Steffen Mazanek wrote:
Hi,
Stefan and Isaac, thx for providing quick advice.
@Stefan: Unfortunately I have to use a list. @Isaac: I do not get it. Could you please provide a short example of your approach?
The question still remains. Which arguments do I have ghc to start with to get the same behavior than hugs with -98 +o (here it works).
I provide my example for testing purposes:
module Test where import Test.QuickCheck import Monad(liftM,liftM2)
type Program = [Stmt] data Stmt = Text | IfElse Program Program | While Program deriving (Eq, Show)
instance Arbitrary [Stmt] where arbitrary = sized genProg instance Arbitrary Stmt where arbitrary = sized genStmt
genStmt::Int->Gen Stmt genStmt 0 = return Text genStmt 1 = return Text genStmt 2 = oneof [return Text, return (While [Text])] genStmt n | n>2 = oneof ([return Text, liftM While (genProg (n-1))]++ [liftM2 IfElse (genProg k) (genProg (n-k-1))|k<-[1..n-2]])
genProg::Int->Gen Program genProg 0 = return [] genProg 1 = return [Text] genProg n | n>1 = oneof ((liftM (\x->[x]) (genStmt n)):[liftM2 (:) (genStmt k) (genProg (n-k))|k<-[1..n-1]])
prop_ConstructParse progr = True where types = progr::Program
main = mapM_ (\(s,a) -> putStrLn s >> a) [("flowchart construct and parse", test prop_ConstructParse)]
is prop_ConstructParse the only thing that breaks when you remove the instance Arbitrary [Stmt] where arbitrary = sized genProg, or have I missed something? If that's all, try this (untested) : prop_ConstructParse = forAll (sized genProg) (\progr -> True) and similarly for other properties. Or, you _can_ use a newtype for quickcheck-only, something like this: newtype P = P { unP :: Program } instance Show P where show = show . unP instance Arbitrary P where arbitrary = sized genProg . unP prop_ConstructParse (P progr) = True Isaac