Hi all I am confused by the GHC profiling output. I have put some abstracts below to illustrate my confusion. I compiled my code with: HFLAGS="-Wall -package lang -prof -auto-all" hmake -ghc main and then ran it with: ./main -t +RTS -p < test5.hs Here is some of main.prof: individual inherited COST CENTRE MODULE entries %time %alloc %time %alloc [...] parse Parser 1 0.0 0.0 81.4 62.3 p_module Parser 0 0.0 0.0 81.4 62.3 <|> PC_base 69517 20.3 5.7 81.4 62.3 [...] p_aexp_list Parser 0 0.0 0.0 0.0 0.3 con2tag_Token# Tokens 880 0.0 0.0 0.0 0.0 pIfThing PC_base 896 0.0 0.0 0.0 0.0 <$ PC 0 0.0 0.0 0.0 0.3 <$> PC 0 0.0 0.0 0.0 0.3 pSucceed PC_base 896 0.0 0.3 0.0 0.3 <*> PC_base 896 0.0 0.0 0.0 0.0 <*> PC_base 896 0.0 0.0 0.0 0.0 p_aexp_tuple Parser 0 0.0 0.0 0.0 0.3 [...] and here is the code for p_aexp_list: p_aexp_list :: Parser Token Aexp p_aexp_list = (Aexp_list . get_rights) <$ pIfThing ((==) (Special '[')) <*> pSList False p_comma p_exp <* pIfThing ((==) (Special ']')) Now basically my problem is how things under p_aexp_list can be entered 896 times if p_aexp_list is entered 0 times - am I reading it wrong? And the only place p_aexp_list is called from is p_aexp_init = p_aexp_qvar <|> p_aexp_gcon <|> p_aexp_literal <|> p_aexp_paren <|> p_aexp_tuple <|> p_aexp_list <|> p_aexp_arith <|> p_aexp_listcomp <|> p_aexp_left <|> p_aexp_right but my reading of the profile output shows it as being called from <|> which is in turn called from p_module (all lines in the second [...] are indented with at least " "). Am I missing something obvious? Thanks Ian