remark-sub-sup

Remark plugin for subscript (_{...}) and superscript (^{...}) syntax.

Install

npm install remark-sub-sup

Use

import { unified } from 'unified'
import remarkParse from 'remark-parse'
import remarkSubSup from 'remark-sub-sup'
import remarkRehype from 'remark-rehype'
import rehypeStringify from 'rehype-stringify'

const html = await unified()
  .use(remarkParse)
  .use(remarkSubSup)
  .use(remarkRehype)
  .use(rehypeStringify)
  .process('H_{2}O and x^{2}')

// Output: <p>H<sub>2</sub>O and x<sup>2</sup></p>

Syntax

H_{2}O              → H<sub>2</sub>O
x^{2}               → x<sup>2</sup>
a_{i}^{j}           → a<sub>i</sub><sup>j</sup>

Nested Braces

f_{g(x)}            → f<sub>g(x)</sub>
_{a{b}c}            → <sub>a{b}c</sub>

Escaping

\_{not sub}         → _{not sub}
_{a\}b}             → <sub>a}b</sub>

Why _{...} / ^{...}?

• No GFM conflict — ~text~ stays as strikethrough
• Familiar — LaTeX users know _{} and ^{}
• Unambiguous — braces clearly delimit content

Related

• micromark-extension-sub-sup — tokenizer
• mdast-util-sub-sup — mdast utilities

License

MIT