{-
(c) The GRASP/AQUA Project, Glasgow University, 1992-1998

-}

{-# LANGUAGE CPP #-}

-- | The @GHC.Builtin.Utils@ interface to the compiler's prelude knowledge.
--
-- This module serves as the central gathering point for names which the
-- compiler knows something about. This includes functions for,
--
--  * discerning whether a 'Name' is known-key
--
--  * given a 'Unique', looking up its corresponding known-key 'Name'
--
-- See Note [Known-key names] and Note [About wired-in things] for information
-- about the two types of prelude things in GHC.
--
module GHC.Builtin.Utils (
        -- * Known-key names
        isKnownKeyName,
        lookupKnownKeyName,
        lookupKnownNameInfo,

        -- ** Internal use
        -- | 'knownKeyNames' is exported to seed the original name cache only;
        -- if you find yourself wanting to look at it you might consider using
        -- 'lookupKnownKeyName' or 'isKnownKeyName'.
        knownKeyNames,

        -- * Miscellaneous
        wiredInIds, ghcPrimIds,
        primOpRules, builtinRules,

        ghcPrimExports,
        ghcPrimDeclDocs,
        primOpId,

        -- * Random other things
        maybeCharLikeCon, maybeIntLikeCon,

        -- * Class categories
        isNumericClass, isStandardClass

    ) where

#include "HsVersions.h"

import GHC.Prelude

import GHC.Builtin.Uniques
import GHC.Types.Unique ( isValidKnownKeyUnique )

import GHC.Core.ConLike ( ConLike(..) )
import GHC.Builtin.Names.TH ( templateHaskellNames )
import GHC.Builtin.Names
import GHC.Core.Opt.ConstantFold
import GHC.Types.Avail
import GHC.Builtin.PrimOps
import GHC.Core.DataCon
import GHC.Types.Basic
import GHC.Types.Id
import GHC.Types.Name
import GHC.Types.Name.Env
import GHC.Types.Id.Make
import GHC.Utils.Outputable
import GHC.Builtin.Types.Prim
import GHC.Builtin.Types
import GHC.Driver.Types
import GHC.Core.Class
import GHC.Core.TyCon
import GHC.Types.Unique.FM
import GHC.Utils.Misc as Utils
import GHC.Builtin.Types.Literals ( typeNatTyCons )
import GHC.Hs.Doc

import Control.Applicative ((<|>))
import Data.List        ( intercalate , find )
import Data.Array
import Data.Maybe
import qualified Data.Map as Map

{-
************************************************************************
*                                                                      *
\subsection[builtinNameInfo]{Lookup built-in names}
*                                                                      *
************************************************************************

Note [About wired-in things]
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
* Wired-in things are Ids\/TyCons that are completely known to the compiler.
  They are global values in GHC, (e.g.  listTyCon :: TyCon).

* A wired-in Name contains the thing itself inside the Name:
        see Name.wiredInNameTyThing_maybe
  (E.g. listTyConName contains listTyCon.

* The name cache is initialised with (the names of) all wired-in things
  (except tuples and sums; see Note [Infinite families of known-key names])

* The type environment itself contains no wired in things. The type
  checker sees if the Name is wired in before looking up the name in
  the type environment.

* GHC.Iface.Make prunes out wired-in things before putting them in an interface file.
  So interface files never contain wired-in things.
-}


