code: function locateRepoReference(value, fromIndex) {
    var hash = value.indexOf('@', fromIndex)
    var issue = value.indexOf('#', fromIndex)
    var index
    var start
    var test
  
    if (hash === -1) {
      index = issue
    } else if (issue === -1) {
      index = hash
    } else {
      index = hash > issue ? issue : hash
    }
  
    start = index
  
    if (start === -1) {
      return index
    }
  
    while (index >= fromIndex) {
      if (!repoCharacter(value.charCodeAt(index - 1))) {
        break
      }
  
      index--
    }
  
    if (index < start && index >= fromIndex) {
      test = start === hash ? hexadecimal : decimal
  
      if (
        test(value.charCodeAt(start + 1)) &&
        !repoCharacter(value.charCodeAt(index - 1))
      ) {
        return index
      }
    }
  
    /* Find the next possible value. */
    return locateRepoReference(value, start + 1)
  }
docs: /* Find a possible reference.