ReactiveCocoaFramework/ReactiveCocoa/RACBlockTrampoline.m

//
//  RACBlockTrampoline.m
//  ReactiveCocoa
//
//  Created by Josh Abernathy on 10/21/12.
//  Copyright (c) 2012 GitHub, Inc. All rights reserved.
//

#import "RACBlockTrampoline.h"
#import "RACTuple.h"

@interface RACBlockTrampoline ()
@property (nonatomic, readonly, copy) id block;
@end

@implementation RACBlockTrampoline

#pragma mark API

- (id)initWithBlock:(id)block {
	self = [super init];
	if (self == nil) return nil;

	_block = [block copy];

	return self;
}

+ (id)invokeBlock:(id)block withArguments:(RACTuple *)arguments {
	NSCParameterAssert(block != NULL);

	RACBlockTrampoline *trampoline = [[self alloc] initWithBlock:block];
	return [trampoline invokeWithArguments:arguments];
}

- (id)invokeWithArguments:(RACTuple *)arguments {
	SEL selector = [self selectorForArgumentCount:arguments.count];
	NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[self methodSignatureForSelector:selector]];
	invocation.selector = selector;
	invocation.target = self;

	for (NSUInteger i = 0; i < arguments.count; i++) {
		id arg = arguments[i];
		NSInteger argIndex = (NSInteger)(i + 2);
		[invocation setArgument:&arg atIndex:argIndex];
	}

	[invocation invoke];
	
	__unsafe_unretained id returnVal;
	[invocation getReturnValue:&returnVal];
	return returnVal;
}

- (SEL)selectorForArgumentCount:(NSUInteger)count {
	NSCParameterAssert(count > 0);

	switch (count) {
		case 0: return NULL;
		case 1: return @selector(performWith:);
		case 2: return @selector(performWith::);
		case 3: return @selector(performWith:::);
		case 4: return @selector(performWith::::);
		case 5: return @selector(performWith:::::);
		case 6: return @selector(performWith::::::);
		case 7: return @selector(performWith:::::::);
		case 8: return @selector(performWith::::::::);
		case 9: return @selector(performWith:::::::::);
		case 10: return @selector(performWith::::::::::);
		case 11: return @selector(performWith:::::::::::);
		case 12: return @selector(performWith::::::::::::);
		case 13: return @selector(performWith:::::::::::::);
		case 14: return @selector(performWith::::::::::::::);
		case 15: return @selector(performWith:::::::::::::::);
	}

	NSCAssert(NO, @"The argument count is too damn high! Only blocks of up to 15 arguments are currently supported.");
	return NULL;
}

- (id)performWith:(id)obj1 {
	id (^block)(id) = self.block;
	return block(obj1);
}

- (id)performWith:(id)obj1 :(id)obj2 {
	id (^block)(id, id) = self.block;
	return block(obj1, obj2);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 {
	id (^block)(id, id, id) = self.block;
	return block(obj1, obj2, obj3);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 {
	id (^block)(id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 {
	id (^block)(id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 {
	id (^block)(id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 {
	id (^block)(id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 {
	id (^block)(id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 {
	id (^block)(id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 :(id)obj10 {
	id (^block)(id, id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9, obj10);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 :(id)obj10 :(id)obj11 {
	id (^block)(id, id, id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9, obj10, obj11);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 :(id)obj10 :(id)obj11 :(id)obj12 {
	id (^block)(id, id, id, id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9, obj10, obj11, obj12);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 :(id)obj10 :(id)obj11 :(id)obj12 :(id)obj13 {
	id (^block)(id, id, id, id, id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9, obj10, obj11, obj12, obj13);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 :(id)obj10 :(id)obj11 :(id)obj12 :(id)obj13 :(id)obj14 {
	id (^block)(id, id, id, id, id, id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9, obj10, obj11, obj12, obj13, obj14);
}

- (id)performWith:(id)obj1 :(id)obj2 :(id)obj3 :(id)obj4 :(id)obj5 :(id)obj6 :(id)obj7 :(id)obj8 :(id)obj9 :(id)obj10 :(id)obj11 :(id)obj12 :(id)obj13 :(id)obj14 :(id)obj15 {
	id (^block)(id, id, id, id, id, id, id, id, id, id, id, id, id, id, id) = self.block;
	return block(obj1, obj2, obj3, obj4, obj5, obj6, obj7, obj8, obj9, obj10, obj11, obj12, obj13, obj14, obj15);
}

@end