Drop PHP 5.6

[thekid]

Scope of Change

This RFC suggests dropping PHP 5.6 support from all libraries.

Rationale

According to https://blog.packagist.com/php-versions-stats-2019-1-edition/ from May 2019, PHP 5 has roughly 10% market share.

Functionality

Dropping PHP 5.6 will be done in conjunction with adding support for XP 10 - see #333

Infrastructure

• Drop from .travis.yml
• Bump version in composer.json
• Remove 6.X versions from dependencies lists in composer.json

Code

• Check for \Exception, replace with \Throwable - https://wiki.php.net/rfc/throwable-interface
• Use $a ?? $default instead of isset($a) ? $a : $default - see https://wiki.php.net/rfc/isset_ternary
• Check whether certain newinstance calls can be replaced by https://wiki.php.net/rfc/anonymous_classes
• Check whether yield from can be used - see https://wiki.php.net/rfc/generator-delegation
• Use ($this->callback)() instead of temporary variables
• Group use declarations via https://wiki.php.net/rfc/group_use_declarations
• Use return types where applicable - see https://wiki.php.net/rfc/return_types

Security considerations

PHP 5.6 is EOL

Speed impact

Better, we can start dropping constructs and BC code for PHP 5.

Dependencies

Major release of each and every library

Related documents

[thekid]

Typical diff, clearly showing other libraries will need updates, too:

diff --git a/.travis.yml b/.travis.yml
index 87f5cdb..5ab646d 100755
--- a/.travis.yml
+++ b/.travis.yml
@@ -5,7 +5,6 @@ language: php
 dist: trusty
 
 php:
-  - 5.6
   - 7.0
   - 7.1
   - 7.2
diff --git a/ChangeLog.md b/ChangeLog.md
index 0156cb5..1ba7821 100755
--- a/ChangeLog.md
+++ b/ChangeLog.md
@@ -3,6 +3,14 @@ Data sequences change log
 
 ## ?.?.? / ????-??-??
 
+## 9.0.0 / ????-??-??
+
+* Added support for XP 10 and newer versions of library dependencies
+  (@thekid)
+* Implemented xp-framework/rfc#334: Drop PHP 5.6. The minimum required
+  PHP version is now 7.0.0!
+  (@thekid)
+
 ## 8.0.3 / 2019-09-29
 
 * Added PHP 7.4 compatibility - @thekid
diff --git a/composer.json b/composer.json
index 60fba7f..b638cd8 100755
--- a/composer.json
+++ b/composer.json
@@ -6,12 +6,12 @@
   "description" : "Data sequences",
   "keywords": ["module", "xp"],
   "require" : {
-    "xp-framework/core": "^9.0 | ^8.0 | ^7.0 | ^6.5",
-    "xp-framework/collections": "^8.0 | ^7.0 | ^6.5",
-    "php" : ">=5.6.0"
+    "xp-framework/core": "^10.0 | ^9.0 | ^8.0 | ^7.0",
+    "xp-framework/collections": "^9.0 | ^8.0 | ^7.0",
+    "php" : ">=7.0.0"
   },
   "require-dev" : {
-    "xp-framework/unittest": "^9.0 | ^8.0 | ^7.0 | ^6.5"
+    "xp-framework/unittest": "^10.0 | ^9.0 | ^8.0 | ^7.0"
   },
   "autoload" : {
     "files" : ["src/main/php/autoload.php"]

[thekid]

Group use statements via script:

<?php namespace rfc334;

use io\collections\iterate\{FilteredIOCollectionIterator, ExtensionEqualsFilter} from 'xp-framework/io-collections';
use io\collections\{FileCollection, FileElement} from 'xp-framework/io-collections';
use io\streams\LinesIn;
use util\cmd\Console;

function rewrite(FileElement $origin, FileElement $target): FileElement {
  $use= [];
  $out= $target->out();
  foreach (new LinesIn($origin->in()) as $line) {
    if (0 === strncmp($line, '<?php', 5)) {
      $out->write($line);
    } else if (0 === strncmp($line, 'use ', 4)) {
      $type= rtrim(substr($line, 4), '; ');
      $p= strrpos($type, '\\');
      $namespace= substr($type, 0, $p);
      if ('{' === $type[$p + 1]) {
        $use[$namespace]= array_merge($use[$namespace] ?? [], preg_split('/, ?/', substr($type, $p + 2, -1)));
      } else {
        $use[$namespace][]= substr($type, $p + 1);
      }
    } else if ($use) {
      ksort($use);
      foreach ($use as $namespace => $classes) {
        if (1 === sizeof($classes)) {
          $out->write(sprintf("\nuse %s\%s;", $namespace, $classes[0]));
        } else {
          sort($classes);
          $out->write(sprintf("\nuse %s\{%s};", $namespace, implode(', ', $classes)));
        }
      }
      $out->write("\n");
      $use= null;
    } else {
      $out->write("\n".$line);
    }
  }
  $out->close();
  return $target;
}

$src= new FilteredIOCollectionIterator(
  new FileCollection($argv[1] ?? 'src'),
  new ExtensionEqualsFilter(\xp::CLASS_FILE_EXT),
  true
);

foreach ($src as $file) {
  Console::write('> ', $file->getURI(), ': ');
  $target= rewrite($file, $file->getOrigin()->newElement('.rewrite'));
  rename($target->getURI(), $file->getURI());
  Console::writeLine('OK');
}

Usage:

$ xp group-use.script.php
> ...\src\main\php\util\data\Aggregations.class.php: OK
> ...\src\main\php\util\data\CannotReset.class.php: OK
# ...

$ git diff
# ...

[thekid]

✅ XP Unittests https://github.com/xp-framework/unittest

[thekid]

✅ XP Compiler (https://github.com/xp-framework/compiler/) & plugins (https://github.com/xp-lang)

[thekid]

Current state:

$ grep 'xp-framework/rfc#334' */ChangeLog.md | cut -d / -f 1
ast
compiler
credentials
hashing
keepass
marshalling
neo4j
php-compact-methods
php-is-operator
php-switch-expression
redis-sessions
redis
tokenize
unittest
uri
websockets
webtest
xp-enums

[thekid]

TODO

• address
• assert
• collections
• command
• csv
• frontend
• ftp
• functions
• geoip
• google-authenticator
• handlebars
• http
• ical
• imaging
• inject
• io-collections
• json-patch
• json
• ldap
• logging
• mail
• markdown
• math
• measure
• mirrors
• mocks
• mustache
• networking
• nsca
• parse
• partial
• patterns
• pivot
• ratelimit
• rdbms
• rest-api
• rest-client
• sequence
• sessions
• stomp
• text-encode
• web-auth
• web
• xml
• yaml
• zip

[thekid]

24 libraries left to go

[thekid]

14 libraries left to go

[thekid]

6 libraries left to go

[thekid]

$ grep '>=5.6.0' */composer.json | wc -l
0