GH-18345: adding Locale::isRightToLeft.

Checks is the locale is written left to right.
It makes sure all the needed likely subtags are included (maximization)
then determines the direction by known matches.

close GH-18351

NEWS

@@ -85,6 +85,8 @@ PHP                                                                        NEWS
     with uninitialised classes or clone failure. (David Carlier)
   . Added DECIMAL_COMPACT_SHORT/DECIMAL_COMPACT_LONG for NumberFormatter class.
     (BogdanUngureanu)
+  . Added Locale::isRightToLeft to check if a locale is written right to left.
+    (David Carlier)
 
 - MySQLi:
   . Fixed bugs GH-17900 and GH-8084 (calling mysqli::__construct twice).

UPGRADING

@@ -309,6 +309,10 @@ PHP 8.5 UPGRADE NOTES
   . Added enchant_dict_remove() to put a word on the exclusion list and
     remove it from the session dictionary.
 
+- Intl:
+  . Added locale_is_right_to_left/Locale::isRightToLeft, returns true if
+    the locale is written right to left (after its enrichment with likely subtags).
+
 - Pdo\Sqlite:
   . Added support for Pdo\Sqlite::setAuthorizer(), which is the equivalent of
     SQLite3::setAuthorizer(). The only interface difference is that the

ext/intl/locale/locale.stub.php

@@ -133,4 +133,9 @@ class Locale
      * @alias locale_accept_from_http
      */
     public static function acceptFromHttp(string $header): string|false {}
+
+    /**
+     * @alias locale_is_right_to_left
+     */
+    public static function isRightToLeft(string $locale): bool {}
 }

ext/intl/locale/locale_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 59861342e0075231d2a576afb2d5df6973d70684 */
+ * Stub hash: f09cfd61f3e20576c7f6d5da17a6d9c009d6ab64 */
 
 ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_INFO_EX(arginfo_class_Locale_getDefault, 0, 0, IS_STRING, 0)
 ZEND_END_ARG_INFO()
@@ -62,6 +62,10 @@ ZEND_BEGIN_ARG_WITH_TENTATIVE_RETURN_TYPE_MASK_EX(arginfo_class_Locale_acceptFro
 	ZEND_ARG_TYPE_INFO(0, header, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_class_Locale_isRightToLeft, 0, 1, _IS_BOOL, 0)
+	ZEND_ARG_TYPE_INFO(0, locale, IS_STRING, 0)
+ZEND_END_ARG_INFO()
+
 ZEND_FUNCTION(locale_get_default);
 ZEND_FUNCTION(locale_set_default);
 ZEND_FUNCTION(locale_get_primary_language);
@@ -80,6 +84,7 @@ ZEND_FUNCTION(locale_filter_matches);
 ZEND_FUNCTION(locale_lookup);
 ZEND_FUNCTION(locale_canonicalize);
 ZEND_FUNCTION(locale_accept_from_http);
+ZEND_FUNCTION(locale_is_right_to_left);
 
 static const zend_function_entry class_Locale_methods[] = {
 	ZEND_RAW_FENTRY("getDefault", zif_locale_get_default, arginfo_class_Locale_getDefault, ZEND_ACC_PUBLIC|ZEND_ACC_STATIC, NULL, NULL)
@@ -100,6 +105,7 @@ static const zend_function_entry class_Locale_methods[] = {
 	ZEND_RAW_FENTRY("lookup", zif_locale_lookup, arginfo_class_Locale_lookup, ZEND_ACC_PUBLIC|ZEND_ACC_STATIC, NULL, NULL)
 	ZEND_RAW_FENTRY("canonicalize", zif_locale_canonicalize, arginfo_class_Locale_canonicalize, ZEND_ACC_PUBLIC|ZEND_ACC_STATIC, NULL, NULL)
 	ZEND_RAW_FENTRY("acceptFromHttp", zif_locale_accept_from_http, arginfo_class_Locale_acceptFromHttp, ZEND_ACC_PUBLIC|ZEND_ACC_STATIC, NULL, NULL)
+	ZEND_RAW_FENTRY("isRightToLeft", zif_locale_is_right_to_left, arginfo_class_Locale_isRightToLeft, ZEND_ACC_PUBLIC|ZEND_ACC_STATIC, NULL, NULL)
 	ZEND_FE_END
 };
 