-- | This list is used to ensure that when you say "Prelude.map" in your source
-- code, or in an interface file, you get a Name with the correct known key (See
-- Note [Known-key names] in "GHC.Builtin.Names")
knownKeyNames :: [Name]
knownKeyNames :: [Name]
knownKeyNames
  | Bool
debugIsOn
  , Just String
badNamesStr <- [Name] -> Maybe String
knownKeyNamesOkay [Name]
all_names
  = String -> [Name]
forall a. String -> a
panic (String
"badAllKnownKeyNames:\n" String -> String -> String
forall a. [a] -> [a] -> [a]
++ String
badNamesStr)
       -- NB: We can't use ppr here, because this is sometimes evaluated in a
       -- context where there are no DynFlags available, leading to a cryptic
       -- "<<details unavailable>>" error. (This seems to happen only in the
       -- stage 2 compiler, for reasons I [Richard] have no clue of.)
  | Bool
otherwise
  = [Name]
all_names
  where
    all_names :: [Name]
all_names =
      -- We exclude most tuples from this list—see
      -- Note [Infinite families of known-key names] in GHC.Builtin.Names.
      -- We make an exception for Solo (i.e., the boxed 1-tuple), since it does
      -- not use special syntax like other tuples.
      -- See Note [One-tuples] (Wrinkle: Make boxed one-tuple names have known keys)
      -- in GHC.Builtin.Types.
      TupleSort -> Int -> Name
tupleTyConName TupleSort
BoxedTuple Int
1 Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
: Boxity -> Int -> Name
tupleDataConName Boxity
Boxed Int
1 Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
:
      [[Name]] -> [Name]
forall (t :: * -> *) a. Foldable t => t [a] -> [a]
concat [ TyCon -> [Name]
wired_tycon_kk_names TyCon
funTyCon
             , (TyCon -> [Name]) -> [TyCon] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyCon -> [Name]
wired_tycon_kk_names [TyCon]
primTyCons
             , (TyCon -> [Name]) -> [TyCon] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyCon -> [Name]
wired_tycon_kk_names [TyCon]
wiredInTyCons
             , (TyCon -> [Name]) -> [TyCon] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyCon -> [Name]
wired_tycon_kk_names [TyCon]
typeNatTyCons
             , (Id -> Name) -> [Id] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map Id -> Name
idName [Id]
wiredInIds
             , (PrimOp -> Name) -> [PrimOp] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpId) [PrimOp]
allThePrimOps
             , (PrimOp -> Name) -> [PrimOp] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpWrapperId) [PrimOp]
allThePrimOps
             , [Name]
basicKnownKeyNames
             , [Name]
templateHaskellNames
             ]
    -- All of the names associated with a wired-in TyCon.
    -- This includes the TyCon itself, its DataCons and promoted TyCons.
    wired_tycon_kk_names :: TyCon -> [Name]
    wired_tycon_kk_names :: TyCon -> [Name]
wired_tycon_kk_names TyCon
tc =
        TyCon -> Name
tyConName TyCon
tc Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
: (TyCon -> [Name]
rep_names TyCon
tc [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++ [Name]
implicits)
      where implicits :: [Name]
implicits = (TyThing -> [Name]) -> [TyThing] -> [Name]
forall (t :: * -> *) a b. Foldable t => (a -> [b]) -> t a -> [b]
concatMap TyThing -> [Name]
thing_kk_names (TyCon -> [TyThing]
implicitTyConThings TyCon
tc)

    wired_datacon_kk_names :: DataCon -> [Name]
    wired_datacon_kk_names :: DataCon -> [Name]
wired_datacon_kk_names DataCon
dc =
      DataCon -> Name
dataConName DataCon
dc Name -> [Name] -> [Name]
forall a. a -> [a] -> [a]
: TyCon -> [Name]
rep_names (DataCon -> TyCon
promoteDataCon DataCon
dc)

    thing_kk_names :: TyThing -> [Name]
    thing_kk_names :: TyThing -> [Name]
thing_kk_names (ATyCon TyCon
tc)                 = TyCon -> [Name]
wired_tycon_kk_names TyCon
tc
    thing_kk_names (AConLike (RealDataCon DataCon
dc)) = DataCon -> [Name]
wired_datacon_kk_names DataCon
dc
    thing_kk_names TyThing
thing                       = [TyThing -> Name
forall a. NamedThing a => a -> Name
getName TyThing
thing]

