Big tidy-up of deriving code

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

diff --git a/compiler/hsSyn/HsTypes.lhs b/compiler/hsSyn/HsTypes.lhs
index 68d2d90..bbe7016 100644 (file)
--- a/compiler/hsSyn/HsTypes.lhs
+++ b/compiler/hsSyn/HsTypes.lhs
@@ -1,7 +1,9 @@
 %
+% (c) The University of Glasgow 2006
 % (c) The GRASP/AQUA Project, Glasgow University, 1992-1998
 %
-\section[HsTypes]{Abstract syntax: user-defined types}
+
+HsTypes: Abstract syntax: user-defined types
 
 \begin{code}
 module HsTypes (
@@ -14,7 +16,7 @@ module HsTypes (
        LBangType, BangType, HsBang(..), 
         getBangType, getBangStrictness, 
        
-       mkExplicitHsForAllTy, mkImplicitHsForAllTy, 
+       mkExplicitHsForAllTy, mkImplicitHsForAllTy, hsExplicitTvs,
        hsTyVarName, hsTyVarNames, replaceTyVarName,
        hsLTyVarName, hsLTyVarNames, hsLTyVarLocName, hsLTyVarLocNames,
        splitHsInstDeclTy, splitHsFunType,
@@ -30,13 +32,11 @@ module HsTypes (
 
 import {-# SOURCE #-} HsExpr ( HsSplice, pprSplice )
 
-import Type            ( Type )
-import {- Kind parts of -} 
-       Type            ( {- instance Outputable Kind -} Kind,
-                         pprParendKind, pprKind, isLiftedTypeKind )
-import BasicTypes      ( IPName, Boxity, tupleParens )
-import SrcLoc          ( Located(..), unLoc, noSrcSpan )
-import StaticFlags     ( opt_PprStyle_Debug )
+import Type
+import HsDoc
+import BasicTypes
+import SrcLoc
+import StaticFlags
 import Outputable
 \end{code}
 
@@ -102,7 +102,8 @@ type HsContext name = [LHsPred name]
 
 type LHsPred name = Located (HsPred name)
 
-data HsPred name = HsClassP name [LHsType name]
+data HsPred name = HsClassP name [LHsType name]                 -- class constraint
+                | HsEqualP (LHsType name) (LHsType name)-- equality constraint
                 | HsIParam (IPName name) (LHsType name)
 
 type LHsType name = Located (HsType name)
@@ -157,6 +158,8 @@ data HsType name
 
   | HsSpliceTy         (HsSplice name)
 
+  | HsDocTy             (LHsType name) (LHsDoc name) -- A documented type
+
 data HsExplicitForAll = Explicit | Implicit
 
 -----------------------
@@ -190,6 +193,12 @@ mk_forall_ty exp  tvs  ty                              = HsForAllTy exp tvs (L noSrcSpan []) ty
 Implicit `plus` Implicit = Implicit
 exp1     `plus` exp2     = Explicit
 
+hsExplicitTvs :: LHsType name -> [name]
+-- The explicitly-given forall'd type variables of a HsType
+hsExplicitTvs (L _ (HsForAllTy Explicit tvs _ _)) = hsLTyVarNames tvs
+hsExplicitTvs other                              = []
+
+---------------------
 type LHsTyVarBndr name = Located (HsTyVarBndr name)
 
 data HsTyVarBndr name
@@ -240,6 +249,7 @@ splitHsInstDeclTy inst_ty
   where
     split_tau tvs cxt (HsPredTy (HsClassP cls tys)) = (tvs, cxt, cls, tys)
     split_tau tvs cxt (HsParTy (L _ ty))           = split_tau tvs cxt ty
+    split_tau _ _ other = pprPanic "splitHsInstDeclTy" (ppr inst_ty)
 
 -- Splits HsType into the (init, last) parts
 -- Breaks up any parens in the result type: 
@@ -259,9 +269,6 @@ splitHsFunType other                   = ([], other)
 %*                                                                     *
 %************************************************************************
 
-NB: these types get printed into interface files, so 
-    don't change the printing format lightly
-
 \begin{code}
 instance (OutputableBndr name) => Outputable (HsType name) where
     ppr ty = pprHsType ty
@@ -271,8 +278,13 @@ instance (Outputable name) => Outputable (HsTyVarBndr name) where
     ppr (KindedTyVar name kind) = pprHsTyVarBndr name kind
 
 instance OutputableBndr name => Outputable (HsPred name) where
-    ppr (HsClassP clas tys) = ppr clas <+> hsep (map (pprParendHsType.unLoc) tys)
-    ppr (HsIParam n ty)    = hsep [ppr n, dcolon, ppr ty]
+    ppr (HsClassP clas tys) = ppr clas <+> hsep (map pprLHsType tys)
+    ppr (HsEqualP t1 t2)    = hsep [pprLHsType t1, ptext SLIT("~"), 
+                                   pprLHsType t2]
+    ppr (HsIParam n ty)     = hsep [ppr n, dcolon, ppr ty]
+
+pprLHsType :: OutputableBndr name => LHsType name -> SDoc
+pprLHsType = pprParendHsType . unLoc
 
 pprHsTyVarBndr :: Outputable name => name -> Kind -> SDoc
 pprHsTyVarBndr name kind | isLiftedTypeKind kind = ppr name
@@ -330,7 +342,6 @@ ppr_mono_ty ctxt_prec (HsForAllTy exp tvs ctxt ty)
   = maybeParen ctxt_prec pREC_FUN $
     sep [pprHsForAll exp tvs ctxt, ppr_mono_lty pREC_TOP ty]
 
--- gaw 2004
 ppr_mono_ty ctxt_prec (HsBangTy b ty)     = ppr b <> ppr ty
 ppr_mono_ty ctxt_prec (HsTyVar name)      = ppr name
 ppr_mono_ty ctxt_prec (HsFunTy ty1 ty2)   = ppr_fun_ty ctxt_prec ty1 ty2
@@ -338,7 +349,7 @@ ppr_mono_ty ctxt_prec (HsTupleTy con tys) = tupleParens con (interpp'SP tys)
 ppr_mono_ty ctxt_prec (HsKindSig ty kind) = parens (ppr_mono_lty pREC_TOP ty <+> dcolon <+> pprKind kind)
 ppr_mono_ty ctxt_prec (HsListTy ty)      = brackets (ppr_mono_lty pREC_TOP ty)
 ppr_mono_ty ctxt_prec (HsPArrTy ty)      = pabrackets (ppr_mono_lty pREC_TOP ty)
-ppr_mono_ty ctxt_prec (HsPredTy pred)     = braces (ppr pred)
+ppr_mono_ty ctxt_prec (HsPredTy pred)     = ppr pred
 ppr_mono_ty ctxt_prec (HsNumTy n)         = integer n  -- generics only
 ppr_mono_ty ctxt_prec (HsSpliceTy s)      = pprSplice s
 
@@ -356,6 +367,9 @@ ppr_mono_ty ctxt_prec (HsParTy ty)
   -- But we still use the precedence stuff to add parens because
   --   toHsType doesn't put in any HsParTys, so we may still need them
 
+ppr_mono_ty ctxt_prec (HsDocTy ty doc)
+  = ppr ty <+> ppr (unLoc doc)
+
 --------------------------
 ppr_fun_ty ctxt_prec ty1 ty2
   = let p1 = ppr_mono_lty pREC_FUN ty1