feat: Provide code fragments feature (#748)

src/core/render/compiler.js

@@ -164,6 +164,7 @@ export class Compiler {
         embed = compileMedia[type].call(this, href, title)
         embed.type = type
       }
+      embed.fragment = config.fragment
 
       return embed
     }

src/core/render/embed.js

@@ -20,6 +20,11 @@ function walkFetchEmbed({embedTokens, compile, fetch}, cb) {
           if (token.embed.type === 'markdown') {
             embedToken = compile.lexer(text)
           } else if (token.embed.type === 'code') {
+            if (token.embed.fragment) {
+              const fragment = token.embed.fragment
+              const pattern = new RegExp(`(?:###|\\/\\/\\/)\\s*\\[${fragment}\\]([\\s\\S]*)(?:###|\\/\\/\\/)\\s*\\[${fragment}\\]`)
+              text = ((text.match(pattern) || [])[1] || '').trim()
+            }
             embedToken = compile.lexer(
               '```' +
                 token.embed.lang +