Files
gf-core/src-3.0/GF/Data/SharedString.hs

20 lines
479 B
Haskell

module GF.Data.SharedString (shareString) where
import Data.HashTable as H
import System.IO.Unsafe (unsafePerformIO)
{-# NOINLINE stringPool #-}
stringPool :: HashTable String String
stringPool = unsafePerformIO $ new (==) hashString
{-# NOINLINE shareString #-}
shareString :: String -> String
shareString s = unsafePerformIO $ do
mv <- H.lookup stringPool s
case mv of
Just s' -> return s'
Nothing -> do
H.insert stringPool s s
return s