markdown2html conversion process

1. define an extensions

function markedMention() {
    
    
    return {
    
    
        extensions: [{
    
    
            name: 'mention',
            level: 'inline',
            start(src) {
    
    
                // console.log("markedMention start....", src);
                return src.indexOf('#')
            },
            tokenizer(src, tokens) {
    
    
                const rule = /^(#[a-zA-Z0-9]+)\s?/
                const match = rule.exec(src)

                // console.log("mention...", match)
                if (match) {
    
    
                    const token = {
    
    
                        type: 'mention',
                        raw: match[0],
                        text: match[1],
                        tokens: [],
                    }
                    return token
                }
            },
            renderer(token) {
    
    
                // console.log("men....", token);
                return `<span class="mention" data-mention="${
      
      token.text}">${
      
      token.text}</span>`;
            },
        }]
    }
}

2. Use marked.use(markedMention)
   1. At this time, name will be used as the unique identifier
   2. Put the tokenizer into the array corresponding to the level, the level can be inline or block
   3. start is placed in the start[Level] (startInline) corresponding to the level
   4. Renderers are set in extensions.renderers according to name
3. The case where the parsing level is inline here
4. When applying, we need to use marked.parse(markdown copy, { gfm: true, ...various configurations})
5. Before using marked.parse, if you need additional extensions, you need to use the .use() method to expand before that, which is equivalent to adding content to the default value (defaults)

// 使用marked.parse，就是在根据defaults来构建一个新的对象。
function marked(src, opt, callback) {
    
    
  return parseMarkdown(Lexer.lex, Parser.parse)(src, opt, callback);
}

// Lexer.lex
lex(src) {
    
    
    src = src.replace(/\r\n|\r/g, '\n');
    let next;
    while (next = this.inlineQueue.shift()) {
    
    
      this.inlineTokens(next.src, next.tokens);
    }

    return this.tokens;
}

// Parser.parse

This is the flowchart I put together, including the conversion process of the markdown2html library.