Coding Standards: Use static closures when not using `$this`.

When a closure does not use `$this`, it can be made `static` for improved performance.

Static closures are supported in PHP since PHP 5.4. ​

Props jrf, hellofromTonya, swissspidy, SergeyBiryukov.
See #53359.
Built from https://develop.svn.wordpress.org/trunk@51657


git-svn-id: http://core.svn.wordpress.org/trunk@51263 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-admin/edit-form-blocks.php

@@ -31,7 +31,7 @@ $current_screen->is_block_editor( true );
 // Default to is-fullscreen-mode to avoid jumps in the UI.
 add_filter(
 	'admin_body_class',
-	function( $classes ) {
+	static function( $classes ) {
 		return "$classes is-fullscreen-mode";
 	}
 );

wp-admin/includes/class-wp-community-events.php

@@ -474,7 +474,7 @@ class WP_Community_Events {
 
 		$future_wordcamps = array_filter(
 			$future_events,
-			function( $wordcamp ) {
+			static function( $wordcamp ) {
 				return 'wordcamp' === $wordcamp['type'];
 			}
 		);

wp-admin/includes/class-wp-site-health-auto-updates.php

@@ -41,7 +41,7 @@ class WP_Site_Health_Auto_Updates {
 
 		$tests = array_filter( $tests );
 		$tests = array_map(
-			function( $test ) {
+			static function( $test ) {
 				$test = (object) $test;
 
 				if ( empty( $test->severity ) ) {

wp-admin/includes/update-core.php

@@ -1658,7 +1658,7 @@ function _upgrade_422_find_genericons_files_in_folder( $directory ) {
 	$dirs = glob( $directory . '*', GLOB_ONLYDIR );
 	$dirs = array_filter(
 		$dirs,
-		function( $dir ) {
+		static function( $dir ) {
 			// Skip any node_modules directories.
 			return false === strpos( $dir, 'node_modules' );
 		}

wp-admin/options-privacy.php

@@ -20,7 +20,7 @@ if ( isset( $_GET['tab'] ) && 'policyguide' === $_GET['tab'] ) {
 
 add_filter(
 	'admin_body_class',
-	function( $body_class ) {
+	static function( $body_class ) {
 		$body_class .= ' privacy-settings ';
 
 		return $body_class;

wp-admin/privacy-policy-guide.php

@@ -19,7 +19,7 @@ if ( ! class_exists( 'WP_Privacy_Policy_Content' ) ) {
 
 add_filter(
 	'admin_body_class',
-	function( $body_class ) {
+	static function( $body_class ) {
 		$body_class .= ' privacy-settings ';
 
 		return $body_class;

wp-content/themes/twentytwenty/classes/class-twentytwenty-customize.php

@@ -186,7 +186,7 @@ if ( ! class_exists( 'TwentyTwenty_Customize' ) ) {
 						'settings'        => 'accent_hue',
 						'description'     => __( 'Apply a custom color for links, buttons, featured images.', 'twentytwenty' ),
 						'mode'            => 'hue',
-						'active_callback' => function() use ( $wp_customize ) {
+						'active_callback' => static function() use ( $wp_customize ) {
 							return ( 'custom' === $wp_customize->get_setting( 'accent_hue_active' )->value() );
 						},
 					)

wp-content/themes/twentytwentyone/classes/class-twenty-twenty-one-customize.php

@@ -92,7 +92,7 @@ if ( ! class_exists( 'Twenty_Twenty_One_Customize' ) ) {
 				array(
 					'capability'        => 'edit_theme_options',
 					'default'           => 'excerpt',
-					'sanitize_callback' => function( $value ) {
+					'sanitize_callback' => static function( $value ) {
 						return 'excerpt' === $value || 'full' === $value ? $value : 'excerpt';
 					},
 				)

