#59: missing and/or erroneous output in deteministic function run from WinHUGS cmd line! ---------------------------------------------+------------------------------ Reporter: ettinger@elmgate.eclipse.co.uk | Owner: neil Type: defect | Status: new Priority: critical | Milestone: Component: winhugs | Version: 200609 Resolution: | Keywords: inconsistent expression evaluation ---------------------------------------------+------------------------------ -- Ticket URL: http://hackage.haskell.org/trac/hugs/ticket/59 Hugs http://www.haskell.org/hugs/ Hugs 98, an interpreter for Haskell

#59: missing and/or erroneous output in deteministic function run from WinHUGS cmd line! ---------------------------------------------+------------------------------ Reporter: ettinger@elmgate.eclipse.co.uk | Owner: Type: defect | Status: new Priority: critical | Milestone: Component: hugs | Version: 200609 Resolution: | Keywords: inconsistent expression evaluation ---------------------------------------------+------------------------------ Old description:

--(Output showing the bug is appended below. It isn't part of the program).

--PLEASE run the function called bug. It will tell you to type a --short expression at the WinHUGS command line. --Retry the expression ten times. I do not get the same result every time! --Do you find the same problem? Please, please let me know either way. --See below for printout of my "impossible" results.

--The functions os and s below will be used to demonstrate the WinHUGS bug: os :: Int -> Int -> Double os i j = -22.0/7.1 s :: [[Int]] -> [[Double]] s dat = [[ sum [ fromIntegral (dat!!i!!j) * os i x * os j y | i <-[0..7] , j <-[0..7] ] | x <- [0..7] ] | y <- [0..7] ]

-- The following functions produce the bug test data: insig :: [Int] insig = [0 | i <-[0..7]] signif :: [Int] signif = [ 1 ] ++ [0 | i <-[1..7]] i = [insig] ++ [signif | i <- [1..7]]

--For instructions on demonstrating the bug, please run the function below: bug = "Please type the following to demonstrate the bug: (take 4.s)i "

Main> (take 4.s)i [[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703]] Main> (take 4.s)i [[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703]] Main>

New description: (Output showing the bug is appended below. It isn't part of the program). PLEASE run the function called bug. It will tell you to type a short expression at the WinHUGS command line. Retry the expression ten times. I do not get the same result every time! Do you find the same problem? Please, please let me know either way. See below for printout of my "impossible" results. The functions os and s below will be used to demonstrate the WinHUGS bug: {{{ os :: Int -> Int -> Double os i j = -22.0/7.1 s :: [[Int]] -> [[Double]] s dat = [[ sum [ fromIntegral (dat!!i!!j) * os i x * os j y | i <-[0..7] , j <-[0..7] ] | x <- [0..7] ] | y <- [0..7] ] }}} The following functions produce the bug test data: {{{ insig :: [Int] insig = [0 | i <-[0..7]] signif :: [Int] signif = [ 1 ] ++ [0 | i <-[1..7]] i = [insig] ++ [signif | i <- [1..7]] }}} Type the following to demonstrate the bug: {{{(take 4.s)i}}} {{{ Main> (take 4.s)i [[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703]] Main> (take 4.s)i [[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703],[67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703,67.2088871255703]] Main> }}} Comment (by ross): I cannot replicate the misbehaviour with the Sep 2006 release under Linux (ix86). -- Ticket URL: http://hackage.haskell.org/trac/hugs/ticket/59 Hugs http://www.haskell.org/hugs/ Hugs 98, an interpreter for Haskell