[commit: hoopl] master: added and exported liftFuel method of FuelMonadT (cf8723c)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/hoopl

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/cf8723c8e7d83a12d6f95abffd58ccb78aa0e0cb

>---------------------------------------------------------------

commit cf8723c8e7d83a12d6f95abffd58ccb78aa0e0cb
Author: Norman Ramsey <nr at cs.tufts.edu>
Date:   Fri Jul 22 15:20:55 2011 -0400

    added and exported liftFuel method of FuelMonadT
    
    method runWithFuel remains hidden and should stay hidden
    
    thanks Justin Bailey for the bug report
    
    
    Signed-off-by: Norman Ramsey <nr at cs.tufts.edu>

>---------------------------------------------------------------

 hoopl.cabal                |    4 +++-
 src/Compiler/Hoopl.hs      |    2 +-
 src/Compiler/Hoopl/Fuel.hs |    4 ++++
 3 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/hoopl.cabal b/hoopl.cabal
index 1991e3f..0aede00 100644
--- a/hoopl.cabal
+++ b/hoopl.cabal
@@ -1,7 +1,9 @@
 Name:                hoopl
-Version:             3.8.7.1
+Version:             3.8.7.2
 -- version 3.8.6.0 is the version that goes with the camera-ready Haskell'10 paper
 -- version 3.8.7.0 works with GHC 7
+-- version 3.8.7.1 adds some unnamed functions without breaking compatibility
+-- version 3.8.7.2 adds Compiler.Hoopl.Fuel.liftFuel
 Description:         Higher-order optimization library
 License:             BSD3
 License-file:        LICENSE
diff --git a/src/Compiler/Hoopl.hs b/src/Compiler/Hoopl.hs
index 40f1b49..de921d6 100644
--- a/src/Compiler/Hoopl.hs
+++ b/src/Compiler/Hoopl.hs
@@ -22,7 +22,7 @@ import Compiler.Hoopl.Combinators
 import Compiler.Hoopl.Dataflow hiding ( wrapFR, wrapFR2, wrapBR, wrapBR2
                                       )
 import Compiler.Hoopl.Debug
-import Compiler.Hoopl.Fuel hiding (withFuel, getFuel, setFuel, FuelMonadT)
+import Compiler.Hoopl.Fuel hiding (withFuel, getFuel, setFuel, runWithFuel)
 import Compiler.Hoopl.Graph hiding 
    ( Body
    , BCat, BHead, BTail, BClosed -- OK to expose BFirst, BMiddle, BLast
diff --git a/src/Compiler/Hoopl/Fuel.hs b/src/Compiler/Hoopl/Fuel.hs
index 260fd43..c9972d0 100644
--- a/src/Compiler/Hoopl/Fuel.hs
+++ b/src/Compiler/Hoopl/Fuel.hs
@@ -29,6 +29,8 @@ fuelRemaining = getFuel
 
 class FuelMonadT fm where
   runWithFuel :: (Monad m, FuelMonad (fm m)) => Fuel -> fm m a -> m a
+  liftFuel    :: (Monad m, FuelMonad (fm m)) => m a -> fm m a
+
 
 
 type Fuel = Int
@@ -64,6 +66,7 @@ instance Monad m => FuelMonad (CheckingFuelMonad m) where
 
 instance FuelMonadT CheckingFuelMonad where
   runWithFuel fuel m = do { (a, _) <- unFM m fuel; return a }
+  liftFuel m = FM $ \f -> do { a <- m; return (a, f) }
 
 ----------------------------------------------------------------
 
@@ -88,6 +91,7 @@ instance CheckpointMonad m => CheckpointMonad (InfiniteFuelMonad m) where
 
 instance FuelMonadT InfiniteFuelMonad where
   runWithFuel _ = unIFM
+  liftFuel = IFM
 
 infiniteFuel :: Fuel -- effectively infinite, any, but subtractable
 infiniteFuel = maxBound