func ExampleScanner_earlyStop() {
	onComma := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		i := bytes.IndexByte(data, ',')
		if i == -1 {
			if !atEOF {
				return 0, nil, nil
			}
			// If we have reached the end, return the last token.
			return 0, data, bufio.ErrFinalToken
		}
		// If the token is "STOP", stop the scanning and ignore the rest.

`Stop` methods have not been called.
Earlier versions of Go did not collect unstopped `Timer`s until after
they had fired and never collected unstopped `Ticker`s.

Second, the timer channel associated with a `Timer` or `Ticker` is
now unbuffered, with capacity 0.
The main effect of this change is that Go now guarantees
that for any call to a `Reset` or `Stop` method, no stale values

			break
		}
	}

	// Now look for the first ASCII non-space byte from the end
	stop := len(s)
	for ; stop > start; stop-- {
		c := s[stop-1]
		if c >= utf8.RuneSelf {
			return TrimFunc(s[start:stop], unicode.IsSpace)
		}
		if asciiSpace[c] == 0 {
			break
		}
	}

	// At this point s[start:stop] starts and ends with an ASCII
	// non-space bytes, so we're done. Non-ASCII cases have already

and the [go command documentation](/cmd/go#hdr-Build_and_test_caching).

### Go 1.23

Go 1.23 changed the channels created by package time to be unbuffered
(synchronous), which makes correct use of the [`Timer.Stop`](/pkg/time/#Timer.Stop)
and [`Timer.Reset`](/pkg/time/#Timer.Reset) method results much easier.
The [`asynctimerchan` setting](/pkg/time/#NewTimer) disables this change.
There are no runtime metrics for this change,

}

// ErrFinalToken is a special sentinel error value. It is intended to be
// returned by a Split function to indicate that the scanning should stop
// with no error. If the token being delivered with this error is not nil,
// the token is the last token.
//
// The value is useful to stop processing early or when it is necessary to
// deliver a final empty token (which is different from a nil token).

	testThreadLockFunc = testThreadLock
}

func testThreadLock(t *testing.T) {
	stop := make(chan int)
	go func() {
		// We need the G continue running,
		// so the M has a chance to run this G.
		for {
			select {
			case <-stop:
				return
			case <-time.After(time.Millisecond * 100):
			}
		}
	}()
	defer close(stop)

	for i := 0; i < 1000; i++ {
		if !C.Ctid() {

of an error message on a given line to deduce the information it
needs. The program is syntactically valid regardless of whether each
name is a type or an ordinary identifier, so there will be no syntax
errors that might stop parsing early.

An error on not-declared:1 indicates that foo is undeclared.
An error on not-type:1 indicates that foo is not a type (if declared at all, it is an identifier).

pkg runtime, func StartTrace() error
pkg runtime, func StopTrace()
pkg runtime, type MemStats struct, GCCPUFraction float64
pkg runtime/trace, func Start(io.Writer) error
pkg runtime/trace, func Stop()
pkg strings, func Compare(string, string) int
pkg strings, func LastIndexByte(string, uint8) int
pkg strings, method (*Reader) Size() int64
pkg syscall (darwin-386), type SysProcAttr struct, Ctty int

Comments serve as program documentation. There are two forms:
</p>

<ol>
<li>
<i>Line comments</i> start with the character sequence <code>//</code>
and stop at the end of the line.
</li>
<li>
<i>General comments</i> start with the character sequence <code>/*</code>
and stop with the first subsequent character sequence <code>*/</code>.
</li>
</ol>

<p>
A comment cannot start inside a <a href="#Rune_literals">rune</a> or

pkg syscall (netbsd-arm64-cgo), const TIOCPKT_START = 8
pkg syscall (netbsd-arm64-cgo), const TIOCPKT_START ideal-int
pkg syscall (netbsd-arm64-cgo), const TIOCPKT_STOP = 4
pkg syscall (netbsd-arm64-cgo), const TIOCPKT_STOP ideal-int
pkg syscall (netbsd-arm64-cgo), const TIOCPTMGET = 1076393030
pkg syscall (netbsd-arm64-cgo), const TIOCPTMGET ideal-int
pkg syscall (netbsd-arm64-cgo), const TIOCPTSNAME = 1076393032