This sounds like an infelicity in COMPLETE pragmas. Do we have a documented
reason why fixing this is impossible?
Richard
> On Oct 25, 2018, at 7:36 AM, Shayan Najd <sh.n...@gmail.com> wrote:
>
> Dear GHC hackers,
>
> On our work on the new front-end AST for GHC [0] based on TTG [1], we
> would like to use a pattern synonym like the following [2]:
>
> {{{
> pattern LL :: HasSrcSpan a => SrcSpan -> SrcSpanLess a -> a
> pattern LL s m <- (decomposeSrcSpan -> (m , s))
> where
> LL s m = composeSrcSpan (m , s)
> }}}
>
> We know that any match on `LL` patterns, makes the pattern matching
> total, as it uses a view pattern with a total output pattern (i.e., in
> `decomposeSrcSpan -> (m , s)`, the pattern `(m , s)` is total).
>
> As far as I understand, currently COMPLETE pragmas cannot be used with
> such a polymorphic pattern.
>
> What do you suggest us to do to avoid the false incomplete pattern
> matching warnings?
>
> Thanks,
> Shayan
>
> [0] https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow
> [1]
> https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow/TreesThatGrowGuidance
> [2]
> https://ghc.haskell.org/trac/ghc/wiki/ImplementingTreesThatGrow/HandlingSourceLocations
> _______________________________________________
> ghc-devs mailing list
> ghc-devs@haskell.org
> http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
_______________________________________________
ghc-devs mailing list
ghc-devs@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs
