[project @ 1998-11-26 09:17:22 by sof]

[ghc-hetmet.git] / ghc / compiler / types / Kind.lhs

diff --git a/ghc/compiler/types/Kind.lhs b/ghc/compiler/types/Kind.lhs
index 5509070..d4fe4a3 100644 (file)
--- a/ghc/compiler/types/Kind.lhs
+++ b/ghc/compiler/types/Kind.lhs
@@ -4,10 +4,9 @@
 \section[Kind]{The @Kind@ datatype}
 
 \begin{code}
-#include "HsVersions.h"
-
 module Kind (
-       Kind(..),               -- Only visible to friends: TcKind
+        GenKind(..),   -- Only visible to friends: TcKind
+       Kind,   
 
        mkArrowKind,
        mkTypeKind,
@@ -19,44 +18,53 @@ module Kind (
 
        pprKind, pprParendKind,
 
-       isUnboxedTypeKind, isTypeKind, isBoxedTypeKind,
-       notArrowKind
+       isUnboxedTypeKind, isTypeKind, isBoxedTypeKind
     ) where
 
-IMP_Ubiq(){-uitous-}
+#include "HsVersions.h"
 
 import Util            ( panic, assertPanic )
-
-import Outputable      ( Outputable(..), pprQuote )
-import Pretty
+import Unique          ( Unique, pprUnique )
+import BasicTypes      ( Unused )
+import Outputable
 \end{code}
 
 \begin{code}
-data Kind
+data GenKind flexi
   = TypeKind           -- Any type (incl unboxed types)
   | BoxedTypeKind      -- Any boxed type
   | UnboxedTypeKind    -- Any unboxed type
-  | ArrowKind Kind Kind
-  deriving Eq
+  | ArrowKind (GenKind flexi) (GenKind flexi)
+  | VarKind Unique flexi
+
+type Kind = GenKind Unused     -- No variables at all
+
+instance Eq (GenKind flexi) where
+  TypeKind          == TypeKind          = True
+  BoxedTypeKind     == BoxedTypeKind    = True
+  UnboxedTypeKind   == UnboxedTypeKind  = True
+  (ArrowKind j1 j2) == (ArrowKind k1 k2) = j1==k1 && j2==k2
+  (VarKind u1 _)    == (VarKind u2 _)    = u1==u2
+  k1               == k2                = False
 
 mkArrowKind      = ArrowKind
 mkTypeKind       = TypeKind
 mkUnboxedTypeKind = UnboxedTypeKind
 mkBoxedTypeKind   = BoxedTypeKind
 
-isTypeKind :: Kind -> Bool
+isTypeKind :: GenKind flexi -> Bool
 isTypeKind TypeKind = True
 isTypeKind other    = False
 
-isBoxedTypeKind :: Kind -> Bool
+isBoxedTypeKind :: GenKind flexi -> Bool
 isBoxedTypeKind BoxedTypeKind = True
 isBoxedTypeKind other         = False
 
-isUnboxedTypeKind :: Kind -> Bool
+isUnboxedTypeKind :: GenKind flexi -> Bool
 isUnboxedTypeKind UnboxedTypeKind = True
 isUnboxedTypeKind other                  = False
 
-hasMoreBoxityInfo :: Kind -> Kind -> Bool
+hasMoreBoxityInfo :: GenKind flexi -> GenKind flexi -> Bool
 
 BoxedTypeKind  `hasMoreBoxityInfo` TypeKind        = True
 BoxedTypeKind   `hasMoreBoxityInfo` BoxedTypeKind   = True
@@ -66,22 +74,21 @@ UnboxedTypeKind `hasMoreBoxityInfo` UnboxedTypeKind = True
 
 TypeKind       `hasMoreBoxityInfo` TypeKind        = True
 
-kind1@(ArrowKind _ _) `hasMoreBoxityInfo` kind2@(ArrowKind _ _) = ASSERT( kind1 == kind2 )
-                                                                 True
+kind1@(ArrowKind _ _) `hasMoreBoxityInfo` kind2@(ArrowKind _ _)
+  = ASSERT( if kind1 == kind2 then True
+           else pprPanic "hadMoreBoxityInfo" (ppr kind1 <> comma <+> ppr kind2) )
+    True
        -- The two kinds can be arrow kinds; for example when unifying
        -- (m1 Int) and (m2 Int) we end up unifying m1 and m2, which should
        -- have the same kind.
 
 kind1          `hasMoreBoxityInfo` kind2           = False
 
-notArrowKind (ArrowKind _ _) = False
-notArrowKind other_kind             = True
-
-resultKind :: Kind -> Kind     -- Get result from arrow kind
+resultKind :: GenKind flexi -> GenKind flexi   -- Get result from arrow kind
 resultKind (ArrowKind _ res_kind) = res_kind
 resultKind other_kind            = panic "resultKind"
 
-argKind :: Kind -> Kind                -- Get argument from arrow kind
+argKind :: GenKind flexi -> GenKind flexi              -- Get argument from arrow kind
 argKind (ArrowKind arg_kind _) = arg_kind
 argKind other_kind            = panic "argKind"
 \end{code}
@@ -89,13 +96,14 @@ argKind other_kind         = panic "argKind"
 Printing
 ~~~~~~~~
 \begin{code}
-instance Outputable Kind where
-  ppr sty kind = pprQuote sty $ \ _ -> pprKind kind
+instance Outputable (GenKind flexi) where
+  ppr kind = pprKind kind
 
-pprKind TypeKind        = char '*'     -- Can be boxed or unboxed
-pprKind BoxedTypeKind   = char '*'
-pprKind UnboxedTypeKind = text  "*#"   -- Unboxed
+pprKind TypeKind          = text "**"  -- Can be boxed or unboxed
+pprKind BoxedTypeKind     = char '*'
+pprKind UnboxedTypeKind   = text  "*#" -- Unboxed
 pprKind (ArrowKind k1 k2) = sep [pprParendKind k1, text "->", pprKind k2]
+pprKind (VarKind u _)     = char 'k' <> pprUnique u
 
 pprParendKind k@(ArrowKind _ _) = parens (pprKind k)
 pprParendKind k                        = pprKind k