X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FbasicTypes%2FBasicTypes.lhs;h=0f7a462b4b060284cb7bc649f0aed31637465781;hb=0e25b971fb86cd91767644301dcfa2c1c413e3a8;hp=39daeeca830ba17853cddba3d6cecb21b78021dd;hpb=506fa77d392191e46c12b2c19387ff5b0888f6a2;p=ghc-hetmet.git

diff --git a/ghc/compiler/basicTypes/BasicTypes.lhs b/ghc/compiler/basicTypes/BasicTypes.lhs
index 39daeec..0f7a462 100644
--- a/ghc/compiler/basicTypes/BasicTypes.lhs
+++ b/ghc/compiler/basicTypes/BasicTypes.lhs
@@ -14,12 +14,31 @@ types that
 
 \begin{code}
 module BasicTypes(
-	Version, Arity, 
+	Version, bumpVersion, initialVersion, bogusVersion,
+
+	Arity, 
+
 	Unused, unused,
-	Fixity(..), FixityDirection(..), defaultFixity,
+
+	Fixity(..), FixityDirection(..),
+	defaultFixity, maxPrecedence, negateFixity, negatePrecedence,
+
 	NewOrData(..), 
+
 	RecFlag(..), isRec, isNonRec,
-	TopLevelFlag(..), isTopLevel, isNotTopLevel
+
+	TopLevelFlag(..), isTopLevel, isNotTopLevel,
+
+	Boxity(..), isBoxed, tupleParens,
+
+	OccInfo(..), seqOccInfo, isFragileOcc, isDeadOcc, isLoopBreaker,
+
+	InsideLam, insideLam, notInsideLam,
+	OneBranch, oneBranch, notOneBranch,
+
+        EP(..),
+
+	StrictnessMark(..), isMarkedUnboxed, isMarkedStrict
    ) where
 
 #include "HsVersions.h"
@@ -62,6 +81,17 @@ type Arity = Int
 
 \begin{code}
 type Version = Int
+
+bogusVersion :: Version	-- Shouldn't look at these
+bogusVersion = error "bogusVersion"
+
+bumpVersion :: Bool -> Version -> Version 
+-- Bump if the predicate (typically equality between old and new) is false
+bumpVersion False v = v+1
+bumpVersion True  v = v
+
+initialVersion :: Version
+initialVersion = 1
 \end{code}
 
 
@@ -87,8 +117,14 @@ instance Outputable FixityDirection where
 instance Eq Fixity where		-- Used to determine if two fixities conflict
   (Fixity p1 dir1) == (Fixity p2 dir2) = p1==p2 && dir1 == dir2
 
+maxPrecedence = (9::Int)
+defaultFixity = Fixity maxPrecedence InfixL
+
+negateFixity :: Fixity
+negateFixity     = Fixity negatePrecedence InfixL  	-- Precedence of unary negate is wired in as infixl 6!
 
-defaultFixity = Fixity 9 InfixL
+negatePrecedence :: Int
+negatePrecedence = 6
 \end{code}
 
 
@@ -102,7 +138,6 @@ defaultFixity = Fixity 9 InfixL
 data NewOrData
   = NewType  	-- "newtype Blah ..."
   | DataType 	-- "data Blah ..."
-  | EnumType	-- Enumeration; all constructors are nullary
   deriving( Eq )	-- Needed because Demand derives Eq
 \end{code}
 
