sum1, -O

[S.D.Mechveliani]

Please, what is the matter here with  ghc-5.00.1

(compiled from source for Linux i386-unknown) ?

  ----------------------
  sum1 :: (Num a) => [a] -> a

  sum1 []     = error "sum1 []\n"
  sum1 (x:xs) = sm xs x  where  sm []     s = s
                              sm (x:xs) s = sm xs (x+s)
  main = putStr ""  
  ----------------------
  ghc -c -O Main.hs

  ghci +RTS -M70m -RTS
  ...
  Main> sum1 [1 .. 1999000]

  GHC's heap exhausted; ...
  ----------------------

Now, if we change it to 
  ...
  main = putStr $ shows (sum1 [1 .. 1999000]) "\n"
,
recompile, then it yields
 
  ghci +RTS -M70m -RTS
  ...
  Main> main
  1998001499500


-----------------
Serge Mechveliani
mechvel at botik.ru