[core][android][darwin] Move number format to i18n

platform/default/src/mbgl/i18n/format_number.cpp

@@ -1,4 +1,4 @@
-#include <mbgl/util/platform.hpp>
+#include <mbgl/i18n/number_format.hpp>
 
 #include <unicode/numberformatter.h>
 

platform/default/src/mbgl/i18n/number_format.cpp

@@ -0,0 +1,41 @@
+#include <mbgl/i18n/number_format.hpp>
+
+#include <unicode/numberformatter.h>
+
+namespace mbgl {
+namespace platform {
+
+std::string formatNumber(double number,
+                         const std::string& localeId,
+                         const std::string& currency,
+                         uint8_t minFractionDigits,
+                         uint8_t maxFractionDigits) {
+    UErrorCode status = U_ZERO_ERROR;
+    icu::UnicodeString ustr;
+    std::string formatted;
+
+    icu::Locale locale = icu::Locale(localeId.c_str());
+    // Print the value as currency
+    if (!currency.empty()) {
+        icu::UnicodeString ucurrency = icu::UnicodeString::fromUTF8(currency);
+        ustr = icu::number::NumberFormatter::with()
+                   .unit(icu::CurrencyUnit(ucurrency.getBuffer(), status))
+                   .locale(locale)
+                   .formatDouble(number, status)
+                   .toString();
+    } else {
+        ustr = icu::number::NumberFormatter::with()
+#if U_ICU_VERSION_MAJOR_NUM >= 62
+                   .precision(icu::number::Precision::minMaxFraction(minFractionDigits, maxFractionDigits))
+#else
+                   .rounding(icu::number::Rounder::minMaxFraction(minFractionDigits, maxFractionDigits))
+#endif
+                   .locale(locale)
+                   .formatDouble(number, status)
+                   .toString();
+    }
+    return ustr.toUTF8String(formatted);
+}
+
+} // namespace platform
+} // namespace mbgl