    {-# LANGUAGE CPP #-}
    {-# LANGUAGE MonadComprehensions #-}
    {-# LANGUAGE OverloadedLists #-}
    {-# LANGUAGE TypeFamilies #-}

    {-# OPTIONS_GHC -Wno-incomplete-uni-patterns   #-}
    {-# OPTIONS_GHC -Wno-incomplete-record-updates #-}

    {-
    (c) The University of Glasgow 2006
    (c) The GRASP/AQUA Project, Glasgow University, 1992-1998

    The @match@ function
    -}

    module GHC.HsToCore.Match
       ( match, matchEquations, matchWrapper, matchSimply
       , matchSinglePat, matchSinglePatVar
       )
    where

    #include "HsVersions.h"

    import GHC.Prelude
    import GHC.Platform

    import {-#SOURCE#-} GHC.HsToCore.Expr (dsLExpr, dsSyntaxExpr)

    import GHC.Types.Basic ( Origin(..), isGenerated, Boxity(..) )
    import GHC.Types.SourceText
    import GHC.Driver.Session
    import GHC.Hs
    import GHC.Tc.Utils.Zonk
    import GHC.Tc.Types.Evidence
    import GHC.Tc.Utils.Monad
    import GHC.HsToCore.Pmc
    import GHC.HsToCore.Pmc.Types ( Nablas, initNablas )
    import GHC.Core
    import GHC.Types.Literal
    import GHC.Core.Utils
    import GHC.Core.Make
    import GHC.HsToCore.Monad
    import GHC.HsToCore.Binds
    import GHC.HsToCore.GuardedRHSs
    import GHC.HsToCore.Utils
    import GHC.Types.Id
    import GHC.Core.ConLike
    import GHC.Core.DataCon
    import GHC.Core.PatSyn
    import GHC.HsToCore.Match.Constructor
    import GHC.HsToCore.Match.Literal
    import GHC.Core.Type
    import GHC.Core.Coercion ( eqCoercion )
    import GHC.Core.TyCon    ( isNewTyCon )
    import GHC.Core.Multiplicity
    import GHC.Builtin.Types
    import GHC.Types.SrcLoc
    import GHC.Data.Maybe
    import GHC.Utils.Misc
    import GHC.Types.Name
    import GHC.Utils.Outputable
    import GHC.Utils.Panic
    import GHC.Data.FastString
    import GHC.Types.Unique
    import GHC.Types.Unique.DFM

    import Control.Monad ( zipWithM, unless, when )
    import Data.List.NonEmpty (NonEmpty(..))
    import qualified Data.List.NonEmpty as NEL
    import qualified Data.Map as Map

    {-
    ************************************************************************
    *                                                                      *
                    The main matching function
    *                                                                      *
    ************************************************************************

    The function @match@ is basically the same as in the Wadler chapter
    from "The Implementation of Functional Programming Languages",
    except it is monadised, to carry around the name supply, info about
    annotations, etc.

    Notes on @match@'s arguments, assuming $m$ equations and $n$ patterns:
    \begin{enumerate}
    \item
    A list of $n$ variable names, those variables presumably bound to the
    $n$ expressions being matched against the $n$ patterns.  Using the
    list of $n$ expressions as the first argument showed no benefit and
    some inelegance.

    \item
    The second argument, a list giving the ``equation info'' for each of
    the $m$ equations:
    \begin{itemize}
    \item
    the $n$ patterns for that equation, and
    \item
    a list of Core bindings [@(Id, CoreExpr)@ pairs] to be ``stuck on
    the front'' of the matching code, as in:
    \begin{verbatim}
    let <binds>
    in  <matching-code>
    \end{verbatim}
    \item
    and finally: (ToDo: fill in)

    The right way to think about the ``after-match function'' is that it
    is an embryonic @CoreExpr@ with a ``hole'' at the end for the
    final ``else expression''.
    \end{itemize}

    There is a data type, @EquationInfo@, defined in module @GHC.HsToCore.Monad@.

    An experiment with re-ordering this information about equations (in
    particular, having the patterns available in column-major order)
    showed no benefit.

    \item
    A default expression---what to evaluate if the overall pattern-match
    fails.  This expression will (almost?) always be
    a measly expression @Var@, unless we know it will only be used once
    (as we do in @glue_success_exprs@).

    Leaving out this third argument to @match@ (and slamming in lots of
    @Var "fail"@s) is a positively {\em bad} idea, because it makes it
    impossible to share the default expressions.  (Also, it stands no
    chance of working in our post-upheaval world of @Locals@.)
    \end{enumerate}

    Note: @match@ is often called via @matchWrapper@ (end of this module),
    a function that does much of the house-keeping that goes with a call
    to @match@.

    It is also worth mentioning the {\em typical} way a block of equations
    is desugared with @match@.  At each stage, it is the first column of
    patterns that is examined.  The steps carried out are roughly:
    \begin{enumerate}
    \item
    Tidy the patterns in column~1 with @tidyEqnInfo@ (this may add
    bindings to the second component of the equation-info):
    \item
    Now {\em unmix} the equations into {\em blocks} [w\/ local function
    @match_groups@], in which the equations in a block all have the same
     match group.
    (see ``the mixture rule'' in SLPJ).
    \item
    Call the right match variant on each block of equations; it will do the
    appropriate thing for each kind of column-1 pattern.
    \end{enumerate}

    We are a little more paranoid about the ``empty rule'' (SLPJ, p.~87)
    than the Wadler-chapter code for @match@ (p.~93, first @match@ clause).
    And gluing the ``success expressions'' together isn't quite so pretty.

    This  @match@ uses @tidyEqnInfo@
    to get `as'- and `twiddle'-patterns out of the way (tidying), before
    applying ``the mixture rule'' (SLPJ, p.~88) [which really {\em
    un}mixes the equations], producing a list of equation-info
    blocks, each block having as its first column patterns compatible with each other.

    Note [Match Ids]
    ~~~~~~~~~~~~~~~~
    Most of the matching functions take an Id or [Id] as argument.  This Id
    is the scrutinee(s) of the match. The desugared expression may
    sometimes use that Id in a local binding or as a case binder.  So it
    should not have an External name; Lint rejects non-top-level binders
    with External names (#13043).

    See also Note [Localise pattern binders] in GHC.HsToCore.Utils
    -}

    type MatchId = Id   -- See Note [Match Ids]

    match :: [MatchId]        -- ^ Variables rep\'ing the exprs we\'re matching with
                              -- ^ See Note [Match Ids]
                              --
                              -- ^ Note that the Match Ids carry not only a name, but
                              -- ^ also the multiplicity at which each column has been
                              -- ^ type checked.
          -> Type             -- ^ Type of the case expression
          -> [EquationInfo]   -- ^ Info about patterns, etc. (type synonym below)
          -> DsM (MatchResult CoreExpr) -- ^ Desugared result!

    match :: [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match [] Kind
    ty [EquationInfo]
    eqns
      = ASSERT2( not (null eqns), ppr ty )
        MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ((MatchResult CoreExpr
     -> MatchResult CoreExpr -> MatchResult CoreExpr)
    -> [MatchResult CoreExpr] -> MatchResult CoreExpr
    forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
    foldr1 MatchResult CoreExpr
    -> MatchResult CoreExpr -> MatchResult CoreExpr
    combineMatchResults [MatchResult CoreExpr]
    match_results)
      where
        match_results :: [MatchResult CoreExpr]
    match_results = [ ASSERT( null (eqn_pats eqn) )
                          EquationInfo -> MatchResult CoreExpr
    eqn_rhs EquationInfo
    eqn
                        | EquationInfo
    eqn <- [EquationInfo]
    eqns ]

    match (Id
    v:[Id]
    vs) Kind
    ty [EquationInfo]
    eqns    -- Eqns *can* be empty
      = ASSERT2( all (isInternalName . idName) vars, ppr vars )
        do  { DynFlags
    dflags <- IOEnv (Env DsGblEnv DsLclEnv) DynFlags
    forall (m :: * -> *). HasDynFlags m => m DynFlags
    getDynFlags
            ; let platform :: Platform
    platform = DynFlags -> Platform
    targetPlatform DynFlags
    dflags
                    -- Tidy the first pattern, generating
                    -- auxiliary bindings if necessary
            ; ([DsWrapper]
    aux_binds, [EquationInfo]
    tidy_eqns) <- (EquationInfo
     -> IOEnv (Env DsGblEnv DsLclEnv) (DsWrapper, EquationInfo))
    -> [EquationInfo]
    -> IOEnv (Env DsGblEnv DsLclEnv) ([DsWrapper], [EquationInfo])
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> m (b, c)) -> [a] -> m ([b], [c])
    mapAndUnzipM (Id
    -> EquationInfo
    -> IOEnv (Env DsGblEnv DsLclEnv) (DsWrapper, EquationInfo)
    tidyEqnInfo Id
    v) [EquationInfo]
    eqns
                    -- Group the equations and match each group in turn
            ; let grouped :: [NonEmpty (PatGroup, EquationInfo)]
    grouped = Platform -> [EquationInfo] -> [NonEmpty (PatGroup, EquationInfo)]
    groupEquations Platform
    platform [EquationInfo]
    tidy_eqns

             -- print the view patterns that are commoned up to help debug
            ; DumpFlag
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall gbl lcl. DumpFlag -> TcRnIf gbl lcl () -> TcRnIf gbl lcl ()
    whenDOptM DumpFlag
    Opt_D_dump_view_pattern_commoning ([NonEmpty (PatGroup, EquationInfo)] -> TcRnIf DsGblEnv DsLclEnv ()
    forall {t :: * -> *} {b}.
    Foldable t =>
    [t (PatGroup, b)] -> TcRnIf DsGblEnv DsLclEnv ()
    debug [NonEmpty (PatGroup, EquationInfo)]
    grouped)

            ; NonEmpty (MatchResult CoreExpr)
    match_results <- [NonEmpty (PatGroup, EquationInfo)]
    -> DsM (NonEmpty (MatchResult CoreExpr))
    match_groups [NonEmpty (PatGroup, EquationInfo)]
    grouped
            ; MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (MatchResult CoreExpr -> DsM (MatchResult CoreExpr))
    -> MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ (DsWrapper -> DsWrapper -> DsWrapper)
    -> DsWrapper -> [DsWrapper] -> DsWrapper
    forall (t :: * -> *) a b.
    Foldable t =>
    (a -> b -> b) -> b -> t a -> b
    foldr DsWrapper -> DsWrapper -> DsWrapper
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    (.) DsWrapper
    forall a. a -> a
    id [DsWrapper]
    aux_binds DsWrapper -> MatchResult CoreExpr -> MatchResult CoreExpr
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$>
                (MatchResult CoreExpr
     -> MatchResult CoreExpr -> MatchResult CoreExpr)
    -> NonEmpty (MatchResult CoreExpr) -> MatchResult CoreExpr
    forall (t :: * -> *) a. Foldable t => (a -> a -> a) -> t a -> a
    foldr1 MatchResult CoreExpr
    -> MatchResult CoreExpr -> MatchResult CoreExpr
    combineMatchResults NonEmpty (MatchResult CoreExpr)
    match_results
            }
      where
        vars :: NonEmpty Id
    vars = Id
    v Id -> [Id] -> NonEmpty Id
    forall a. a -> [a] -> NonEmpty a
    :| [Id]
    vs

        dropGroup :: Functor f => f (PatGroup,EquationInfo) -> f EquationInfo
        dropGroup :: forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup = ((PatGroup, EquationInfo) -> EquationInfo)
    -> f (PatGroup, EquationInfo) -> f EquationInfo
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap (PatGroup, EquationInfo) -> EquationInfo
    forall a b. (a, b) -> b
    snd

        match_groups :: [NonEmpty (PatGroup,EquationInfo)] -> DsM (NonEmpty (MatchResult CoreExpr))
        -- Result list of [MatchResult CoreExpr] is always non-empty
        match_groups :: [NonEmpty (PatGroup, EquationInfo)]
    -> DsM (NonEmpty (MatchResult CoreExpr))
    match_groups [] = Id -> Kind -> DsM (NonEmpty (MatchResult CoreExpr))
    matchEmpty Id
    v Kind
    ty
        match_groups (NonEmpty (PatGroup, EquationInfo)
    g:[NonEmpty (PatGroup, EquationInfo)]
    gs) = (NonEmpty (PatGroup, EquationInfo) -> DsM (MatchResult CoreExpr))
    -> NonEmpty (NonEmpty (PatGroup, EquationInfo))
    -> DsM (NonEmpty (MatchResult CoreExpr))
    forall (t :: * -> *) (m :: * -> *) a b.
    (Traversable t, Monad m) =>
    (a -> m b) -> t a -> m (t b)
    mapM NonEmpty (PatGroup, EquationInfo) -> DsM (MatchResult CoreExpr)
    match_group (NonEmpty (NonEmpty (PatGroup, EquationInfo))
     -> DsM (NonEmpty (MatchResult CoreExpr)))
    -> NonEmpty (NonEmpty (PatGroup, EquationInfo))
    -> DsM (NonEmpty (MatchResult CoreExpr))
    forall a b. (a -> b) -> a -> b
    $ NonEmpty (PatGroup, EquationInfo)
    g NonEmpty (PatGroup, EquationInfo)
    -> [NonEmpty (PatGroup, EquationInfo)]
    -> NonEmpty (NonEmpty (PatGroup, EquationInfo))
    forall a. a -> [a] -> NonEmpty a
    :| [NonEmpty (PatGroup, EquationInfo)]
    gs

        match_group :: NonEmpty (PatGroup,EquationInfo) -> DsM (MatchResult CoreExpr)
        match_group :: NonEmpty (PatGroup, EquationInfo) -> DsM (MatchResult CoreExpr)
    match_group eqns :: NonEmpty (PatGroup, EquationInfo)
    eqns@((PatGroup
    group,EquationInfo
    _) :| [(PatGroup, EquationInfo)]
    _)
            = case PatGroup
    group of
                PgCon {}  -> NonEmpty Id
    -> Kind
    -> NonEmpty (NonEmpty EquationInfo)
    -> DsM (MatchResult CoreExpr)
    matchConFamily  NonEmpty Id
    vars Kind
    ty ([NonEmpty EquationInfo] -> NonEmpty (NonEmpty EquationInfo)
    forall {a}. [a] -> NonEmpty a
    ne ([NonEmpty EquationInfo] -> NonEmpty (NonEmpty EquationInfo))
    -> [NonEmpty EquationInfo] -> NonEmpty (NonEmpty EquationInfo)
    forall a b. (a -> b) -> a -> b
    $ [(DataCon, EquationInfo)] -> [NonEmpty EquationInfo]
    forall a.
    Uniquable a =>
    [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    subGroupUniq [(DataCon
    c,EquationInfo
    e) | (PgCon DataCon
    c, EquationInfo
    e) <- [(PatGroup, EquationInfo)]
    eqns'])
                PgSyn {}  -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchPatSyn     NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PgLit {}  -> NonEmpty Id
    -> Kind
    -> NonEmpty (NonEmpty EquationInfo)
    -> DsM (MatchResult CoreExpr)
    matchLiterals   NonEmpty Id
    vars Kind
    ty ([NonEmpty EquationInfo] -> NonEmpty (NonEmpty EquationInfo)
    forall {a}. [a] -> NonEmpty a
    ne ([NonEmpty EquationInfo] -> NonEmpty (NonEmpty EquationInfo))
    -> [NonEmpty EquationInfo] -> NonEmpty (NonEmpty EquationInfo)
    forall a b. (a -> b) -> a -> b
    $ [(Literal, EquationInfo)] -> [NonEmpty EquationInfo]
    forall a. Ord a => [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    subGroupOrd [(Literal
    l,EquationInfo
    e) | (PgLit Literal
    l, EquationInfo
    e) <- [(PatGroup, EquationInfo)]
    eqns'])
                PatGroup
    PgAny     -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchVariables  NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PgN {}    -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchNPats      NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PgOverS {}-> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchNPats      NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PgNpK {}  -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchNPlusKPats NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PatGroup
    PgBang    -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchBangs      NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PgCo {}   -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchCoercion   NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PgView {} -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchView       NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
                PatGroup
    PgOverloadedList -> NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchOverloadedList NonEmpty Id
    vars Kind
    ty (NonEmpty (PatGroup, EquationInfo) -> NonEmpty EquationInfo
    forall (f :: * -> *).
    Functor f =>
    f (PatGroup, EquationInfo) -> f EquationInfo
    dropGroup NonEmpty (PatGroup, EquationInfo)
    eqns)
          where eqns' :: [(PatGroup, EquationInfo)]
    eqns' = NonEmpty (PatGroup, EquationInfo) -> [(PatGroup, EquationInfo)]
    forall a. NonEmpty a -> [a]
    NEL.toList NonEmpty (PatGroup, EquationInfo)
    eqns
                ne :: [a] -> NonEmpty a
    ne [a]
    l = case [a] -> Maybe (NonEmpty a)
    forall a. [a] -> Maybe (NonEmpty a)
    NEL.nonEmpty [a]
    l of
                  Just NonEmpty a
    nel -> NonEmpty a
    nel
                  Maybe (NonEmpty a)
    Nothing -> String -> SDoc -> NonEmpty a
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "match match_group" (SDoc -> NonEmpty a) -> SDoc -> NonEmpty a
    forall a b. (a -> b) -> a -> b
    $ String -> SDoc
    text String
    "Empty result should be impossible since input was non-empty"

