Return default system locale for carrier region on unsupported devices. Update docs.

Author: egoldfarb

libPhoneNumber/NBPhoneNumberUtil.h

@@ -39,9 +39,7 @@
 
 - (NSString *)extractPossibleNumber:(NSString *)phoneNumber;
 - (NSNumber *)extractCountryCode:(NSString *)fullNumber nationalNumber:(NSString **)nationalNumber;
-#if !TARGET_OS_TV
 - (NSString *)countryCodeByCarrier;
-#endif
 
 - (NSString *)getNddPrefixForRegion:(NSString *)regionCode stripNonDigits:(BOOL)stripNonDigits;
 - (NSString *)getNationalSignificantNumber:(NBPhoneNumber *)phoneNumber;

libPhoneNumber/NBPhoneNumberUtil.m

@@ -3447,30 +3447,26 @@ - (NBPhoneNumber *)parse:(NSString *)numberToParse
 }
 
 /**
- * Parses a string using the phone's carrier region (when available, ZZ otherwise).
- * This uses the country the sim card in the phone is registered with.
+ * Parses a string using the phone's carrier region (when available, uses system locale otherwise).
+ * This uses the country the SIM card in the phone is registered with.
  * For example if you have an AT&T sim card but are in Europe, this will parse the
  * number using +1 (AT&T is a US Carrier) as the default country code.
- * This also works for CDMA phones which don't have a sim card.
+ * This also works for multi-SIM phones, using the SIM region of default voice line.
  */
 - (NBPhoneNumber *)parseWithPhoneCarrierRegion:(NSString *)numberToParse error:(NSError **)error {
   numberToParse = NormalizeNonBreakingSpace(numberToParse);
 
-  NSString *defaultRegion = nil;
-#if !TARGET_OS_TV
-  defaultRegion = [self countryCodeByCarrier];
-#else
-  defaultRegion = [[NSLocale currentLocale] objectForKey:NSLocaleCountryCode];
-#endif
-
+  NSString *defaultRegion = [self countryCodeByCarrier];
   return [self parse:numberToParse defaultRegion:defaultRegion error:error];
 }
 
-#if !TARGET_OS_TV
 - (NSString *)countryCodeByCarrier {
+#if !TARGET_OS_TV
   return [[CNContactsUserDefaults sharedDefaults].countryCode uppercaseString];
-}
+#else
+  return [[NSLocale currentLocale] objectForKey:NSLocaleCountryCode];
 #endif
+}
 
 /**
  * Parses a string and returns it in proto buffer format. This method differs

libPhoneNumberShortNumber/NBShortNumberUtil.h

@@ -25,8 +25,10 @@ typedef NS_ENUM(NSUInteger, NBEShortNumberCost) {
 
 @property(nonatomic) NSDictionary<NSNumber *, NSArray<NSString *> *> *countryToRegionCodeMap;
 
-/// Initialize short number util with a default metadata helper.
-- (instancetype)init;
+/// Short number util singleton with a default metadata helper.
++ (NBShortNumberUtil *)sharedInstance;
+
+- (instancetype)init NS_UNAVAILABLE;
 
 /// Initialize short number util with a metadata helper.
 /// @param helper A metadata helper.

libPhoneNumberShortNumber/NBShortNumberUtil.m

@@ -25,6 +25,17 @@ @implementation NBShortNumberUtil {
   NBPhoneNumberUtil *_phoneUtil;
 }
 
++ (NBShortNumberUtil *)sharedInstance {
+  static NBShortNumberUtil *sharedOnceInstance = nil;
+  static dispatch_once_t onceToken;
+  dispatch_once(&onceToken, ^{
+    sharedOnceInstance =
+        [[self alloc] initWithMetadataHelper:[[NBShortNumberMetadataHelper alloc] init]
+                             phoneNumberUtil:[NBPhoneNumberUtil sharedInstance]];
+  });
+  return sharedOnceInstance;
+}
+
 - (instancetype)initWithMetadataHelper:(NBShortNumberMetadataHelper *)helper
                        phoneNumberUtil:(NBPhoneNumberUtil *)phoneNumberUtil {
   self = [super init];
@@ -36,11 +47,6 @@ - (instancetype)initWithMetadataHelper:(NBShortNumberMetadataHelper *)helper
   return self;
 }
 
-- (instancetype)init {
-  return [self initWithMetadataHelper:[[NBShortNumberMetadataHelper alloc] init]
-                      phoneNumberUtil:[NBPhoneNumberUtil sharedInstance]];
-}
-
 - (BOOL)isPossibleShortNumber:(NBPhoneNumber *)phoneNumber forRegion:(NSString *)regionDialingFrom {
   if (![self doesPhoneNumber:phoneNumber matchesRegion:regionDialingFrom]) {
     return NO;

libPhoneNumberShortNumber/README.md

@@ -46,7 +46,7 @@ import libPhoneNumberShortNumber
 
 ## Usage - **NBShortNumberUtil**
 ```obj-c
-NBShortNumberUtil *shortNumberUtil = [[NBShortNumberUtil alloc] init];
+NBShortNumberUtil *shortNumberUtil = [NBShortNumberUtil sharedInstance];
 
     // possibleNumber                  : +33123456
     NSLog(@"Is possible short number: %d",