X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2FbasicTypes%2FBasicTypes.lhs;h=b0100e659e06ea98439738f6e6047b8ca4a45514;hb=1bba522f5ec82c43abd2ba4e84127b9c915dd020;hp=ded171f06b9e21c3253d5683474f3a676a5a9951;hpb=123e3135b5f7c666f716a503e754aaf738e78ba6;p=ghc-hetmet.git

diff --git a/ghc/compiler/basicTypes/BasicTypes.lhs b/ghc/compiler/basicTypes/BasicTypes.lhs
index ded171f..b0100e6 100644
--- a/ghc/compiler/basicTypes/BasicTypes.lhs
+++ b/ghc/compiler/basicTypes/BasicTypes.lhs
@@ -14,13 +14,28 @@ types that
 
 \begin{code}
 module BasicTypes(
-	Version, Arity, 
+	Version, bumpVersion, initialVersion, bogusVersion,
+
+	Arity, 
+
 	Unused, unused,
+
 	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
+
    ) where
 
 #include "HsVersions.h"
@@ -63,6 +78,15 @@ type Arity = Int
 
 \begin{code}
 type Version = Int
+
+bogusVersion :: Version	-- Shouldn't look at these
+bogusVersion = error "bogusVersion"
+
+bumpVersion :: Version -> Version 
+bumpVersion v = v+1
+
+initialVersion :: Version
+initialVersion = 1
 \end{code}
 
 
@@ -109,7 +133,6 @@ negatePrecedence = 6
 data NewOrData
   = NewType  	-- "newtype Blah ..."
   | DataType 	-- "data Blah ..."
-  | EnumType	-- Enumeration; all constructors are nullary
   deriving( Eq )	-- Needed because Demand derives Eq
 \end{code}
 
@@ -135,6 +158,28 @@ 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}
 %*									*
 %************************************************************************
@@ -151,3 +196,72 @@ isNonRec :: RecFlag -> Bool
 isNonRec Recursive    = False
 isNonRec NonRecursive = True
 \end{code}
+
+
+%************************************************************************
+%*									*
+\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}
+