// as always, holds unprocessed text.
type SplitFunc func(data []byte, atEOF bool) (advance int, token []byte, err error)

// Errors returned by Scanner.
var (
	ErrTooLong         = errors.New("bufio.Scanner: token too long")
	ErrNegativeAdvance = errors.New("bufio.Scanner: SplitFunc returns negative advance count")
	ErrAdvanceTooFar   = errors.New("bufio.Scanner: SplitFunc returns advance count beyond input")

	m, ok := b.tryGrowByReslice(len(s))
	if !ok {
		m = b.grow(len(s))
	}
	return copy(b.buf[m:], s), nil
}

// MinRead is the minimum slice size passed to a Read call by
// [Buffer.ReadFrom]. As long as the [Buffer] has at least MinRead bytes beyond
// what is required to hold the contents of r, ReadFrom will not grow the
// underlying buffer.
const MinRead = 512

	// an old zip32 file that was sharding inputs into the largest chunks
	// possible (or is just malicious; search the web for 42.zip).
	// If needUSize is true still, it means we didn't see a zip64 extension.
	// As long as the compressed size is not also 2³²-1 (implausible)
	// and the header is not also 2³²-1 (equally implausible),
	// accept the uncompressed size 2³²-1 as valid.
	// If nothing else, this keeps archive/zip working with 42.zip.

look in the source for the <code>obj</code> support library for
that architecture, located in the directory <code>src/cmd/internal/obj/arm</code>.
In that directory is a file <code>a.out.go</code>; it contains
a long list of constants starting with <code>A</code>, like this:
</p>

<pre>
const (
	AAND = obj.ABaseARM + obj.A_ARCHSPECIFIC + iota
	AEOR
	ASUB
	ARSB
	AADD
	...
</pre>

<p>

				return err
			}
			tw.curr = &sparseFileWriter{tw.curr, spd, 0}
		}
	*/
	return nil
}

func (tw *Writer) writeGNUHeader(hdr *Header) error {
	// Use long-link files if Name or Linkname exceeds the field size.
	const longName = "././@LongLink"
	if len(hdr.Name) > nameSize {
		data := hdr.Name + "\x00"

		name    string
		extra   []byte
		wanterr error
	}{
		{
			name:    strings.Repeat("x", 1<<16),
			extra:   []byte{},
			wanterr: errLongName,
		},
		{
			name:    "long_extra",
			extra:   bytes.Repeat([]byte{0xff}, 1<<16),
			wanterr: errLongExtra,
		},
	}

	// write a zip file
	buf := new(bytes.Buffer)
	w := NewWriter(buf)

	for _, test := range headerTests {

		}
		c0 := sep[0]
		c1 := sep[1]
		i := 0
		t := len(s) - n + 1
		fails := 0
		for i < t {
			if s[i] != c0 {
				// IndexByte is faster than bytealg.Index, so use it as long as
				// we're not getting lots of false positives.
				o := IndexByte(s[i+1:t], c0)
				if o < 0 {
					return -1
				}
				i += o + 1
			}
			if s[i+1] == c1 && Equal(s[i:i+n], sep) {

<p>
Function literals are <i>closures</i>: they may refer to variables
defined in a surrounding function. Those variables are then shared between
the surrounding function and the function literal, and they survive as long
as they are accessible.
</p>


<h3 id="Primary_expressions">Primary expressions</h3>

<p>
Primary expressions are the operands for unary and binary expressions.
</p>

		// It was verified to work with GNU tar 1.27.1 and BSD tar 3.1.2.
		//  dd if=/dev/zero bs=1G count=16 >> writer-big-long.tar
		//  gnutar -xvf writer-big-long.tar
		//  bsdtar -xvf writer-big-long.tar
		//
		// This file is in PAX format.
		file: "testdata/writer-big-long.tar",
		tests: []testFnc{
			testHeader{Header{
				Typeflag: TypeReg,
				Name:     strings.Repeat("longname/", 15) + "16gig.txt",

				break
			}
			runeCount++
			got, _ := utf8.DecodeRune(s.Bytes())
			if got != expect {
				t.Errorf("#%d: %d: expected %q got %q", n, i, expect, got)
			}
		}
		if s.Scan() {
			t.Errorf("#%d: scan ran too long, got %q", n, s.Text())
		}
		testRuneCount := utf8.RuneCountInString(test)
		if runeCount != testRuneCount {
			t.Errorf("#%d: termination expected at %d; got %d", n, testRuneCount, runeCount)
		}
		err := s.Err()