vectorise: Put it out of its misery

Poor DPH and its vectoriser have long been languishing; sadly it seems there is
little chance that the effort will be rekindled. Every few years we discuss
what to do with this mass of code and at least once we have agreed that it
should be archived on a branch and removed from `master`. Here we do just that,
eliminating heaps of dead code in the process.

Here we drop the ParallelArrays extension, the vectoriser, and the `vector` and
`primitive` submodules.

Test Plan: Validate

Reviewers: simonpj, simonmar, hvr, goldfire, alanz

Reviewed By: simonmar

Subscribers: goldfire, rwbarton, thomie, mpickering, carter

Differential Revision: https://phabricator.haskell.org/D4761

2 files changed, 1 insertions, 99 deletions

diff --git a/compiler/prelude/PrelNames.hs b/compiler/prelude/PrelNames.hs
index fd324cb43e..88541120ca 100644
--- a/compiler/prelude/PrelNames.hs
+++ b/compiler/prelude/PrelNames.hs
@@ -543,9 +543,6 @@ dATA_TYPE_EQUALITY = mkBaseModule (fsLit "Data.Type.Equality")
 dATA_COERCE     = mkBaseModule (fsLit "Data.Coerce")
 dEBUG_TRACE     = mkBaseModule (fsLit "Debug.Trace")
 
-gHC_PARR' :: Module
-gHC_PARR' = mkBaseModule (fsLit "GHC.PArr")
-
 gHC_SRCLOC :: Module
 gHC_SRCLOC = mkBaseModule (fsLit "GHC.SrcLoc")
 
@@ -1744,10 +1741,6 @@ funPtrTyConKey                          = mkPreludeTyConUnique 76
 tVarPrimTyConKey                        = mkPreludeTyConUnique 77
 compactPrimTyConKey                     = mkPreludeTyConUnique 78
 
--- Parallel array type constructor
-parrTyConKey :: Unique
-parrTyConKey                            = mkPreludeTyConUnique 82
-
 -- dotnet interop
 objectTyConKey :: Unique
 objectTyConKey                          = mkPreludeTyConUnique 83
@@ -1938,10 +1931,6 @@ inlDataConKey                           = mkPreludeDataConUnique 21
 inrDataConKey                           = mkPreludeDataConUnique 22
 genUnitDataConKey                       = mkPreludeDataConUnique 23
 
--- Data constructor for parallel arrays
-parrDataConKey :: Unique
-parrDataConKey                          = mkPreludeDataConUnique 24
-
 leftDataConKey, rightDataConKey :: Unique
 leftDataConKey                          = mkPreludeDataConUnique 25
 rightDataConKey                         = mkPreludeDataConUnique 26
diff --git a/compiler/prelude/TysWiredIn.hs b/compiler/prelude/TysWiredIn.hs
index 72c24edc3c..0817a75898 100644
--- a/compiler/prelude/TysWiredIn.hs
+++ b/compiler/prelude/TysWiredIn.hs
@@ -95,11 +95,6 @@ module TysWiredIn (
         unicodeStarKindTyCon, unicodeStarKindTyConName,
         liftedTypeKindTyCon, constraintKindTyCon,
 
-        -- * Parallel arrays
-        mkPArrTy,
-        parrTyCon, parrFakeCon, isPArrTyCon, isPArrFakeCon,
-        parrTyCon_RDR, parrTyConName,
-
         -- * Equality predicates
         heqTyCon, heqClass, heqDataCon,
         coercibleTyCon, coercibleTyConName, coercibleDataCon, coercibleClass,
@@ -220,7 +215,6 @@ wiredInTyCons = [ -- Units are not treated like other tuples, because then
                 , word8TyCon
                 , listTyCon
                 , maybeTyCon
-                , parrTyCon
                 , heqTyCon
                 , coercibleTyCon
                 , typeNatKindCon
@@ -445,14 +439,8 @@ vecElemDataConNames = zipWith3Lazy mk_special_dc_name
 mk_special_dc_name :: FastString -> Unique -> DataCon -> Name
 mk_special_dc_name fs u dc = mkWiredInDataConName UserSyntax gHC_TYPES fs u dc
 
