you're inside the module, so you have access to all top-level bindings, not just to the export list.
the issue with the implicit `module Main(main) where` is that it errors if main is not defined, even though that's a perfectly harmless situation. (i hope i got the question right?) On Tue, May 16, 2017 at 05:53:17PM +0000, Adam Bergmark wrote: > Date: Tue, 16 May 2017 17:53:17 +0000 > From: Adam Bergmark <a...@bergmark.nl> > To: José Manuel Calderón Trilla <j...@jmct.cc>, haskell-prime@haskell.org > Subject: Re: Default module header `module Main where` > > GHCIs current behavior seems inconsistent with this, why is foo accessible > and why don't I get an unused warning like i do if i have an explicit > `module Main (main) where`? > > ``` > $ cat Main.hs > main :: IO () > main = pure () > > foo :: Int > foo = 1 > > $ ghci Main.hs -Wall > GHCi, version 8.0.2: http://www.haskell.org/ghc/ :? for help > Loaded GHCi configuration from /Users/adam.bergmark/.ghci > [1 of 1] Compiling Main ( Main.hs, interpreted ) > Ok, modules loaded: Main. > > λ foo > 1 > ``` > > On Tue, 16 May 2017 at 19:00 José Manuel Calderón Trilla <j...@jmct.cc> > wrote: > > > Agreed, this sounds sensible. > > > > Can anyone think of any unintended consequences? > > > > -Jose > > > > On Tue, May 16, 2017, at 09:50 AM, Iavor Diatchki wrote: > > > > That seems fairly reasonable to me. > > > > -Iavor > > > > On Tue, May 16, 2017 at 7:18 AM, Joachim Breitner < > > m...@joachim-breitner.de> wrote: > > > > Hi, > > > > a very small proposal to be considered for Haskell': > > > > Currently, the report states > > > > An abbreviated form of module, consisting only of the module body, > > is permitted. If this is used, the header is assumed to be ‘module > > Main(main) where’. > > > > I propose to change that to > > > > An abbreviated form of module, consisting only of the module body, > > is permitted. If this is used, the header is assumed to be ‘module > > Main where’. > > > > The rationale is that a main-less main module is still useful, e.g. > > when you are working a lot in GHCi, and offload a few extensions to a > > separate file. Currently, tools like hdevtools will complain about a > > missing main function when editing such a file. > > > > It would also work better with GHC’s -main-is flag, and avoid problems > > like the one described in https://ghc.haskell.org/trac/ghc/ticket/13704 > > > > > > I don’t see any downsides. When compiling to a binary, implementations > > are still able to detect that a Main module is not imported by any > > other module and only the main function is used, and optimize as if > > only main were exported. > > > > Greetings, > > Joachim > > > > > > > > -- > > Joachim “nomeata” Breitner > > m...@joachim-breitner.de • https://www.joachim-breitner.de/ > > XMPP: nome...@joachim-breitner.de • OpenPGP-Key: 0xF0FBF51F > > Debian Developer: nome...@debian.org > > _______________________________________________ > > Haskell-prime mailing list > > Haskell-prime@haskell.org > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime > > > > *_______________________________________________* > > Haskell-prime mailing list > > Haskell-prime@haskell.org > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime > > > > > > _______________________________________________ > > Haskell-prime mailing list > > Haskell-prime@haskell.org > > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime > > > _______________________________________________ > Haskell-prime mailing list > Haskell-prime@haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime -- https://zerobuzz.net/ m...@zerobuzz.net +49 179 7733 223 _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-prime