wp-content/themes/twentytwentyone/classes/class-twenty-twenty-one-dark-mode.php

@@ -153,7 +153,7 @@ class Twenty_Twenty_One_Dark_Mode {
 				array(
 					'section'         => 'colors',
 					'priority'        => 100,
-					'active_callback' => function() {
+					'active_callback' => static function() {
 						return 127 >= Twenty_Twenty_One_Custom_Colors::get_relative_luminance_from_hex( get_theme_mod( 'background_color', 'D1E4DD' ) );
 					},
 				)
@@ -165,7 +165,7 @@ class Twenty_Twenty_One_Dark_Mode {
 			array(
 				'capability'        => 'edit_theme_options',
 				'default'           => false,
-				'sanitize_callback' => function( $value ) {
+				'sanitize_callback' => static function( $value ) {
 					return (bool) $value;
 				},
 			)
@@ -188,7 +188,7 @@ class Twenty_Twenty_One_Dark_Mode {
 				'label'           => esc_html__( 'Dark Mode support', 'twentytwentyone' ),
 				'priority'        => 110,
 				'description'     => $description,
-				'active_callback' => function( $value ) {
+				'active_callback' => static function( $value ) {
 					return 127 < Twenty_Twenty_One_Custom_Colors::get_relative_luminance_from_hex( get_theme_mod( 'background_color', 'D1E4DD' ) );
 				},
 			)

wp-includes/block-supports/duotone.php

@@ -361,7 +361,7 @@ function wp_render_duotone_support( $block_content, $block ) {
 
 	$selectors        = explode( ',', $duotone_support );
 	$selectors_scoped = array_map(
-		function ( $selector ) use ( $duotone_id ) {
+		static function ( $selector ) use ( $duotone_id ) {
 			return '.' . $duotone_id . ' ' . trim( $selector );
 		},
 		$selectors

wp-includes/block-supports/layout.php

@@ -131,7 +131,7 @@ function wp_restore_group_inner_container( $block_content, $block ) {
 	$replace_regex   = '/(^\s*<div\b[^>]*wp-block-group[^>]*>)(.*)(<\/div>\s*$)/ms';
 	$updated_content = preg_replace_callback(
 		$replace_regex,
-		function( $matches ) {
+		static function( $matches ) {
 			return $matches[1] . '<div class="wp-block-group__inner-container">' . $matches[2] . '</div>' . $matches[3];
 		},
 		$block_content

wp-includes/block-template.php

@@ -124,7 +124,7 @@ function resolve_block_template( $template_type, $template_hierarchy ) {
 
 	usort(
 		$templates,
-		function ( $template_a, $template_b ) use ( $slug_priorities ) {
+		static function ( $template_a, $template_b ) use ( $slug_priorities ) {
 			return $slug_priorities[ $template_a->slug ] - $slug_priorities[ $template_b->slug ];
 		}
 	);

wp-includes/class-wp-theme-json.php

@@ -636,7 +636,7 @@ class WP_Theme_JSON {
 
 		$declaration_block = array_reduce(
 			$declarations,
-			function ( $carry, $element ) {
+			static function ( $carry, $element ) {
 				return $carry .= $element['name'] . ': ' . $element['value'] . ';'; },
 			''
 		);

wp-includes/formatting.php

@@ -3113,7 +3113,7 @@ function wp_rel_nofollow( $text ) {
 	$text = stripslashes( $text );
 	$text = preg_replace_callback(
 		'|<a (.+?)>|i',
-		function( $matches ) {
+		static function( $matches ) {
 			return wp_rel_callback( $matches, 'nofollow' );
 		},
 		$text
@@ -3147,7 +3147,7 @@ function wp_rel_ugc( $text ) {
 	$text = stripslashes( $text );
 	$text = preg_replace_callback(
 		'|<a (.+?)>|i',
-		function( $matches ) {
+		static function( $matches ) {
 			return wp_rel_callback( $matches, 'nofollow ugc' );
 		},
 		$text

