PLBlocks 项目简介
如果是Mac 10.6 或 iOS 4.0 之前的平台可以利用 PLBlocks 這個project得以支援Block語法。 Plausible Blocks (PLBlocks) provides a drop-in runtime and toolchain for using blocks in iPhone 2.2+ and Mac OS X 10.5 applications. Both the runtime and compiler patches are direct backports from Apple's Snow Leopard source releases.