[project @ 1997-03-14 07:52:06 by simonpj]

[ghc-hetmet.git] / ghc / compiler / typecheck / TcKind.lhs

diff --git a/ghc/compiler/typecheck/TcKind.lhs b/ghc/compiler/typecheck/TcKind.lhs
index a233623..8dd9e5b 100644 (file)
--- a/ghc/compiler/typecheck/TcKind.lhs
+++ b/ghc/compiler/typecheck/TcKind.lhs
@@ -1,9 +1,11 @@
 \begin{code}
+#include "HsVersions.h"
+
 module TcKind (
 
        Kind, mkTypeKind, mkBoxedTypeKind, mkUnboxedTypeKind, mkArrowKind, 
-       isSubKindOf,    -- Kind -> Kind -> Bool
-       resultKind,     -- Kind -> Kind
+       hasMoreBoxityInfo,      -- Kind -> Kind -> Bool
+       resultKind,             -- Kind -> Kind
 
        TcKind, mkTcTypeKind, mkTcArrowKind, mkTcVarKind,
        newKindVar,     -- NF_TcM s (TcKind s)
@@ -11,15 +13,17 @@ module TcKind (
        unifyKind,      -- TcKind s -> TcKind s -> TcM s ()
 
        kindToTcKind,   -- Kind     -> TcKind s
-       tcKindToKind    -- TcKind s -> NF_TcM s Kind
+       tcDefaultKind   -- TcKind s -> NF_TcM s Kind
   ) where
 
+IMP_Ubiq(){-uitous-}
+
 import Kind
 import TcMonad
 
-import Ubiq
 import Unique  ( Unique, pprUnique10 )
 import Pretty
+import Util    ( nOfThem )
 \end{code}
 
 
@@ -39,7 +43,7 @@ newKindVar = tcGetUnique              `thenNF_Tc` \ uniq ->
             returnNF_Tc (TcVarKind uniq box)
 
 newKindVars :: Int -> NF_TcM s [TcKind s]
-newKindVars n = mapNF_Tc (\_->newKindVar) (take n (repeat ()))
+newKindVars n = mapNF_Tc (\ _ -> newKindVar) (nOfThem n ())
 \end{code}
 
 
@@ -77,7 +81,7 @@ I'm not convinced it would save time, and it's a little tricky to get right.
 unify_var uniq1 box1 kind2
   = tcReadMutVar box1  `thenNF_Tc` \ maybe_kind1 ->
     case maybe_kind1 of
-      Just kind1 -> unify_kind kind1 kind1
+      Just kind1 -> unify_kind kind1 kind2
       Nothing    -> unify_unbound_var uniq1 box1 kind2
 
 unify_unbound_var uniq1 box1 kind2@(TcVarKind uniq2 box2)
@@ -127,22 +131,27 @@ kindToTcKind UnboxedTypeKind   = TcTypeKind
 kindToTcKind (ArrowKind k1 k2) = TcArrowKind (kindToTcKind k1) (kindToTcKind k2)
 
 
-tcKindToKind :: TcKind s -> NF_TcM s Kind
+-- Default all unbound kinds to TcTypeKind, and return the
+-- corresponding Kind as well.
+tcDefaultKind :: TcKind s -> NF_TcM s Kind
 
-tcKindToKind TcTypeKind
-  = returnNF_Tc TypeKind
+tcDefaultKind TcTypeKind
+  = returnNF_Tc BoxedTypeKind
 
-tcKindToKind (TcArrowKind kind1 kind2)
-  = tcKindToKind kind1 `thenNF_Tc` \ k1 ->
-    tcKindToKind kind2 `thenNF_Tc` \ k2 ->
+tcDefaultKind (TcArrowKind kind1 kind2)
+  = tcDefaultKind kind1        `thenNF_Tc` \ k1 ->
+    tcDefaultKind kind2        `thenNF_Tc` \ k2 ->
     returnNF_Tc (ArrowKind k1 k2)
 
        -- Here's where we "default" unbound kinds to BoxedTypeKind
-tcKindToKind (TcVarKind uniq box)
+tcDefaultKind (TcVarKind uniq box)
   = tcReadMutVar box   `thenNF_Tc` \ maybe_kind ->
     case maybe_kind of
-       Nothing   -> returnNF_Tc BoxedTypeKind  -- Default is kind Type for unbound
-       Just kind -> tcKindToKind kind
+       Just kind -> tcDefaultKind kind
+
+       Nothing   ->    -- Default unbound variables to kind Type
+                    tcWriteMutVar box (Just TcTypeKind)        `thenNF_Tc_`
+                    returnNF_Tc BoxedTypeKind
 
 zonkTcKind :: TcKind s -> NF_TcM s (TcKind s)
 -- Removes variables that have now been bound.
@@ -170,11 +179,11 @@ instance Outputable (TcKind s) where
   ppr sty kind = ppr_kind sty kind
 
 ppr_kind sty TcTypeKind 
-  = ppStr "*"
+  = ppChar '*'
 ppr_kind sty (TcArrowKind kind1 kind2) 
-  = ppSep [ppr_parend sty kind1, ppStr "->", ppr_kind sty kind2]
+  = ppSep [ppr_parend sty kind1, ppPStr SLIT("->"), ppr_kind sty kind2]
 ppr_kind sty (TcVarKind uniq box) 
-  = ppBesides [ppStr "k", pprUnique10 uniq]
+  = ppBesides [ppChar 'k', pprUnique10 uniq]
 
 ppr_parend sty kind@(TcArrowKind _ _) = ppBesides [ppChar '(', ppr_kind sty kind, ppChar ')']
 ppr_parend sty other_kind            = ppr_kind sty other_kind
@@ -186,20 +195,20 @@ Errors and contexts
 ~~~~~~~~~~~~~~~~~~~
 \begin{code}
 unifyKindCtxt kind1 kind2 sty
-  = ppHang (ppStr "When unifying two kinds") 4
-          (ppSep [ppr sty kind1, ppStr "and", ppr sty kind2])
+  = ppHang (ppPStr SLIT("When unifying two kinds")) 4
+          (ppSep [ppr sty kind1, ppPStr SLIT("and"), ppr sty kind2])
 
 kindOccurCheck kind1 kind2 sty
-  = ppHang (ppStr "Cannot construct the infinite kind:") 4
-       (ppSep [ppBesides [ppStr "`", ppr sty kind1, ppStr "'"],
-               ppStr "=",
-               ppBesides [ppStr "`", ppr sty kind1, ppStr "'"],
-               ppStr "(\"occurs check\")"])
+  = ppHang (ppPStr SLIT("Cannot construct the infinite kind:")) 4
+       (ppSep [ppBesides [ppChar '`', ppr sty kind1, ppChar '\''],
+               ppChar '=',
+               ppBesides [ppChar '`', ppr sty kind1, ppChar '\''],
+               ppPStr SLIT("(\"occurs check\")")])
 
 kindMisMatchErr kind1 kind2 sty
- = ppHang (ppStr "Couldn't match the kind") 4
-       (ppSep [ppBesides [ppStr "`", ppr sty kind1, ppStr "'"],
-               ppStr "against",
-               ppBesides [ppStr "`", ppr sty kind1, ppStr "'"]
+ = ppHang (ppPStr SLIT("Couldn't match the kind")) 4
+       (ppSep [ppBesides [ppChar '`', ppr sty kind1, ppChar '\''],
+               ppPStr SLIT("against"),
+               ppBesides [ppChar '`', ppr sty kind2, ppChar '\'']
        ])
 \end{code}