The author overlooked the most mind-bending feature of Ruby blocks, the thing that makes them so very different than lambdas in other languages: Blocks can retu

The author overlooked the most mind-bending feature of Ruby blocks, the thing that makes them so very different than lambdas in other languages: Blocks can return from the enclosing function. def process collection.each do |element| return element if condition end end This has the effect of popping three (or more) frames off the stack. From the perspective of #each, yield never returns.