#5712: Can't define constructors to be infix (as far as Show is concerned) with
GADT syntax
------------------------------+---------------------------------------------
Reporter: benmachine | Owner:
Type: feature request | Status: new
Priority: normal | Component: Compiler
Version: 7.3 | Keywords:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: Other | Testcase:
Blockedby: | Blocking:
Related: |
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Okay so, if you define a data type like this:
{{{
data Two a = a :. a deriving Show
}}}
then `show (1 :. 2) == "1 :. 2"`. On the other hand, if you define the
data type like so:
{{{
data Two a = (:.) a a deriving Show
}}}
then `show (1 :. 2) == "(:.) 1 2".
This kind of makes sense since how the constructor is defined by the user
gives some hint as to how it should be used. The only problem is you can't
give that hint if you're using GADT syntax, since then constructors are
given without explicit arguments.
I don't see an easy way to let you give that hint, but I think it would be
reasonable to just guess that any constructor with a symbol name (i.e. one
starting with `:`) should be considered infix.
--
Ticket URL: <http://hackage.haskell.org/trac/ghc/ticket/5712>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
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