module ALife.Creatur.Namer
(
Namer(..),
SimpleNamer,
mkSimpleNamer
) where
import ALife.Creatur.Counter (PersistentCounter, current, increment,
mkPersistentCounter)
import ALife.Creatur.Util (stateMap)
import Control.Monad.State (StateT, get, gets)
class Namer n where
genName :: StateT n IO String
data SimpleNamer = SimpleNamer
{
prefix :: String,
counter :: PersistentCounter
} deriving (Show, Eq)
mkSimpleNamer :: String -> FilePath -> SimpleNamer
mkSimpleNamer s f = SimpleNamer s $ mkPersistentCounter f
withCounter :: StateT PersistentCounter IO x -> StateT SimpleNamer IO x
withCounter runProgram = do
u <- get
stateMap (\c -> u {counter=c}) counter runProgram
instance Namer SimpleNamer where
genName = do
p <- gets prefix
k <- withCounter (increment >> current)
return $ p ++ show k