1 files changed, 36 insertions, 0 deletions
diff --git a/platform/darwin/src/number_format.mm b/platform/darwin/src/number_format.mm
new file mode 100644
index 0000000000..86f16eb6dd
--- /dev/null
+++ b/platform/darwin/src/number_format.mm
@@ -0,0 +1,36 @@
+#import <Foundation/Foundation.h>
+
+#include <mbgl/i18n/number_format.hpp>
+
+namespace mbgl {
+namespace platform {
+
+std::string formatNumber(double number, const std::string& localeId, const std::string& currency,
+                         uint8_t minFractionDigits, uint8_t maxFractionDigits) {
+
+    static NSNumberFormatter *numberFormatter;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        numberFormatter = [[NSNumberFormatter alloc] init];
+    });
+
+    numberFormatter.locale = !localeId.empty() ? [NSLocale localeWithLocaleIdentifier:@(localeId.c_str())] : nil;
+    numberFormatter.currencyCode = !currency.empty() ? @(currency.c_str()) : nil;
+    if (currency.empty()) {
+        numberFormatter.minimumFractionDigits = minFractionDigits;
+        numberFormatter.maximumFractionDigits = maxFractionDigits;
+        numberFormatter.numberStyle = NSNumberFormatterDecimalStyle;
+    } else {
+        // Reset fraction digits to NSNumberFormatter's default values, so that the
+        // system will choose formatting based on number formatter locale.
+        numberFormatter.minimumFractionDigits = 0;
+        numberFormatter.maximumFractionDigits = 0;
+        numberFormatter.numberStyle = NSNumberFormatterCurrencyStyle;
+    }
+    NSString *formatted = [numberFormatter stringFromNumber:@(number)];
+    std::string result = std::string([formatted UTF8String]);
+    return result;
+}
+
+} // namespace platform
+} // namespace mbgl