    -- The TyConRepName for a known-key TyCon has a known key,
    -- but isn't itself an implicit thing.  Yurgh.
    -- NB: if any of the wired-in TyCons had record fields, the record
    --     field names would be in a similar situation.  Ditto class ops.
    --     But it happens that there aren't any
    rep_names :: TyCon -> [Name]
rep_names TyCon
tc = case TyCon -> Maybe Name
tyConRepName_maybe TyCon
tc of
                        Just Name
n  -> [Name
n]
                        Maybe Name
Nothing -> []

-- | Check the known-key names list of consistency.
knownKeyNamesOkay :: [Name] -> Maybe String
knownKeyNamesOkay :: [Name] -> Maybe String
knownKeyNamesOkay [Name]
all_names
  | ns :: [Name]
ns@(Name
_:[Name]
_) <- (Name -> Bool) -> [Name] -> [Name]
forall a. (a -> Bool) -> [a] -> [a]
filter (Bool -> Bool
not (Bool -> Bool) -> (Name -> Bool) -> Name -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Unique -> Bool
isValidKnownKeyUnique (Unique -> Bool) -> (Name -> Unique) -> Name -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> Unique
forall a. Uniquable a => a -> Unique
getUnique) [Name]
all_names
  = String -> Maybe String
forall a. a -> Maybe a
Just (String -> Maybe String) -> String -> Maybe String
forall a b. (a -> b) -> a -> b
$ String
"    Out-of-range known-key uniques: ["
        String -> String -> String
forall a. [a] -> [a] -> [a]
++ String -> [String] -> String
forall a. [a] -> [[a]] -> [a]
intercalate String
", " ((Name -> String) -> [Name] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map (OccName -> String
occNameString (OccName -> String) -> (Name -> OccName) -> Name -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> OccName
nameOccName) [Name]
ns) String -> String -> String
forall a. [a] -> [a] -> [a]
++
         String
"]"
  | [(Unique, [Name])] -> Bool
forall (t :: * -> *) a. Foldable t => t a -> Bool
null [(Unique, [Name])]
badNamesPairs
  = Maybe String
forall a. Maybe a
Nothing
  | Bool
otherwise
  = String -> Maybe String
forall a. a -> Maybe a
Just String
badNamesStr
  where
    namesEnv :: NameEnv [Name]
namesEnv      = (NameEnv [Name] -> Name -> NameEnv [Name])
-> NameEnv [Name] -> [Name] -> NameEnv [Name]
forall (t :: * -> *) b a.
Foldable t =>
(b -> a -> b) -> b -> t a -> b
foldl' (\NameEnv [Name]
m Name
n -> (Name -> [Name] -> [Name])
-> (Name -> [Name])
-> NameEnv [Name]
-> Name
-> Name
-> NameEnv [Name]
forall a b.
(a -> b -> b) -> (a -> b) -> NameEnv b -> Name -> a -> NameEnv b
extendNameEnv_Acc (:) Name -> [Name]
forall a. a -> [a]
Utils.singleton NameEnv [Name]
m Name
n Name
n)
                           NameEnv [Name]
forall key elt. UniqFM key elt
emptyUFM [Name]
all_names
    badNamesEnv :: NameEnv [Name]
badNamesEnv   = ([Name] -> Bool) -> NameEnv [Name] -> NameEnv [Name]
forall elt. (elt -> Bool) -> NameEnv elt -> NameEnv elt
filterNameEnv (\[Name]
ns -> [Name]
ns [Name] -> Int -> Bool
forall a. [a] -> Int -> Bool
`lengthExceeds` Int
1) NameEnv [Name]
namesEnv
    badNamesPairs :: [(Unique, [Name])]
badNamesPairs = NameEnv [Name] -> [(Unique, [Name])]
forall key elt. UniqFM key elt -> [(Unique, elt)]
nonDetUFMToList NameEnv [Name]
badNamesEnv
      -- It's OK to use nonDetUFMToList here because the ordering only affects
      -- the message when we get a panic
    badNamesStrs :: [String]
badNamesStrs  = ((Unique, [Name]) -> String) -> [(Unique, [Name])] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map (Unique, [Name]) -> String
forall {a}. Show a => (a, [Name]) -> String
pairToStr [(Unique, [Name])]
badNamesPairs
    badNamesStr :: String
badNamesStr   = [String] -> String
unlines [String]
badNamesStrs

