16)

API

This package exports the identifier toNlcst. There is no default export.

toNlcst(tree, file, Parser[, options])

Turn an mdast tree into an nlcst tree.

👉 Note: tree must have positional info and file must be a VFile corresponding to tree.

Parameters

• tree (MdastNode) — mdast tree to transform
• file (VFile) — virtual file
• Parser (ParserConstructor or ParserInstance) — parser to use
• options (Options, optional) — configuration

Returns

nlcst tree (NlcstNode).

Options

Configuration (TypeScript type).

Fields

ignore

List of mdast node types to ignore (Array<string>, optional).

The types 'table', 'tableRow', and 'tableCell' are always ignored.

Say we have the following file example.md:

A paragraph.

> A paragraph in a block quote.

…and if we now transform with ignore: ['blockquote'], we get:

RootNode[2] (1:1-3:1, 0-14)
├─0 ParagraphNode[1] (1:1-1:13, 0-12)
│   └─0 SentenceNode[4] (1:1-1:13, 0-12)
│       ├─0 WordNode[1] (1:1-1:2, 0-1)
│       │   └─0 TextNode "A" (1:1-1:2, 0-1)
│       ├─1 WhiteSpaceNode " " (1:2-1:3, 1-2)
│       ├─2 WordNode[1] (1:3-1:12, 2-11)
│       │   └─0 TextNode "paragraph" (1:3-1:12, 2-11)
│       └─3 PunctuationNode "." (1:12-1:13, 11-12)
└─1 WhiteSpaceNode "\n\n" (1:13-3:1, 12-14)

source

List of mdast node types to mark as nlcst source nodes (Array<string>, optional).

The type 'inlineCode' is always marked as source.

Say we have the following file example.md:

A paragraph.

> A paragraph in a block quote.

…and if we now transform with source: ['blockquote'], we get:

RootNode[3] (1:1-3:32, 0-45)
├─0 ParagraphNode[1] (1:1-1:13, 0-12)
│   └─0 SentenceNode[4] (1:1-1:13, 0-12)
│       ├─0 WordNode[1] (1:1-1:2, 0-1)
│       │   └─0 TextNode "A" (1:1-1:2, 0-1)
│       ├─1 WhiteSpaceNode " " (1:2-1:3, 1-2)
│       ├─2 WordNode[1] (1:3-1:12, 2-11)
│       │   └─0 TextNode "paragraph" (1:3-1:12, 2-11)
│       └─3 PunctuationNode "." (1:12-1:13, 11-12)
├─1 WhiteSpaceNode "\n\n" (1:13-3:1, 12-14)
└─2 ParagraphNode[1] (3:1-3:32, 14-45)
    └─0 SentenceNode[1] (3:1-3:32, 14-45)
        └─0 SourceNode "> A paragraph in a block quote." (3:1-3:32, 14-45)

ParserConstructor

Create a new parser (TypeScript type).

Type

type ParserConstructor = new () => ParserInstance

ParserInstance

nlcst parser (TypeScript type).

For example, parse-dutch, parse-english, or parse-latin.

Type

type ParserInstance = {
  tokenizeSentencePlugins: ((node: NlcstSentence) => undefined)[]
  tokenizeParagraphPlugins: ((node: NlcstParagraph) => undefined)[]
  tokenizeRootPlugins: ((node: NlcstRoot) => undefined)[]
  parse(value: string | null | undefined): NlcstRoot
  tokenize(value: string | null | undefined): Array<NlcstSentenceContent>
}

Types

This package is fully typed with TypeScript. It exports the types Options, ParserConstructor, and ParserInstance.

Compatibility

Projects maintained by the unified collective are compatible with maintained versions of Node.js.

When we cut a new major release, we drop support for unmaintained versions of Node. This means we try to keep the current release line, mdast-util-to-nlcst@^7, compatible with Node.js 16.

Security

Use of mdast-util-to-nlcst does not involve hast so there are no openings for cross-site scripting (XSS) attacks.

Related

• mdast-util-to-hast — transform mdast to hast
• hast-util-to-nlcst — transform hast to nlcst
• hast-util-to-mdast — transform hast to mdast
• hast-util-to-xast — transform hast to xast
• hast-util-sanitize — sanitize hast nodes

Contribute

See contributing.md in syntax-tree/.github for ways to get started. See support.md for ways to get help.

This project has a code of conduct. By interacting with this repository, organization, or community you agree to abide by its terms.

License

MIT © Titus Wormer