here is the output of main = print $ product [1..100] ghc-core-html --ghc-option=-ddump-simpl --ghc-option=-dsuppress-all fact.hs https://rawgit.com/

here is the output of main = print $ product [1..100] ghc-core-html --ghc-option=-ddump-simpl --ghc-option=-dsuppress-all fact.hs https://rawgit.com/jonschoning/c4ad2129aa7d258e65f9/raw/f8edf61aaba6a7a28dc60bb935738d648e53335c/fact.html https://rawgit.com/jonschoning/c4ad2129aa7d258e65f9/raw/f8ed... you can see main_go (plusInteger x_a3Sq main4) (timesInteger eta_B1 x_a3Sq); where it compiles to a recursive loop with an accumulator typicall the [1..100] gets compiled to (enumFromTo 1 100) and it can be desugared further.. so, yeah, foldmap compiles to foldr which may compile down further