ext/intl/locale/locale_methods.c

@@ -1619,3 +1619,19 @@ PHP_FUNCTION(locale_accept_from_http)
 	RETURN_STRINGL(resultLocale, len);
 }
 /* }}} */
+
+PHP_FUNCTION(locale_is_right_to_left)
+{
+	char *locale;
+	size_t locale_len;
+
+	ZEND_PARSE_PARAMETERS_START(1, 1)
+		Z_PARAM_STRING(locale, locale_len)
+	ZEND_PARSE_PARAMETERS_END();
+
+	if (!locale_len) {
+		locale = (char *)intl_locale_get_default();
+	}
+
+	RETURN_BOOL(uloc_isRightToLeft(locale));
+}

ext/intl/php_intl.stub.php

@@ -501,6 +501,8 @@ function locale_lookup(array $languageTag, string $locale, bool $canonicalize =
 
 function locale_accept_from_http(string $header): string|false {}
 
+function locale_is_right_to_left(string $locale): bool {}
+
 /* msgformat */
 
 function msgfmt_create(string $locale, string $pattern): ?MessageFormatter {}

ext/intl/php_intl_arginfo.h

@@ -1,5 +1,5 @@
 /* This is a generated file, edit the .stub.php file instead.
- * Stub hash: 168eabfdcbf29189f2327448f104ea98752d1c5a */
+ * Stub hash: 4fb44fc170e74af2e9fb52c5a1029004f708fcda */
 
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_intlcal_create_instance, 0, 0, IntlCalendar, 1)
 	ZEND_ARG_INFO_WITH_DEFAULT_VALUE(0, timezone, "null")
@@ -566,6 +566,10 @@ ZEND_BEGIN_ARG_WITH_RETURN_TYPE_MASK_EX(arginfo_locale_accept_from_http, 0, 1, M
 	ZEND_ARG_TYPE_INFO(0, header, IS_STRING, 0)
 ZEND_END_ARG_INFO()
 
+ZEND_BEGIN_ARG_WITH_RETURN_TYPE_INFO_EX(arginfo_locale_is_right_to_left, 0, 1, _IS_BOOL, 0)
+	ZEND_ARG_TYPE_INFO(0, locale, IS_STRING, 0)
+ZEND_END_ARG_INFO()
+
 ZEND_BEGIN_ARG_WITH_RETURN_OBJ_INFO_EX(arginfo_msgfmt_create, 0, 2, MessageFormatter, 1)
 	ZEND_ARG_TYPE_INFO(0, locale, IS_STRING, 0)
 	ZEND_ARG_TYPE_INFO(0, pattern, IS_STRING, 0)
@@ -920,6 +924,7 @@ ZEND_FUNCTION(locale_filter_matches);
 ZEND_FUNCTION(locale_canonicalize);
 ZEND_FUNCTION(locale_lookup);
 ZEND_FUNCTION(locale_accept_from_http);
+ZEND_FUNCTION(locale_is_right_to_left);
 ZEND_FUNCTION(msgfmt_create);
 ZEND_FUNCTION(msgfmt_format);
 ZEND_FUNCTION(msgfmt_format_message);
@@ -1107,6 +1112,7 @@ static const zend_function_entry ext_functions[] = {
 	ZEND_FE(locale_canonicalize, arginfo_locale_canonicalize)
 	ZEND_FE(locale_lookup, arginfo_locale_lookup)
 	ZEND_FE(locale_accept_from_http, arginfo_locale_accept_from_http)
+	ZEND_FE(locale_is_right_to_left, arginfo_locale_is_right_to_left)
 	ZEND_FE(msgfmt_create, arginfo_msgfmt_create)
 	ZEND_FE(msgfmt_format, arginfo_msgfmt_format)
 	ZEND_FE(msgfmt_format_message, arginfo_msgfmt_format_message)

ext/intl/tests/locale_is_right_to_left.phpt

@@ -0,0 +1,16 @@
+--TEST--
+locale_is_right_to_left
+--EXTENSIONS--
+intl
+--FILE--
+<?php
+var_dump(Locale::isRightToLeft("en-US"));
+var_dump(Locale::isRightToLeft("\INVALID\\"));
+var_dump(Locale::isRightToLeft(""));
+var_dump(Locale::isRightToLeft("ar"));
+?>
+--EXPECT--
+bool(false)
+bool(false)
+bool(false)
+bool(true)