I use the Hugs98 heap profiler, and it sometimes produces lines that the
hp2ps program cannot digest (under MacOS). The lines look like
Undefined member: member: nal 27
about which hp2ps says
line 31: integer must follow identifier
and aborts.
The program I ran was the following:
---- file Shuffle.hs -----------------------------------------------------
module Shuffle (
shuffle
) where
import Random
getRandomIndex :: [a] -> IO(Int)
getRandomIndex ls = getStdRandom(randomR(0, (length ls) - 1))
remove :: Int -> [a] -> [a]
remove 0 (x:xs) = xs
remove n (x:xs) | n>0 = x: remove (n-1) xs
remove _ (_:_) = error "remove: negative argument"
remove _ [] = error "remove: too large argument"
shuffle :: [a] -> IO [a]
shuffle [] = return []
shuffle ls = do i <- getRandomIndex ls
do l <- shuffle (remove i ls)
return ((ls !! i) : l)
---- file Card.hs -----------------------------------------------------
module Card (
) where
import Shuffle
data Suit = Spade | Heart | Diamond | Club
deriving (Eq, Ord, Enum)
instance Show(Suit) where
show Spade = "S"
show Heart = "H"
show Diamond = "D"
show Club = "C"
data Rank = Ace | R2 | R3 | R4 | R5 | R6 | R7 | R8 | R9 | R10
| Jack | Queen | King
deriving (Eq, Ord, Enum)
instance Show(Rank) where
show Ace = "A"
show R2 = "2"
show R3 = "3"
show R4 = "4"
show R5 = "5"
show R6 = "6"
show R7 = "7"
show R8 = "8"
show R9 = "9"
show R10 = "0"
show Jack = "J"
show Queen = "Q"
show King = "K"
data Card = Card(Suit, Rank)
deriving (Eq, Ord)
instance Show(Card) where
show (Card(s, r)) = show s ++ show r
ranks = [ toEnum x :: Rank | x <- [0..12] ]
suits = [ toEnum x :: Suit | x <- [0..3] ]
deck = [ Card(s, r) | s <- suits, r <- ranks ]
shuffledDeck = do d <- shuffle deck
putStr (show d)
---- Hugs98 interaction -----------------------------------------------------
[Load Card module]
Card> :s -d1000
Card> shuffledDeck
[Produces the file "profile.hp", which is sent to the hp2ps program.]
Hans Aberg
