Ain’t it lovely? Took long enough.

Ain’t it lovely? Took long enough.


NSCoding

Interface Builder 3.0 is a beautiful thing, but I had trouble creating a plugin that allowed me to drag and drop a simple object into a NIB. With views, it’s trivial, but I couldn’t figure out why my object wasn’t draggable, even though it appeared in my plugin.

The answer is the NSCoding protocol. Because objects have to be archived to and unarchived from the NIB, you have to implement NSCoding, even if the methods do nothing.

Hope this helps. 

“During their operations they seem to focus entirely on the process, but very little on the quality of the code.”
— Zed Shaw. This describes 20% of the companies I’ve worked for or with. The rest don’t focus on either one.

Fuck MySpace

  • Gregory: Fuck MySpace. I can't wait until I can abandon that abomination.
  • Todd: lol
  • Gregory: In fact, I'm posting that to my tumble log.
“Men of lofty genius when they are doing the least work are the most active.”
— Leonard da Vinci
Now I'll be able to "Get Things Done"!

OmniFocus is a new application — no beta as of this writing — that allows one to focus on Getting Things Done®. I can’t wait. :)

My nephew Jacob relishes a fry.

My nephew Jacob relishes a fry.


Monad Epiphany

I’ve just had an epiphany about Haskell monad transformers. Consider the following nested monad transformers:

type ErrorStateIO = ErrorT String (StateT Int IO) Int

I’d always thought that IO was the innermost monad, and some people erroneously describe this as the “IO monad wrapped in the StateT monad transformer which is in turn wrapped in the ErrorT monad transformer.”

It’s actually the reverse. IO is the outermost monad, and this makes sense because in an implementation with ErrorStateIO as the return type, one has to use use “lift” to talk to the next outermost layer. This can be demonstrated by the following code.

evalStateT (runErrorT (foo 2)) 2

That’s how we call these nested monads. Note that evalStateT is again outermost of the monad transformers. (IO is implicitly outermost as a part of StateT.) The return type of evalStateT is IO (Either String Int).

I’m new to Haskell and never realized this. But it makes enormous sense. I’m getting better than ever at using monads and monad transformers, but I don’t fully understand their internals. I’m hoping for another epiphany.

Haskell is so parsimonious and elegant, it feels like poetry, not programming.

“I’m the monolith and you’re the fuckin’ monkey.”
— Todd Sternisha