code: function createExceptionsPattern(exceptions) {
      let pattern = "";
  
      /*
       * A space or an exception pattern sequence.
       * []                 ==> "\s"
       * ["-"]              ==> "(?:\s|\-+$)"
       * ["-", "="]         ==> "(?:\s|(?:\-+|=+)$)"
       * ["-", "=", "--=="] ==> "(?:\s|(?:\-+|=+|(?:\-\-==)+)$)" ==> https://jex.im/regulex/#!embed=false&flags=&re=(%3F%3A%5Cs%7C(%3F%3A%5C-%2B%7C%3D%2B%7C(%3F%3A%5C-%5C-%3D%3D)%2B)%24)
       */
      if (exceptions.length === 0) {
  
          // a space.
          pattern += "\\s";
      } else {
  
          // a space or...
          pattern += "(?:\\s|";
  
          if (exceptions.length === 1) {
  
              // a sequence of the exception pattern.
              pattern += escapeAndRepeat(exceptions[0]);
          } else {
  
              // a sequence of one of the exception patterns.
              pattern += "(?:";
              pattern += exceptions.map(escapeAndRepeat).join("|");
              pattern += ")";
          }
          pattern += `(?:$|[${Array.from(astUtils.LINEBREAKS).join("")}]))`;
      }
  
      return pattern;
  }
docs: Creates string pattern for exceptions.
  Generated pattern:
  
  1. A space or an exception pattern sequence.
  
  @param {string[]} exceptions - An exception pattern list.
  @returns {string} A regular expression string for exceptions.