[Haskell-cafe] Differences in optimisiation with interactive and compiled mode

[Branimir Maksimovic]

It seems that compiled programs run better then interactive ones.
Following program with GHC works with pretty good performance in comparison 
to C++
one with similar but non recursive algorithm and beats it in memory 
consumtion. It only takes
about 2mb of ram  somehow when running compiled. I'm really amased.
But in interactive mode both GHC and Hugs fail due heap exhaustion and 
running
takes ages.Please can someone explain why?
I intent to use only compiled Haskell anyway so GHC satisfies.


Greetings, Bane.

program performs search replace on a String

module Main where
import IO
main = do
        hSetBuffering stdout LineBuffering
        let sr = "search"
            rp = "replace"
            str= " able search sea baker search charlie \""
            out = searchr sr rp (take  (1000000*(length str)) $ infinite 
str)
            out1 = searchr sr rp (take (1000001*(length str)) $ infinite 
str)
        putStrLn $ "Working:" ++ sr ++ " " ++ rp ++ " " ++ str
        putStrLn $ (show (out == out1)) ++ "\n" ++ "\nDone\n"
{- search replace " able search baker search charlie " -}

-------------------------------------------------------------------------------
infinite xs = xs ++ infinite xs

searchr :: String->String->String -> String
searchr [] _ xs = xs
searchr _ [] xs = xs
searchr _ _ [] = []
searchr sr rp xs | fst fnd   = rp ++ searchr sr rp (snd $ snd fnd)
                 | otherwise = (reverse $ fst $ snd fnd) ++
                                    searchr sr rp (snd $ snd fnd)
                 where fnd = searchr' sr xs ""

searchr' :: String->String->String -> (Bool,(String,String))
searchr' (sr:srs) xs fndSoFar = searchr'' (sr:srs) xs fndSoFar sr

searchr'' :: String->String->String->Char -> (Bool,(String,String))
searchr'' [] xs fnd _ = (True,(fnd,xs))
searchr'' _ [] fnd _ = (False,(fnd,[]))
searchr'' (sr:srs) (x:xs) fndSoFar s | sr == x = searchr'' srs xs xxs s
                                    | otherwise = (False,searchr''' s xs 
xxs) -- (False,(xxs,xs))
                                  where xxs = x:fndSoFar

searchr''' :: Char->String->String -> (String,String)
searchr''' sr [] fndSoFar = (fndSoFar,[])
searchr''' sr (x:xs) fndSoFar | sr /= x = searchr''' sr xs (x:fndSoFar)
                             | otherwise = (fndSoFar,x:xs)
-------------------------------------------------------------------------------

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