Let's walk through my thoughts.
Hmm, okay so Spock looks nice. Neat! The routing code looks very easy to read:
main = do
spockCfg Hello world!"
get "users" $ do
Spock.json (A.object [ "users" .= users ])
get ("users" var "friends") $ \userID -> do
Spock.json (A.object [ "userID" .= (userID :: Int), "friends" .= A.Null ])
Alright, let's figure out how this works.
runSpock :: Port -> IO Middleware -> IO ()
Okay that makes sense. Takes in a port, some middleware and spits out IO. Not crazy. Hmm, okay these dollar signs are making things a little confusing, but I can figure out that spock returns an IO Middleware and therefore we can see that spock takes the output of the right do block along with spockCfg. Not the easiest to scan at first glance because of the right to left reading but okay.
Let's look at get.
get :: HasRep xs => RouteSpec xs ps ctx conn sess st
Ah, okay, so uh...this doesn't appear to be a function. Oh, I see, here it is:
type RouteSpec xs ps ctx conn sess st = Path xs ps -> HVectElim xs (SpockActionCtx ctx conn sess st ()) -> SpockCtxM ctx conn sess st ()
Well I'm not really sure what xs, ps or st are. And HVectElim doesn't tell me anything. Path is pretty clear and SpockCtxM is a monad of sorts. But what the hell is HVectElim? Alright whatever, let's just figure it out via the signatures of Spock.html/Spock.json. Which are...nowhere to be found in the documentation. I looked them up in the index and nope, no entries. I'm very confused about what HVectElim is and why that would be a fine name.
I can continue past this point, but you get my gist.
This is actually way better than my other experiences with Haskell and web dev, but it's by no means an easy or fun experience reading this code. Variable names like xs, ps, etc. are great when you're dealing with a generic list but they get old when that's the only documentation (because "type signatures are documentation" is totally infallible). And a name like HVectElim is just baffling. What, did they charge you per letter? Did half your keys fall out? Why is that a good name?
I really want to use Haskell for something useful. But I'm running into pain points trying to understand a glorified Hello World. Now granted I'm by no means a great Haskell programmer. But that's kind of the point. I understand monads. I get functors and applicatives. I should be able to write a dumb Hello World app dammit.