X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2FhsSyn%2FHsBinds.lhs;h=a9fa8e8ae2c7075359d15eb93f9c4b3db3e431cf;hb=57984dc34dcb242772bb81f1795c9afa3b7c36c1;hp=b8501d770f69c6e957d289bdfa69159221c2ceea;hpb=08ffc9074d79fd8117a090024068936a04360a17;p=ghc-hetmet.git

diff --git a/compiler/hsSyn/HsBinds.lhs b/compiler/hsSyn/HsBinds.lhs
index b8501d7..a9fa8e8 100644
--- a/compiler/hsSyn/HsBinds.lhs
+++ b/compiler/hsSyn/HsBinds.lhs
@@ -81,40 +81,44 @@ type LHsBindLR idL idR = Located (HsBindLR idL idR)
 type LHsBindsLR idL idR = Bag (LHsBindLR idL idR)
 
 data HsBindLR idL idR
-  = FunBind {	-- FunBind is used for both functions 	f x = e
-		-- and variables			f = \x -> e
--- Reason 1: Special case for type inference: see TcBinds.tcMonoBinds
---
--- Reason 2: instance decls can only have FunBinds, which is convenient
---	     If you change this, you'll need to change e.g. rnMethodBinds
-
--- But note that the form	f :: a->a = ...
--- parses as a pattern binding, just like
---			(f :: a -> a) = ... 
+  = -- | FunBind is used for both functions   @f x = e@
+    -- and variables                          @f = \x -> e@
+    --
+    -- Reason 1: Special case for type inference: see 'TcBinds.tcMonoBinds'.
+    --
+    -- Reason 2: Instance decls can only have FunBinds, which is convenient.
+    --           If you change this, you'll need to change e.g. rnMethodBinds
+    --
+    -- But note that the form                 @f :: a->a = ...@
+    -- parses as a pattern binding, just like
+    --                                        @(f :: a -> a) = ... @
+    FunBind {
 
 	fun_id :: Located idL,
 
-	fun_infix :: Bool,	-- True => infix declaration
+	fun_infix :: Bool,	-- ^ True => infix declaration
 
-	fun_matches :: MatchGroup idR,	-- The payload
+	fun_matches :: MatchGroup idR,	-- ^ The payload
 
-	fun_co_fn :: HsWrapper,	-- Coercion from the type of the MatchGroup to the type of
+	fun_co_fn :: HsWrapper,	-- ^ Coercion from the type of the MatchGroup to the type of
 				-- the Id.  Example:
+                                -- @
 				--	f :: Int -> forall a. a -> a
 				--	f x y = y
+                                -- @
 				-- Then the MatchGroup will have type (Int -> a' -> a')
 				-- (with a free type variable a').  The coercion will take
 				-- a CoreExpr of this type and convert it to a CoreExpr of
 				-- type 	Int -> forall a'. a' -> a'
 				-- Notice that the coercion captures the free a'.
 
-	bind_fvs :: NameSet,	-- After the renamer, this contains a superset of the 
+	bind_fvs :: NameSet,	-- ^ After the renamer, this contains a superset of the
 				-- Names of the other binders in this binding group that 
 				-- are free in the RHS of the defn
 				-- Before renaming, and after typechecking, 
 				-- the field is unused; it's just an error thunk
 
-        fun_tick :: Maybe (Int,[idR])   -- This is the (optional) module-local tick number. 
+        fun_tick :: Maybe (Int,[idR])   -- ^ This is the (optional) module-local tick number.
     }
 
   | PatBind {	-- The pattern is never a simple variable;
@@ -127,12 +131,15 @@ data HsBindLR idL idR
 
   | VarBind {	-- Dictionary binding and suchlike 
 	var_id :: idL,		-- All VarBinds are introduced by the type checker
-	var_rhs :: LHsExpr idR	-- Located only for consistency
+	var_rhs :: LHsExpr idR,	-- Located only for consistency
+	var_inline :: Bool	-- True <=> inline this binding regardless
+				--	(used for implication constraints)
     }
 
   | AbsBinds {					-- Binds abstraction; TRANSLATION
-       abs_tvs     :: [TyVar],  
-	abs_dicts   :: [DictId],
+        abs_tvs     :: [TyVar],  
+	abs_dicts   :: [DictId],		-- Includes equality constraints
+
        -- AbsBinds only gets used when idL = idR after renaming,
        -- but these need to be idL's for the collect... code in HsUtil to have
        -- the right type
@@ -340,11 +347,14 @@ data HsWrapper
   | WpCast Coercion		-- A cast:  [] `cast` co
 				-- Guaranteed not the identity coercion
 
-  | WpApp Var			-- [] d		the 'd' is a type-class dictionary
+  | WpApp Var			-- [] d		the 'd' is a type-class dictionary or coercion variable
+
   | WpTyApp Type		-- [] t		the 't' is a type or corecion
+    	    			--      ToDo: it'd be tidier if 't' was always a type (not coercion),
+				--	      but that is inconvenient in Inst.instCallDicts
+
   | WpLam Var	 		-- \d. []	the 'd' is a type-class dictionary or coercion variable
   | WpTyLam TyVar 		-- \a. []	the 'a' is a type variable (not coercion var)
-  | WpInline			-- inline_me []   Wrap inline around the thing
 
 	-- Non-empty bindings, so that the identity coercion
 	-- is always exactly WpHole
@@ -365,7 +375,6 @@ pprHsWrapper it wrap =
         help it (WpLam id)    = sep [ptext (sLit "\\") <> pprBndr LambdaBind id <> dot, it]
         help it (WpTyLam tv)  = sep [ptext (sLit "/\\") <> pprBndr LambdaBind tv <> dot, it]
         help it (WpLet binds) = sep [ptext (sLit "let") <+> braces (ppr binds), it]
-        help it WpInline      = sep [ptext (sLit "_inline_me_"), it]
     in
       -- in debug mode, print the wrapper
       -- otherwise just print what's inside
@@ -379,13 +388,13 @@ c1 <.> c2    = c1 `WpCompose` c2
 mkWpTyApps :: [Type] -> HsWrapper
 mkWpTyApps tys = mk_co_fn WpTyApp (reverse tys)
 
-mkWpApps :: [Id] -> HsWrapper
+mkWpApps :: [Var] -> HsWrapper
 mkWpApps ids = mk_co_fn WpApp (reverse ids)
 
 mkWpTyLams :: [TyVar] -> HsWrapper
 mkWpTyLams ids = mk_co_fn WpTyLam ids
 
-mkWpLams :: [Id] -> HsWrapper
+mkWpLams :: [Var] -> HsWrapper
 mkWpLams ids = mk_co_fn WpLam ids
 
 mk_co_fn :: (a -> HsWrapper) -> [a] -> HsWrapper