Support file for "Inside the Bracket, part 4" . This shows fake implementation of a method.

marsupial.m

#import <Foundation/Foundation.h>

// clang -g -fobjc-arc -Wall -framework Foundation -o marsupial marsupial.m


@interface NSObject (AllThingsCanDance)
- (void) wombatDance: (int) repetitions;
@end


@interface Marsupial : NSObject
@end // Marsupial


@implementation Marsupial

- (NSMethodSignature *) methodSignatureForSelector: (SEL) selector {

    NSMethodSignature *signature;

    if (selector == @selector(wombatDance:)) {
        char *typeEncodings;
        asprintf(&typeEncodings, "%s%s%s%s",
                 @encode(void),     // return
                 @encode(id),       // self
                 @encode(SEL),      // _cmd
                 @encode(int));     // repetitions
        signature =
            [NSMethodSignature signatureWithObjCTypes: typeEncodings];
        free (typeEncodings);

    } else {
        signature = [super methodSignatureForSelector: selector];
    }

    if (signature == nil) {
        NSLog (@"no signature for %@", NSStringFromSelector(selector));
    }

    return signature;

} // methodSignatureForSelector


- (void) forwardInvocation: (NSInvocation *) invocation {
    if (invocation.selector == @selector(wombatDance:)) {
        NSInteger repetitions = 0;
        [invocation getArgument: &repetitions  atIndex: 2];
        NSLog (@"You spin me right round baby right round %ld times", repetitions);

    } else {
        [super forwardInvocation: invocation];
    }
}

@end // Marsupial


int main (void) {
    @autoreleasepool {
        Marsupial *pouchy = [Marsupial new];
        [pouchy wombatDance: 23];
    }

    return 0;
} // main