}

// next returns the next rune in the input.
func (l *lexer) next() rune {
	if int(l.pos) >= len(l.input) {
		l.atEOF = true
		return eof
	}
	r, w := utf8.DecodeRuneInString(l.input[l.pos:])
	l.pos += Pos(w)
	if r == '\n' {
		l.line++
	}
	return r
}

// peek returns but does not consume the next rune in the input.
func (l *lexer) peek() rune {
	r := l.next()
	l.backup()

    final AtomicInteger numCalls = new AtomicInteger();

    Runnable runMe =
        new Runnable() {
          @Override
          public void run() {
            numCalls.incrementAndGet();
            throw new RuntimeException("FAKE EXCEPTION!");
          }
        };

    e.execute(runMe);
    e.execute(runMe);
    fakePool.runAll();

    assertEquals(2, numCalls.get());
  }

}

var sinkInt int

func BenchmarkRuneCount(b *testing.B) {
	// Each sub-benchmark counts the runes in a string in a different way.
	b.Run("lenruneslice", func(b *testing.B) {
		for _, sd := range stringdata {
			b.Run(sd.name, func(b *testing.B) {
				for i := 0; i < b.N; i++ {
					sinkInt += len([]rune(sd.data))
				}
			})
		}
	})
	b.Run("rangeloop", func(b *testing.B) {

				pc = inst.Arg
				goto CheckAndLoop
			} else {
				b.push(re, pc, pos, true)
				pc = inst.Out
				goto CheckAndLoop
			}

		case syntax.InstAltMatch:
			// One opcode consumes runes; the other leads to match.
			switch re.prog.Inst[inst.Out].Op {
			case syntax.InstRune, syntax.InstRune1, syntax.InstRuneAny, syntax.InstRuneAnyNotNL:
				// inst.Arg is the match.
				b.push(re, inst.Arg, pos, false)

	}
	// The open bracket must be preceeded by a link-adjacent rune (or by nothing).
	if t := plainText(i - 1); t != "" {
		r, _ := utf8.DecodeLastRuneInString(t)
		if !isLinkAdjacentRune(r) {
			return ""
		}
	}
	// The element after the next must be a ']'.
	if plainText(i+2) != "]" {
		return ""
	}
	// The ']' must be followed by a link-adjacent rune (or by nothing).
	if t := plainText(i + 3); t != "" {

    final AtomicInteger numCalls = new AtomicInteger();

    Runnable runMe =
        new Runnable() {
          @Override
          public void run() {
            numCalls.incrementAndGet();
            throw new RuntimeException("FAKE EXCEPTION!");
          }
        };

    e.execute(runMe);
    e.execute(runMe);
    fakePool.runAll();

    assertEquals(2, numCalls.get());
  }

	}

	// We create separate byte and rune types for better error messages
	// rather than just creating type alias *Sym's for the uint8 and
	// int32  Hence, (bytetype|runtype).Sym.isAlias() is false.
	// TODO(gri) Should we get rid of this special case (at the cost
	// of less informative error messages involving bytes and runes)?
	// NOTE(rsc): No, the error message quality is important.

			t.Errorf("%s(%q) = %q; want %q", funcName, tc.in, actual, tc.out)
		}
	}
}

func tenRunes(r rune) string {
	runes := make([]rune, 10)
	for i := range runes {
		runes[i] = r
	}
	return string(runes)
}

// User-defined self-inverse mapping function
func rot13(r rune) rune {
	const step = 13
	if r >= 'a' && r <= 'z' {
		return ((r - 'a' + step) % 26) + 'a'
	}

			ss = 0
			continue
		}
		info := f.info(src, i)
		if info.size == 0 {
			if atEOF {
				// include incomplete runes
				return n, true
			}
			return lastSegStart, true
		}
		// This block needs to be before the next, because it is possible to
		// have an overflow for runes that are starters (e.g. with U+FF9E).
		switch ss.next(info) {
		case ssStarter:
			lastSegStart = i
		case ssOverflow:

// A mapFunc takes a context set to the current rune and writes the mapped
// version to the same context. It may advance the context to the next rune. It
// returns whether a checkpoint is possible: whether the pDst bytes written to
// dst so far won't need changing as we see more source bytes.
type mapFunc func(*context) bool

// A spanFunc takes a context set to the current rune and returns whether this