        -- FIXME: we should also warn about view patterns that should be
        -- commoned up but are not

        -- print some stuff to see what's getting grouped
        -- use -dppr-debug to see the resolution of overloaded literals
        debug :: [t (PatGroup, b)] -> TcRnIf DsGblEnv DsLclEnv ()
    debug [t (PatGroup, b)]
    eqns =
            let gs :: [[GenLocated SrcSpanAnnA (HsExpr GhcTc)]]
    gs = (t (PatGroup, b) -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)])
    -> [t (PatGroup, b)] -> [[GenLocated SrcSpanAnnA (HsExpr GhcTc)]]
    forall a b. (a -> b) -> [a] -> [b]
    map (\t (PatGroup, b)
    group -> ((PatGroup, b)
     -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
     -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)])
    -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    -> t (PatGroup, b)
    -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    forall (t :: * -> *) a b.
    Foldable t =>
    (a -> b -> b) -> b -> t a -> b
    foldr (\ (PatGroup
    p,b
    _) -> \[GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    acc ->
                                               case PatGroup
    p of PgView LHsExpr GhcTc
    e Kind
    _ -> GenLocated SrcSpanAnnA (HsExpr GhcTc)
    LHsExpr GhcTc
    eGenLocated SrcSpanAnnA (HsExpr GhcTc)
    -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    forall a. a -> [a] -> [a]
    :[GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    acc
                                                         PatGroup
    _ -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    acc) [] t (PatGroup, b)
    group) [t (PatGroup, b)]
    eqns
                maybeWarn :: [SDoc] -> TcRnIf DsGblEnv DsLclEnv ()
    maybeWarn [] = () -> TcRnIf DsGblEnv DsLclEnv ()
    forall (m :: * -> *) a. Monad m => a -> m a
    return ()
                maybeWarn [SDoc]
    l = WarnReason -> SDoc -> TcRnIf DsGblEnv DsLclEnv ()
    warnDs WarnReason
    NoReason ([SDoc] -> SDoc
    vcat [SDoc]
    l)
            in
              [SDoc] -> TcRnIf DsGblEnv DsLclEnv ()
    maybeWarn ([SDoc] -> TcRnIf DsGblEnv DsLclEnv ())
    -> [SDoc] -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $ (([GenLocated SrcSpanAnnA (HsExpr GhcTc)] -> SDoc)
    -> [[GenLocated SrcSpanAnnA (HsExpr GhcTc)]] -> [SDoc]
    forall a b. (a -> b) -> [a] -> [b]
    map (\[GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    g -> String -> SDoc
    text String
    "Putting these view expressions into the same case:" SDoc -> SDoc -> SDoc
    <+> ([GenLocated SrcSpanAnnA (HsExpr GhcTc)] -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    g))
                           (([GenLocated SrcSpanAnnA (HsExpr GhcTc)] -> Bool)
    -> [[GenLocated SrcSpanAnnA (HsExpr GhcTc)]]
    -> [[GenLocated SrcSpanAnnA (HsExpr GhcTc)]]
    forall a. (a -> Bool) -> [a] -> [a]
    filter (Bool -> Bool
    not (Bool -> Bool)
    -> ([GenLocated SrcSpanAnnA (HsExpr GhcTc)] -> Bool)
    -> [GenLocated SrcSpanAnnA (HsExpr GhcTc)]
    -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . [GenLocated SrcSpanAnnA (HsExpr GhcTc)] -> Bool
    forall (t :: * -> *) a. Foldable t => t a -> Bool
    null) [[GenLocated SrcSpanAnnA (HsExpr GhcTc)]]
    gs))

    matchEmpty :: MatchId -> Type -> DsM (NonEmpty (MatchResult CoreExpr))
    -- See Note [Empty case expressions]
    matchEmpty :: Id -> Kind -> DsM (NonEmpty (MatchResult CoreExpr))
    matchEmpty Id
    var Kind
    res_ty
      = NonEmpty (MatchResult CoreExpr)
    -> DsM (NonEmpty (MatchResult CoreExpr))
    forall (m :: * -> *) a. Monad m => a -> m a
    return [(CoreExpr -> DsM CoreExpr) -> MatchResult CoreExpr
    forall a. (CoreExpr -> DsM a) -> MatchResult a
    MR_Fallible CoreExpr -> DsM CoreExpr
    mk_seq]
      where
        mk_seq :: CoreExpr -> DsM CoreExpr
    mk_seq CoreExpr
    fail = CoreExpr -> DsM CoreExpr
    forall (m :: * -> *) a. Monad m => a -> m a
    return (CoreExpr -> DsM CoreExpr) -> CoreExpr -> DsM CoreExpr
    forall a b. (a -> b) -> a -> b
    $ CoreExpr -> Scaled Kind -> Kind -> [CoreAlt] -> CoreExpr
    mkWildCase (Id -> CoreExpr
    forall b. Id -> Expr b
    Var Id
    var) (Id -> Scaled Kind
    idScaledType Id
    var) Kind
    res_ty
                                          [AltCon -> [Id] -> CoreExpr -> CoreAlt
    forall b. AltCon -> [b] -> Expr b -> Alt b
    Alt AltCon
    DEFAULT [] CoreExpr
    fail]

    matchVariables :: NonEmpty MatchId -> Type -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    -- Real true variables, just like in matchVar, SLPJ p 94
    -- No binding to do: they'll all be wildcards by now (done in tidy)
    matchVariables :: NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchVariables (Id
    _ :| [Id]
    vars) Kind
    ty NonEmpty EquationInfo
    eqns = [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match [Id]
    vars Kind
    ty ([EquationInfo] -> DsM (MatchResult CoreExpr))
    -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ NonEmpty EquationInfo -> [EquationInfo]
    forall a. NonEmpty a -> [a]
    NEL.toList (NonEmpty EquationInfo -> [EquationInfo])
    -> NonEmpty EquationInfo -> [EquationInfo]
    forall a b. (a -> b) -> a -> b
    $ NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall (f :: * -> *). Functor f => f EquationInfo -> f EquationInfo
    shiftEqns NonEmpty EquationInfo
    eqns

    matchBangs :: NonEmpty MatchId -> Type -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchBangs :: NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchBangs (Id
    var :| [Id]
    vars) Kind
    ty NonEmpty EquationInfo
    eqns
      = do  { MatchResult CoreExpr
    match_result <- [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match (Id
    varId -> [Id] -> [Id]
    forall a. a -> [a] -> [a]
    :[Id]
    vars) Kind
    ty ([EquationInfo] -> DsM (MatchResult CoreExpr))
    -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ NonEmpty EquationInfo -> [EquationInfo]
    forall a. NonEmpty a -> [a]
    NEL.toList (NonEmpty EquationInfo -> [EquationInfo])
    -> NonEmpty EquationInfo -> [EquationInfo]
    forall a b. (a -> b) -> a -> b
    $
                (Pat GhcTc -> Pat GhcTc) -> EquationInfo -> EquationInfo
    decomposeFirstPat Pat GhcTc -> Pat GhcTc
    getBangPat (EquationInfo -> EquationInfo)
    -> NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> NonEmpty EquationInfo
    eqns
            ; MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Id -> Kind -> MatchResult CoreExpr -> MatchResult CoreExpr
    mkEvalMatchResult Id
    var Kind
    ty MatchResult CoreExpr
    match_result) }

    matchCoercion :: NonEmpty MatchId -> Type -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    -- Apply the coercion to the match variable and then match that
    matchCoercion :: NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchCoercion (Id
    var :| [Id]
    vars) Kind
    ty (eqns :: NonEmpty EquationInfo
    eqns@(EquationInfo
    eqn1 :| [EquationInfo]
    _))
      = do  { let XPat (CoPat HsWrapper
    co Pat GhcTc
    pat Kind
    _) = EquationInfo -> Pat GhcTc
    firstPat EquationInfo
    eqn1
            ; let pat_ty' :: Kind
    pat_ty' = Pat GhcTc -> Kind
    hsPatType Pat GhcTc
    pat
            ; Id
    var' <- Id -> Kind -> Kind -> DsM Id
    newUniqueId Id
    var (Id -> Kind
    idMult Id
    var) Kind
    pat_ty'
            ; MatchResult CoreExpr
    match_result <- [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match (Id
    var'Id -> [Id] -> [Id]
    forall a. a -> [a] -> [a]
    :[Id]
    vars) Kind
    ty ([EquationInfo] -> DsM (MatchResult CoreExpr))
    -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ NonEmpty EquationInfo -> [EquationInfo]
    forall a. NonEmpty a -> [a]
    NEL.toList (NonEmpty EquationInfo -> [EquationInfo])
    -> NonEmpty EquationInfo -> [EquationInfo]
    forall a b. (a -> b) -> a -> b
    $
                (Pat GhcTc -> Pat GhcTc) -> EquationInfo -> EquationInfo
    decomposeFirstPat Pat GhcTc -> Pat GhcTc
    getCoPat (EquationInfo -> EquationInfo)
    -> NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> NonEmpty EquationInfo
    eqns
            ; DsWrapper
    core_wrap <- HsWrapper -> DsM DsWrapper
    dsHsWrapper HsWrapper
    co
            ; let bind :: Bind Id
    bind = Id -> CoreExpr -> Bind Id
    forall b. b -> Expr b -> Bind b
    NonRec Id
    var' (DsWrapper
    core_wrap (Id -> CoreExpr
    forall b. Id -> Expr b
    Var Id
    var))
            ; MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Bind Id -> MatchResult CoreExpr -> MatchResult CoreExpr
    mkCoLetMatchResult Bind Id
    bind MatchResult CoreExpr
    match_result) }

    matchView :: NonEmpty MatchId -> Type -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    -- Apply the view function to the match variable and then match that
    matchView :: NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchView (Id
    var :| [Id]
    vars) Kind
    ty (eqns :: NonEmpty EquationInfo
    eqns@(EquationInfo
    eqn1 :| [EquationInfo]
    _))
      = do  { -- we could pass in the expr from the PgView,
             -- but this needs to extract the pat anyway
             -- to figure out the type of the fresh variable
             let ViewPat XViewPat GhcTc
    _ LHsExpr GhcTc
    viewExpr (L SrcSpanAnnA
    _ Pat GhcTc
    pat) = EquationInfo -> Pat GhcTc
    firstPat EquationInfo
    eqn1
             -- do the rest of the compilation
            ; let pat_ty' :: Kind
    pat_ty' = Pat GhcTc -> Kind
    hsPatType Pat GhcTc
    pat
            ; Id
    var' <- Id -> Kind -> Kind -> DsM Id
    newUniqueId Id
    var (Id -> Kind
    idMult Id
    var) Kind
    pat_ty'
            ; MatchResult CoreExpr
    match_result <- [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match (Id
    var'Id -> [Id] -> [Id]
    forall a. a -> [a] -> [a]
    :[Id]
    vars) Kind
    ty ([EquationInfo] -> DsM (MatchResult CoreExpr))
    -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ NonEmpty EquationInfo -> [EquationInfo]
    forall a. NonEmpty a -> [a]
    NEL.toList (NonEmpty EquationInfo -> [EquationInfo])
    -> NonEmpty EquationInfo -> [EquationInfo]
    forall a b. (a -> b) -> a -> b
    $
                (Pat GhcTc -> Pat GhcTc) -> EquationInfo -> EquationInfo
    decomposeFirstPat Pat GhcTc -> Pat GhcTc
    getViewPat (EquationInfo -> EquationInfo)
    -> NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> NonEmpty EquationInfo
    eqns
             -- compile the view expressions
            ; CoreExpr
    viewExpr' <- LHsExpr GhcTc -> DsM CoreExpr
    dsLExpr LHsExpr GhcTc
    viewExpr
            ; MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Id -> CoreExpr -> MatchResult CoreExpr -> MatchResult CoreExpr
    mkViewMatchResult Id
    var'
                        (SDoc -> CoreExpr -> DsWrapper
    mkCoreAppDs (String -> SDoc
    text String
    "matchView") CoreExpr
    viewExpr' (Id -> CoreExpr
    forall b. Id -> Expr b
    Var Id
    var))
                        MatchResult CoreExpr
    match_result) }

    matchOverloadedList :: NonEmpty MatchId -> Type -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchOverloadedList :: NonEmpty Id
    -> Kind -> NonEmpty EquationInfo -> DsM (MatchResult CoreExpr)
    matchOverloadedList (Id
    var :| [Id]
    vars) Kind
    ty (eqns :: NonEmpty EquationInfo
    eqns@(EquationInfo
    eqn1 :| [EquationInfo]
    _))
    -- Since overloaded list patterns are treated as view patterns,
    -- the code is roughly the same as for matchView
      = do { let ListPat (ListPatTc Kind
    elt_ty (Just (Kind
    _,SyntaxExpr GhcTc
    e))) [LPat GhcTc]
    _ = EquationInfo -> Pat GhcTc
    firstPat EquationInfo
    eqn1
           ; Id
    var' <- Id -> Kind -> Kind -> DsM Id
    newUniqueId Id
    var (Id -> Kind
    idMult Id
    var) (Kind -> Kind
    mkListTy Kind
    elt_ty)  -- we construct the overall type by hand
           ; MatchResult CoreExpr
    match_result <- [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match (Id
    var'Id -> [Id] -> [Id]
    forall a. a -> [a] -> [a]
    :[Id]
    vars) Kind
    ty ([EquationInfo] -> DsM (MatchResult CoreExpr))
    -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ NonEmpty EquationInfo -> [EquationInfo]
    forall a. NonEmpty a -> [a]
    NEL.toList (NonEmpty EquationInfo -> [EquationInfo])
    -> NonEmpty EquationInfo -> [EquationInfo]
    forall a b. (a -> b) -> a -> b
    $
               (Pat GhcTc -> Pat GhcTc) -> EquationInfo -> EquationInfo
    decomposeFirstPat Pat GhcTc -> Pat GhcTc
    getOLPat (EquationInfo -> EquationInfo)
    -> NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> NonEmpty EquationInfo
    eqns -- getOLPat builds the pattern inside as a non-overloaded version of the overloaded list pattern
           ; CoreExpr
    e' <- SyntaxExpr GhcTc -> [CoreExpr] -> DsM CoreExpr
    dsSyntaxExpr SyntaxExpr GhcTc
    e [Id -> CoreExpr
    forall b. Id -> Expr b
    Var Id
    var]
           ; MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Id -> CoreExpr -> MatchResult CoreExpr -> MatchResult CoreExpr
    mkViewMatchResult Id
    var' CoreExpr
    e' MatchResult CoreExpr
    match_result)
           }

