I agree, I don't think this is a bug. If the grammar actually says that this is legal, then I think the grammar is wrong.
On Sun, Feb 14, 2010 at 1:48 AM, John Launchbury <j...@galois.com> wrote: > I don't think this is a bug. I do not expect to be able to unfold a > definition without some syntactic issues. For example, > > two = 1+1 > four = 2 * two > > but unfolding fails (four = 2 * 1 + 1). In general, we expect to have to > parenthesize things when unfolding them. > > John > > > On Feb 13, 2010, at 11:56 AM, Simon Marlow wrote: > >> On 09/02/10 21:43, S. Doaitse Swierstra wrote: >>> One we start discussing syntax again it might be a good occasion to >>> reformulate/make more precise a few points. >>> >>> The following program is accepted by the Utrecht Haskell Compiler (here >>> we took great effort to follow the report closely ;-} instead of >>> spending our time on n+k patterns), but not by the GHC and Hugs. >>> >>> module Main where >>> >>> -- this is a (rather elaborate) definition of the number 1 >>> one = let x=1 in x >>> >>> -- this is a definition of the successor function using section notation >>> increment = ( one + ) >>> >>> -- but if we now unfold the definition of one we get a parser error in GHC >>> increment' = ( let x=1 in x + ) >> >> Now that *is* an interesting example. I had no idea we had a bug in that >> area. Seems to me that it ought to be possible to fix it by refactoring the >> grammar, but I haven't tried yet. >> >> Are there any more of these that you know about? >> >> Cheers, >> Simon >> _______________________________________________ >> Haskell-prime mailing list >> Haskell-prime@haskell.org >> http://www.haskell.org/mailman/listinfo/haskell-prime > > _______________________________________________ > Haskell-prime mailing list > Haskell-prime@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-prime > _______________________________________________ Haskell-prime mailing list Haskell-prime@haskell.org http://www.haskell.org/mailman/listinfo/haskell-prime