Migration80/new-features-Phpdoc专题

新特性

PHP 核心中的新特性

命名参数

注解（Attributes）

新增注解的功能。

构造器属性提升（Constructor Property Promotion）

新增构造器属性提升功能（在构造函数中声明类的属性）。

联合类型

新增联合类型。

Match 表达式

新增 match 表达式。

Nullsafe 运算符

新增 Nullsafe 运算符(?->)。

其他新特性

新增 WeakMap 类。
新增 ValueError 类。

现在，只要类型兼容，任意数量的函数参数都可以用一个可变参数替换。例如允许编写下面的代码：

<?php
class A {
     public function method(int $many, string $parameters, $here) {}
}
class B extends A {
     public function method(...$everything) {}
}
?>

static ("后期静态绑定"中) 可以作为返回类型：

<?php
class Test {
     public function create(): static {
          return new static();
     }
}
?>

现在可以通过 $object::class 获取类名，返回的结果和 get_class($object) 一致。
new、instanceof 可用于任何表达式，用法为 new (expression)(...$args) 和 $obj instanceof (expression)。
添加对一些变量语法一致性的修复，例如现在能够编写 Foo::BAR::$baz。
添加 Stringable interface，当一个类定义 __toString() 方法后会自动实现该接口。
Trait 可以定义私有抽象方法（abstract private method）。类必须实现 trait 定义的该方法。

可作为表达式使用 throw。使得可以编写以下用法：

<?php
$fn = fn() => throw new Exception('Exception in arrow function');
$user = $session->user ?? throw new Exception('Must have user');

参数列表中的末尾逗号为可选。

<?php
function functionWithLongSignature(
    Type1 $parameter1,
    Type2 $parameter2, // <-- 这个逗号也被允许了
) {
}

现在允许 catch (Exception) 一个 exception 而无需捕获到变量中。
支持 mixed 类型。

Private methods declared on a parent class no longer enforce any inheritance rules on the methods of a child class (with the exception of final private constructors). The following example illustrates which restrictions have been removed:

<?php
class ParentClass {
    private function method1() {}
    private function method2() {}
    private static function method3() {}
    // Throws a warning, as "final" no longer has an effect:
    private final function method4() {}
}
class ChildClass extends ParentClass {
    // All of the following are now allowed, even though the modifiers aren't
    // the same as for the private methods in the parent class.
    public abstract function method1() {}
    public static function method2() {}
    public function method3() {}
    public function method4() {}
}
?>

get_resource_id has been added, which returns the same value as (int) $resource. It provides the same functionality under a clearer API.

Date and Time

DateTime::createFromInterface and DateTimeImmutable::createFromInterface have been added.
The DateTime format specifier p has been added, which is the same as P but returns Z rather than +00:00 for UTC.

DOM

DOMParentNode and DOMChildNode with new traversal and manipulation APIs have been added.

Filter

FILTER_VALIDATE_BOOL has been added as an alias for FILTER_VALIDATE_BOOLEAN. The new name is preferred, as it uses the canonical type name.

Enchant

enchant_dict_add, enchant_dict_is_added, and LIBENCHANT_VERSION have been added.

FPM

Added a new option pm.status_listen that allows getting the status from different endpoint (e.g. port or UDS file) which is useful for getting the status when all children are busy with serving long running requests.

Hash

HashContext objects can now be serialized.

Internationalization Functions

The IntlDateFormatter::RELATIVE_FULL, IntlDateFormatter::RELATIVE_LONG, IntlDateFormatter::RELATIVE_MEDIUM, and IntlDateFormatter::RELATIVE_SHORT constants have been added.

LDAP

ldap_count_references has been added, which returns the number of reference messages in a search result.

OPcache

If the opcache.record_warnings ini setting is enabled, OPcache will record compile-time warnings and replay them on the next include, even if it is served from cache.

