[project @ 2001-12-20 11:19:05 by simonpj]

[ghc-hetmet.git] / ghc / compiler / hsSyn / HsDecls.lhs

diff --git a/ghc/compiler/hsSyn/HsDecls.lhs b/ghc/compiler/hsSyn/HsDecls.lhs
index a54f5e3..2e69ac0 100644 (file)
--- a/ghc/compiler/hsSyn/HsDecls.lhs
+++ b/ghc/compiler/hsSyn/HsDecls.lhs
@@ -277,10 +277,8 @@ data TyClDecl name pat
                tcdTyVars :: [HsTyVarBndr name], -- type variables
                tcdCons   :: [ConDecl name],     -- data constructors (empty if abstract)
                tcdNCons  :: Int,                -- Number of data constructors (valid even if type is abstract)
-               tcdDerivs :: Maybe [name],       -- derivings; Nothing => not specified
-                                -- (i.e., derive default); Just [] => derive
-                                -- *nothing*; Just <list> => as you would
-                                -- expect...
+               tcdDerivs :: Maybe (HsContext name),    -- derivings; Nothing => not specified
+                                                       -- Just [] => derive exactly what is asked
                tcdSysNames :: DataSysNames name,       -- Generic converter functions
                tcdLoc      :: SrcLoc
     }
@@ -515,7 +513,7 @@ pp_tydecl pp_head pp_decl_rhs derivings
        pp_decl_rhs,
        case derivings of
          Nothing          -> empty
-         Just ds          -> hsep [ptext SLIT("deriving"), parens (interpp'SP ds)]
+         Just ds          -> hsep [ptext SLIT("deriving"), ppr_hs_context ds]
     ])
 \end{code}