    -- decompose the first pattern and leave the rest alone
    decomposeFirstPat :: (Pat GhcTc -> Pat GhcTc) -> EquationInfo -> EquationInfo
    decomposeFirstPat :: (Pat GhcTc -> Pat GhcTc) -> EquationInfo -> EquationInfo
    decomposeFirstPat Pat GhcTc -> Pat GhcTc
    extractpat (eqn :: EquationInfo
    eqn@(EqnInfo { eqn_pats :: EquationInfo -> [Pat GhcTc]
    eqn_pats = Pat GhcTc
    pat : [Pat GhcTc]
    pats }))
            = EquationInfo
    eqn { eqn_pats :: [Pat GhcTc]
    eqn_pats = Pat GhcTc -> Pat GhcTc
    extractpat Pat GhcTc
    pat Pat GhcTc -> [Pat GhcTc] -> [Pat GhcTc]
    forall a. a -> [a] -> [a]
    : [Pat GhcTc]
    pats}
    decomposeFirstPat Pat GhcTc -> Pat GhcTc
    _ EquationInfo
    _ = String -> EquationInfo
    forall a. String -> a
    panic String
    "decomposeFirstPat"

    getCoPat, getBangPat, getViewPat, getOLPat :: Pat GhcTc -> Pat GhcTc
    getCoPat :: Pat GhcTc -> Pat GhcTc
    getCoPat (XPat (CoPat HsWrapper
    _ Pat GhcTc
    pat Kind
    _)) = Pat GhcTc
    pat
    getCoPat Pat GhcTc
    _                   = String -> Pat GhcTc
    forall a. String -> a
    panic String
    "getCoPat"
    getBangPat :: Pat GhcTc -> Pat GhcTc
    getBangPat (BangPat XBangPat GhcTc
    _ LPat GhcTc
    pat  ) = GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat
    getBangPat Pat GhcTc
    _                 = String -> Pat GhcTc
    forall a. String -> a
    panic String
    "getBangPat"
    getViewPat :: Pat GhcTc -> Pat GhcTc
    getViewPat (ViewPat XViewPat GhcTc
    _ LHsExpr GhcTc
    _ LPat GhcTc
    pat) = GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat
    getViewPat Pat GhcTc
    _                 = String -> Pat GhcTc
    forall a. String -> a
    panic String
    "getViewPat"
    getOLPat :: Pat GhcTc -> Pat GhcTc
    getOLPat (ListPat (ListPatTc Kind
    ty (Just (Kind, SyntaxExpr GhcTc)
    _)) [LPat GhcTc]
    pats)
            = XListPat GhcTc -> [LPat GhcTc] -> Pat GhcTc
    forall p. XListPat p -> [LPat p] -> Pat p
    ListPat (Kind -> Maybe (Kind, SyntaxExpr GhcTc) -> ListPatTc
    ListPatTc Kind
    ty Maybe (Kind, SyntaxExpr GhcTc)
    forall a. Maybe a
    Nothing)  [LPat GhcTc]
    pats
    getOLPat Pat GhcTc
    _                   = String -> Pat GhcTc
    forall a. String -> a
    panic String
    "getOLPat"

    {-
    Note [Empty case alternatives]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    The list of EquationInfo can be empty, arising from
        case x of {}   or    \case {}
    In that situation we desugar to
        case x of { _ -> error "pattern match failure" }
    The *desugarer* isn't certain whether there really should be no
    alternatives, so it adds a default case, as it always does.  A later
    pass may remove it if it's inaccessible.  (See also Note [Empty case
    alternatives] in GHC.Core.)

    We do *not* desugar simply to
       error "empty case"
    or some such, because 'x' might be bound to (error "hello"), in which
    case we want to see that "hello" exception, not (error "empty case").
    See also Note [Case elimination: lifted case] in GHC.Core.Opt.Simplify.

    ************************************************************************
    *                                                                      *
                    Tidying patterns
    *                                                                      *
    ************************************************************************

    Tidy up the leftmost pattern in an @EquationInfo@, given the variable @v@
    which will be scrutinised.

    This makes desugaring the pattern match simpler by transforming some of
    the patterns to simpler forms. (Tuples to Constructor Patterns)

    Among other things in the resulting Pattern:
    * Variables and irrefutable(lazy) patterns are replaced by Wildcards
    * As patterns are replaced by the patterns they wrap.

    The bindings created by the above patterns are put into the returned wrapper
    instead.

    This means a definition of the form:
      f x = rhs
    when called with v get's desugared to the equivalent of:
      let x = v
      in
      f _ = rhs

    The same principle holds for as patterns (@) and
    irrefutable/lazy patterns (~).
    In the case of irrefutable patterns the irrefutable pattern is pushed into
    the binding.

    Pattern Constructors which only represent syntactic sugar are converted into
    their desugared representation.
    This usually means converting them to Constructor patterns but for some
    depends on enabled extensions. (Eg OverloadedLists)

    GHC also tries to convert overloaded Literals into regular ones.

    The result of this tidying is that the column of patterns will include
    only these which can be assigned a PatternGroup (see patGroup).

    -}

    tidyEqnInfo :: Id -> EquationInfo
                -> DsM (DsWrapper, EquationInfo)
            -- DsM'd because of internal call to dsLHsBinds
            --      and mkSelectorBinds.
            -- "tidy1" does the interesting stuff, looking at
            -- one pattern and fiddling the list of bindings.
            --
            -- POST CONDITION: head pattern in the EqnInfo is
            --      one of these for which patGroup is defined.

    tidyEqnInfo :: Id
    -> EquationInfo
    -> IOEnv (Env DsGblEnv DsLclEnv) (DsWrapper, EquationInfo)
    tidyEqnInfo Id
    _ (EqnInfo { eqn_pats :: EquationInfo -> [Pat GhcTc]
    eqn_pats = [] })
      = String -> IOEnv (Env DsGblEnv DsLclEnv) (DsWrapper, EquationInfo)
    forall a. String -> a
    panic String
    "tidyEqnInfo"

    tidyEqnInfo Id
    v eqn :: EquationInfo
    eqn@(EqnInfo { eqn_pats :: EquationInfo -> [Pat GhcTc]
    eqn_pats = Pat GhcTc
    pat : [Pat GhcTc]
    pats, eqn_orig :: EquationInfo -> Origin
    eqn_orig = Origin
    orig })
      = do { (DsWrapper
    wrap, Pat GhcTc
    pat') <- Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    orig Pat GhcTc
    pat
           ; (DsWrapper, EquationInfo)
    -> IOEnv (Env DsGblEnv DsLclEnv) (DsWrapper, EquationInfo)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    wrap, EquationInfo
    eqn { eqn_pats :: [Pat GhcTc]
    eqn_pats = Pat GhcTc
    pat' Pat GhcTc -> [Pat GhcTc] -> [Pat GhcTc]
    forall a. a -> [a] -> [a]
    : [Pat GhcTc]
    pats }) }

    tidy1 :: Id                  -- The Id being scrutinised
          -> Origin              -- Was this a pattern the user wrote?
          -> Pat GhcTc           -- The pattern against which it is to be matched
          -> DsM (DsWrapper,     -- Extra bindings to do before the match
                  Pat GhcTc)     -- Equivalent pattern

    -------------------------------------------------------
    --      (pat', mr') = tidy1 v pat mr
    -- tidies the *outer level only* of pat, giving pat'
    -- It eliminates many pattern forms (as-patterns, variable patterns,
    -- list patterns, etc) and returns any created bindings in the wrapper.

    tidy1 :: Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (ParPat XParPat GhcTc
    _ LPat GhcTc
    pat)      = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat)
    tidy1 Id
    v Origin
    o (SigPat XSigPat GhcTc
    _ LPat GhcTc
    pat HsPatSigType (NoGhcTc GhcTc)
    _)    = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat)
    tidy1 Id
    _ Origin
    _ (WildPat XWildPat GhcTc
    ty)        = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, XWildPat GhcTc -> Pat GhcTc
    forall p. XWildPat p -> Pat p
    WildPat XWildPat GhcTc
    ty)
    tidy1 Id
    v Origin
    o (BangPat XBangPat GhcTc
    _ (L SrcSpanAnnA
    l Pat GhcTc
    p)) = Id
    -> Origin -> SrcSpanAnnA -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    l Pat GhcTc
    p

            -- case v of { x -> mr[] }
            -- = case v of { _ -> let x=v in mr[] }
    tidy1 Id
    v Origin
    _ (VarPat XVarPat GhcTc
    _ (L SrcSpanAnnN
    _ Id
    var))
      = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Id -> Id -> DsWrapper
    wrapBind Id
    var Id
    v, XWildPat GhcTc -> Pat GhcTc
    forall p. XWildPat p -> Pat p
    WildPat (Id -> Kind
    idType Id
    var))

            -- case v of { x@p -> mr[] }
            -- = case v of { p -> let x=v in mr[] }
    tidy1 Id
    v Origin
    o (AsPat XAsPat GhcTc
    _ (L SrcSpanAnnN
    _ Id
    var) LPat GhcTc
    pat)
      = do  { (DsWrapper
    wrap, Pat GhcTc
    pat') <- Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat)
            ; (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (Id -> Id -> DsWrapper
    wrapBind Id
    var Id
    v DsWrapper -> DsWrapper -> DsWrapper
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . DsWrapper
    wrap, Pat GhcTc
    pat') }

    {- now, here we handle lazy patterns:
        tidy1 v ~p bs = (v, v1 = case v of p -> v1 :
                            v2 = case v of p -> v2 : ... : bs )

        where the v_i's are the binders in the pattern.

        ToDo: in "v_i = ... -> v_i", are the v_i's really the same thing?

        The case expr for v_i is just: match [v] [(p, [], \ x -> Var v_i)] any_expr
    -}

    tidy1 Id
    v Origin
    _ (LazyPat XLazyPat GhcTc
    _ LPat GhcTc
    pat)
        -- This is a convenient place to check for unlifted types under a lazy pattern.
        -- Doing this check during type-checking is unsatisfactory because we may
        -- not fully know the zonked types yet. We sure do here.
      = do  { let unlifted_bndrs :: [Id]
    unlifted_bndrs = (Id -> Bool) -> [Id] -> [Id]
    forall a. (a -> Bool) -> [a] -> [a]
    filter (HasDebugCallStack => Kind -> Bool
    Kind -> Bool
    isUnliftedType (Kind -> Bool) -> (Id -> Kind) -> Id -> Bool
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . Id -> Kind
    idType) (CollectFlag GhcTc -> LPat GhcTc -> [IdP GhcTc]
    forall p. CollectPass p => CollectFlag p -> LPat p -> [IdP p]
    collectPatBinders CollectFlag GhcTc
    forall p. CollectFlag p
    CollNoDictBinders LPat GhcTc
    pat)
            ; Bool -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless ([Id] -> Bool
    forall (t :: * -> *) a. Foldable t => t a -> Bool
    null [Id]
    unlifted_bndrs) (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $
              SrcSpan
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a. SrcSpan -> DsM a -> DsM a
    putSrcSpanDs (GenLocated SrcSpanAnnA (Pat GhcTc) -> SrcSpan
    forall a e. GenLocated (SrcSpanAnn' a) e -> SrcSpan
    getLocA GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat) (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $
              SDoc -> TcRnIf DsGblEnv DsLclEnv ()
    errDs (SDoc -> Int -> SDoc -> SDoc
    hang (String -> SDoc
    text String
    "A lazy (~) pattern cannot bind variables of unlifted type." SDoc -> SDoc -> SDoc
    $$
                           String -> SDoc
    text String
    "Unlifted variables:")
                        Int
    2 ([SDoc] -> SDoc
    vcat ((Id -> SDoc) -> [Id] -> [SDoc]
    forall a b. (a -> b) -> [a] -> [b]
    map (\Id
    id -> Id -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Id
    id SDoc -> SDoc -> SDoc
    <+> SDoc
    dcolon SDoc -> SDoc -> SDoc
    <+> Kind -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr (Id -> Kind
    idType Id
    id))
                                     [Id]
    unlifted_bndrs)))

            ; (Id
    _,[(Id, CoreExpr)]
    sel_prs) <- [[CoreTickish]]
    -> LPat GhcTc -> CoreExpr -> DsM (Id, [(Id, CoreExpr)])
    mkSelectorBinds [] LPat GhcTc
    pat (Id -> CoreExpr
    forall b. Id -> Expr b
    Var Id
    v)
            ; let sel_binds :: [Bind Id]
    sel_binds =  [Id -> CoreExpr -> Bind Id
    forall b. b -> Expr b -> Bind b
    NonRec Id
    b CoreExpr
    rhs | (Id
    b,CoreExpr
    rhs) <- [(Id, CoreExpr)]
    sel_prs]
            ; (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([Bind Id] -> DsWrapper
    mkCoreLets [Bind Id]
    sel_binds, XWildPat GhcTc -> Pat GhcTc
    forall p. XWildPat p -> Pat p
    WildPat (Id -> Kind
    idType Id
    v)) }

    tidy1 Id
    _ Origin
    _ (ListPat (ListPatTc Kind
    ty Maybe (Kind, SyntaxExpr GhcTc)
    Nothing) [LPat GhcTc]
    pats )
      = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    list_ConPat)
      where
        list_ConPat :: GenLocated SrcSpanAnnA (Pat GhcTc)
    list_ConPat = (GenLocated SrcSpanAnnA (Pat GhcTc)
     -> GenLocated SrcSpanAnnA (Pat GhcTc)
     -> GenLocated SrcSpanAnnA (Pat GhcTc))
    -> GenLocated SrcSpanAnnA (Pat GhcTc)
    -> [GenLocated SrcSpanAnnA (Pat GhcTc)]
    -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall (t :: * -> *) a b.
    Foldable t =>
    (a -> b -> b) -> b -> t a -> b
    foldr (\ GenLocated SrcSpanAnnA (Pat GhcTc)
    x GenLocated SrcSpanAnnA (Pat GhcTc)
    y -> DataCon -> [LPat GhcTc] -> [Kind] -> LPat GhcTc
    mkPrefixConPat DataCon
    consDataCon [Item [GenLocated SrcSpanAnnA (Pat GhcTc)]
    GenLocated SrcSpanAnnA (Pat GhcTc)
    x, Item [GenLocated SrcSpanAnnA (Pat GhcTc)]
    GenLocated SrcSpanAnnA (Pat GhcTc)
    y] [Item [Kind]
    Kind
    ty])
                            (Kind -> LPat GhcTc
    mkNilPat Kind
    ty)
                            [GenLocated SrcSpanAnnA (Pat GhcTc)]
    [LPat GhcTc]
    pats

    tidy1 Id
    _ Origin
    _ (TuplePat XTuplePat GhcTc
    tys [LPat GhcTc]
    pats Boxity
    boxity)
      = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    tuple_ConPat)
      where
        arity :: Int
    arity = [GenLocated SrcSpanAnnA (Pat GhcTc)] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length [GenLocated SrcSpanAnnA (Pat GhcTc)]
    [LPat GhcTc]
    pats
        tuple_ConPat :: LPat GhcTc
    tuple_ConPat = DataCon -> [LPat GhcTc] -> [Kind] -> LPat GhcTc
    mkPrefixConPat (Boxity -> Int -> DataCon
    tupleDataCon Boxity
    boxity Int
    arity) [LPat GhcTc]
    pats [Kind]
    tys'
        tys' :: [Kind]
    tys' = case Boxity
    boxity of
                 Boxity
    Unboxed -> (Kind -> Kind) -> [Kind] -> [Kind]
    forall a b. (a -> b) -> [a] -> [b]
    map HasDebugCallStack => Kind -> Kind
    Kind -> Kind
    getRuntimeRep [Kind]
    XTuplePat GhcTc
    tys [Kind] -> [Kind] -> [Kind]
    forall a. [a] -> [a] -> [a]
    ++ [Kind]
    XTuplePat GhcTc
    tys
                 Boxity
    Boxed   -> [Kind]
    XTuplePat GhcTc
    tys
               -- See Note [Unboxed tuple RuntimeRep vars] in TyCon

    tidy1 Id
    _ Origin
    _ (SumPat XSumPat GhcTc
    tys LPat GhcTc
    pat Int
    alt Int
    arity)
      = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    sum_ConPat)
      where
        sum_ConPat :: LPat GhcTc
    sum_ConPat = DataCon -> [LPat GhcTc] -> [Kind] -> LPat GhcTc
    mkPrefixConPat (Int -> Int -> DataCon
    sumDataCon Int
    alt Int
    arity) [Item [GenLocated SrcSpanAnnA (Pat GhcTc)]
    LPat GhcTc
    pat] ((Kind -> Kind) -> [Kind] -> [Kind]
    forall a b. (a -> b) -> [a] -> [b]
    map HasDebugCallStack => Kind -> Kind
    Kind -> Kind
    getRuntimeRep [Kind]
    XSumPat GhcTc
    tys [Kind] -> [Kind] -> [Kind]
    forall a. [a] -> [a] -> [a]
    ++ [Kind]
    XSumPat GhcTc
    tys)
                     -- See Note [Unboxed tuple RuntimeRep vars] in TyCon

