[Haskell-cafe] Shrink function names

[Viktor Dukhovni]

On Sun, Sep 19, 2021 at 07:58:22AM -0400, Brandon Allbery wrote:

> On Sun, Sep 19, 2021 at 3:02 AM Viktor Dukhovni <ietf-dane at dukhovni.org>
> wrote:
>
> > I don't know how to suppress unexported constructor names appearing in the
> > compiled code, perhaps someone else does, or it might not be possible...
>
> I would ask if there's a "deriving Show" involved.

My test code does not.

    $ rm foo.o foo.hi
    $ ghc -fhide-source-paths -dno-typeable-binds -dsuppress-type-signatures -optl-s -O2 foo.hs
    [1 of 1] Compiling Main
    Linking foo ...
    $ strings -a foo | grep -i secret
    main:Main.AnotherSecret

    $ cat foo.hs
    module Main (main) where

    import System.Environment
    import Data.Maybe

    data SecretName = AnotherSecret String Int

    secretName :: [String] -> Maybe SecretName
    secretName = fmap (AnotherSecret <$> id <*> (+ 42) . read) . listToMaybe
    {-# NOINLINE secretName #-}

    main :: IO ()
    main = secretName <$> getArgs >>= mapM_ (\ (AnotherSecret a b) -> print (a, b))

With a deriving (Show) instance, I see a second occurence:

    main:Main.AnotherSecret
    AnotherSecret

-- 
    Viktor.