index.js

    /**
     * critic markup	              HTML         	          LaTeX
       {--[text]--}	          <del>[text]</del>	                    \st{[text]}
        {++[text]++}          	<ins>[text]</ins>	                    \underline{[text]}
        {~~[text1]~>[text2]~~}	<del>[text1]</del><ins>[text2]</ins>	\st{[text1]}\underline{[text2]}
        {==[text]==}          	<mark>[text]</mark>	                  \hl{[text]}
        {>>[text]<<}          	<aside>[text]</aside>                	\marginpar{[text]}
      */
    /**
     * CriticMarkup rule
     */
module.exports = function critcmarkup_plugin(md) {
    md.inline.ruler.before('strikethrough', 'critic-markup', (state, silent)=> {
      const src = state.src,
            pos = state.pos
      if (src[pos] === '{' && (
        (src[pos + 1] === '-' && src[pos + 2] === '-') ||
        (src[pos + 1] === '+' && src[pos + 2] === '+') ||
        (src[pos + 1] === '~' && src[pos + 2] === '~') ||
        (src[pos + 1] === '=' && src[pos + 2] === '=') ||
        (src[pos + 1] === '>' && src[pos + 2] === '>')
      )) {
        let tag = src.slice(pos+1, pos+3)
        let closeTag = tag
        if (closeTag[0] === '>')
          closeTag = '<<}'
        else
          closeTag = closeTag + '}'

        let i = pos + 3,
            end = -1,
            content = null
        while(i < src.length) {
          if (src.startsWith(closeTag, i)) {
            end = i
            break
          }

          i += 1
        }

        if (end >= 0)
          content = src.slice(pos + 3, end)
        else
          return false

        if (content && !silent) {
          const token = state.push('critic-markup')
          token.content = content
          token.tag = tag

          state.pos = end + closeTag.length
          return true
        } else {
          return false
        }
      } else {
        return false
      }
    })

    /**
     * CriticMarkup renderer
     */
    md.renderer.rules['critic-markup'] = (tokens, idx)=> {
      const token = tokens[idx],
            tag = token['tag'],
            content = token['content']
      if (tag === '--') {
        return `<del>${content}</del>`
      } else if (tag === '++') {
        return `<ins>${content}</ins>`
      } else if (tag === '==') {
        return `<mark>${content}</mark>`
      } else if (tag === '>>') {
        return `<span style="display:none">${content}</span>`
      } else { // {~~[text1]~>[text2]~~}
        const arr = content.split('~>')
        if (arr.length === 2) {
          return `<del>${arr[0]}</del><ins>${arr[1]}</ins>`
        } else {
          return `<code>Error: ~> not found.</code>`
        }
      }
    }
};