    -- LitPats: we *might* be able to replace these w/ a simpler form
    tidy1 Id
    _ Origin
    o (LitPat XLitPat GhcTc
    _ HsLit GhcTc
    lit)
      = do { Bool -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless (Origin -> Bool
    isGenerated Origin
    o) (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $
               HsLit GhcTc -> TcRnIf DsGblEnv DsLclEnv ()
    warnAboutOverflowedLit HsLit GhcTc
    lit
           ; (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, HsLit GhcTc -> Pat GhcTc
    tidyLitPat HsLit GhcTc
    lit) }

    -- NPats: we *might* be able to replace these w/ a simpler form
    tidy1 Id
    _ Origin
    o (NPat XNPat GhcTc
    ty (L SrcSpan
    _ lit :: HsOverLit GhcTc
    lit@OverLit { ol_val :: forall p. HsOverLit p -> OverLitVal
    ol_val = OverLitVal
    v }) Maybe (SyntaxExpr GhcTc)
    mb_neg SyntaxExpr GhcTc
    eq)
      = do { Bool -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless (Origin -> Bool
    isGenerated Origin
    o) (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $
               let lit' :: HsOverLit GhcTc
    lit' | Just SyntaxExpr GhcTc
    _ <- Maybe (SyntaxExpr GhcTc)
    mb_neg = HsOverLit GhcTc
    lit{ ol_val :: OverLitVal
    ol_val = OverLitVal -> OverLitVal
    negateOverLitVal OverLitVal
    v }
                        | Bool
    otherwise = HsOverLit GhcTc
    lit
               in HsOverLit GhcTc -> TcRnIf DsGblEnv DsLclEnv ()
    warnAboutOverflowedOverLit HsOverLit GhcTc
    lit'
           ; (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, HsOverLit GhcTc
    -> Maybe (SyntaxExpr GhcTc)
    -> SyntaxExpr GhcTc
    -> Kind
    -> Pat GhcTc
    tidyNPat HsOverLit GhcTc
    lit Maybe (SyntaxExpr GhcTc)
    mb_neg SyntaxExpr GhcTc
    eq Kind
    XNPat GhcTc
    ty) }

    -- NPlusKPat: we may want to warn about the literals
    tidy1 Id
    _ Origin
    o n :: Pat GhcTc
    n@(NPlusKPat XNPlusKPat GhcTc
    _ LIdP GhcTc
    _ (L SrcSpan
    _ HsOverLit GhcTc
    lit1) HsOverLit GhcTc
    lit2 SyntaxExpr GhcTc
    _ SyntaxExpr GhcTc
    _)
      = do { Bool -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    unless (Origin -> Bool
    isGenerated Origin
    o) (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $ do
               HsOverLit GhcTc -> TcRnIf DsGblEnv DsLclEnv ()
    warnAboutOverflowedOverLit HsOverLit GhcTc
    lit1
               HsOverLit GhcTc -> TcRnIf DsGblEnv DsLclEnv ()
    warnAboutOverflowedOverLit HsOverLit GhcTc
    lit2
           ; (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, Pat GhcTc
    n) }

    -- Everything else goes through unchanged...
    tidy1 Id
    _ Origin
    _ Pat GhcTc
    non_interesting_pat
      = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, Pat GhcTc
    non_interesting_pat)

    --------------------
    tidy_bang_pat :: Id -> Origin -> SrcSpanAnnA -> Pat GhcTc
                  -> DsM (DsWrapper, Pat GhcTc)

    -- Discard par/sig under a bang
    tidy_bang_pat :: Id
    -> Origin -> SrcSpanAnnA -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    _ (ParPat XParPat GhcTc
    _ (L SrcSpanAnnA
    l Pat GhcTc
    p)) = Id
    -> Origin -> SrcSpanAnnA -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    l Pat GhcTc
    p
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    _ (SigPat XSigPat GhcTc
    _ (L SrcSpanAnnA
    l Pat GhcTc
    p) HsPatSigType (NoGhcTc GhcTc)
    _) = Id
    -> Origin -> SrcSpanAnnA -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    l Pat GhcTc
    p

    -- Push the bang-pattern inwards, in the hope that
    -- it may disappear next time
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    l (AsPat XAsPat GhcTc
    x LIdP GhcTc
    v' LPat GhcTc
    p)
      = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (XAsPat GhcTc -> LIdP GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XAsPat p -> LIdP p -> LPat p -> Pat p
    AsPat XAsPat GhcTc
    x LIdP GhcTc
    v' (SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    l (XBangPat GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XBangPat p -> LPat p -> Pat p
    BangPat NoExtField
    XBangPat GhcTc
    noExtField LPat GhcTc
    p)))
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    l (XPat (CoPat HsWrapper
    w Pat GhcTc
    p Kind
    t))
      = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (XXPat GhcTc -> Pat GhcTc
    forall p. XXPat p -> Pat p
    XPat (XXPat GhcTc -> Pat GhcTc) -> XXPat GhcTc -> Pat GhcTc
    forall a b. (a -> b) -> a -> b
    $ HsWrapper -> Pat GhcTc -> Kind -> CoPat
    CoPat HsWrapper
    w (XBangPat GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XBangPat p -> LPat p -> Pat p
    BangPat NoExtField
    XBangPat GhcTc
    noExtField (SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    l Pat GhcTc
    p)) Kind
    t)

    -- Discard bang around strict pattern
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    _ p :: Pat GhcTc
    p@(LitPat {})    = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o Pat GhcTc
    p
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    _ p :: Pat GhcTc
    p@(ListPat {})   = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o Pat GhcTc
    p
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    _ p :: Pat GhcTc
    p@(TuplePat {})  = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o Pat GhcTc
    p
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    _ p :: Pat GhcTc
    p@(SumPat {})    = Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o Pat GhcTc
    p

    -- Data/newtype constructors
    tidy_bang_pat Id
    v Origin
    o SrcSpanAnnA
    l p :: Pat GhcTc
    p@(ConPat { pat_con :: forall p. Pat p -> XRec p (ConLikeP p)
    pat_con = L SrcSpanAnnN
    _ (RealDataCon DataCon
    dc)
                                  , pat_args :: forall p. Pat p -> HsConPatDetails p
    pat_args = HsConPatDetails GhcTc
    args
                                  , pat_con_ext :: forall p. Pat p -> XConPat p
    pat_con_ext = ConPatTc
                                    { cpt_arg_tys :: ConPatTc -> [Kind]
    cpt_arg_tys = [Kind]
    arg_tys
                                    }
                                  })
      -- Newtypes: push bang inwards (#9844)
      =
        if TyCon -> Bool
    isNewTyCon (DataCon -> TyCon
    dataConTyCon DataCon
    dc)
          then Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o (Pat GhcTc
    p { pat_args :: HsConPatDetails GhcTc
    pat_args = SrcSpanAnnA
    -> Kind -> HsConPatDetails GhcTc -> HsConPatDetails GhcTc
    push_bang_into_newtype_arg SrcSpanAnnA
    l (Scaled Kind -> Kind
    forall a. Scaled a -> a
    scaledThing Scaled Kind
    ty) HsConPatDetails GhcTc
    args })
          else Id -> Origin -> Pat GhcTc -> DsM (DsWrapper, Pat GhcTc)
    tidy1 Id
    v Origin
    o Pat GhcTc
    p  -- Data types: discard the bang
        where
          (Scaled Kind
    ty:[Scaled Kind]
    _) = DataCon -> [Kind] -> [Scaled Kind]
    dataConInstArgTys DataCon
    dc [Kind]
    arg_tys

    -------------------
    -- Default case, leave the bang there:
    --    VarPat,
    --    LazyPat,
    --    WildPat,
    --    ViewPat,
    --    pattern synonyms (ConPatOut with PatSynCon)
    --    NPat,
    --    NPlusKPat
    --
    -- For LazyPat, remember that it's semantically like a VarPat
    --  i.e.  !(~p) is not like ~p, or p!  (#8952)
    --
    -- NB: SigPatIn, ConPatIn should not happen

    tidy_bang_pat Id
    _ Origin
    _ SrcSpanAnnA
    l Pat GhcTc
    p = (DsWrapper, Pat GhcTc) -> DsM (DsWrapper, Pat GhcTc)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (DsWrapper
    idDsWrapper, XBangPat GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XBangPat p -> LPat p -> Pat p
    BangPat NoExtField
    XBangPat GhcTc
    noExtField (SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    l Pat GhcTc
    p))

    -------------------
    push_bang_into_newtype_arg :: SrcSpanAnnA
                               -> Type -- The type of the argument we are pushing
                                       -- onto
                               -> HsConPatDetails GhcTc -> HsConPatDetails GhcTc
    -- See Note [Bang patterns and newtypes]
    -- We are transforming   !(N p)   into   (N !p)
    push_bang_into_newtype_arg :: SrcSpanAnnA
    -> Kind -> HsConPatDetails GhcTc -> HsConPatDetails GhcTc
    push_bang_into_newtype_arg SrcSpanAnnA
    l Kind
    _ty (PrefixCon [HsPatSigType (NoGhcTc GhcTc)]
    ts (LPat GhcTc
    arg:[LPat GhcTc]
    args))
      = ASSERT( null args)
        [HsPatSigType (GhcPass 'Renamed)]
    -> [GenLocated SrcSpanAnnA (Pat GhcTc)]
    -> HsConDetails
         (HsPatSigType (GhcPass 'Renamed))
         (GenLocated SrcSpanAnnA (Pat GhcTc))
         (HsRecFields GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc)))
    forall tyarg arg rec.
    [tyarg] -> [arg] -> HsConDetails tyarg arg rec
    PrefixCon [HsPatSigType (NoGhcTc GhcTc)]
    [HsPatSigType (GhcPass 'Renamed)]
    ts [SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    l (XBangPat GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XBangPat p -> LPat p -> Pat p
    BangPat NoExtField
    XBangPat GhcTc
    noExtField LPat GhcTc
    arg)]
    push_bang_into_newtype_arg SrcSpanAnnA
    l Kind
    _ty (RecCon HsRecFields GhcTc (LPat GhcTc)
    rf)
      | HsRecFields { rec_flds :: forall p arg. HsRecFields p arg -> [LHsRecField p arg]
    rec_flds = L SrcSpanAnnA
    lf HsRecField' (FieldOcc GhcTc) (GenLocated SrcSpanAnnA (Pat GhcTc))
    fld : [LHsRecField GhcTc (LPat GhcTc)]
    flds } <- HsRecFields GhcTc (LPat GhcTc)
    rf
      , HsRecField { hsRecFieldArg :: forall id arg. HsRecField' id arg -> arg
    hsRecFieldArg = GenLocated SrcSpanAnnA (Pat GhcTc)
    arg } <- HsRecField' (FieldOcc GhcTc) (GenLocated SrcSpanAnnA (Pat GhcTc))
    fld
      = ASSERT( null flds)
        HsRecFields GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc))
    -> HsConDetails
         (HsPatSigType (GhcPass 'Renamed))
         (GenLocated SrcSpanAnnA (Pat GhcTc))
         (HsRecFields GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc)))
    forall tyarg arg rec. rec -> HsConDetails tyarg arg rec
    RecCon (HsRecFields GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc))
    HsRecFields GhcTc (LPat GhcTc)
    rf { rec_flds :: [LHsRecField GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc))]
    rec_flds = [SrcSpanAnnA
    -> HsRecField'
         (FieldOcc GhcTc) (GenLocated SrcSpanAnnA (Pat GhcTc))
    -> GenLocated
         SrcSpanAnnA
         (HsRecField' (FieldOcc GhcTc) (GenLocated SrcSpanAnnA (Pat GhcTc)))
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    lf (HsRecField' (FieldOcc GhcTc) (GenLocated SrcSpanAnnA (Pat GhcTc))
    fld { hsRecFieldArg :: GenLocated SrcSpanAnnA (Pat GhcTc)
    hsRecFieldArg
                                               = SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    l (XBangPat GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XBangPat p -> LPat p -> Pat p
    BangPat NoExtField
    XBangPat GhcTc
    noExtField GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    arg) })] })
    push_bang_into_newtype_arg SrcSpanAnnA
    l Kind
    ty (RecCon HsRecFields GhcTc (LPat GhcTc)
    rf) -- If a user writes !(T {})
      | HsRecFields { rec_flds :: forall p arg. HsRecFields p arg -> [LHsRecField p arg]
    rec_flds = [] } <- HsRecFields GhcTc (LPat GhcTc)
    rf
      = [HsPatSigType (GhcPass 'Renamed)]
    -> [GenLocated SrcSpanAnnA (Pat GhcTc)]
    -> HsConDetails
         (HsPatSigType (GhcPass 'Renamed))
         (GenLocated SrcSpanAnnA (Pat GhcTc))
         (HsRecFields GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc)))
    forall tyarg arg rec.
    [tyarg] -> [arg] -> HsConDetails tyarg arg rec
    PrefixCon [] [SrcSpanAnnA -> Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall l e. l -> e -> GenLocated l e
    L SrcSpanAnnA
    l (XBangPat GhcTc -> LPat GhcTc -> Pat GhcTc
    forall p. XBangPat p -> LPat p -> Pat p
    BangPat NoExtField
    XBangPat GhcTc
    noExtField (Pat GhcTc -> GenLocated SrcSpanAnnA (Pat GhcTc)
    forall a an. a -> LocatedAn an a
    noLocA (XWildPat GhcTc -> Pat GhcTc
    forall p. XWildPat p -> Pat p
    WildPat Kind
    XWildPat GhcTc
    ty)))]
    push_bang_into_newtype_arg SrcSpanAnnA
    _ Kind
    _ HsConPatDetails GhcTc
    cd
      = String
    -> SDoc
    -> HsConDetails
         (HsPatSigType (GhcPass 'Renamed))
         (GenLocated SrcSpanAnnA (Pat GhcTc))
         (HsRecFields GhcTc (GenLocated SrcSpanAnnA (Pat GhcTc)))
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "push_bang_into_newtype_arg" (HsConPatDetails GhcTc -> SDoc
    forall (p :: Pass).
    (OutputableBndrId p, Outputable (Anno (IdGhcP p))) =>
    HsConPatDetails (GhcPass p) -> SDoc
    pprConArgs HsConPatDetails GhcTc
    cd)

    {-
    Note [Bang patterns and newtypes]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    For the pattern  !(Just pat)  we can discard the bang, because
    the pattern is strict anyway. But for !(N pat), where
      newtype NT = N Int
    we definitely can't discard the bang.  #9844.

