* This is a big deal - we're talking factors of 2-8 in microbenchmarks, not just 10-20%. (This is
   * a hotspot optimizer bug, which should be fixed, but that's a separate, big project).
   *
   * The coding pattern above is heavily used in java.util, e.g. in ArrayList. There is a
   * RangeCheckMicroBenchmark in the JDK that was used to test this.
   *

      case 1:
        return is(sequence.charAt(0));
      case 2:
        return isEither(sequence.charAt(0), sequence.charAt(1));
      default:
        // TODO(lowasser): is it potentially worth just going ahead and building a precomputed
        // matcher?
        return new AnyOf(sequence);
    }
  }

  /**
   * Returns a {@code char} matcher that matches any BMP character not present in the given

      if ((c0 < 'a' || c0 > 'z') && (c0 < 'A' || c0 > 'Z')) return -1 // Not a scheme start char.

      characters@ for (i in pos + 1 until limit) {
        return when (input[i]) {
          // Scheme character. Keep going.
          in 'a'..'z', in 'A'..'Z', in '0'..'9', '+', '-', '.' -> continue@characters

          // Scheme prefix!
          ':' -> i

          // Non-scheme character before the first ':'.