)

// Pass a func value from nestedCall to goCallback using an integer token.
var callbackMutex sync.Mutex
var callbackToken int
var callbackFuncs = make(map[int]func())

// nestedCall calls into C, back into Go, and finally to f.
func nestedCall(f func()) {
	// callback(x) calls goCallback(x)
	callbackMutex.Lock()
	callbackToken++
	i := callbackToken
	callbackFuncs[i] = f
	callbackMutex.Unlock()

//
// 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).
// One could achieve the same behavior with a custom error value but
// providing one here is tidier.
// See the emptyFinalToken example for a use of this value.
var ErrFinalToken = errors.New("final token")

// Scan advances the [Scanner] to the next token, which will then be

</p>

<p>
There are five precedence levels for binary operators.
Multiplication operators bind strongest, followed by addition
operators, comparison operators, <code>&amp;&amp;</code> (logical AND),
and finally <code>||</code> (logical OR):
</p>

<pre class="grammar">
Precedence    Operator
    5             *  /  %  &lt;&lt;  &gt;&gt;  &amp;  &amp;^
    4             +  -  |  ^

		a->r = sin(a->p0);
	}

What happens at link time depends on whether the final binary is linked
using the internal or external mode. If other packages are compiled in
"external only" mode, then the final link will be an external one.
Otherwise the link will be an internal one.

The linking directives are used according to the kind of final link
used.

		t.Errorf("%s: string(buf.Bytes()) == %q, s == %q", testname, string(bytes), s)
	}
}

// Fill buf through n writes of string fus.
// The initial contents of buf corresponds to the string s;
// the result is the final contents of buf returned as a string.
func fillString(t *testing.T, testname string, buf *Buffer, s string, n int, fus string) string {
	check(t, testname+" (fill 1)", buf, s)
	for ; n > 0; n-- {
		m, err := buf.WriteString(fus)

		b[0x2d]++
	})
}

func returnCorruptNotStreamedZip() (r io.ReaderAt, size int64) {
	return messWith("crc32-not-streamed.zip", func(b []byte) {
		// Corrupt foo.txt's final crc32 byte, in both
		// the file header and TOC. (0x7e -> 0x7f)
		b[0x11]++
		b[0x9d]++

		// TODO(bradfitz): add a new test that only corrupts
		// one of these values, and verify that that's also an

	// subcommand output (e.g., it might not be \n-terminated).
	var exitReStr strings.Builder
	for i := 1; i <= len(exitStr); i++ {
		fmt.Fprintf(&exitReStr, "%s$|", exitStr[:i])
	}
	// Finally, match the exit string along with an exit code.
	// This is the only case we use a group, and we'll use this
	// group to extract the numeric code.
	fmt.Fprintf(&exitReStr, "%s([0-9]+)$", exitStr)

		return "", "", s, ErrHeader
	}
	n -= int64(len(nStr) + 1) // convert from index in s to index in rest
	if n <= 0 {
		return "", "", s, ErrHeader
	}

	// Extract everything between the space and the final newline.
	rec, nl, rem := rest[:n-1], rest[n-1:n], rest[n:]
	if nl != "\n" {
		return "", "", s, ErrHeader
	}

	// The first equals separates the key from the value.
	k, v, ok = strings.Cut(rec, "=")

			typedef[n.Mangle] = n.Type
		}
	}
}

// mangleName does name mangling to translate names
// from the original Go source files to the names
// used in the final Go files generated by cgo.
func (p *Package) mangleName(n *Name) {
	// When using gccgo variables have to be
	// exported so that they become global symbols
	// that the C code can refer to.
	prefix := "_C"

// The simplest use of a Scanner, to read standard input as a set of lines.
func ExampleScanner_lines() {
	scanner := bufio.NewScanner(os.Stdin)
	for scanner.Scan() {
		fmt.Println(scanner.Text()) // Println will add back the final '\n'
	}
	if err := scanner.Err(); err != nil {
		fmt.Fprintln(os.Stderr, "reading standard input:", err)
	}
}

// Return the most recent call to Scan as a []byte.
func ExampleScanner_Bytes() {