    So what we do is to push the bang inwards, in the hope that it will
    get discarded there.  So we transform
       !(N pat)   into    (N !pat)

    But what if there is nothing to push the bang onto? In at least one instance
    a user has written !(N {}) which we translate into (N !_). See #13215

    \noindent
    {\bf Previous @matchTwiddled@ stuff:}

    Now we get to the only interesting part; note: there are choices for
    translation [from Simon's notes]; translation~1:
    \begin{verbatim}
    deTwiddle [s,t] e
    \end{verbatim}
    returns
    \begin{verbatim}
    [ w = e,
      s = case w of [s,t] -> s
      t = case w of [s,t] -> t
    ]
    \end{verbatim}

    Here \tr{w} is a fresh variable, and the \tr{w}-binding prevents multiple
    evaluation of \tr{e}.  An alternative translation (No.~2):
    \begin{verbatim}
    [ w = case e of [s,t] -> (s,t)
      s = case w of (s,t) -> s
      t = case w of (s,t) -> t
    ]
    \end{verbatim}

    ************************************************************************
    *                                                                      *
    \subsubsection[improved-unmixing]{UNIMPLEMENTED idea for improved unmixing}
    *                                                                      *
    ************************************************************************

    We might be able to optimise unmixing when confronted by
    only-one-constructor-possible, of which tuples are the most notable
    examples.  Consider:
    \begin{verbatim}
    f (a,b,c) ... = ...
    f d ... (e:f) = ...
    f (g,h,i) ... = ...
    f j ...       = ...
    \end{verbatim}
    This definition would normally be unmixed into four equation blocks,
    one per equation.  But it could be unmixed into just one equation
    block, because if the one equation matches (on the first column),
    the others certainly will.

    You have to be careful, though; the example
    \begin{verbatim}
    f j ...       = ...
    -------------------
    f (a,b,c) ... = ...
    f d ... (e:f) = ...
    f (g,h,i) ... = ...
    \end{verbatim}
    {\em must} be broken into two blocks at the line shown; otherwise, you
    are forcing unnecessary evaluation.  In any case, the top-left pattern
    always gives the cue.  You could then unmix blocks into groups of...
    \begin{description}
    \item[all variables:]
    As it is now.
    \item[constructors or variables (mixed):]
    Need to make sure the right names get bound for the variable patterns.
    \item[literals or variables (mixed):]
    Presumably just a variant on the constructor case (as it is now).
    \end{description}

    ************************************************************************
    *                                                                      *
    *  matchWrapper: a convenient way to call @match@                      *
    *                                                                      *
    ************************************************************************
    \subsection[matchWrapper]{@matchWrapper@: a convenient interface to @match@}

    Calls to @match@ often involve similar (non-trivial) work; that work
    is collected here, in @matchWrapper@.  This function takes as
    arguments:
    \begin{itemize}
    \item
    Typechecked @Matches@ (of a function definition, or a case or lambda
    expression)---the main input;
    \item
    An error message to be inserted into any (runtime) pattern-matching
    failure messages.
    \end{itemize}

    As results, @matchWrapper@ produces:
    \begin{itemize}
    \item
    A list of variables (@Locals@) that the caller must ``promise'' to
    bind to appropriate values; and
    \item
    a @CoreExpr@, the desugared output (main result).
    \end{itemize}

    The main actions of @matchWrapper@ include:
    \begin{enumerate}
    \item
    Flatten the @[TypecheckedMatch]@ into a suitable list of
    @EquationInfo@s.
    \item
    Create as many new variables as there are patterns in a pattern-list
    (in any one of the @EquationInfo@s).
    \item
    Create a suitable ``if it fails'' expression---a call to @error@ using
    the error-string input; the {\em type} of this fail value can be found
    by examining one of the RHS expressions in one of the @EquationInfo@s.
    \item
    Call @match@ with all of this information!
    \end{enumerate}
    -}

    matchWrapper
      :: HsMatchContext GhcRn              -- ^ For shadowing warning messages
      -> Maybe (LHsExpr GhcTc)             -- ^ Scrutinee. (Just scrut) for a case expr
                                           --      case scrut of { p1 -> e1 ... }
                                           --   (and in this case the MatchGroup will
                                           --    have all singleton patterns)
                                           --   Nothing for a function definition
                                           --      f p1 q1 = ...  -- No "scrutinee"
                                           --      f p2 q2 = ...  -- in this case
      -> MatchGroup GhcTc (LHsExpr GhcTc)  -- ^ Matches being desugared
      -> DsM ([Id], CoreExpr)              -- ^ Results (usually passed to 'match')

    {-
     There is one small problem with the Lambda Patterns, when somebody
     writes something similar to:
    \begin{verbatim}
        (\ (x:xs) -> ...)
    \end{verbatim}
     he/she don't want a warning about incomplete patterns, that is done with
     the flag @opt_WarnSimplePatterns@.
     This problem also appears in the:
    \begin{itemize}
    \item @do@ patterns, but if the @do@ can fail
          it creates another equation if the match can fail
          (see @GHC.HsToCore.Expr.doDo@ function)
    \item @let@ patterns, are treated by @matchSimply@
       List Comprension Patterns, are treated by @matchSimply@ also
    \end{itemize}

    We can't call @matchSimply@ with Lambda patterns,
    due to the fact that lambda patterns can have more than
    one pattern, and match simply only accepts one pattern.

    JJQC 30-Nov-1997
    -}

    matchWrapper :: HsMatchContext (GhcPass 'Renamed)
    -> Maybe (LHsExpr GhcTc)
    -> MatchGroup GhcTc (LHsExpr GhcTc)
    -> DsM ([Id], CoreExpr)
    matchWrapper HsMatchContext (GhcPass 'Renamed)
    ctxt Maybe (LHsExpr GhcTc)
    mb_scr (MG { mg_alts :: forall p body. MatchGroup p body -> XRec p [LMatch p body]
    mg_alts = L SrcSpanAnnL
    _ [GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    matches
                                 , mg_ext :: forall p body. MatchGroup p body -> XMG p body
    mg_ext = MatchGroupTc [Scaled Kind]
    arg_tys Kind
    rhs_ty
                                 , mg_origin :: forall p body. MatchGroup p body -> Origin
    mg_origin = Origin
    origin })
      = do  { DynFlags
    dflags <- IOEnv (Env DsGblEnv DsLclEnv) DynFlags
    forall (m :: * -> *). HasDynFlags m => m DynFlags
    getDynFlags
            ; SrcSpan
    locn   <- DsM SrcSpan
    getSrcSpanDs

            ; [Id]
    new_vars    <- case [GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    matches of
                               []    -> [Scaled Kind] -> IOEnv (Env DsGblEnv DsLclEnv) [Id]
    newSysLocalsDsNoLP [Scaled Kind]
    arg_tys
                               (GenLocated
      SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))
    m:[GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    _) ->
                                [(Kind, Pat GhcTc)] -> IOEnv (Env DsGblEnv DsLclEnv) [Id]
    selectMatchVars (String
    -> (Scaled Kind
        -> GenLocated SrcSpanAnnA (Pat GhcTc) -> (Kind, Pat GhcTc))
    -> [Scaled Kind]
    -> [GenLocated SrcSpanAnnA (Pat GhcTc)]
    -> [(Kind, Pat GhcTc)]
    forall a b c. String -> (a -> b -> c) -> [a] -> [b] -> [c]
    zipWithEqual String
    "matchWrapper"
                                                  (\Scaled Kind
    a GenLocated SrcSpanAnnA (Pat GhcTc)
    b -> (Scaled Kind -> Kind
    forall a. Scaled a -> Kind
    scaledMult Scaled Kind
    a, GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    b))
                                                    [Scaled Kind]
    arg_tys
                                                    (LMatch GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))
    -> [LPat GhcTc]
    forall (id :: Pass) body.
    LMatch (GhcPass id) body -> [LPat (GhcPass id)]
    hsLMatchPats GenLocated
      SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))
    LMatch GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))
    m))

            -- Pattern match check warnings for /this match-group/.
            -- @rhss_nablas@ is a flat list of covered Nablas for each RHS.
            -- Each Match will split off one Nablas for its RHSs from this.
            ; [(Nablas, NonEmpty Nablas)]
    matches_nablas <- if DynFlags -> Origin -> HsMatchContext (GhcPass 'Renamed) -> Bool
    forall id. DynFlags -> Origin -> HsMatchContext id -> Bool
    isMatchContextPmChecked DynFlags
    dflags Origin
    origin HsMatchContext (GhcPass 'Renamed)
    ctxt
                then Maybe (LHsExpr GhcTc)
    -> [Id]
    -> DsM [(Nablas, NonEmpty Nablas)]
    -> DsM [(Nablas, NonEmpty Nablas)]
    forall a. Maybe (LHsExpr GhcTc) -> [Id] -> DsM a -> DsM a
    addHsScrutTmCs Maybe (LHsExpr GhcTc)
    mb_scr [Id]
    new_vars (DsM [(Nablas, NonEmpty Nablas)]
     -> DsM [(Nablas, NonEmpty Nablas)])
    -> DsM [(Nablas, NonEmpty Nablas)]
    -> DsM [(Nablas, NonEmpty Nablas)]
    forall a b. (a -> b) -> a -> b
    $
                     -- See Note [Long-distance information]
                     DsMatchContext
    -> [Id]
    -> [LMatch GhcTc (LHsExpr GhcTc)]
    -> DsM [(Nablas, NonEmpty Nablas)]
    pmcMatches (HsMatchContext (GhcPass 'Renamed) -> SrcSpan -> DsMatchContext
    DsMatchContext HsMatchContext (GhcPass 'Renamed)
    ctxt SrcSpan
    locn) [Id]
    new_vars [GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    [LMatch GhcTc (LHsExpr GhcTc)]
    matches
                else [(Nablas, NonEmpty Nablas)] -> DsM [(Nablas, NonEmpty Nablas)]
    forall (f :: * -> *) a. Applicative f => a -> f a
    pure ([LMatch GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))]
    -> [(Nablas, NonEmpty Nablas)]
    forall b. [LMatch GhcTc b] -> [(Nablas, NonEmpty Nablas)]
    initNablasMatches [GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    [LMatch GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))]
    matches)

            ; [EquationInfo]
    eqns_info   <- (GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))
     -> (Nablas, NonEmpty Nablas)
     -> IOEnv (Env DsGblEnv DsLclEnv) EquationInfo)
    -> [GenLocated
          SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    -> [(Nablas, NonEmpty Nablas)]
    -> IOEnv (Env DsGblEnv DsLclEnv) [EquationInfo]
    forall (m :: * -> *) a b c.
    Applicative m =>
    (a -> b -> m c) -> [a] -> [b] -> m [c]
    zipWithM GenLocated
      SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))
    -> (Nablas, NonEmpty Nablas)
    -> IOEnv (Env DsGblEnv DsLclEnv) EquationInfo
    LMatch GhcTc (LHsExpr GhcTc)
    -> (Nablas, NonEmpty Nablas)
    -> IOEnv (Env DsGblEnv DsLclEnv) EquationInfo
    mk_eqn_info [GenLocated
       SrcSpanAnnA (Match GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc)))]
    matches [(Nablas, NonEmpty Nablas)]
    matches_nablas

            ; CoreExpr
    result_expr <- DsM CoreExpr -> DsM CoreExpr
    handleWarnings (DsM CoreExpr -> DsM CoreExpr) -> DsM CoreExpr -> DsM CoreExpr
    forall a b. (a -> b) -> a -> b
    $
                             HsMatchContext (GhcPass 'Renamed)
    -> [Id] -> [EquationInfo] -> Kind -> DsM CoreExpr
    matchEquations HsMatchContext (GhcPass 'Renamed)
    ctxt [Id]
    new_vars [EquationInfo]
    eqns_info Kind
    rhs_ty
            ; ([Id], CoreExpr) -> DsM ([Id], CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return ([Id]
    new_vars, CoreExpr
    result_expr) }
      where
        -- Called once per equation in the match, or alternative in the case
        mk_eqn_info :: LMatch GhcTc (LHsExpr GhcTc) -> (Nablas, NonEmpty Nablas) -> DsM EquationInfo
        mk_eqn_info :: LMatch GhcTc (LHsExpr GhcTc)
    -> (Nablas, NonEmpty Nablas)
    -> IOEnv (Env DsGblEnv DsLclEnv) EquationInfo
    mk_eqn_info (L SrcSpanAnnA
    _ (Match { m_pats :: forall p body. Match p body -> [LPat p]
    m_pats = [LPat GhcTc]
    pats, m_grhss :: forall p body. Match p body -> GRHSs p body
    m_grhss = GRHSs GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))
    grhss })) (Nablas
    pat_nablas, NonEmpty Nablas
    rhss_nablas)
          = do { DynFlags
    dflags <- IOEnv (Env DsGblEnv DsLclEnv) DynFlags
    forall (m :: * -> *). HasDynFlags m => m DynFlags
    getDynFlags
               ; let upats :: [Pat GhcTc]
    upats = (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc)
    -> [GenLocated SrcSpanAnnA (Pat GhcTc)] -> [Pat GhcTc]
    forall a b. (a -> b) -> [a] -> [b]
    map (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc)
    -> (GenLocated SrcSpanAnnA (Pat GhcTc)
        -> GenLocated SrcSpanAnnA (Pat GhcTc))
    -> GenLocated SrcSpanAnnA (Pat GhcTc)
    -> Pat GhcTc
    forall b c a. (b -> c) -> (a -> b) -> a -> c
    . DynFlags -> LPat GhcTc -> LPat GhcTc
    decideBangHood DynFlags
    dflags) [GenLocated SrcSpanAnnA (Pat GhcTc)]
    [LPat GhcTc]
    pats
               -- pat_nablas is the covered set *after* matching the pattern, but
               -- before any of the GRHSs. We extend the environment with pat_nablas
               -- (via updPmNablas) so that the where-clause of 'grhss' can profit
               -- from that knowledge (#18533)
               ; MatchResult CoreExpr
    match_result <- Nablas -> DsM (MatchResult CoreExpr) -> DsM (MatchResult CoreExpr)
    forall a. Nablas -> DsM a -> DsM a
    updPmNablas Nablas
    pat_nablas (DsM (MatchResult CoreExpr) -> DsM (MatchResult CoreExpr))
    -> DsM (MatchResult CoreExpr) -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $
                                 HsMatchContext (GhcPass 'Renamed)
    -> GRHSs GhcTc (LHsExpr GhcTc)
    -> Kind
    -> NonEmpty Nablas
    -> DsM (MatchResult CoreExpr)
    dsGRHSs HsMatchContext (GhcPass 'Renamed)
    ctxt GRHSs GhcTc (GenLocated SrcSpanAnnA (HsExpr GhcTc))
    GRHSs GhcTc (LHsExpr GhcTc)
    grhss Kind
    rhs_ty NonEmpty Nablas
    rhss_nablas
               ; EquationInfo -> IOEnv (Env DsGblEnv DsLclEnv) EquationInfo
    forall (m :: * -> *) a. Monad m => a -> m a
    return EqnInfo { eqn_pats :: [Pat GhcTc]
    eqn_pats = [Pat GhcTc]
    upats
                                , eqn_orig :: Origin
    eqn_orig = Origin
    FromSource
                                , eqn_rhs :: MatchResult CoreExpr
    eqn_rhs  = MatchResult CoreExpr
    match_result } }

        handleWarnings :: DsM CoreExpr -> DsM CoreExpr
    handleWarnings = if Origin -> Bool
    isGenerated Origin
    origin
                         then DsM CoreExpr -> DsM CoreExpr
    forall a. DsM a -> DsM a
    discardWarningsDs
                         else DsM CoreExpr -> DsM CoreExpr
    forall a. a -> a
    id

        initNablasMatches :: [LMatch GhcTc b] -> [(Nablas, NonEmpty Nablas)]
        initNablasMatches :: forall b. [LMatch GhcTc b] -> [(Nablas, NonEmpty Nablas)]
    initNablasMatches [LMatch GhcTc b]
    ms
          = (GenLocated (Anno (Match GhcTc b)) (Match GhcTc b)
     -> (Nablas, NonEmpty Nablas))
    -> [GenLocated (Anno (Match GhcTc b)) (Match GhcTc b)]
    -> [(Nablas, NonEmpty Nablas)]
    forall a b. (a -> b) -> [a] -> [b]
    map (\(L Anno (Match GhcTc b)
    _ Match GhcTc b
    m) -> (Nablas
    initNablas, GRHSs GhcTc b -> NonEmpty Nablas
    forall b. GRHSs GhcTc b -> NonEmpty Nablas
    initNablasGRHSs (Match GhcTc b -> GRHSs GhcTc b
    forall p body. Match p body -> GRHSs p body
    m_grhss Match GhcTc b
    m))) [GenLocated (Anno (Match GhcTc b)) (Match GhcTc b)]
    [LMatch GhcTc b]
    ms

