On 27 Jan 2008, at 11:18 PM, L.Guo wrote:
Hi,
How do you organize code ?
Here is a sample.
Acturally, I am thinking about using this plan.
Any suggestions ?
-- BasicalType.hs
type Position = (Int,Int)
data Box = Box { pos :: Position }
data Chain = Chain { pos :: [Position] }
-- Object.hs
import BasicalType
class Object o where
pos :: o -> [Position]
-- Type.hs
import BasicalType
import Object
instance Object Box where
pos = return . BasicalType.pos
instance Object Chain where
pos = BasicalType.pos
-- Main.hs
import Type
...
I would recommend against this; Type.hs should define the types
directly, and define or import the Object class.
In particular, IIRC GHC wants ever instance in the same module as
either the type or the class definition, for performance reasons
(this is the most common pattern, so it gets special optimizations).
jcc
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