Comments on: Tell, Don’t Ask – Part 1

By: Will Smith

Will Smith — Wed, 09 Sep 2009 15:33:05 +0000

I think it is important for the owner to know if the dog is hungry before he attempts to feed the dog. I’m not interested in forcing kibbles on a dog that isn’t hungry.

In this situation, I think some message or event would work out nicely. The dog could simply have a “IsHungry” event that the owner subscribes to. Then the owner knows exactly when to feed the dog.

I know that is how it works in my house

By: jim barritt

jim barritt — Sat, 05 Sep 2009 11:51:33 +0000

Hi ketan,

Nice example,
I had a similar example of a dog wagging its tail.you don’t wag the dogs tail, you pat the dog or (as in this case) show it some food and it wags its own tail.

Jim

By: Ben

Ben — Fri, 04 Sep 2009 08:59:05 +0000

Nice example, it also describes improving an abstraction.

Adding the feed method to Dog is good because it conceals implementation details. Dog is no longer exposing the fact that it has a mouth, so there is no way for clients to depend on it.

Dog is now refactorable to Pet, too. And PetOwner can get a worm farm…

By: Steve Lindsey

Steve Lindsey — Fri, 04 Sep 2009 07:53:06 +0000

“Rarely do I like to read code that is verbose and does too much orchestration in order to do something that is orthognal to what I’m looking for”

Do you not see the irony in this statement.