}

func TestWriterReset(t *testing.T) {
	var buf1, buf2, buf3, buf4, buf5 strings.Builder
	w := NewWriter(&buf1)
	w.WriteString("foo")

	w.Reset(&buf2) // and not flushed
	w.WriteString("bar")
	w.Flush()
	if buf1.String() != "" {
		t.Errorf("buf1 = %q; want empty", buf1.String())
	}
	if buf2.String() != "bar" {
		t.Errorf("buf2 = %q; want bar", buf2.String())
	}

	arr    [64]byte
	arrPtr *[64]byte
	buf1   []byte
	buf2   []byte
	str1   string
	str2   string
}

func (b *Buffer) foo() { // ERROR "b does not escape$"
	b.buf1 = b.buf1[1:2]   // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2\]$"
	b.buf1 = b.buf1[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2:3\]$"

	arr    [64]byte
	arrPtr *[64]byte
	buf1   []byte
	buf2   []byte
	str1   string
	str2   string
}

func (b *Buffer) foo() { // ERROR "b does not escape$"
	b.buf1 = b.buf1[1:2]   // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2\]$"
	b.buf1 = b.buf1[1:2:3] // ERROR "\(\*Buffer\).foo ignoring self-assignment in b.buf1 = b.buf1\[1:2:3\]$"

import (
	"bytes"
	"regexp"
	"runtime"
	"strconv"
)

func main() {
	buf1 := make([]byte, 1000)
	buf2 := make([]byte, 1000)

	runtime.Stack(buf1, false)      // CALL is last instruction on this line
	n := runtime.Stack(buf2, false) // CALL is followed by load of result from stack

	buf1 = buf1[:bytes.IndexByte(buf1, 0)]
	buf2 = buf2[:n]

	re := regexp.MustCompile(`(?m)^main\.main\(\)\n.*/issue7690.go:([0-9]+)`)

	doBench(b, func(b *testing.B, buf0 []byte, level, n int) {
		b.ReportAllocs()
		b.StopTimer()
		b.SetBytes(int64(n))

		compressed := new(bytes.Buffer)
		w, err := NewWriter(compressed, level)
		if err != nil {
			b.Fatal(err)
		}
		for i := 0; i < n; i += len(buf0) {
			if len(buf0) > n-i {
				buf0 = buf0[:n-i]
			}
			io.Copy(w, bytes.NewReader(buf0))
		}
		w.Close()
		buf1 := compressed.Bytes()

// The noescape comment only applies to the next func,
// which must not have a body.

//go:noescape

func F1([]byte)

func F2([]byte)

func G() {
	var buf1 [10]byte
	F1(buf1[:])

	var buf2 [10]byte // ERROR "moved to heap: buf2"
	F2(buf2[:])

	"runtime"
	"testing"
)

func BenchmarkEncode(b *testing.B) {
	doBench(b, func(b *testing.B, buf0 []byte, level, n int) {
		b.StopTimer()
		b.SetBytes(int64(n))

		buf1 := make([]byte, n)
		for i := 0; i < n; i += len(buf0) {
			if len(buf0) > n-i {
				buf0 = buf0[:n-i]
			}
			copy(buf1[i:], buf0)
		}
		buf0 = nil
		w, err := NewWriter(io.Discard, level)
		if err != nil {
			b.Fatal(err)
		}

}

func BenchmarkEncoder(b *testing.B) {
	buf, err := os.ReadFile("../testdata/e.txt")
	if err != nil {
		b.Fatal(err)
	}
	if len(buf) == 0 {
		b.Fatalf("test file has no data")
	}

	for e := 4; e <= 6; e++ {
		n := int(math.Pow10(e))
		buf0 := buf
		buf1 := make([]byte, n)
		for i := 0; i < n; i += len(buf0) {
			if len(buf0) > n-i {
				buf0 = buf0[:n-i]
			}
			copy(buf1[i:], buf0)
		}

	// read
}

func ExampleMultiWriter() {
	r := strings.NewReader("some io.Reader stream to be read\n")

	var buf1, buf2 strings.Builder
	w := io.MultiWriter(&buf1, &buf2)

	if _, err := io.Copy(w, r); err != nil {
		log.Fatal(err)
	}

	fmt.Print(buf1.String())
	fmt.Print(buf2.String())

	// Output:
	// some io.Reader stream to be read
	// some io.Reader stream to be read
}

	}
	for i, c := range runes {
		buf := make([]byte, 3)
		size := utf8.EncodeRune(buf, c)
		fmt.Printf("%d: %d %[2]s %d\n", i, buf, size)
	}
	// Output:
	// 0: [239 191 189] � 3
	// 1: [239 191 189] � 3
	// 2: [239 191 189] � 3
}

func ExampleFullRune() {
	buf := []byte{228, 184, 150} // 世
	fmt.Println(utf8.FullRune(buf))
	fmt.Println(utf8.FullRune(buf[:2]))
	// Output:
	// true
	// false