On Fri, Jan 20 2023, David Feuer wrote:

I don't know what all that means exactly (especially since GHC's demand signatures have changed recently in a way I don't understand at all). But for hiding divergence, one option is to use a module with demand analysis disabled. Try {-# options_ghc -fno-strictness #-}. You'll likely need to put oops in its own module to avoid interfering with desired optimizations.

THanks for the suggestion! So I did this: {-# options_ghc -fno-strictness #-} module ConCat.Oops(oops) where import GHC.Stack (errorWithStackTrace) -- for oops -- | Pseudo function to fool GHC's divergence checker. oops :: String -> b oops str = errorWithStackTrace ("Oops: "++str) {-# NOINLINE oops #-} ... but am getting the same result from the divergence checker, sadly ... -- Regards, Mike

Actually, getting that arity probably isn't important anyway.... Try O0. On Fri, Jan 20, 2023, 5:26 AM David Feuer wrote:

What if you go with the big hammer for that module: -O0? My main concern about that is that you won't get arity analysis. There may be some more -f flags I've missed...

On Fri, Jan 20, 2023, 5:17 AM Michael Sperber wrote:

...

On Fri, Jan 20 2023, David Feuer wrote:

...

I don't know what all that means exactly (especially since GHC's demand signatures have changed recently in a way I don't understand at all). But for hiding divergence, one option is to use a module with demand analysis disabled. Try {-# options_ghc -fno-strictness #-}. You'll likely need to put oops in its own module to avoid interfering with desired optimizations.

THanks for the suggestion!

So I did this:

{-# options_ghc -fno-strictness #-} module ConCat.Oops(oops) where

import GHC.Stack (errorWithStackTrace) -- for oops

-- | Pseudo function to fool GHC's divergence checker. oops :: String -> b oops str = errorWithStackTrace ("Oops: "++str) {-# NOINLINE oops #-}

... but am getting the same result from the divergence checker, sadly ...

-- Regards, Mike