編集: ここで最新の要点: https://gist.github.com/fjolnir/cd72ea39be1476023adf
古いスレッドですが、解決策を探しているときに見つけたので、実装を投稿することにしました。
フォーマッター自体は円の配置を処理しませんが、円の外で簡単に行うことができます。(以下の例が示すように)
以下の期待される出力は次のとおりです。
2015-03-11 18:00:13.376 LENumberFormatter[82736:3604947] 12億3,460万円
2015-03-11 18:00:13.377 LENumberFormatter[82736:3604947] 25円
-
@import Foundation;
@import ObjectiveC.message;
typedef NS_ENUM(NSUInteger, LENumberFormatterAbbreviationStyle) {
kLEAbbreviateShort, // 2.5m
kLEAbbreviateNormal // 2m 5k
};
@interface LENumberFormatter : NSNumberFormatter
@property(nonatomic) BOOL abbreviateLargeNumbers;
@property(nonatomic) LENumberFormatterAbbreviationStyle abbreviationStyle;
@end
@implementation LENumberFormatter
- (instancetype)init
{
if((self = [super init])) {
self.abbreviationStyle = [self _usingKanjiNumbers]
? kLEAbbreviateNormal
: kLEAbbreviateShort;
}
return self;
}
- (NSString *)stringForObjectValue:(id const)aObj
{
if(!_abbreviateLargeNumbers || ![aObj isKindOfClass:[NSNumber class]])
return [super stringForObjectValue:aObj];
// Copy ourselves to get format the partial digits using the settings on self
LENumberFormatter * const partialFormatter = [self copy];
partialFormatter.currencySymbol = @"";
if(_abbreviationStyle == kLEAbbreviateNormal)
partialFormatter.maximumFractionDigits = 0;
NSString *(^partialFormat)(NSNumber*) = ^(NSNumber *num) {
NSString *(*superImp)(struct objc_super*,SEL,NSNumber*) = (void*)&objc_msgSendSuper;
return superImp(&(struct objc_super) { partialFormatter, self.superclass }, _cmd, num);
};
double n = [aObj doubleValue];
BOOL const shortFormat = _abbreviationStyle == kLEAbbreviateShort;
NSDictionary * const separators = [self _localizedGroupingSeparators];
NSArray * const separatorExponents = [separators.allKeys sortedArrayUsingSelector:@selector(compare:)];
BOOL const currencySymbolIsSuffix = [self.positiveFormat hasSuffix:@"¤"];
NSMutableString * const result = currencySymbolIsSuffix || self.numberStyle != NSNumberFormatterCurrencyStyle
? [NSMutableString new]
: [self.currencySymbol mutableCopy];
NSUInteger significantDigits = 0;
NSNumber *lastExp = nil;
for(NSNumber *exp in separatorExponents.reverseObjectEnumerator) {
double divisor = pow(10, exp.shortValue);
if(divisor > n)
continue;
if(lastExp)
significantDigits += lastExp.doubleValue - exp.doubleValue;
lastExp = exp;
if(self.usesSignificantDigits && significantDigits >= self.maximumSignificantDigits)
break;
double partialNum = shortFormat
? n/divisor
: floor(n/divisor);
NSString * const digits = [self _groupRecursively] && ![exp isEqual:@0]
? [partialFormatter stringFromNumber:@(partialNum)]
: partialFormat(@(partialNum));
[result appendFormat:@"%@%@", digits, separators[exp]];
n = fmod(n, divisor);
if(shortFormat)
break; // Just use a float+first hit
// If we make it here, partialNum is integral and we can use log10 to find the number of digits
significantDigits += log10(partialNum) + 1;
partialFormatter.maximumSignificantDigits -= digits.length;
}
if(n > 0
&& !shortFormat
&& (!self.usesSignificantDigits || significantDigits < self.maximumSignificantDigits))
{
partialFormatter.maximumFractionDigits = self.maximumFractionDigits;
[result appendString:partialFormat(@(n))];
}
if(self.numberStyle == NSNumberFormatterCurrencyStyle && currencySymbolIsSuffix && self.currencySymbol)
[result appendString:self.currencySymbol];
return result.length > 0
? [result stringByTrimmingCharactersInSet:NSCharacterSet.whitespaceAndNewlineCharacterSet]
: [super stringForObjectValue:aObj];
}
- (BOOL)_usingKanjiNumbers
{
return [self.locale.localeIdentifier rangeOfString:@"^(ja|zh)_"
options:NSRegularExpressionSearch].location != NSNotFound;
}
- (NSDictionary *)_localizedGroupingSeparators
{
if(self._usingKanjiNumbers)
return @{ @2: @"百", @3: @"千", @4: @"万", @8: @"億" };
else {
NSBundle * const bundle = [NSBundle bundleForClass:self.class];
return @{
@3: [bundle localizedStringForKey:@"thousandSuffix" value:@"k " table:nil],
@6: [bundle localizedStringForKey:@"millionSuffix" value:@"m " table:nil]
};
}
}
- (BOOL)_groupRecursively
{
// Return _usingKanjiNumbers if you want:
// 12億3千4百56万7千8百90
// Rather than:
// 1億2,3456万7千8百90
return NO;
}
- (instancetype)copyWithZone:(NSZone * const)aZone
{
LENumberFormatter * const copy = [super copyWithZone:aZone];
copy.abbreviateLargeNumbers = _abbreviateLargeNumbers;
copy.abbreviationStyle = _abbreviationStyle;
return copy;
}
@end
int main(int argc, char *argv[]) {
@autoreleasepool {
LENumberFormatter * const f = [LENumberFormatter new];
f.locale = [NSLocale localeWithLocaleIdentifier:@"ja_JP"];
// f.locale = [NSLocale localeWithLocaleIdentifier:@"en_US"];
f.numberStyle = NSNumberFormatterCurrencyStyle;
f.abbreviateLargeNumbers = YES;
f.abbreviationStyle = kLEAbbreviateNormal; // Automatic if using system locale
f.maximumSignificantDigits = 5;
f.usesSignificantDigits = YES;
// f.currencyCode = @"JPY";
// f.currencySymbol = @"¥";
if([f.locale.localeIdentifier hasPrefix:@"ja"]) {
f.positiveFormat = @"#,##0¤";
if([f.currencyCode isEqualToString:@"JPY"])
// We allow ourselves this special case because *日本円 just looks dumb
f.currencySymbol = @"円";
else
f.currencySymbol = [f.locale displayNameForKey:NSLocaleCurrencyCode
value:f.currencyCode];
}
NSLog(@"%@", [f stringFromNumber:@1234567890]);
NSLog(@"%@", [f stringFromNumber:@25]);
}
}