blob: 9d037b51206a6063a86ac81cae5d68246f5b0bbb (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
|
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
|
