<ul>
            <li>{@code length(string)}: Returns the length of the given string.</li>
            <li>{@code upper(string)}: Converts the string to uppercase.</li>
            <li>{@code lower(string)}: Converts the string to lowercase.</li>
            <li>{@code substring(string, start, [end])}: Returns a substring of the given string.</li>

# 並行処理と async / await

*path operation 関数*のための `async def` に関する詳細と非同期 (asynchronous) コード、並行処理 (Concurrency)、そして、並列処理 (Parallelism) の背景について。

## 急いでいますか？

<abbr title="too long; didn't read (長すぎて読めない人のための要約という意味のスラング)"><strong>TL;DR:</strong></abbr>

次のような、`await` を使用して呼び出すべきサードパーティライブラリを使用している場合:

```Python
results = await some_library()
```

以下の様に `async def` を使用して*path operation 関数*を宣言します。

```Python hl_lines="2"
@app.get('/')

// parseString parses bytes as a NUL-terminated C-style string.
// If a NUL byte is not found then the whole slice is returned as a string.
func (*parser) parseString(b []byte) string {
	if i := bytes.IndexByte(b, 0); i >= 0 {
		return string(b[:i])
	}
	return string(b)
}

// formatString copies s into b, NUL-terminating if possible.
func (f *formatter) formatString(b []byte, s string) {
	if len(s) > len(b) {
		f.err = ErrFieldTooLong

	if objInfo.VersionID != "" && objInfo.VersionID != nullVersionID {
		w.Header()[xhttp.AmzVersionID] = []string{objInfo.VersionID}
	}

	if objInfo.ReplicationStatus.String() != "" {
		w.Header()[xhttp.AmzBucketReplicationStatus] = []string{objInfo.ReplicationStatus.String()}
	}

	if objInfo.IsRemote() {
		// Check if object is being restored. For more information on x-amz-restore header see

	case int64:
		return float64(x), nil
	case string:
		f, err := strconv.ParseFloat(strings.TrimSpace(x), 64)
		if err != nil {
			return 0, errCastFailure("could not parse as float")
		}
		return f, nil
	case []byte:
		f, err := strconv.ParseFloat(strings.TrimSpace(string(x)), 64)
		if err != nil {
			return 0, errCastFailure("could not parse as float")
		}
		return f, nil
	default:

func parseRequestRangeSpec(rangeString string) (hrange *HTTPRangeSpec, err error) {
	// Return error if given range string doesn't start with byte range prefix.
	if !strings.HasPrefix(rangeString, byteRangePrefix) {
		return nil, fmt.Errorf("'%s' does not start with '%s'", rangeString, byteRangePrefix)
	}

	// Trim byte range prefix.
	byteRangeString := strings.TrimPrefix(rangeString, byteRangePrefix)

	const input = "1234 5678 1234567901234567890"
	scanner := bufio.NewScanner(strings.NewReader(input))
	// Create a custom split function by wrapping the existing ScanWords function.
	split := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
		advance, token, err = bufio.ScanWords(data, atEOF)
		if err == nil && token != nil {
			_, err = strconv.ParseInt(string(token), 10, 32)
		}
		return
	}

func putOptsFromReq(ctx context.Context, r *http.Request, bucket, object string, metadata map[string]string) (opts ObjectOptions, err error) {
	return putOpts(ctx, bucket, object, r.Form.Get(xhttp.VersionID), r.Header, metadata)
}

func putOpts(ctx context.Context, bucket, object, vid string, hdrs http.Header, metadata map[string]string) (opts ObjectOptions, err error) {

}

func parseGoroutineType2(path string) (map[time.Duration][]string, error) {
	f, err := os.Open(path)
	if err != nil {
		return nil, err
	}

	bf := bytes.Buffer{}

	save := func(s string) {
		bf.WriteString(s + "\n")
	}
	reset := func() {
		bf.Reset()
	}

	ret := make(map[time.Duration][]string)

	s := bufio.NewScanner(f)
	s.Split(bufio.ScanLines)

	var (

// getScope generate a string of a specific date, an AWS region, and a service.
func getScope(t time.Time, region string) string {
	scope := strings.Join([]string{
		t.Format(yyyymmdd),
		region,
		string(serviceS3),
		"aws4_request",
	}, SlashSeparator)
	return scope
}

// getStringToSign a string based on selected query values.
func getStringToSign(canonicalRequest string, t time.Time, scope string) string {