        initNablasGRHSs :: GRHSs GhcTc b -> NonEmpty Nablas
        initNablasGRHSs :: forall b. GRHSs GhcTc b -> NonEmpty Nablas
    initNablasGRHSs GRHSs GhcTc b
    m = String -> Maybe (NonEmpty Nablas) -> NonEmpty Nablas
    forall a. HasCallStack => String -> Maybe a -> a
    expectJust String
    "GRHSs non-empty"
                          (Maybe (NonEmpty Nablas) -> NonEmpty Nablas)
    -> Maybe (NonEmpty Nablas) -> NonEmpty Nablas
    forall a b. (a -> b) -> a -> b
    $ [Nablas] -> Maybe (NonEmpty Nablas)
    forall a. [a] -> Maybe (NonEmpty a)
    NEL.nonEmpty
                          ([Nablas] -> Maybe (NonEmpty Nablas))
    -> [Nablas] -> Maybe (NonEmpty Nablas)
    forall a b. (a -> b) -> a -> b
    $ Int -> Nablas -> [Nablas]
    forall a. Int -> a -> [a]
    replicate ([GenLocated (Anno (GRHS GhcTc b)) (GRHS GhcTc b)] -> Int
    forall (t :: * -> *) a. Foldable t => t a -> Int
    length (GRHSs GhcTc b -> [LGRHS GhcTc b]
    forall p body. GRHSs p body -> [LGRHS p body]
    grhssGRHSs GRHSs GhcTc b
    m)) Nablas
    initNablas

    matchEquations  :: HsMatchContext GhcRn
                    -> [MatchId] -> [EquationInfo] -> Type
                    -> DsM CoreExpr
    matchEquations :: HsMatchContext (GhcPass 'Renamed)
    -> [Id] -> [EquationInfo] -> Kind -> DsM CoreExpr
    matchEquations HsMatchContext (GhcPass 'Renamed)
    ctxt [Id]
    vars [EquationInfo]
    eqns_info Kind
    rhs_ty
      = do  { MatchResult CoreExpr
    match_result <- [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match [Id]
    vars Kind
    rhs_ty [EquationInfo]
    eqns_info

            ; CoreExpr
    fail_expr <- HsMatchContext (GhcPass 'Renamed) -> Kind -> DsM CoreExpr
    mkFailExpr HsMatchContext (GhcPass 'Renamed)
    ctxt Kind
    rhs_ty

            ; MatchResult CoreExpr -> CoreExpr -> DsM CoreExpr
    extractMatchResult MatchResult CoreExpr
    match_result CoreExpr
    fail_expr }

    -- | @matchSimply@ is a wrapper for 'match' which deals with the
    -- situation where we want to match a single expression against a single
    -- pattern. It returns an expression.
    matchSimply :: CoreExpr                 -- ^ Scrutinee
                -> HsMatchContext GhcRn     -- ^ Match kind
                -> LPat GhcTc               -- ^ Pattern it should match
                -> CoreExpr                 -- ^ Return this if it matches
                -> CoreExpr                 -- ^ Return this if it doesn't
                -> DsM CoreExpr
    -- Some reasons 'matchSimply' is not defined using 'matchWrapper' (#18572):
    --   * Some call sites like in 'deBindComp' specify a @fail_expr@ that isn't a
    --     straight @patError@
    --   * It receives an already desugared 'CoreExpr' for the scrutinee, not an
    --     'HsExpr' like 'matchWrapper' expects
    --   * Filling in all the phony fields for the 'MatchGroup' for a single pattern
    --     match is awkward
    --   * And we still export 'matchSinglePatVar', so not much is gained if we
    --     don't also implement it in terms of 'matchWrapper'
    matchSimply :: CoreExpr
    -> HsMatchContext (GhcPass 'Renamed)
    -> LPat GhcTc
    -> CoreExpr
    -> CoreExpr
    -> DsM CoreExpr
    matchSimply CoreExpr
    scrut HsMatchContext (GhcPass 'Renamed)
    hs_ctx LPat GhcTc
    pat CoreExpr
    result_expr CoreExpr
    fail_expr = do
        let
          match_result :: MatchResult CoreExpr
    match_result = CoreExpr -> MatchResult CoreExpr
    cantFailMatchResult CoreExpr
    result_expr
          rhs_ty :: Kind
    rhs_ty       = CoreExpr -> Kind
    exprType CoreExpr
    fail_expr
            -- Use exprType of fail_expr, because won't refine in the case of failure!
        MatchResult CoreExpr
    match_result' <- CoreExpr
    -> HsMatchContext (GhcPass 'Renamed)
    -> LPat GhcTc
    -> Kind
    -> MatchResult CoreExpr
    -> DsM (MatchResult CoreExpr)
    matchSinglePat CoreExpr
    scrut HsMatchContext (GhcPass 'Renamed)
    hs_ctx LPat GhcTc
    pat Kind
    rhs_ty MatchResult CoreExpr
    match_result
        MatchResult CoreExpr -> CoreExpr -> DsM CoreExpr
    extractMatchResult MatchResult CoreExpr
    match_result' CoreExpr
    fail_expr

    matchSinglePat :: CoreExpr -> HsMatchContext GhcRn -> LPat GhcTc
                   -> Type -> MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    -- matchSinglePat ensures that the scrutinee is a variable
    -- and then calls matchSinglePatVar
    --
    -- matchSinglePat does not warn about incomplete patterns
    -- Used for things like [ e | pat <- stuff ], where
    -- incomplete patterns are just fine

    matchSinglePat :: CoreExpr
    -> HsMatchContext (GhcPass 'Renamed)
    -> LPat GhcTc
    -> Kind
    -> MatchResult CoreExpr
    -> DsM (MatchResult CoreExpr)
    matchSinglePat (Var Id
    var) HsMatchContext (GhcPass 'Renamed)
    ctx LPat GhcTc
    pat Kind
    ty MatchResult CoreExpr
    match_result
      | Bool -> Bool
    not (Name -> Bool
    isExternalName (Id -> Name
    idName Id
    var))
      = Id
    -> Maybe CoreExpr
    -> HsMatchContext (GhcPass 'Renamed)
    -> LPat GhcTc
    -> Kind
    -> MatchResult CoreExpr
    -> DsM (MatchResult CoreExpr)
    matchSinglePatVar Id
    var Maybe CoreExpr
    forall a. Maybe a
    Nothing HsMatchContext (GhcPass 'Renamed)
    ctx LPat GhcTc
    pat Kind
    ty MatchResult CoreExpr
    match_result

    matchSinglePat CoreExpr
    scrut HsMatchContext (GhcPass 'Renamed)
    hs_ctx LPat GhcTc
    pat Kind
    ty MatchResult CoreExpr
    match_result
      = do { Id
    var           <- Kind -> LPat GhcTc -> DsM Id
    selectSimpleMatchVarL Kind
    Many LPat GhcTc
    pat
                                -- matchSinglePat is only used in matchSimply, which
                                -- is used in list comprehension, arrow notation,
                                -- and to create field selectors. All of which only
                                -- bind unrestricted variables, hence the 'Many'
                                -- above.
           ; MatchResult CoreExpr
    match_result' <- Id
    -> Maybe CoreExpr
    -> HsMatchContext (GhcPass 'Renamed)
    -> LPat GhcTc
    -> Kind
    -> MatchResult CoreExpr
    -> DsM (MatchResult CoreExpr)
    matchSinglePatVar Id
    var (CoreExpr -> Maybe CoreExpr
    forall a. a -> Maybe a
    Just CoreExpr
    scrut) HsMatchContext (GhcPass 'Renamed)
    hs_ctx LPat GhcTc
    pat Kind
    ty MatchResult CoreExpr
    match_result
           ; MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall (m :: * -> *) a. Monad m => a -> m a
    return (MatchResult CoreExpr -> DsM (MatchResult CoreExpr))
    -> MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    forall a b. (a -> b) -> a -> b
    $ Id -> CoreExpr -> DsWrapper
    bindNonRec Id
    var CoreExpr
    scrut DsWrapper -> MatchResult CoreExpr -> MatchResult CoreExpr
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    <$> MatchResult CoreExpr
    match_result'
           }

    matchSinglePatVar :: Id   -- See Note [Match Ids]
                      -> Maybe CoreExpr -- ^ The scrutinee the match id is bound to
                      -> HsMatchContext GhcRn -> LPat GhcTc
                      -> Type -> MatchResult CoreExpr -> DsM (MatchResult CoreExpr)
    matchSinglePatVar :: Id
    -> Maybe CoreExpr
    -> HsMatchContext (GhcPass 'Renamed)
    -> LPat GhcTc
    -> Kind
    -> MatchResult CoreExpr
    -> DsM (MatchResult CoreExpr)
    matchSinglePatVar Id
    var Maybe CoreExpr
    mb_scrut HsMatchContext (GhcPass 'Renamed)
    ctx LPat GhcTc
    pat Kind
    ty MatchResult CoreExpr
    match_result
      = ASSERT2( isInternalName (idName var), ppr var )
        do { DynFlags
    dflags <- IOEnv (Env DsGblEnv DsLclEnv) DynFlags
    forall (m :: * -> *). HasDynFlags m => m DynFlags
    getDynFlags
           ; SrcSpan
    locn   <- DsM SrcSpan
    getSrcSpanDs
           -- Pattern match check warnings
           ; Bool -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall (f :: * -> *). Applicative f => Bool -> f () -> f ()
    when (DynFlags -> Origin -> HsMatchContext (GhcPass 'Renamed) -> Bool
    forall id. DynFlags -> Origin -> HsMatchContext id -> Bool
    isMatchContextPmChecked DynFlags
    dflags Origin
    FromSource HsMatchContext (GhcPass 'Renamed)
    ctx) (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $
               Maybe CoreExpr
    -> [Id]
    -> TcRnIf DsGblEnv DsLclEnv ()
    -> TcRnIf DsGblEnv DsLclEnv ()
    forall a. Maybe CoreExpr -> [Id] -> DsM a -> DsM a
    addCoreScrutTmCs Maybe CoreExpr
    mb_scrut [Item [Id]
    Id
    var] (TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ())
    -> TcRnIf DsGblEnv DsLclEnv () -> TcRnIf DsGblEnv DsLclEnv ()
    forall a b. (a -> b) -> a -> b
    $
               DsMatchContext -> Id -> Pat GhcTc -> TcRnIf DsGblEnv DsLclEnv ()
    pmcPatBind (HsMatchContext (GhcPass 'Renamed) -> SrcSpan -> DsMatchContext
    DsMatchContext HsMatchContext (GhcPass 'Renamed)
    ctx SrcSpan
    locn) Id
    var (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    pat)

           ; let eqn_info :: EquationInfo
    eqn_info = EqnInfo { eqn_pats :: [Pat GhcTc]
    eqn_pats = [GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc (DynFlags -> LPat GhcTc -> LPat GhcTc
    decideBangHood DynFlags
    dflags LPat GhcTc
    pat)]
                                    , eqn_orig :: Origin
    eqn_orig = Origin
    FromSource
                                    , eqn_rhs :: MatchResult CoreExpr
    eqn_rhs  = MatchResult CoreExpr
    match_result }
           ; [Id] -> Kind -> [EquationInfo] -> DsM (MatchResult CoreExpr)
    match [Item [Id]
    Id
    var] Kind
    ty [Item [EquationInfo]
    EquationInfo
    eqn_info] }

    {-
    ************************************************************************
    *                                                                      *
                    Pattern classification
    *                                                                      *
    ************************************************************************
    -}

    data PatGroup
      = PgAny               -- Immediate match: variables, wildcards,
                            --                  lazy patterns
      | PgCon DataCon       -- Constructor patterns (incl list, tuple)
      | PgSyn PatSyn [Type] -- See Note [Pattern synonym groups]
      | PgLit Literal       -- Literal patterns
      | PgN   FractionalLit -- Overloaded numeric literals;
                            -- see Note [Don't use Literal for PgN]
      | PgOverS FastString  -- Overloaded string literals
      | PgNpK Integer       -- n+k patterns
      | PgBang              -- Bang patterns
      | PgCo Type           -- Coercion patterns; the type is the type
                            --      of the pattern *inside*
      | PgView (LHsExpr GhcTc) -- view pattern (e -> p):
                            -- the LHsExpr is the expression e
               Type         -- the Type is the type of p (equivalently, the result type of e)
      | PgOverloadedList

    {- Note [Don't use Literal for PgN]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    Previously we had, as PatGroup constructors

      | ...
      | PgN   Literal       -- Overloaded literals
      | PgNpK Literal       -- n+k patterns
      | ...

    But Literal is really supposed to represent an *unboxed* literal, like Int#.
    We were sticking the literal from, say, an overloaded numeric literal pattern
    into a LitInt constructor. This didn't really make sense; and we now have
    the invariant that value in a LitInt must be in the range of the target
    machine's Int# type, and an overloaded literal could meaningfully be larger.

    Solution: For pattern grouping purposes, just store the literal directly in
    the PgN constructor as a FractionalLit if numeric, and add a PgOverStr constructor
    for overloaded strings.
    -}

    groupEquations :: Platform -> [EquationInfo] -> [NonEmpty (PatGroup, EquationInfo)]
    -- If the result is of form [g1, g2, g3],
    -- (a) all the (pg,eq) pairs in g1 have the same pg
    -- (b) none of the gi are empty
    -- The ordering of equations is unchanged
    groupEquations :: Platform -> [EquationInfo] -> [NonEmpty (PatGroup, EquationInfo)]
    groupEquations Platform
    platform [EquationInfo]
    eqns
      = ((PatGroup, EquationInfo) -> (PatGroup, EquationInfo) -> Bool)
    -> [(PatGroup, EquationInfo)]
    -> [NonEmpty (PatGroup, EquationInfo)]
    forall (f :: * -> *) a.
    Foldable f =>
    (a -> a -> Bool) -> f a -> [NonEmpty a]
    NEL.groupBy (PatGroup, EquationInfo) -> (PatGroup, EquationInfo) -> Bool
    same_gp ([(PatGroup, EquationInfo)] -> [NonEmpty (PatGroup, EquationInfo)])
    -> [(PatGroup, EquationInfo)]
    -> [NonEmpty (PatGroup, EquationInfo)]
    forall a b. (a -> b) -> a -> b
    $ [(Platform -> Pat GhcTc -> PatGroup
    patGroup Platform
    platform (EquationInfo -> Pat GhcTc
    firstPat EquationInfo
    eqn), EquationInfo
    eqn) | EquationInfo
    eqn <- [EquationInfo]
    eqns]
      -- comprehension on NonEmpty
      where
        same_gp :: (PatGroup,EquationInfo) -> (PatGroup,EquationInfo) -> Bool
        (PatGroup
    pg1,EquationInfo
    _) same_gp :: (PatGroup, EquationInfo) -> (PatGroup, EquationInfo) -> Bool
    `same_gp` (PatGroup
    pg2,EquationInfo
    _) = PatGroup
    pg1 PatGroup -> PatGroup -> Bool
    `sameGroup` PatGroup
    pg2

