(Prism.languages.bison = Prism.languages.extend('c', {})),
  Prism.languages.insertBefore('bison', 'comment', {
    bison: {
      pattern: /^(?:[^%]|%(?!%))*%%[\s\S]*?%%/,
      inside: {
        c: {
          pattern: /%\{[\s\S]*?%\}|\{(?:\{[^}]*\}|[^{}])*\}/,
          inside: {
            delimiter: { pattern: /^%?\{|%?\}$/, alias: 'punctuation' },
            'bison-variable': {
              pattern: /[$@](?:<[^\s>]+>)?[\w$]+/,
              alias: 'variable',
              inside: { punctuation: /<|>/ },
            },
            rest: Prism.languages.c,
          },
        },
        comment: Prism.languages.c.comment,
        string: Prism.languages.c.string,
        property: /\S+(?=:)/,
        keyword: /%\w+/,
        number: { pattern: /(^|[^@])\b(?:0x[\da-f]+|\d+)/i, lookbehind: !0 },
        punctuation: /%[%?]|[|:;\[\]<>]/,
      },
    },
  });