wp-includes/rest-api.php

@@ -3227,7 +3227,7 @@ function rest_get_endpoint_args_for_schema( $schema, $method = WP_REST_Server::C
 function rest_convert_error_to_response( $error ) {
 	$status = array_reduce(
 		$error->get_all_error_data(),
-		function ( $status, $error_data ) {
+		static function ( $status, $error_data ) {
 			return is_array( $error_data ) && isset( $error_data['status'] ) ? $error_data['status'] : $status;
 		},
 		500

wp-includes/rest-api/endpoints/class-wp-rest-controller.php

@@ -597,7 +597,7 @@ abstract class WP_REST_Controller {
 		// Return the list of all requested fields which appear in the schema.
 		return array_reduce(
 			$requested_fields,
-			function( $response_fields, $field ) use ( $fields ) {
+			static function( $response_fields, $field ) use ( $fields ) {
 				if ( in_array( $field, $fields, true ) ) {
 					$response_fields[] = $field;
 					return $response_fields;

wp-includes/rest-api/endpoints/class-wp-rest-plugins-controller.php

@@ -381,7 +381,7 @@ class WP_REST_Plugins_Controller extends WP_REST_Controller {
 		$installed_locales = apply_filters( 'plugins_update_check_locales', $installed_locales );
 
 		$language_packs = array_map(
-			function( $item ) {
+			static function( $item ) {
 				return (object) $item;
 			},
 			$api->language_packs
@@ -389,7 +389,7 @@ class WP_REST_Plugins_Controller extends WP_REST_Controller {
 
 		$language_packs = array_filter(
 			$language_packs,
-			function( $pack ) use ( $installed_locales ) {
+			static function( $pack ) use ( $installed_locales ) {
 				return in_array( $pack->language, $installed_locales, true );
 			}
 		);

wp-includes/rest-api/endpoints/class-wp-rest-widget-types-controller.php

@@ -85,7 +85,7 @@ class WP_REST_Widget_Types_Controller extends WP_REST_Controller {
 					'form_data' => array(
 						'description'       => __( 'Serialized widget form data to encode into instance settings.' ),
 						'type'              => 'string',
-						'sanitize_callback' => function( $string ) {
+						'sanitize_callback' => static function( $string ) {
 							$array = array();
 							wp_parse_str( $string, $array );
 							return $array;

wp-includes/rest-api/endpoints/class-wp-rest-widgets-controller.php

@@ -792,7 +792,7 @@ class WP_REST_Widgets_Controller extends WP_REST_Controller {
 					'type'        => 'string',
 					'context'     => array(),
 					'arg_options' => array(
-						'sanitize_callback' => function( $string ) {
+						'sanitize_callback' => static function( $string ) {
 							$array = array();
 							wp_parse_str( $string, $array );
 							return $array;

wp-includes/script-loader.php

@@ -2692,7 +2692,7 @@ function wp_maybe_inline_styles() {
 		// Reorder styles array based on size.
 		usort(
 			$styles,
-			function( $a, $b ) {
+			static function( $a, $b ) {
 				return ( $a['size'] <= $b['size'] ) ? -1 : 1;
 			}
 		);

wp-includes/update.php

@@ -517,7 +517,7 @@ function wp_update_plugins( $extra_stats = array() ) {
 		}
 	}
 
-	$sanitize_plugin_update_payload = function( &$item ) {
+	$sanitize_plugin_update_payload = static function( &$item ) {
 		$item = (object) $item;
 
 		unset( $item->translations, $item->compatibility );

wp-includes/user.php

@@ -3459,7 +3459,7 @@ function wp_user_personal_data_exporter( $email_address ) {
 		// Remove items that use reserved names.
 		$extra_data = array_filter(
 			$_extra_data,
-			function( $item ) use ( $reserved_names ) {
+			static function( $item ) use ( $reserved_names ) {
 				return ! in_array( $item['name'], $reserved_names, true );
 			}
 		);

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9-alpha-51655';
+$wp_version = '5.9-alpha-51657';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.