[commit: ghc] master: Remove Coercible documentation from compiler/prelude/primops.txt.pp (1dd38a5)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/1dd38a54bb29387d9e9c549dbb020bc9ed4ecb91/ghc

>---------------------------------------------------------------

commit 1dd38a54bb29387d9e9c549dbb020bc9ed4ecb91
Author: Joachim Breitner <mail at joachim-breitner.de>
Date:   Thu Jan 30 16:28:00 2014 +0000

    Remove Coercible documentation from compiler/prelude/primops.txt.pp
    
    We want it to show up in GHC.Exts, so we need to put the documentation
    in GHC.Types, where the datatype Coercible is defined.


>---------------------------------------------------------------

1dd38a54bb29387d9e9c549dbb020bc9ed4ecb91
 compiler/prelude/primops.txt.pp |   41 ---------------------------------------
 1 file changed, 41 deletions(-)

diff --git a/compiler/prelude/primops.txt.pp b/compiler/prelude/primops.txt.pp
index 36eec67..d2978dc 100644
--- a/compiler/prelude/primops.txt.pp
+++ b/compiler/prelude/primops.txt.pp
@@ -2365,47 +2365,6 @@ pseudoop   "coerce"
    }
 
 primclass Coercible a b
-   { This two-parameter class has instances for types {\tt a} and {\tt b} if
-     the compiler can infer that they have the same representation. This class
-     does not have regular instances; instead they are created on-the-fly during
-     type-checking. Trying to manually declare an instance of {\tt Coercible}
-     is an error.
-
-     Nevertheless one can pretend that the following three kinds of instances
-     exist. First, as a trivial base-case:
-
-     {\tt instance a a}
-
-     Furthermore, for every type constructor there is
-     an instance that allows to coerce under the type constructor. For
-     example, let {\tt D} be a prototypical type constructor ({\tt data} or {\tt
-     newtype}) with three type arguments, which have roles Nominal,
-     Representational resp. Phantom. Then there is an instance of the form
-
-     {\tt instance Coercible b b' => Coercible (D a b c) (D a b' c')}
-
-     Note that the nominal type arguments are equal, the representational type
-     arguments can differ, but need to have a {\tt Coercible} instance
-     themself, and the phantom type arguments can be changed arbitrarily.
-
-     In SafeHaskell code, this instance is only usable if the constructors of
-     every type constructor used in the definition of {\tt D} (including
-     those of {\tt D} itself) are in scope.
-
-     The third kind of instance exists for every {\tt newtype NT = MkNT T} and
-     comes in two variants, namely
-
-     {\tt instance Coercible a T => Coercible a NT}
-
-     {\tt instance Coercible T b => Coercible NT b}
-
-     This instance is only usable if the constructor {\tt MkNT} is in scope.
-
-     If, as a library author of a type constructor like {\tt Set a}, you
-     want to prevent a user of your module to write
-     {\tt coerce :: Set T -> Set NT},
-     you need to set the role of {\tt Set}'s type parameter to Nominal.
-   }
 
 ------------------------------------------------------------------------
 section "SIMD Vectors"