    pairToStr :: (a, [Name]) -> String
pairToStr (a
uniq, [Name]
ns) = String
"        " String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           a -> String
forall a. Show a => a -> String
show a
uniq String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           String
": [" String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           String -> [String] -> String
forall a. [a] -> [[a]] -> [a]
intercalate String
", " ((Name -> String) -> [Name] -> [String]
forall a b. (a -> b) -> [a] -> [b]
map (OccName -> String
occNameString (OccName -> String) -> (Name -> OccName) -> Name -> String
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> OccName
nameOccName) [Name]
ns) String -> String -> String
forall a. [a] -> [a] -> [a]
++
                           String
"]"

-- | Given a 'Unique' lookup its associated 'Name' if it corresponds to a
-- known-key thing.
lookupKnownKeyName :: Unique -> Maybe Name
lookupKnownKeyName :: Unique -> Maybe Name
lookupKnownKeyName Unique
u =
    Unique -> Maybe Name
knownUniqueName Unique
u Maybe Name -> Maybe Name -> Maybe Name
forall (f :: * -> *) a. Alternative f => f a -> f a -> f a
<|> UniqFM Name Name -> Unique -> Maybe Name
forall key elt. UniqFM key elt -> Unique -> Maybe elt
lookupUFM_Directly UniqFM Name Name
knownKeysMap Unique
u

-- | Is a 'Name' known-key?
isKnownKeyName :: Name -> Bool
isKnownKeyName :: Name -> Bool
isKnownKeyName Name
n =
    Maybe Name -> Bool
forall a. Maybe a -> Bool
isJust (Unique -> Maybe Name
knownUniqueName (Unique -> Maybe Name) -> Unique -> Maybe Name
forall a b. (a -> b) -> a -> b
$ Name -> Unique
nameUnique Name
n) Bool -> Bool -> Bool
|| Name -> UniqFM Name Name -> Bool
forall key elt. Uniquable key => key -> UniqFM key elt -> Bool
elemUFM Name
n UniqFM Name Name
knownKeysMap

-- | Maps 'Unique's to known-key names.
--
-- The type is @UniqFM Name Name@ to denote that the 'Unique's used
-- in the domain are 'Unique's associated with 'Name's (as opposed
-- to some other namespace of 'Unique's).
knownKeysMap :: UniqFM Name Name
knownKeysMap :: UniqFM Name Name
knownKeysMap = [Name] -> UniqFM Name Name
forall key. Uniquable key => [key] -> UniqFM key key
listToIdentityUFM [Name]
knownKeyNames

-- | Given a 'Unique' lookup any associated arbitrary SDoc's to be displayed by
-- GHCi's ':info' command.
lookupKnownNameInfo :: Name -> SDoc
lookupKnownNameInfo :: Name -> SDoc
lookupKnownNameInfo Name
name = case NameEnv SDoc -> Name -> Maybe SDoc
forall a. NameEnv a -> Name -> Maybe a
lookupNameEnv NameEnv SDoc
knownNamesInfo Name
name of
    -- If we do find a doc, we add comment delimiters to make the output
    -- of ':info' valid Haskell.
    Maybe SDoc
Nothing  -> SDoc
empty
    Just SDoc
doc -> [SDoc] -> SDoc
vcat [String -> SDoc
text String
"{-", SDoc
doc, String -> SDoc
text String
"-}"]

