code: function hash(eat, value, silent) {
    var self = this
    var index = shaEnd(value, 0)
    var subvalue
    var href
    var now
    var node
    var exit
  
    if (index === -1) {
      return
    }
  
    subvalue = value.slice(0, index)
  
    if (isBlacklisted(subvalue)) {
      return
    }
  
    /* istanbul ignore if - maybe used by plug-ins */
    if (silent) {
      return true
    }
  
    href = gh(self.githubRepo) + 'commit/' + subvalue
    now = eat.now()
    exit = self.enterLink()
  
    node = eat(subvalue)({
      type: 'link',
      title: null,
      url: href,
      children: self.tokenizeInline(subvalue, now)
    })
  
    exit()
  
    node.children = [
      {
        type: 'inlineCode',
        value: abbr(subvalue),
        position: node.children[0].position
      }
    ]
  
    return node
  }
docs: /* Tokenise a hash.