Move InId/OutId to CoreSyn

It turned out that many different modules defined the same type
synonyms (InId, OutId, InType, OutType, etc) for the same purpose.

This patch is refactoring only: it moves all those definitions to
CoreSyn.

8 files changed, 51 insertions, 84 deletions

diff --git a/compiler/coreSyn/CoreLint.hs b/compiler/coreSyn/CoreLint.hs
index 345e4b5f97..b4946a274b 100644
--- a/compiler/coreSyn/CoreLint.hs
+++ b/compiler/coreSyn/CoreLint.hs
@@ -601,24 +601,12 @@ the desugarer.
 ************************************************************************
 -}
 
-type InType      = Type
-type InCoercion  = Coercion
-type InVar       = Var
-type InTyVar     = Var
-type InCoVar     = Var
-
-type OutType     = Type -- Substitution has been applied to this,
-                        -- but has not been linted yet
-type OutKind     = Kind
+-- For OutType, OutKind, the substitution has been applied,
+--                       but has not been linted yet
 
 type LintedType  = Type -- Substitution applied, and type is linted
 type LintedKind  = Kind
 
-type OutCoercion    = Coercion
-type OutVar         = Var
-type OutTyVar       = TyVar
-type OutCoVar       = Var
-
 lintCoreExpr :: CoreExpr -> LintM OutType
 -- The returned type has the substitution from the monad
 -- already applied to it:
diff --git a/compiler/coreSyn/CoreSubst.hs b/compiler/coreSyn/CoreSubst.hs
index ffd8c2a024..e8a8f6ea55 100644
--- a/compiler/coreSyn/CoreSubst.hs
+++ b/compiler/coreSyn/CoreSubst.hs
@@ -81,6 +81,7 @@ import Data.List
 
 import TysWiredIn
 
+
 {-
 ************************************************************************
 *                                                                      *
@@ -907,14 +908,6 @@ simpleOptPgm dflags this_mod binds rules vects
           (subst', Nothing)    -> (subst', binds')
           (subst', Just bind') -> (subst', bind':binds')
 
-----------------------
-type InVar   = Var
-type OutVar  = Var
-type InId    = Id
-type OutId   = Id
-type InExpr  = CoreExpr
-type OutExpr = CoreExpr
-
 -- In these functions the substitution maps InVar -> OutExpr
 
 ----------------------
diff --git a/compiler/coreSyn/CoreSyn.hs b/compiler/coreSyn/CoreSyn.hs
index cf570211f5..52ffad041b 100644
--- a/compiler/coreSyn/CoreSyn.hs
+++ b/compiler/coreSyn/CoreSyn.hs
@@ -13,6 +13,12 @@ module CoreSyn (
         CoreProgram, CoreExpr, CoreAlt, CoreBind, CoreArg, CoreBndr,
         TaggedExpr, TaggedAlt, TaggedBind, TaggedArg, TaggedBndr(..), deTagExpr,
 
+        -- * In/Out type synonyms
+        InId, InBind, InExpr, InAlt, InArg, InType, InKind,
+               InBndr, InVar, InCoercion, InTyVar, InCoVar,
+        OutId, OutBind, OutExpr, OutAlt, OutArg, OutType, OutKind,
+               OutBndr, OutVar, OutCoercion, OutTyVar, OutCoVar,
+
         -- ** 'Expr' construction
         mkLets, mkLams,
         mkApps, mkTyApps, mkCoApps, mkVarApps,
@@ -40,6 +46,7 @@ module CoreSyn (
         isValArg, isTypeArg, isTyCoArg, valArgCount, valBndrCount,
         isRuntimeArg, isRuntimeVar,
 
+        -- * Tick-related functions
         tickishCounts, tickishScoped, tickishScopesLike, tickishFloatable,
         tickishCanSplit, mkNoCount, mkNoScope,
         tickishIsCode, tickishPlace,
@@ -393,7 +400,7 @@ The levity-polymorphism invariants are these:
 A type (t::TYPE r) is "levity polymorphic" if 'r' has any free variables.
 
 For example
-  (\(r::RuntimeRep). \(a::TYPE r). \(x::a). e
+  \(r::RuntimeRep). \(a::TYPE r). \(x::a). e
 is illegal because x's type has kind (TYPE r), which has 'r' free.
 
 Note [CoreSyn let goal]
@@ -461,6 +468,44 @@ this exhaustive list can be empty!
 
 ************************************************************************
 *                                                                      *
+            In/Out type synonyms
+*                                                                      *
+********************************************************************* -}
+
+{- Many passes apply a substitution, and it's very handy to have type
+   synonyms to remind us whether or not the subsitution has been applied -}
+
+-- Pre-cloning or substitution
+type InBndr     = CoreBndr
+type InVar      = Var
+type InTyVar    = TyVar
+type InCoVar    = CoVar
+type InId       = Id
+type InType     = Type
+type InKind     = Kind
+type InBind     = CoreBind
+type InExpr     = CoreExpr
+type InAlt      = CoreAlt
+type InArg      = CoreArg
+type InCoercion = Coercion
+
+-- Post-cloning or substitution
+type OutBndr     = CoreBndr
+type OutVar      = Var
+type OutId       = Id
+type OutTyVar    = TyVar
+type OutCoVar    = CoVar
+type OutType     = Type
+type OutKind     = Kind
+type OutCoercion = Coercion
+type OutBind     = CoreBind
+type OutExpr     = CoreExpr
+type OutAlt      = CoreAlt
+type OutArg      = CoreArg
+
+
+{- *********************************************************************
+*                                                                      *
               Ticks
 *                                                                      *
 ************************************************************************
@@ -1091,7 +1136,7 @@ data UnfoldingGuidance
                 -- Used (a) for small *and* cheap unfoldings
                 --      (b) for INLINE functions
                 -- See Note [INLINE for small functions] in CoreUnfold
-      ug_arity    :: Arity,             -- Number of value arguments expected
+      ug_arity    :: Arity,     -- Number of value arguments expected
 