-- A map from Uniques to SDocs, used in GHCi's ':info' command. (#12390)
knownNamesInfo :: NameEnv SDoc
knownNamesInfo :: NameEnv SDoc
knownNamesInfo = Name -> SDoc -> NameEnv SDoc
forall a. Name -> a -> NameEnv a
unitNameEnv Name
coercibleTyConName (SDoc -> NameEnv SDoc) -> SDoc -> NameEnv SDoc
forall a b. (a -> b) -> a -> b
$
    [SDoc] -> SDoc
vcat [ String -> SDoc
text String
"Coercible is a special constraint with custom solving rules."
         , String -> SDoc
text String
"It is not a class."
         , String -> SDoc
text String
"Please see section `The Coercible constraint`"
         , String -> SDoc
text String
"of the user's guide for details." ]

{-
We let a lot of "non-standard" values be visible, so that we can make
sense of them in interface pragmas. It's cool, though they all have
"non-standard" names, so they won't get past the parser in user code.

************************************************************************
*                                                                      *
                PrimOpIds
*                                                                      *
************************************************************************
-}

primOpIds :: Array Int Id
-- A cache of the PrimOp Ids, indexed by PrimOp tag
primOpIds :: Array Int Id
primOpIds = (Int, Int) -> [(Int, Id)] -> Array Int Id
forall i e. Ix i => (i, i) -> [(i, e)] -> Array i e
array (Int
1,Int
maxPrimOpTag) [ (PrimOp -> Int
primOpTag PrimOp
op, PrimOp -> Id
mkPrimOpId PrimOp
op)
                                   | PrimOp
op <- [PrimOp]
allThePrimOps ]

primOpId :: PrimOp -> Id
primOpId :: PrimOp -> Id
primOpId PrimOp
op = Array Int Id
primOpIds Array Int Id -> Int -> Id
forall i e. Ix i => Array i e -> i -> e
! PrimOp -> Int
primOpTag PrimOp
op

{-
************************************************************************
*                                                                      *
            Export lists for pseudo-modules (GHC.Prim)
*                                                                      *
************************************************************************

GHC.Prim "exports" all the primops and primitive types, some
wired-in Ids.
-}

ghcPrimExports :: [IfaceExport]
ghcPrimExports :: [IfaceExport]
ghcPrimExports
 = (Id -> IfaceExport) -> [Id] -> [IfaceExport]
forall a b. (a -> b) -> [a] -> [b]
map (Name -> IfaceExport
avail (Name -> IfaceExport) -> (Id -> Name) -> Id -> IfaceExport
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> Name
idName) [Id]
ghcPrimIds [IfaceExport] -> [IfaceExport] -> [IfaceExport]
forall a. [a] -> [a] -> [a]
++
   (PrimOp -> IfaceExport) -> [PrimOp] -> [IfaceExport]
forall a b. (a -> b) -> [a] -> [b]
map (Name -> IfaceExport
avail (Name -> IfaceExport) -> (PrimOp -> Name) -> PrimOp -> IfaceExport
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpId) [PrimOp]
allThePrimOps [IfaceExport] -> [IfaceExport] -> [IfaceExport]
forall a. [a] -> [a] -> [a]
++
   [ Name -> [Name] -> [FieldLabel] -> IfaceExport
AvailTC Name
n [Name
n] []
   | TyCon
tc <- TyCon
funTyCon TyCon -> [TyCon] -> [TyCon]
forall a. a -> [a] -> [a]
: [TyCon]
exposedPrimTyCons, let n :: Name
n = TyCon -> Name
tyConName TyCon
tc  ]

