Hi Will, Will Ness wrote:
Will Ness
writes: CORRECTION: just with "gaps" (but not the other ones), changing the "g" function from composed pieces into a "normal" code, it did it! (probably some ghc version-specific stuff at play):
g xs = 3 : gaps 5 ( foldi (\(x:xs) -> (x:) . union xs) [[x*x, x*x+2*x..] | x <- xs] )
addition: with gaps k xs = minus [k,k+2..] xs it also runs without the space leak, but with gaps k = minus [k,k+2..] the leak reappears.
I'm not sure that I tried the same code as you did, but for me both these versions were leaky. I cannot explain why, but I see that in the resulting core (ghc ... -ddump-simpl) the [5,7..] list ends up as a top level constant, despite -fno-full-laziness. So the cause of the space leak remains the same -- the [5,7..] list is being shared among several invocations of g. Tricky. Bertram