       ug_unsat_ok  :: Bool,     -- True <=> ok to inline even if unsaturated
       ug_boring_ok :: Bool      -- True <=> ok to inline even if the context is boring
diff --git a/compiler/simplCore/CSE.hs b/compiler/simplCore/CSE.hs
index 039da8e763..42a2d289a2 100644
--- a/compiler/simplCore/CSE.hs
+++ b/compiler/simplCore/CSE.hs
@@ -17,7 +17,7 @@ import Id               ( Id, idType, idUnfolding, idInlineActivation
 import CoreUtils        ( mkAltExpr
                         , exprIsTrivial, exprOkForSpeculation
                         , stripTicksE, stripTicksT, mkTicks )
-import Type             ( Type, tyConAppArgs, isUnliftedType )
+import Type             ( tyConAppArgs, isUnliftedType )
 import CoreSyn
 import Outputable
 import BasicTypes       ( isAlwaysActive )
@@ -368,15 +368,6 @@ cseCase env scrut bndr ty alts
 ************************************************************************
 -}
 
-type InExpr  = CoreExpr         -- Pre-cloning
-type InId    = Id
-type InAlt   = CoreAlt
-type InType  = Type
-
-type OutExpr  = CoreExpr        -- Post-cloning
-type OutId    = Id
-type OutType  = Type
-
 data CSEnv
   = CS { cs_subst :: Subst  -- Maps InBndrs to OutExprs
             -- The substitution variables to
diff --git a/compiler/simplCore/SetLevels.hs b/compiler/simplCore/SetLevels.hs
index ef98e7b915..bb1045740d 100644
--- a/compiler/simplCore/SetLevels.hs
+++ b/compiler/simplCore/SetLevels.hs
@@ -935,11 +935,6 @@ countFreeIds = nonDetFoldUDFM add 0
 ************************************************************************
 -}
 
-type InVar  = Var   -- Pre  cloning
-type InId   = Id    -- Pre  cloning
-type OutVar = Var   -- Post cloning
-type OutId  = Id    -- Post cloning
-
 data LevelEnv
   = LE { le_switches :: FloatOutSwitches
        , le_ctxt_lvl :: Level           -- The current level
diff --git a/compiler/simplCore/SimplEnv.hs b/compiler/simplCore/SimplEnv.hs
index 7061540942..59ac440230 100644
--- a/compiler/simplCore/SimplEnv.hs
+++ b/compiler/simplCore/SimplEnv.hs
@@ -7,11 +7,6 @@
 {-# LANGUAGE CPP #-}
 
 module SimplEnv (
-        -- * Basic types
-        InId, InBind, InExpr, InAlt, InArg, InType, InBndr, InVar,
-        OutId, OutTyVar, OutBind, OutExpr, OutAlt, OutArg, OutType, OutBndr, OutVar,
-        InCoercion, OutCoercion,
-
         -- * The simplifier mode
         setMode, getMode, updMode,
 
@@ -65,35 +60,6 @@ import Data.List
 {-
 ************************************************************************
 *                                                                      *
-\subsection[Simplify-types]{Type declarations}
-*                                                                      *
-************************************************************************
--}
-
-type InBndr     = CoreBndr
-type InVar      = Var                   -- Not yet cloned
-type InId       = Id                    -- Not yet cloned
-type InType     = Type                  -- Ditto
-type InBind     = CoreBind
-type InExpr     = CoreExpr
-type InAlt      = CoreAlt
-type InArg      = CoreArg
-type InCoercion = Coercion
-
-type OutBndr     = CoreBndr
-type OutVar      = Var                  -- Cloned
-type OutId       = Id                   -- Cloned
-type OutTyVar    = TyVar                -- Cloned
-type OutType     = Type                 -- Cloned
-type OutCoercion = Coercion
-type OutBind     = CoreBind
-type OutExpr     = CoreExpr
-type OutAlt      = CoreAlt
-type OutArg      = CoreArg
-
-{-
-************************************************************************
-*                                                                      *
 \subsubsection{The @SimplEnv@ type}
 *                                                                      *
 ************************************************************************
diff --git a/compiler/simplStg/UnariseStg.hs b/compiler/simplStg/UnariseStg.hs
index a393e8fae9..fc30859980 100644
--- a/compiler/simplStg/UnariseStg.hs
+++ b/compiler/simplStg/UnariseStg.hs
@@ -265,8 +265,6 @@ extendRho rho x (UnaryVal val)
 --------------------------------------------------------------------------------
 
 type OutStgExpr = StgExpr
-type InId       = Id
-type OutId      = Id
 type InStgAlt   = StgAlt
 type InStgArg   = StgArg
 type OutStgArg  = StgArg
diff --git a/compiler/specialise/SpecConstr.hs b/compiler/specialise/SpecConstr.hs
index 2f2087cd2e..4aa7f04f5f 100644
--- a/compiler/specialise/SpecConstr.hs
+++ b/compiler/specialise/SpecConstr.hs
@@ -788,15 +788,6 @@ data ScEnv = SCE { sc_dflags    :: DynFlags,
              }
 
 ---------------------
--- As we go, we apply a substitution (sc_subst) to the current term
-type InExpr = CoreExpr          -- _Before_ applying the subst
-type InVar  = Var
-
-type OutExpr = CoreExpr         -- _After_ applying the subst
-type OutId   = Id
-type OutVar  = Var
-
----------------------
 type HowBoundEnv = VarEnv HowBound      -- Domain is OutVars
 
 ---------------------