## New Features

### PHP Core

#### More Flexible Heredoc and Nowdoc Syntax

The closing marker for doc strings is no longer required to be followed by a semicolon or newline. Additionally the closing marker may be indented, in which case the indentation will be stripped from all lines in the doc string.

#### Array Destructuring supports Reference Assignments

Array destructuring now supports reference assignments using the syntax [&$a, [$b, &$c]] = $d. The same is also supported for list().

#### Instanceof Operator accepts Literals

instanceof now allows literals as the first operand, in which case the result is always `FALSE`.

#### CompileError Exception instead of some Compilation Errors

A new CompileError exception has been added, from which ParseError inherits. A small number of compilation errors will now throw a CompileError instead of generating a fatal error. Currently this only affects compilation errors that may be thrown by token_get_all() in `TOKEN_PARSE` mode, but more errors may be converted in the future.

#### Trailing Commas are allowed in Calls

Trailing commas in function and method calls are now allowed.

#### Argon2id Support

The --with-password-argon2[=dir] configure argument now provides support for both Argon2i and Argon2id hashes in the password_hash(), password_verify(), password_get_info(), and password_needs_rehash() functions. Passwords may be hashed and verified using the `PASSWORD_ARGON2ID` constant. Support for both Argon2i and Argon2id in the password_*() functions now requires PHP be linked against libargon2 reference library ≥ 20161029.

### FastCGI Process Manager

New options have been added to customize the FPM logging:

log_limit
  This global option can be used for setting the log limit for the logged line which allows to log messages longer than 1024 characters without wrapping. It also fixes various wrapping issues.
log_buffering
  This global option allows an experimental logging without extra buffering.
decorate_workers_output
  This pool option allows to disable the output decoration for workers output when catch_workers_output is enabled.

### BC Math Functions

bcscale() can now also be used as getter to retrieve the current scale in use.

### Lightweight Directory Access Protocol

Full support for LDAP Controls has been added to the LDAP querying functions and ldap_parse_result():

- A $serverctrls parameter to send controls to the server in ldap_add(), ldap_mod_replace(), ldap_mod_add(), ldap_mod_del(), ldap_rename(), ldap_compare(), ldap_delete(), ldap_modify_batch(), ldap_search(), ldap_list() and ldap_read() has been added.
- The out parameter $serverctrls to get controls from the server in ldap_parse_result() has been added.
- Support for `LDAP_OPT_SERVER_CONTROLS` and `LDAP_OPT_CLIENT_CONTROLS` in ldap_get_option() and ldap_set_option() has been fixed.

### Multibyte String Functions

#### Full Case-Mapping and Case-Folding Support

Support for full case-mapping and case-folding has been added. Unlike simple case-mapping, full case-mapping may change the length of the string. For example:

`<?php
mb_strtoupper("Straße");
// Produces STRAßE on PHP 7.2
// Produces STRASSE on PHP 7.3
?>`
The different casing mapping and folding modes are available through mb_convert_case():

- `MB_CASE_LOWER` (used by mb_strtolower())
- `MB_CASE_UPPER` (used by mb_strtoupper())
- `MB_CASE_TITLE`
- `MB_CASE_FOLD`
- `MB_CASE_LOWER_SIMPLE`
- `MB_CASE_UPPER_SIMPLE`
- `MB_CASE_TITLE_SIMPLE`
- `MB_CASE_FOLD_SIMPLE` (used by case-insensitive operations)

Only unconditional, language agnostic full case-mapping is performed.

#### Case-Insensitive String Operations use Case-Folding

Case-insensitive string operations now use case-folding instead of case- mapping during comparisons. This means that more characters will be considered (case insensitively) equal now.

#### MB_CASE_TITLE performs Title-Case Conversion

mb_convert_case() with `MB_CASE_TITLE` now performs title-case conversion based on the Cased and CaseIgnorable derived Unicode properties. In particular this also improves handling of quotes and apostrophes.

#### Unicode 11 Support

The Multibyte String data tables have been updated for Unicode 11.

#### Long String Support

The Multibyte String Functions now correctly support strings larger than 2GB.

#### Performance Improvements

Performance of the Multibyte String extension has been significantly improved across the board. The largest improvements are in case conversion functions.

#### Named Captures Support

The mb_ereg_* functions now support named captures. Matching functions like mb_ereg() will now return named captures both using their group number and their name, similar to PCRE:

`<?php
mb_ereg('(?<word>\w+)', '国', $matches);
// => [0 => "国", 1 => "国", "word" => "国"];
?>`
Additionally, mb_ereg_replace() now supports the `\k<>` and `\k''` notations to reference named captures in the replacement string:
`<?php
mb_ereg_replace('\s*(?<word>\w+)\s*', "_\k<word>_\k'word'_", ' foo ');
// => "_foo_foo_"
?>`
`\k<>` and `\k''` can also be used for numbered references, which also works with group numbers greater than 9.

### Readline

Support for the completion_append_character and completion_suppress_append options has been added to readline_info(). These options are only available if PHP is linked against libreadline (rather than libedit).