Set of functions for safe extraction of parsed values from JSON/XML dictionaries

SafeTypes.h

//
//  SafeTypes.h
//
// Contains functions for safe values extraction from id types
//
//  Created by Alexs on 17.11.16.
//

/**
*  Accepts string and return string itself if it's not nil and empty string otherwise
*/
NS_INLINE NSString *__nonnull NOT_NIL_STRING(NSString *__nullable value) {
    return value == nil ? @"" : value;
}

/**
 * Gets NSInteger value from NSString or NSValue type and converts it to NSNumber
 */
NS_INLINE NSNumber *__nullable SafeNumberInt(id __nullable value) {
    if (value == nil)
        return nil;
    if ([value respondsToSelector:@selector(integerValue)]) {
        return @([value integerValue]);
    } else {
        NSLog(@"TYPE ERROR: Can't extract integer value from %@ in %@", value, [NSThread callStackSymbols]);
        return nil;
    }
}

/**
 * Gets double value from NSString or NSValue type and converts it to NSNumber
 */
NS_INLINE NSNumber *__nullable SafeNumberDouble(id __nullable value) {
    if (value == nil)
        return nil;
    if ([value respondsToSelector:@selector(doubleValue)]) {
        return @([value doubleValue]);
    } else {
        NSLog(@"TYPE ERROR: Can't extract double value from %@ in %@", value, [NSThread callStackSymbols]);
        return nil;
    }
}

/**
 * Returns string value of object, using [NSString stringWithFormat:%@]
 */
NS_INLINE NSString *__nullable SafeString(id __nullable value) {
    return value == nil ? nil : [NSString stringWithFormat:@"%@", value];
}

/**
 * Returns object if it is NSDictionary or nil, if it's not a Dictionary
 */
NS_INLINE NSDictionary *__nullable SafeDictionary(id __nullable value) {
    if (value == nil)
        return nil;
    if ([value isKindOfClass:[NSDictionary class]]) {
        return value;
    } else {
        NSLog(@"TYPE ERROR: Expected dictionary, but got %@ in %@", value, [NSThread callStackSymbols]);
        return nil;
    }
}

/**
 * Returns object if it is NSArray or nil, if it's not an Array
 */
NS_INLINE NSArray *__nullable SafeArray(id __nullable value) {
    if (value == nil)
        return nil;
    if ([value isKindOfClass:[NSArray class]]) {
        return value;
    } else {
        NSLog(@"TYPE ERROR: Expected array, but got %@ in %@", value, [NSThread callStackSymbols]);
        return nil;
    }
}