haskell - Can we deforest nqueens program using short cut deforestation? -

i trying see if nqueens program can deforested using short cut deforestation, code using is,

n = 8   nqueens 0 = [[]]   nqueens k = [p:q | p <- [1..n], q <- nqueens (k-1), safe p q k]   

and safe defined usual.

i tried getting see output of ghc enabling optimizations difficult understand.

thank you.

you don't need @ core. there other intermediate forms may more useful. docs:

use debug flag -ddump-simpl-stats see rules fired. if need more information, -ddump-rule-firings shows each individual rule firing , -ddump-rule-rewrites shows code looks before , after rewrite

http://www.haskell.org/ghc/docs/7.4.1/html/users_guide/rewrite-rules.html