ghcPrimDeclDocs :: DeclDocMap
ghcPrimDeclDocs :: DeclDocMap
ghcPrimDeclDocs = Map Name HsDocString -> DeclDocMap
DeclDocMap (Map Name HsDocString -> DeclDocMap)
-> Map Name HsDocString -> DeclDocMap
forall a b. (a -> b) -> a -> b
$ [(Name, HsDocString)] -> Map Name HsDocString
forall k a. Ord k => [(k, a)] -> Map k a
Map.fromList ([(Name, HsDocString)] -> Map Name HsDocString)
-> [(Name, HsDocString)] -> Map Name HsDocString
forall a b. (a -> b) -> a -> b
$ ((String, String) -> Maybe (Name, HsDocString))
-> [(String, String)] -> [(Name, HsDocString)]
forall a b. (a -> Maybe b) -> [a] -> [b]
mapMaybe (String, String) -> Maybe (Name, HsDocString)
findName [(String, String)]
primOpDocs
  where
    names :: [Name]
names = (Id -> Name) -> [Id] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map Id -> Name
idName [Id]
ghcPrimIds [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++
            (PrimOp -> Name) -> [PrimOp] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map (Id -> Name
idName (Id -> Name) -> (PrimOp -> Id) -> PrimOp -> Name
forall b c a. (b -> c) -> (a -> b) -> a -> c
. PrimOp -> Id
primOpId) [PrimOp]
allThePrimOps [Name] -> [Name] -> [Name]
forall a. [a] -> [a] -> [a]
++
            (TyCon -> Name) -> [TyCon] -> [Name]
forall a b. (a -> b) -> [a] -> [b]
map TyCon -> Name
tyConName (TyCon
funTyCon TyCon -> [TyCon] -> [TyCon]
forall a. a -> [a] -> [a]
: [TyCon]
exposedPrimTyCons)
    findName :: (String, String) -> Maybe (Name, HsDocString)
findName (String
nameStr, String
doc)
      | Just Name
name <- (Name -> Bool) -> [Name] -> Maybe Name
forall (t :: * -> *) a. Foldable t => (a -> Bool) -> t a -> Maybe a
find ((String
nameStr String -> String -> Bool
forall a. Eq a => a -> a -> Bool
==) (String -> Bool) -> (Name -> String) -> Name -> Bool
forall b c a. (b -> c) -> (a -> b) -> a -> c
. Name -> String
forall a. NamedThing a => a -> String
getOccString) [Name]
names
      = (Name, HsDocString) -> Maybe (Name, HsDocString)
forall a. a -> Maybe a
Just (Name
name, String -> HsDocString
mkHsDocString String
doc)
      | Bool
otherwise = Maybe (Name, HsDocString)
forall a. Maybe a
Nothing

{-
************************************************************************
*                                                                      *
            Built-in keys
*                                                                      *
************************************************************************

ToDo: make it do the ``like'' part properly (as in 0.26 and before).
-}

maybeCharLikeCon, maybeIntLikeCon :: DataCon -> Bool
maybeCharLikeCon :: DataCon -> Bool
maybeCharLikeCon DataCon
con = DataCon
con DataCon -> Unique -> Bool
forall a. Uniquable a => a -> Unique -> Bool
`hasKey` Unique
charDataConKey
maybeIntLikeCon :: DataCon -> Bool
maybeIntLikeCon  DataCon
con = DataCon
con DataCon -> Unique -> Bool
forall a. Uniquable a => a -> Unique -> Bool
`hasKey` Unique
intDataConKey

{-
************************************************************************
*                                                                      *
            Class predicates
*                                                                      *
************************************************************************
-}

isNumericClass, isStandardClass :: Class -> Bool

isNumericClass :: Class -> Bool
isNumericClass     Class
clas = Class -> Unique
classKey Class
clas Unique -> [Unique] -> Bool
forall a. Eq a => a -> [a] -> Bool
`is_elem` [Unique]
numericClassKeys
isStandardClass :: Class -> Bool
isStandardClass    Class
clas = Class -> Unique
classKey Class
clas Unique -> [Unique] -> Bool
forall a. Eq a => a -> [a] -> Bool
`is_elem` [Unique]
standardClassKeys

is_elem :: Eq a => a -> [a] -> Bool
is_elem :: forall a. Eq a => a -> [a] -> Bool
is_elem = String -> a -> [a] -> Bool
forall a. Eq a => String -> a -> [a] -> Bool
isIn String
"is_X_Class"