Reducing BOOLs.

Reducer.m

@interface Reducer : NSObject
+ (id(^)())reduceToBoolMultiple:(NSNumber *)boolArgs, ... NS_REQUIRES_NIL_TERMINATION;
+ (id(^)())reduceToBoolArray:(NSArray *)array;
@end

@implementation Reducer

+ (id (^)())reduceToBoolMultiple:(NSNumber *)firstArg, ... NS_REQUIRES_NIL_TERMINATION {

    BOOL retVal = firstArg.boolValue;
    va_list args;
    va_start(args, firstArg);
    for (NSNumber *arg = firstArg; arg; arg = va_arg(args, NSNumber *)) {
        retVal = arg.boolValue && retVal;
    }
    va_end(args);

    return ^id {
        return @(retVal);
    };
}

+ (id (^)())reduceToBoolArray:(NSArray *)array {

    BOOL retVal = [[array firstObject] boolValue];
    for (int i = 1; i < array.count; i++) {
        retVal = [array[i] boolValue] && retVal;
    }
    return ^id {
        return @(retVal);
    };
}

@end