@@ -128,6 +163,28 @@ isTopLevel NotTopLevel  = False
 
 %************************************************************************
 %*									*
+\subsection[Top-level/local]{Top-level/not-top level flag}
+%*									*
+%************************************************************************
+
+\begin{code}
+data Boxity
+  = Boxed
+  | Unboxed
+  deriving( Eq )
+
+isBoxed :: Boxity -> Bool
+isBoxed Boxed   = True
+isBoxed Unboxed = False
+
+tupleParens :: Boxity -> SDoc -> SDoc
+tupleParens Boxed   p = parens p
+tupleParens Unboxed p = ptext SLIT("(#") <+> p <+> ptext SLIT("#)")
+\end{code}
+
+
+%************************************************************************
+%*									*
 \subsection[Recursive/Non-Recursive]{Recursive/Non-Recursive flag}
 %*									*
 %************************************************************************
@@ -144,3 +201,137 @@ isNonRec :: RecFlag -> Bool
 isNonRec Recursive    = False
 isNonRec NonRecursive = True
 \end{code}
+
+%************************************************************************
+%*									*
+\subsection[Generic]{Generic flag}
+%*									*
+%************************************************************************
+
+This is the "Embedding-Projection pair" datatype, it contains 
+two pieces of code (normally either RenamedHsExpr's or Id's)
+If we have a such a pair (EP from to), the idea is that 'from' and 'to'
+represents functions of type 
+
+	from :: T -> Tring
+	to   :: Tring -> T
+
+And we should have 
+
+	to (from x) = x
+
+T and Tring are arbitrary, but typically T is the 'main' type while
+Tring is the 'representation' type.  (This just helps us remember 
+whether to use 'from' or 'to'.
+
+\begin{code}
+data EP a = EP { fromEP :: a,	-- :: T -> Tring
+		 toEP   :: a }	-- :: Tring -> T
+\end{code}
+
+Embedding-projection pairs are used in several places:
+
+First of all, each type constructor has an EP associated with it, the
+code in EP converts (datatype T) from T to Tring and back again.
+
+Secondly, when we are filling in Generic methods (in the typechecker, 
+tcMethodBinds), we are constructing bimaps by induction on the structure
+of the type of the method signature.
+
+
+%************************************************************************
+%*									*
+\subsection{Occurrence information}
+%*									*
+%************************************************************************
+
+This data type is used exclusively by the simplifier, but it appears in a
+SubstResult, which is currently defined in VarEnv, which is pretty near
+the base of the module hierarchy.  So it seemed simpler to put the
+defn of OccInfo here, safely at the bottom
+
+\begin{code}
+data OccInfo 
+  = NoOccInfo
+
+  | IAmDead		-- Marks unused variables.  Sometimes useful for
+			-- lambda and case-bound variables.
+
+  | OneOcc InsideLam
+
+ 	   OneBranch
+
+  | IAmALoopBreaker	-- Used by the occurrence analyser to mark loop-breakers
+			-- in a group of recursive definitions
+
+seqOccInfo :: OccInfo -> ()
+seqOccInfo (OneOcc in_lam once) = in_lam `seq` once `seq` ()
+seqOccInfo occ			= ()
+
+type InsideLam = Bool	-- True <=> Occurs inside a non-linear lambda
+			-- Substituting a redex for this occurrence is
+			-- dangerous because it might duplicate work.
+insideLam    = True
+notInsideLam = False
+
+type OneBranch = Bool	-- True <=> Occurs in only one case branch
+			--	so no code-duplication issue to worry about
+oneBranch    = True
+notOneBranch = False
+
+isLoopBreaker :: OccInfo -> Bool
+isLoopBreaker IAmALoopBreaker = True
+isLoopBreaker other	      = False
+
+isDeadOcc :: OccInfo -> Bool
+isDeadOcc IAmDead = True
+isDeadOcc other	  = False
+
+isFragileOcc :: OccInfo -> Bool
+isFragileOcc (OneOcc _ _) = True
+isFragileOcc other	      = False
+\end{code}
+
+\begin{code}
+instance Outputable OccInfo where
+  -- only used for debugging; never parsed.  KSW 1999-07
+  ppr NoOccInfo  			  	  = empty
+  ppr IAmALoopBreaker 				  = ptext SLIT("_Kx")
+  ppr IAmDead					  = ptext SLIT("_Kd")
+  ppr (OneOcc inside_lam one_branch) | inside_lam = ptext SLIT("_Kl")
+				     | one_branch = ptext SLIT("_Ks")
+				     | otherwise  = ptext SLIT("_Ks*")
+
+instance Show OccInfo where
+  showsPrec p occ = showsPrecSDoc p (ppr occ)
+\end{code}
+
+%************************************************************************
+%*									*
+\subsection{Strictness indication}
+%*									*
+%************************************************************************
+
+The strictness annotations on types in data type declarations
+e.g. 	data T = MkT !Int !(Bool,Bool)
+
+\begin{code}
+data StrictnessMark
+   = MarkedUserStrict	-- "!"  in a source decl
+   | MarkedStrict	-- "!"  in an interface decl: strict but not unboxed
+   | MarkedUnboxed	-- "!!" in an interface decl: unboxed 
+   | NotMarkedStrict	-- No annotation at all
+   deriving( Eq )
+
+isMarkedUnboxed MarkedUnboxed = True
+isMarkedUnboxed other	      = False
+
+isMarkedStrict NotMarkedStrict = False
+isMarkedStrict other	       = True	-- All others are strict
+
+instance Outputable StrictnessMark where
+  ppr MarkedUserStrict = ptext SLIT("!u")
+  ppr MarkedStrict     = ptext SLIT("!")
+  ppr MarkedUnboxed    = ptext SLIT("! !")
+  ppr NotMarkedStrict  = empty
+\end{code}