Git.hs

module Git where

import Data.ByteString
import Data.Time
import qualified Data.Map as M

-- | Objects that are stored in the git storage by SHA1. Just a dummy class in this demonstration.
class Storable a

newtype Object = Object { objectData :: ByteString }
instance Storable Object

type FileName = ByteString
type BranchName = ByteString
type Author = ByteString

newtype Tree = Tree (M.Map FileName Object)
instance Storable Tree

data Commit = Commit { commitAuthor :: Author
                     , commitDate :: UTCTime
                     , commitParents :: [Commit]
                     , commitTree :: Tree
                     }
instance Storable Commit

data Repo = Repo { repoIndex :: Tree -- also known as Staging Area
                 , repoBranches :: M.Map BranchName Commit
                 , repoStorage :: () -- dummy for the big git storage
                 }
instance Storable Repo

-- this model completely ignores packed files