    -- TODO Make subGroup1 using a NonEmptyMap
    subGroup :: (m -> [NonEmpty EquationInfo]) -- Map.elems
             -> m -- Map.empty
             -> (a -> m -> Maybe (NonEmpty EquationInfo)) -- Map.lookup
             -> (a -> NonEmpty EquationInfo -> m -> m) -- Map.insert
             -> [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    -- Input is a particular group.  The result sub-groups the
    -- equations by with particular constructor, literal etc they match.
    -- Each sub-list in the result has the same PatGroup
    -- See Note [Take care with pattern order]
    -- Parameterized by map operations to allow different implementations
    -- and constraints, eg. types without Ord instance.
    subGroup :: forall m a.
    (m -> [NonEmpty EquationInfo])
    -> m
    -> (a -> m -> Maybe (NonEmpty EquationInfo))
    -> (a -> NonEmpty EquationInfo -> m -> m)
    -> [(a, EquationInfo)]
    -> [NonEmpty EquationInfo]
    subGroup m -> [NonEmpty EquationInfo]
    elems m
    empty a -> m -> Maybe (NonEmpty EquationInfo)
    lookup a -> NonEmpty EquationInfo -> m -> m
    insert [(a, EquationInfo)]
    group
        = (NonEmpty EquationInfo -> NonEmpty EquationInfo)
    -> [NonEmpty EquationInfo] -> [NonEmpty EquationInfo]
    forall (f :: * -> *) a b. Functor f => (a -> b) -> f a -> f b
    fmap NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall a. NonEmpty a -> NonEmpty a
    NEL.reverse ([NonEmpty EquationInfo] -> [NonEmpty EquationInfo])
    -> [NonEmpty EquationInfo] -> [NonEmpty EquationInfo]
    forall a b. (a -> b) -> a -> b
    $ m -> [NonEmpty EquationInfo]
    elems (m -> [NonEmpty EquationInfo]) -> m -> [NonEmpty EquationInfo]
    forall a b. (a -> b) -> a -> b
    $ (m -> (a, EquationInfo) -> m) -> m -> [(a, EquationInfo)] -> m
    forall (t :: * -> *) b a.
    Foldable t =>
    (b -> a -> b) -> b -> t a -> b
    foldl' m -> (a, EquationInfo) -> m
    accumulate m
    empty [(a, EquationInfo)]
    group
      where
        accumulate :: m -> (a, EquationInfo) -> m
    accumulate m
    pg_map (a
    pg, EquationInfo
    eqn)
          = case a -> m -> Maybe (NonEmpty EquationInfo)
    lookup a
    pg m
    pg_map of
              Just NonEmpty EquationInfo
    eqns -> a -> NonEmpty EquationInfo -> m -> m
    insert a
    pg (EquationInfo -> NonEmpty EquationInfo -> NonEmpty EquationInfo
    forall a. a -> NonEmpty a -> NonEmpty a
    NEL.cons EquationInfo
    eqn NonEmpty EquationInfo
    eqns) m
    pg_map
              Maybe (NonEmpty EquationInfo)
    Nothing   -> a -> NonEmpty EquationInfo -> m -> m
    insert a
    pg [Item (NonEmpty EquationInfo)
    EquationInfo
    eqn] m
    pg_map
        -- pg_map :: Map a [EquationInfo]
        -- Equations seen so far in reverse order of appearance

    subGroupOrd :: Ord a => [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    subGroupOrd :: forall a. Ord a => [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    subGroupOrd = (Map a (NonEmpty EquationInfo) -> [NonEmpty EquationInfo])
    -> Map a (NonEmpty EquationInfo)
    -> (a
        -> Map a (NonEmpty EquationInfo) -> Maybe (NonEmpty EquationInfo))
    -> (a
        -> NonEmpty EquationInfo
        -> Map a (NonEmpty EquationInfo)
        -> Map a (NonEmpty EquationInfo))
    -> [(a, EquationInfo)]
    -> [NonEmpty EquationInfo]
    forall m a.
    (m -> [NonEmpty EquationInfo])
    -> m
    -> (a -> m -> Maybe (NonEmpty EquationInfo))
    -> (a -> NonEmpty EquationInfo -> m -> m)
    -> [(a, EquationInfo)]
    -> [NonEmpty EquationInfo]
    subGroup Map a (NonEmpty EquationInfo) -> [NonEmpty EquationInfo]
    forall k a. Map k a -> [a]
    Map.elems Map a (NonEmpty EquationInfo)
    forall k a. Map k a
    Map.empty a -> Map a (NonEmpty EquationInfo) -> Maybe (NonEmpty EquationInfo)
    forall k a. Ord k => k -> Map k a -> Maybe a
    Map.lookup a
    -> NonEmpty EquationInfo
    -> Map a (NonEmpty EquationInfo)
    -> Map a (NonEmpty EquationInfo)
    forall k a. Ord k => k -> a -> Map k a -> Map k a
    Map.insert

    subGroupUniq :: Uniquable a => [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    subGroupUniq :: forall a.
    Uniquable a =>
    [(a, EquationInfo)] -> [NonEmpty EquationInfo]
    subGroupUniq =
      (UniqDFM a (NonEmpty EquationInfo) -> [NonEmpty EquationInfo])
    -> UniqDFM a (NonEmpty EquationInfo)
    -> (a
        -> UniqDFM a (NonEmpty EquationInfo)
        -> Maybe (NonEmpty EquationInfo))
    -> (a
        -> NonEmpty EquationInfo
        -> UniqDFM a (NonEmpty EquationInfo)
        -> UniqDFM a (NonEmpty EquationInfo))
    -> [(a, EquationInfo)]
    -> [NonEmpty EquationInfo]
    forall m a.
    (m -> [NonEmpty EquationInfo])
    -> m
    -> (a -> m -> Maybe (NonEmpty EquationInfo))
    -> (a -> NonEmpty EquationInfo -> m -> m)
    -> [(a, EquationInfo)]
    -> [NonEmpty EquationInfo]
    subGroup UniqDFM a (NonEmpty EquationInfo) -> [NonEmpty EquationInfo]
    forall key elt. UniqDFM key elt -> [elt]
    eltsUDFM UniqDFM a (NonEmpty EquationInfo)
    forall key elt. UniqDFM key elt
    emptyUDFM ((UniqDFM a (NonEmpty EquationInfo)
     -> a -> Maybe (NonEmpty EquationInfo))
    -> a
    -> UniqDFM a (NonEmpty EquationInfo)
    -> Maybe (NonEmpty EquationInfo)
    forall a b c. (a -> b -> c) -> b -> a -> c
    flip UniqDFM a (NonEmpty EquationInfo)
    -> a -> Maybe (NonEmpty EquationInfo)
    forall key elt.
    Uniquable key =>
    UniqDFM key elt -> key -> Maybe elt
    lookupUDFM) (\a
    k NonEmpty EquationInfo
    v UniqDFM a (NonEmpty EquationInfo)
    m -> UniqDFM a (NonEmpty EquationInfo)
    -> a -> NonEmpty EquationInfo -> UniqDFM a (NonEmpty EquationInfo)
    forall key elt.
    Uniquable key =>
    UniqDFM key elt -> key -> elt -> UniqDFM key elt
    addToUDFM UniqDFM a (NonEmpty EquationInfo)
    m a
    k NonEmpty EquationInfo
    v)

    {- Note [Pattern synonym groups]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    If we see
      f (P a) = e1
      f (P b) = e2
        ...
    where P is a pattern synonym, can we put (P a -> e1) and (P b -> e2) in the
    same group?  We can if P is a constructor, but /not/ if P is a pattern synonym.
    Consider (#11224)
       -- readMaybe :: Read a => String -> Maybe a
       pattern PRead :: Read a => () => a -> String
       pattern PRead a <- (readMaybe -> Just a)

       f (PRead (x::Int))  = e1
       f (PRead (y::Bool)) = e2
    This is all fine: we match the string by trying to read an Int; if that
    fails we try to read a Bool. But clearly we can't combine the two into a single
    match.

    Conclusion: we can combine when we invoke PRead /at the same type/.  Hence
    in PgSyn we record the instantiating types, and use them in sameGroup.

    Note [Take care with pattern order]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    In the subGroup function we must be very careful about pattern re-ordering,
    Consider the patterns [ (True, Nothing), (False, x), (True, y) ]
    Then in bringing together the patterns for True, we must not
    swap the Nothing and y!
    -}

    sameGroup :: PatGroup -> PatGroup -> Bool
    -- Same group means that a single case expression
    -- or test will suffice to match both, *and* the order
    -- of testing within the group is insignificant.
    sameGroup :: PatGroup -> PatGroup -> Bool
    sameGroup PatGroup
    PgAny         PatGroup
    PgAny         = Bool
    True
    sameGroup PatGroup
    PgBang        PatGroup
    PgBang        = Bool
    True
    sameGroup (PgCon DataCon
    _)     (PgCon DataCon
    _)     = Bool
    True    -- One case expression
    sameGroup (PgSyn PatSyn
    p1 [Kind]
    t1) (PgSyn PatSyn
    p2 [Kind]
    t2) = PatSyn
    p1PatSyn -> PatSyn -> Bool
    forall a. Eq a => a -> a -> Bool
    ==PatSyn
    p2 Bool -> Bool -> Bool
    && [Kind] -> [Kind] -> Bool
    eqTypes [Kind]
    t1 [Kind]
    t2
                                                    -- eqTypes: See Note [Pattern synonym groups]
    sameGroup (PgLit Literal
    _)     (PgLit Literal
    _)     = Bool
    True    -- One case expression
    sameGroup (PgN FractionalLit
    l1)      (PgN FractionalLit
    l2)      = FractionalLit
    l1FractionalLit -> FractionalLit -> Bool
    forall a. Eq a => a -> a -> Bool
    ==FractionalLit
    l2  -- Order is significant
            -- Order is significant, match PgN after PgLit
            -- If the exponents are small check for value equality rather than syntactic equality
            -- This is implemented in the Eq instance for FractionalLit, we do this to avoid
            -- computing the value of excessivly large rationals.
    sameGroup (PgOverS FastString
    s1)  (PgOverS FastString
    s2)  = FastString
    s1FastString -> FastString -> Bool
    forall a. Eq a => a -> a -> Bool
    ==FastString
    s2
    sameGroup (PgNpK Integer
    l1)    (PgNpK Integer
    l2)    = Integer
    l1Integer -> Integer -> Bool
    forall a. Eq a => a -> a -> Bool
    ==Integer
    l2  -- See Note [Grouping overloaded literal patterns]
    sameGroup (PgCo Kind
    t1)     (PgCo Kind
    t2)     = Kind
    t1 Kind -> Kind -> Bool
    `eqType` Kind
    t2
            -- CoPats are in the same goup only if the type of the
            -- enclosed pattern is the same. The patterns outside the CoPat
            -- always have the same type, so this boils down to saying that
            -- the two coercions are identical.
    sameGroup (PgView LHsExpr GhcTc
    e1 Kind
    t1) (PgView LHsExpr GhcTc
    e2 Kind
    t2) = (LHsExpr GhcTc, Kind) -> (LHsExpr GhcTc, Kind) -> Bool
    viewLExprEq (LHsExpr GhcTc
    e1,Kind
    t1) (LHsExpr GhcTc
    e2,Kind
    t2)
           -- ViewPats are in the same group iff the expressions
           -- are "equal"---conservatively, we use syntactic equality
    sameGroup PatGroup
    _          PatGroup
    _          = Bool
    False

    -- An approximation of syntactic equality used for determining when view
    -- exprs are in the same group.
    -- This function can always safely return false;
    -- but doing so will result in the application of the view function being repeated.
    --
    -- Currently: compare applications of literals and variables
    --            and anything else that we can do without involving other
    --            HsSyn types in the recursion
    --
    -- NB we can't assume that the two view expressions have the same type.  Consider
    --   f (e1 -> True) = ...
    --   f (e2 -> "hi") = ...
    viewLExprEq :: (LHsExpr GhcTc,Type) -> (LHsExpr GhcTc,Type) -> Bool
    viewLExprEq :: (LHsExpr GhcTc, Kind) -> (LHsExpr GhcTc, Kind) -> Bool
    viewLExprEq (LHsExpr GhcTc
    e1,Kind
    _) (LHsExpr GhcTc
    e2,Kind
    _) = LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e2
      where
        lexp :: LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
        lexp :: LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e LHsExpr GhcTc
    e' = HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp (GenLocated SrcSpanAnnA (HsExpr GhcTc) -> HsExpr GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (HsExpr GhcTc)
    LHsExpr GhcTc
    e) (GenLocated SrcSpanAnnA (HsExpr GhcTc) -> HsExpr GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (HsExpr GhcTc)
    LHsExpr GhcTc
    e')

        ---------
        exp :: HsExpr GhcTc -> HsExpr GhcTc -> Bool
        -- real comparison is on HsExpr's
        -- strip parens
        exp :: HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp (HsPar XPar GhcTc
    _ (L SrcSpanAnnA
    _ HsExpr GhcTc
    e)) HsExpr GhcTc
    e'   = HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp HsExpr GhcTc
    e HsExpr GhcTc
    e'
        exp HsExpr GhcTc
    e (HsPar XPar GhcTc
    _ (L SrcSpanAnnA
    _ HsExpr GhcTc
    e'))   = HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp HsExpr GhcTc
    e HsExpr GhcTc
    e'
        -- because the expressions do not necessarily have the same type,
        -- we have to compare the wrappers
        exp (XExpr (WrapExpr (HsWrap HsWrapper
    h HsExpr GhcTc
    e))) (XExpr (WrapExpr (HsWrap  HsWrapper
    h' HsExpr GhcTc
    e'))) =
          HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    h HsWrapper
    h' Bool -> Bool -> Bool
    && HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp HsExpr GhcTc
    e HsExpr GhcTc
    e'
        exp (XExpr (ExpansionExpr (HsExpanded HsExpr (GhcPass 'Renamed)
    _ HsExpr GhcTc
    b))) (XExpr (ExpansionExpr (HsExpanded HsExpr (GhcPass 'Renamed)
    _ HsExpr GhcTc
    b'))) =
          HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp HsExpr GhcTc
    b HsExpr GhcTc
    b'
        exp (HsVar XVar GhcTc
    _ LIdP GhcTc
    i) (HsVar XVar GhcTc
    _ LIdP GhcTc
    i') =  GenLocated SrcSpanAnnN Id
    LIdP GhcTc
    i GenLocated SrcSpanAnnN Id -> GenLocated SrcSpanAnnN Id -> Bool
    forall a. Eq a => a -> a -> Bool
    == GenLocated SrcSpanAnnN Id
    LIdP GhcTc
    i'
        exp (HsConLikeOut XConLikeOut GhcTc
    _ ConLike
    c) (HsConLikeOut XConLikeOut GhcTc
    _ ConLike
    c') = ConLike
    c ConLike -> ConLike -> Bool
    forall a. Eq a => a -> a -> Bool
    == ConLike
    c'
        -- the instance for IPName derives using the id, so this works if the
        -- above does
        exp (HsIPVar XIPVar GhcTc
    _ HsIPName
    i) (HsIPVar XIPVar GhcTc
    _ HsIPName
    i') = HsIPName
    i HsIPName -> HsIPName -> Bool
    forall a. Eq a => a -> a -> Bool
    == HsIPName
    i'
        exp (HsOverLit XOverLitE GhcTc
    _ HsOverLit GhcTc
    l) (HsOverLit XOverLitE GhcTc
    _ HsOverLit GhcTc
    l') =
            -- Overloaded lits are equal if they have the same type
            -- and the data is the same.
            -- this is coarser than comparing the SyntaxExpr's in l and l',
            -- which resolve the overloading (e.g., fromInteger 1),
            -- because these expressions get written as a bunch of different variables
            -- (presumably to improve sharing)
            Kind -> Kind -> Bool
    eqType (HsOverLit GhcTc -> Kind
    overLitType HsOverLit GhcTc
    l) (HsOverLit GhcTc -> Kind
    overLitType HsOverLit GhcTc
    l') Bool -> Bool -> Bool
    && HsOverLit GhcTc
    l HsOverLit GhcTc -> HsOverLit GhcTc -> Bool
    forall a. Eq a => a -> a -> Bool
    == HsOverLit GhcTc
    l'
        exp (HsApp XApp GhcTc
    _ LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e2) (HsApp XApp GhcTc
    _ LHsExpr GhcTc
    e1' LHsExpr GhcTc
    e2') = LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e1' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e2 LHsExpr GhcTc
    e2'
        -- the fixities have been straightened out by now, so it's safe
        -- to ignore them?
        exp (OpApp XOpApp GhcTc
    _ LHsExpr GhcTc
    l LHsExpr GhcTc
    o LHsExpr GhcTc
    ri) (OpApp XOpApp GhcTc
    _ LHsExpr GhcTc
    l' LHsExpr GhcTc
    o' LHsExpr GhcTc
    ri') =
            LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    l LHsExpr GhcTc
    l' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    o LHsExpr GhcTc
    o' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    ri LHsExpr GhcTc
    ri'
        exp (NegApp XNegApp GhcTc
    _ LHsExpr GhcTc
    e SyntaxExpr GhcTc
    n) (NegApp XNegApp GhcTc
    _ LHsExpr GhcTc
    e' SyntaxExpr GhcTc
    n') = LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e LHsExpr GhcTc
    e' Bool -> Bool -> Bool
    && SyntaxExpr GhcTc -> SyntaxExpr GhcTc -> Bool
    syn_exp SyntaxExpr GhcTc
    n SyntaxExpr GhcTc
    n'
        exp (SectionL XSectionL GhcTc
    _ LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e2) (SectionL XSectionL GhcTc
    _ LHsExpr GhcTc
    e1' LHsExpr GhcTc
    e2') =
            LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e1' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e2 LHsExpr GhcTc
    e2'
        exp (SectionR XSectionR GhcTc
    _ LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e2) (SectionR XSectionR GhcTc
    _ LHsExpr GhcTc
    e1' LHsExpr GhcTc
    e2') =
            LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e1' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e2 LHsExpr GhcTc
    e2'
        exp (ExplicitTuple XExplicitTuple GhcTc
    _ [HsTupArg GhcTc]
    es1 Boxity
    _) (ExplicitTuple XExplicitTuple GhcTc
    _ [HsTupArg GhcTc]
    es2 Boxity
    _) =
            (HsTupArg GhcTc -> HsTupArg GhcTc -> Bool)
    -> [HsTupArg GhcTc] -> [HsTupArg GhcTc] -> Bool
    forall a. (a -> a -> Bool) -> [a] -> [a] -> Bool
    eq_list HsTupArg GhcTc -> HsTupArg GhcTc -> Bool
    tup_arg [HsTupArg GhcTc]
    es1 [HsTupArg GhcTc]
    es2
        exp (ExplicitSum XExplicitSum GhcTc
    _ Int
    _ Int
    _ LHsExpr GhcTc
    e) (ExplicitSum XExplicitSum GhcTc
    _ Int
    _ Int
    _ LHsExpr GhcTc
    e') = LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e LHsExpr GhcTc
    e'
        exp (HsIf XIf GhcTc
    _ LHsExpr GhcTc
    e LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e2) (HsIf XIf GhcTc
    _ LHsExpr GhcTc
    e' LHsExpr GhcTc
    e1' LHsExpr GhcTc
    e2') =
            LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e LHsExpr GhcTc
    e' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e1' Bool -> Bool -> Bool
    && LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e2 LHsExpr GhcTc
    e2'

