patch adding runST for LazyST

[Byron Cook]

hi,

here is a patch that adds a lazy runST to the glaExts/LazyST.lhs module


---------------------------------------------------------------
*** LazyST.lhs.orig     Mon Dec  1 09:53:08 1997
--- LazyST.lhs  Wed Dec  3 02:50:42 1997
***************
*** 10,29 ****
  \begin{code}
  module LazyST (
  
!       ST,
  
!       unsafeInterleaveST,
  
          -- ST is one, so you'll likely need some Monad bits
          module Monad,
  
!       ST.STRef,
!       newSTRef, readSTRef, writeSTRef,
  
!       ST.STArray,
!       newSTArray, readSTArray, writeSTArray, Ix,
  
!       strictToLazyST, lazyToStrictST
      ) where
  
  import qualified ST
--- 10,32 ----
  \begin{code}
  module LazyST (
  
!         ST,
  
!         unsafeInterleaveST,
  
          -- ST is one, so you'll likely need some Monad bits
          module Monad,
+         runST,
  
!         ST.STRef,
!         newSTRef, readSTRef, writeSTRef,
  
!         STArray,
!         newSTArray, readSTArray, writeSTArray, boundsSTArray,
!         thawSTArray, freezeSTArray, unsafeFreezeSTArray,
!         Ix,
  
!         strictToLazyST, lazyToStrictST
      ) where
  
  import qualified ST
***************
*** 33,39 ****
--- 36,45 ----
  import PrelBase       ( Eq(..), Int, Bool, ($), ()(..) )
  import Monad
  import Ix
+ import GHC
  
+ runST (ST f) = let (x,_) = f (STBase.S# realWorld#) in x
+ 
  newtype ST s a = ST (STBase.State s -> (a,STBase.State s))
  
  instance Monad (ST s) where