OpenSSL

Added Cryptographic Message Syntax (CMS) (» RFC 5652) support composed of functions for encryption, decryption, signing, verifying and reading. The API is similar to the API for PKCS #7 functions with an addition of new encoding constants: OPENSSL_ENCODING_DER, OPENSSL_ENCODING_SMIME and OPENSSL_ENCODING_PEM:

openssl_cms_encrypt encrypts the message in the file with the certificates and outputs the result to the supplied file.
openssl_cms_decrypt that decrypts the S/MIME message in the file and outputs the results to the supplied file.
openssl_cms_read that exports the CMS file to an array of PEM certificates.
openssl_cms_sign that signs the MIME message in the file with a cert and key and output the result to the supplied file.
openssl_cms_verify that verifies that the data block is intact, the signer is who they say they are, and returns the certs of the signers.

Regular Expressions (Perl-Compatible)

preg_last_error_msg has been added, which returns a human-readable message for the last PCRE error. It complements preg_last_error, which returns an integer enum value instead.

Reflection

The following methods can now return information about default values of parameters of internal functions:
- ReflectionParameter::isDefaultValueAvailable
- ReflectionParameter::getDefaultValue
- ReflectionParameter::isDefaultValueConstant
- ReflectionParameter::getDefaultValueConstantName

SQLite3

SQLite3::setAuthorizer and respective class constants have been added to set a userland callback that will be used to authorize or not an action on the database.

Standard Library

str_contains, str_starts_with and str_ends_with have been added, which check whether haystack contains, starts with or ends with needle, respectively.
fdiv has been added, which performs a floating-point division under IEEE 754 semantics. Division by zero is considered well-defined and will return one of Inf, -Inf or NaN.
get_debug_type has been added, which returns a type useful for error messages. Unlike gettype, it uses canonical type names, returns class names for objects, and indicates the resource type for resources.
printf and friends now support the %h and %H format specifiers. These are the same as %g and %G, but always use "." as the decimal separator, rather than determining it through the LC_NUMERIC locale.
printf and friends now support using "*" as width or precision, in which case the width/precision is passed as an argument to printf. This also allows using precision -1 with %g, %G, %h and %H. For example, the following code can be used to reproduce PHP's default floating point formatting:
```
<?php
printf("%.*H", (int) ini_get("precision"), $float);
printf("%.*H", (int) ini_get("serialize_precision"), $float);
?>
```
proc_open now supports pseudo-terminal (PTY) descriptors. The following attaches stdin, stdout and stderr to the same PTY:
```
<?php
$proc = proc_open($command, [['pty'], ['pty'], ['pty']], $pipes);
?>
```
proc_open now supports socket pair descriptors. The following attaches a distinct socket pair to stdin, stdout and stderr:
```
<?php
$proc = proc_open($command, [['socket'], ['socket'], ['socket']], $pipes);
?>
```
Unlike pipes, sockets do not suffer from blocking I/O issues on Windows. However, not all programs may work correctly with stdio sockets.
Sorting functions are now stable, which means that equal-comparing elements will retain their original order.
array_diff, array_intersect and their variations can now be used with a single array as argument. This means that usages like the following are now possible:
```
<?php
// OK even if $excludes is empty:
array_diff($array, ...$excludes);
// OK even if $arrays only contains a single array:
array_intersect(...$arrays);
?>
```
The flag parameter of ob_implicit_flush was changed to accept a bool rather than an int.

Tokenizer

PhpToken adds an object-based interface to the tokenizer. It provides a more uniform and ergonomic representation, while being more memory efficient and faster.

Zip

The Zip extension has been updated to version 1.19.1.
New ZipArchive::setMtimeName and ZipArchive::setMtimeIndex to set the modification time of an entry.
New ZipArchive::registerProgressCallback to provide updates during archive close.
New ZipArchive::registerCancelCallback to allow cancellation during archive close.
New ZipArchive::replaceFile to replace an entry content.
New ZipArchive::isCompressionMethodSupported to check optional compression features.
New ZipArchive::isEncryptionMethodSupported to check optional encryption features.
The ZipArchive::lastId property to get the index value of the last added entry has been added.
Errors can now be checked after an archive has been closed using the ZipArchive::status and ZipArchive::statusSys properties, or the ZipArchive::getStatusString method.
The 'remove_path' option of ZipArchive::addGlob and ZipArchive::addPattern is now treated as an arbitrary string prefix (for consistency with the 'add_path' option), whereas formerly it was treated as a directory name.
Optional compression / encryption features are now listed in phpinfo.