        -- Enhancement: could implement equality for more expressions
        --   if it seems useful
        -- But no need for HsLit, ExplicitList, ExplicitTuple,
        -- because they cannot be functions
        exp HsExpr GhcTc
    _ HsExpr GhcTc
    _  = Bool
    False

        ---------
        syn_exp :: SyntaxExpr GhcTc -> SyntaxExpr GhcTc -> Bool
        syn_exp :: SyntaxExpr GhcTc -> SyntaxExpr GhcTc -> Bool
    syn_exp (SyntaxExprTc { syn_expr :: SyntaxExprTc -> HsExpr GhcTc
    syn_expr      = HsExpr GhcTc
    expr1
                              , syn_arg_wraps :: SyntaxExprTc -> [HsWrapper]
    syn_arg_wraps = [HsWrapper]
    arg_wraps1
                              , syn_res_wrap :: SyntaxExprTc -> HsWrapper
    syn_res_wrap  = HsWrapper
    res_wrap1 })
                (SyntaxExprTc { syn_expr :: SyntaxExprTc -> HsExpr GhcTc
    syn_expr      = HsExpr GhcTc
    expr2
                              , syn_arg_wraps :: SyntaxExprTc -> [HsWrapper]
    syn_arg_wraps = [HsWrapper]
    arg_wraps2
                              , syn_res_wrap :: SyntaxExprTc -> HsWrapper
    syn_res_wrap  = HsWrapper
    res_wrap2 })
          = HsExpr GhcTc -> HsExpr GhcTc -> Bool
    exp HsExpr GhcTc
    expr1 HsExpr GhcTc
    expr2 Bool -> Bool -> Bool
    &&
            [Bool] -> Bool
    forall (t :: * -> *). Foldable t => t Bool -> Bool
    and (String
    -> (HsWrapper -> HsWrapper -> Bool)
    -> [HsWrapper]
    -> [HsWrapper]
    -> [Bool]
    forall a b c. String -> (a -> b -> c) -> [a] -> [b] -> [c]
    zipWithEqual String
    "viewLExprEq" HsWrapper -> HsWrapper -> Bool
    wrap [HsWrapper]
    arg_wraps1 [HsWrapper]
    arg_wraps2) Bool -> Bool -> Bool
    &&
            HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    res_wrap1 HsWrapper
    res_wrap2
        syn_exp SyntaxExpr GhcTc
    SyntaxExprTc
    NoSyntaxExprTc SyntaxExpr GhcTc
    SyntaxExprTc
    NoSyntaxExprTc = Bool
    True
        syn_exp SyntaxExpr GhcTc
    _              SyntaxExpr GhcTc
    _              = Bool
    False

        ---------
        tup_arg :: HsTupArg GhcTc -> HsTupArg GhcTc -> Bool
    tup_arg (Present XPresent GhcTc
    _ LHsExpr GhcTc
    e1)           (Present XPresent GhcTc
    _ LHsExpr GhcTc
    e2)         = LHsExpr GhcTc -> LHsExpr GhcTc -> Bool
    lexp LHsExpr GhcTc
    e1 LHsExpr GhcTc
    e2
        tup_arg (Missing (Scaled Kind
    _ Kind
    t1)) (Missing (Scaled Kind
    _ Kind
    t2)) = Kind -> Kind -> Bool
    eqType Kind
    t1 Kind
    t2
        tup_arg HsTupArg GhcTc
    _ HsTupArg GhcTc
    _ = Bool
    False

        ---------
        wrap :: HsWrapper -> HsWrapper -> Bool
        -- Conservative, in that it demands that wrappers be
        -- syntactically identical and doesn't look under binders
        --
        -- Coarser notions of equality are possible
        -- (e.g., reassociating compositions,
        --        equating different ways of writing a coercion)
        wrap :: HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    WpHole HsWrapper
    WpHole = Bool
    True
        wrap (WpCompose HsWrapper
    w1 HsWrapper
    w2) (WpCompose HsWrapper
    w1' HsWrapper
    w2') = HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    w1 HsWrapper
    w1' Bool -> Bool -> Bool
    && HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    w2 HsWrapper
    w2'
        wrap (WpFun HsWrapper
    w1 HsWrapper
    w2 Scaled Kind
    _ SDoc
    _) (WpFun HsWrapper
    w1' HsWrapper
    w2' Scaled Kind
    _ SDoc
    _) = HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    w1 HsWrapper
    w1' Bool -> Bool -> Bool
    && HsWrapper -> HsWrapper -> Bool
    wrap HsWrapper
    w2 HsWrapper
    w2'
        wrap (WpCast TcCoercionR
    co)       (WpCast TcCoercionR
    co')        = TcCoercionR
    co TcCoercionR -> TcCoercionR -> Bool
    `eqCoercion` TcCoercionR
    co'
        wrap (WpEvApp EvTerm
    et1)     (WpEvApp EvTerm
    et2)       = EvTerm
    et1 EvTerm -> EvTerm -> Bool
    `ev_term` EvTerm
    et2
        wrap (WpTyApp Kind
    t)       (WpTyApp Kind
    t')        = Kind -> Kind -> Bool
    eqType Kind
    t Kind
    t'
        -- Enhancement: could implement equality for more wrappers
        --   if it seems useful (lams and lets)
        wrap HsWrapper
    _ HsWrapper
    _ = Bool
    False

        ---------
        ev_term :: EvTerm -> EvTerm -> Bool
        ev_term :: EvTerm -> EvTerm -> Bool
    ev_term (EvExpr (Var Id
    a)) (EvExpr  (Var Id
    b))
          = Id -> Kind
    idType Id
    a Kind -> Kind -> Bool
    `eqType` Id -> Kind
    idType Id
    b
            -- The /type/ of the evidence matters, not its precise proof term.
            -- Caveat: conceivably a sufficiently exotic use of incoherent instances
            -- could make a difference, but remember this is only used within the
            -- pattern matches for a single function, so it's hard to see how that
            -- could really happen.  And we don't want accidentally different proofs
            -- to prevent spotting equalities, and hence degrade pattern-match
            -- overlap checking.
        ev_term (EvExpr (Coercion TcCoercionR
    a)) (EvExpr (Coercion TcCoercionR
    b))
          = TcCoercionR
    a TcCoercionR -> TcCoercionR -> Bool
    `eqCoercion` TcCoercionR
    b
        ev_term EvTerm
    _ EvTerm
    _ = Bool
    False

        ---------
        eq_list :: (a->a->Bool) -> [a] -> [a] -> Bool
        eq_list :: forall a. (a -> a -> Bool) -> [a] -> [a] -> Bool
    eq_list a -> a -> Bool
    _  []     []     = Bool
    True
        eq_list a -> a -> Bool
    _  []     (a
    _:[a]
    _)  = Bool
    False
        eq_list a -> a -> Bool
    _  (a
    _:[a]
    _)  []     = Bool
    False
        eq_list a -> a -> Bool
    eq (a
    x:[a]
    xs) (a
    y:[a]
    ys) = a -> a -> Bool
    eq a
    x a
    y Bool -> Bool -> Bool
    && (a -> a -> Bool) -> [a] -> [a] -> Bool
    forall a. (a -> a -> Bool) -> [a] -> [a] -> Bool
    eq_list a -> a -> Bool
    eq [a]
    xs [a]
    ys

    patGroup :: Platform -> Pat GhcTc -> PatGroup
    patGroup :: Platform -> Pat GhcTc -> PatGroup
    patGroup Platform
    _ (ConPat { pat_con :: forall p. Pat p -> XRec p (ConLikeP p)
    pat_con = L SrcSpanAnnN
    _ ConLike
    con
                       , pat_con_ext :: forall p. Pat p -> XConPat p
    pat_con_ext = ConPatTc { cpt_arg_tys :: ConPatTc -> [Kind]
    cpt_arg_tys = [Kind]
    tys }
                       })
     | RealDataCon DataCon
    dcon <- ConLike
    con              = DataCon -> PatGroup
    PgCon DataCon
    dcon
     | PatSynCon PatSyn
    psyn <- ConLike
    con                = PatSyn -> [Kind] -> PatGroup
    PgSyn PatSyn
    psyn [Kind]
    tys
    patGroup Platform
    _ (WildPat {})                 = PatGroup
    PgAny
    patGroup Platform
    _ (BangPat {})                 = PatGroup
    PgBang
    patGroup Platform
    _ (NPat XNPat GhcTc
    _ (L SrcSpan
    _ (OverLit {ol_val :: forall p. HsOverLit p -> OverLitVal
    ol_val=OverLitVal
    oval})) Maybe (SyntaxExpr GhcTc)
    mb_neg SyntaxExpr GhcTc
    _) =
      case (OverLitVal
    oval, Maybe SyntaxExprTc -> Bool
    forall a. Maybe a -> Bool
    isJust Maybe (SyntaxExpr GhcTc)
    Maybe SyntaxExprTc
    mb_neg) of
        (HsIntegral   IntegralLit
    i, Bool
    is_neg) -> FractionalLit -> PatGroup
    PgN (Bool -> Integer -> FractionalLit
    integralFractionalLit Bool
    is_neg (if Bool
    is_neg
                                                                        then Integer -> Integer
    forall a. Num a => a -> a
    negate (IntegralLit -> Integer
    il_value IntegralLit
    i)
                                                                        else IntegralLit -> Integer
    il_value IntegralLit
    i))
        (HsFractional FractionalLit
    f, Bool
    is_neg)
          | Bool
    is_neg    -> FractionalLit -> PatGroup
    PgN (FractionalLit -> PatGroup) -> FractionalLit -> PatGroup
    forall a b. (a -> b) -> a -> b
    $! FractionalLit -> FractionalLit
    negateFractionalLit FractionalLit
    f
          | Bool
    otherwise -> FractionalLit -> PatGroup
    PgN FractionalLit
    f
        (HsIsString SourceText
    _ FastString
    s, Bool
    _) -> ASSERT(isNothing mb_neg)
                                FastString -> PatGroup
    PgOverS FastString
    s
    patGroup Platform
    _ (NPlusKPat XNPlusKPat GhcTc
    _ LIdP GhcTc
    _ (L SrcSpan
    _ (OverLit {ol_val :: forall p. HsOverLit p -> OverLitVal
    ol_val=OverLitVal
    oval})) HsOverLit GhcTc
    _ SyntaxExpr GhcTc
    _ SyntaxExpr GhcTc
    _) =
      case OverLitVal
    oval of
       HsIntegral IntegralLit
    i -> Integer -> PatGroup
    PgNpK (IntegralLit -> Integer
    il_value IntegralLit
    i)
       OverLitVal
    _ -> String -> SDoc -> PatGroup
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "patGroup NPlusKPat" (OverLitVal -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr OverLitVal
    oval)
    patGroup Platform
    _ (XPat (CoPat HsWrapper
    _ Pat GhcTc
    p Kind
    _))         = Kind -> PatGroup
    PgCo  (Pat GhcTc -> Kind
    hsPatType Pat GhcTc
    p)
                                                        -- Type of innelexp pattern
    patGroup Platform
    _ (ViewPat XViewPat GhcTc
    _ LHsExpr GhcTc
    expr LPat GhcTc
    p)           = LHsExpr GhcTc -> Kind -> PatGroup
    PgView LHsExpr GhcTc
    expr (Pat GhcTc -> Kind
    hsPatType (GenLocated SrcSpanAnnA (Pat GhcTc) -> Pat GhcTc
    forall l e. GenLocated l e -> e
    unLoc GenLocated SrcSpanAnnA (Pat GhcTc)
    LPat GhcTc
    p))
    patGroup Platform
    _ (ListPat (ListPatTc Kind
    _ (Just (Kind, SyntaxExpr GhcTc)
    _)) [LPat GhcTc]
    _) = PatGroup
    PgOverloadedList
    patGroup Platform
    platform (LitPat XLitPat GhcTc
    _ HsLit GhcTc
    lit)        = Literal -> PatGroup
    PgLit (Platform -> HsLit GhcTc -> Literal
    hsLitKey Platform
    platform HsLit GhcTc
    lit)
    patGroup Platform
    _ Pat GhcTc
    pat                          = String -> SDoc -> PatGroup
    forall a. HasCallStack => String -> SDoc -> a
    pprPanic String
    "patGroup" (Pat GhcTc -> SDoc
    forall a. Outputable a => a -> SDoc
    ppr Pat GhcTc
    pat)

    {-
    Note [Grouping overloaded literal patterns]
    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    WATCH OUT!  Consider

            f (n+1) = ...
            f (n+2) = ...
            f (n+1) = ...

    We can't group the first and third together, because the second may match
    the same thing as the first.  Same goes for *overloaded* literal patterns
            f 1 True = ...
            f 2 False = ...
            f 1 False = ...
    If the first arg matches '1' but the second does not match 'True', we
    cannot jump to the third equation!  Because the same argument might
    match '2'!
    Hence we don't regard 1 and 2, or (n+1) and (n+2), as part of the same group.
    -}