// return true if the string includes a port.
func hasPort(s string) bool { return strings.LastIndex(s, ":") > strings.LastIndex(s, "]") }

// removeEmptyPort strips the empty port in ":port" to ""
// as mandated by RFC 3986 Section 6.2.3.
func removeEmptyPort(host string) string {
	if hasPort(host) {
		return strings.TrimSuffix(host, ":")
	}
	return host
}

   *   <li>Underscores ('_') are permitted wherever dashes ('-') are permitted.
   *   <li>Parts other than the final part may start with a digit, as mandated by <a
   *       href="https://tools.ietf.org/html/rfc1123#section-2">RFC 1123</a>.
   * </ul>
   *
   * @param domain A domain name (not IP address)
   * @throws IllegalArgumentException if {@code domain} is not syntactically valid according to
   *     {@link #isValid}

pkg debug/pe, type Reloc struct
pkg debug/pe, type Reloc struct, SymbolTableIndex uint32
pkg debug/pe, type Reloc struct, Type uint16
pkg debug/pe, type Reloc struct, VirtualAddress uint32
pkg debug/pe, type Section struct, Relocs []Reloc
pkg debug/pe, type StringTable []uint8
pkg encoding/base64, method (Encoding) Strict() *Encoding
pkg encoding/json, method (RawMessage) MarshalJSON() ([]uint8, error)

Along with caching, partial computations are a critical performance optimization to ensure that we do not need to build (or send) every resource to every proxy on every change. This is discussed more in the Config Serving section.

### Config Serving

Config serving is the layer that actually accepts proxy clients, connected over bidirectional gRPC streams, and serve them the required configuration.

/// info | Información

Si ya pasaste por todo el tutorial y volviste a la sección de los tipos, una buena referencia es <a href="https://mypy.readthedocs.io/en/latest/cheat_sheet_py3.html" class="external-link" target="_blank">la "cheat sheet" de `mypy`</a>.

///

## Dependencies with `yield`, `HTTPException`, `except` and Background Tasks

/// warning

You most probably don't need these technical details, you can skip this section and continue below.

These details are useful mainly if you were using a version of FastAPI prior to 0.106.0 and used resources from dependencies with `yield` in background tasks.

///

이 예전 OpenAPI-특화 `examples` 매개변수는 이제 FastAPI `0.103.0`부터 `openapi_examples`입니다.

///

### JSON 스키마의 `examples` 필드

하지만, 후에 JSON 스키마는 <a href="https://json-schema.org/draft/2019-09/json-schema-validation.html#rfc.section.9.5" class="external-link" target="_blank">`examples`</a>필드를 명세서의 새 버전에 추가했습니다.

그리고 새로운 OpenAPI 3.1.0은 이 새로운 `examples` 필드가 포함된 최신 버전 (JSON 스키마 2020-12)을 기반으로 했습니다.

**FastAPI** doesn't enforce any specific meaning.

The information here is presented as a guideline, not a requirement.

For example, when using GraphQL you normally perform all the actions using only `POST` operations.

///

### Step 4: define the **path operation function**

This is our "**path operation function**":

* **path**: is `/`.
* **operation**: is `get`.

    // places left to rotate.
    int m = -distance % length;
    m = (m < 0) ? m + length : m;
    // The current index of what will become the first element of the rotated section.
    int newFirstIndex = m + fromIndex;
    if (newFirstIndex == fromIndex) {
      return;
    }

    reverse(array, fromIndex, newFirstIndex);
    reverse(array, newFirstIndex, toIndex);

    // places left to rotate.
    int m = -distance % length;
    m = (m < 0) ? m + length : m;
    // The current index of what will become the first element of the rotated section.
    int newFirstIndex = m + fromIndex;
    if (newFirstIndex == fromIndex) {
      return;
    }

    reverse(array, fromIndex, newFirstIndex);
    reverse(array, newFirstIndex, toIndex);