How to read Haskell
Revision as of 10:53, 3 August 2006
This stub is intended to become a tutorial on reading Haskell. It's aimed at the non-Haskeller who probably doesn't care too much about trying to write code, but wants to understand it.
1 The tutorial
...needs to be written
-- insert here some horrible (for the non-Haskeller) long example -- something we can work through slowly (and show why we find it beautiful)
1.1 Hint: order doesn't matter
Outside of a monad, it really doesn't matter what order things in Haskell code appear. So if you see something like this...
foo = whatTheHeckIsBar
you should take into account that
whatTheHeckIsBar may be defined somewhere below
- scope in a nutshell
- except for monads? explain
1.2 Hint: use type signatures
When you see stuff like this
-- example please! foo :: Bar Ping Pong -> Baz Zed Dubya -> IO (DoublePlus Good)
...don't fight it! These are type signatures and they are an incredibly useful way of getting a rough idea what a function is supposed to do.
2 What confuses non-Haskellers
Since this tutorial is not yet written, we encourage you to note here the things which confuse non-Haskellers about the code code.
- layout instead of semicolons?
- super-super-concise stuff (things using liftM and liftM2)
- the difference between and
x <- foo
x = foo