Added parser and abstract syntax support for stand-alone deriving declarations.

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

diff --git a/compiler/hsSyn/HsDecls.lhs b/compiler/hsSyn/HsDecls.lhs
index 2128ad3..2310551 100644 (file)
--- a/compiler/hsSyn/HsDecls.lhs
+++ b/compiler/hsSyn/HsDecls.lhs
@@ -9,7 +9,7 @@ Definitions for: @TyDecl@ and @oCnDecl@, @ClassDecl@,
 \begin{code}
 module HsDecls (
        HsDecl(..), LHsDecl, TyClDecl(..), LTyClDecl, 
-       InstDecl(..), LInstDecl, NewOrData(..),
+       InstDecl(..), LInstDecl, DerivDecl(..), LDerivDecl, NewOrData(..),
        RuleDecl(..), LRuleDecl, RuleBndr(..),
        DefaultDecl(..), LDefaultDecl, SpliceDecl(..),
        ForeignDecl(..), LForeignDecl, ForeignImport(..), ForeignExport(..),
@@ -67,6 +67,7 @@ type LHsDecl id = Located (HsDecl id)
 data HsDecl id
   = TyClD      (TyClDecl id)
   | InstD      (InstDecl  id)
+  | DerivD      (DerivDecl id)
   | ValD       (HsBind id)
   | SigD       (Sig id)
   | DefD       (DefaultDecl id)
@@ -153,6 +154,7 @@ instance OutputableBndr name => Outputable (HsDecl name) where
     ppr (ValD binds) = ppr binds
     ppr (DefD def)   = ppr def
     ppr (InstD inst) = ppr inst
+    ppr (DerivD deriv) = ppr deriv
     ppr (ForD fd)    = ppr fd
     ppr (SigD sd)    = ppr sd
     ppr (RuleD rd)   = ppr rd
@@ -715,6 +717,23 @@ instDeclATs (InstDecl _ _ _ ats) = ats
 
 %************************************************************************
 %*                                                                     *
+\subsection[DerivDecl]{A stand-alone instance deriving declaration
+%*                                                                     *
+%************************************************************************
+
+\begin{code}
+type LDerivDecl name = Located (DerivDecl name)
+
+data DerivDecl name
+  = DerivDecl (Located name) (LHsType name)
+
+instance (OutputableBndr name) => Outputable (DerivDecl name) where
+    ppr (DerivDecl cls ty)
+      = hsep [ptext SLIT("deriving"), ppr cls, ppr ty]
+\end{code}
+
+%************************************************************************
+%*                                                                     *
 \subsection[DefaultDecl]{A @default@ declaration}
 %*                                                                     *
 %************************************************************************