-parrTyConName, parrDataConName :: Name
-parrTyConName   = mkWiredInTyConName   BuiltInSyntax
-                    gHC_PARR' (fsLit "[::]") parrTyConKey parrTyCon
-parrDataConName = mkWiredInDataConName UserSyntax
-                    gHC_PARR' (fsLit "PArr") parrDataConKey parrDataCon
-
 boolTyCon_RDR, false_RDR, true_RDR, intTyCon_RDR, charTyCon_RDR,
-    intDataCon_RDR, listTyCon_RDR, consDataCon_RDR, parrTyCon_RDR :: RdrName
+    intDataCon_RDR, listTyCon_RDR, consDataCon_RDR :: RdrName
 boolTyCon_RDR   = nameRdrName boolTyConName
 false_RDR       = nameRdrName falseDataConName
 true_RDR        = nameRdrName trueDataConName
@@ -461,7 +449,6 @@ charTyCon_RDR   = nameRdrName charTyConName
 intDataCon_RDR  = nameRdrName intDataConName
 listTyCon_RDR   = nameRdrName listTyConName
 consDataCon_RDR = nameRdrName consDataConName
-parrTyCon_RDR   = nameRdrName parrTyConName
 
 {-
 ************************************************************************
@@ -692,8 +679,6 @@ isBuiltInOcc_maybe occ =
       "[]" -> Just $ choose_ns listTyConName nilDataConName
       ":"    -> Just consDataConName
 
-      "[::]" -> Just parrTyConName
-
       -- boxed tuple data/tycon
       "()"    -> Just $ tup_name Boxed 0
       _ | Just rest <- "(" `BS.stripPrefix` name
@@ -1518,78 +1503,6 @@ mkSumTy :: [Type] -> Type
 mkSumTy tys = mkTyConApp (sumTyCon (length tys))
                          (map getRuntimeRep tys ++ tys)
 
-{- *********************************************************************
-*                                                                      *
-        The parallel-array type,  [::]
-*                                                                      *
-************************************************************************
-
-Special syntax for parallel arrays needs some wired in definitions.
--}
-
--- | Construct a type representing the application of the parallel array constructor
-mkPArrTy    :: Type -> Type
-mkPArrTy ty  = mkTyConApp parrTyCon [ty]
-
--- | Represents the type constructor of parallel arrays
---
---  * This must match the definition in @PrelPArr@
---
--- NB: Although the constructor is given here, it will not be accessible in
---     user code as it is not in the environment of any compiled module except
---     @PrelPArr@.
---
-parrTyCon :: TyCon
-parrTyCon  = pcTyCon parrTyConName Nothing alpha_tyvar [parrDataCon]
-
-parrDataCon :: DataCon
-parrDataCon  = pcDataCon
-                 parrDataConName
-                 alpha_tyvar            -- forall'ed type variables
-                 [intTy,                -- 1st argument: Int
-                  mkTyConApp            -- 2nd argument: Array# a
-                    arrayPrimTyCon
-                    alpha_ty]
-                 parrTyCon
-
--- | Check whether a type constructor is the constructor for parallel arrays
-isPArrTyCon    :: TyCon -> Bool
-isPArrTyCon tc  = tyConName tc == parrTyConName
-
--- | Fake array constructors
---
--- * These constructors are never really used to represent array values;
---   however, they are very convenient during desugaring (and, in particular,
---   in the pattern matching compiler) to treat array pattern just like
---   yet another constructor pattern
---
-parrFakeCon                        :: Arity -> DataCon
-parrFakeCon i | i > mAX_TUPLE_SIZE  = mkPArrFakeCon  i  -- build one specially
-parrFakeCon i                       = parrFakeConArr!i
-
--- pre-defined set of constructors
---
-parrFakeConArr :: Array Int DataCon
-parrFakeConArr  = array (0, mAX_TUPLE_SIZE) [(i, mkPArrFakeCon i)
-                                            | i <- [0..mAX_TUPLE_SIZE]]
-
--- build a fake parallel array constructor for the given arity
---
-mkPArrFakeCon       :: Int -> DataCon
-mkPArrFakeCon arity  = data_con
-  where
-        data_con  = pcDataCon name [tyvar] tyvarTys parrTyCon
-        tyvar     = head alphaTyVars
-        tyvarTys  = replicate arity $ mkTyVarTy tyvar
-        nameStr   = mkFastString ("MkPArr" ++ show arity)
-        name      = mkWiredInName gHC_PARR' (mkDataOccFS nameStr) unique
-                                  (AConLike (RealDataCon data_con)) UserSyntax
-        unique      = mkPArrDataConUnique arity
-
--- | Checks whether a data constructor is a fake constructor for parallel arrays
-isPArrFakeCon      :: DataCon -> Bool
-isPArrFakeCon dcon  = dcon == parrFakeCon (dataConSourceArity dcon)
-
 -- Promoted Booleans
 
 promotedFalseDataCon, promotedTrueDataCon :: TyCon