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--                                                              -*-haskell-*-
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-- ---------------------------------------------------------------------------
-- (c) The University of Glasgow 1997-2003
---
-- The GHC grammar.
--
-- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
-- ---------------------------------------------------------------------------

{
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{-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
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{-# OPTIONS -Wwarn -w #-}
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-- The above warning supression flag is a temporary kludge.
-- While working on this module you are encouraged to remove it and fix
-- any warnings in the module. See
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--     http://ghc.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
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-- for details

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-- | This module provides the generated Happy parser for Haskell. It exports
-- a number of parsers which may be used in any library that uses the GHC API.
-- A common usage pattern is to initialize the parser state with a given string
-- and then parse that string:
--
-- @
--     runParser :: DynFlags -> String -> P a -> ParseResult a
--     runParser flags str parser = unP parser parseState
--     where
--       filename = "\<interactive\>"
--       location = mkRealSrcLoc (mkFastString filename) 1 1
--       buffer = stringToStringBuffer str
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--       parseState = mkPState flags buffer location
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-- @
module Parser (parseModule, parseImport, parseStatement,
               parseDeclaration, parseExpression, parseTypeSignature,
               parseFullStmt, parseStmt, parseIdentifier,
               parseType, parseHeader) where

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-- base
import Control.Monad    ( unless, liftM )
import GHC.Exts
import Data.Char
import Control.Monad    ( mplus )
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-- compiler/hsSyn
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import HsSyn
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-- compiler/main
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import HscTypes         ( IsBootInterface, WarningTxt(..) )
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import DynFlags

-- compiler/utils
import OrdList
import BooleanFormula   ( BooleanFormula, mkAnd, mkOr, mkTrue, mkVar )
import FastString
import Maybes           ( orElse )
import Outputable

-- compiler/basicTypes
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import RdrName
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import OccName          ( varName, dataName, tcClsName, tvName, startsWithUnderscore )
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import DataCon          ( DataCon, dataConName )
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import SrcLoc
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import Module
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import BasicTypes

-- compiler/types
import Type             ( funTyCon )
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import Kind             ( Kind, liftedTypeKind, unliftedTypeKind, mkArrowKind )
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import Class            ( FunDep )
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-- compiler/parser
import RdrHsSyn
import Lexer
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import HaddockUtils
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import ApiAnnotation
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-- compiler/typecheck
import TcEvidence       ( emptyTcEvBinds )
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-- compiler/prelude
import ForeignCall
import TysPrim          ( liftedTypeKindTyConName, eqPrimTyCon )
import TysWiredIn       ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
                          unboxedUnitTyCon, unboxedUnitDataCon,
                          listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR, eqTyCon_RDR )
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-- compiler/utils
import Util             ( looksLikePackageName )

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}

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{- Last updated: 03 Mar 2015
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Conflicts: 48 shift/reduce
           1  reduce/reduce

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If you modify this parser and add a conflict, please update this comment.
You can learn more about the conflicts by passing 'happy' the -i flag:
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    happy -agc --strict compiler/parser/Parser.y -idetailed-info
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How is this section formatted? Look up the state the conflict is
reported at, and copy the list of applicable rules (at the top).  Mark
*** for the rule that is the conflicting reduction (that is, the
interpretation which is NOT taken).  NB: Happy doesn't print a rule in a
state if it is empty, but you should include it in the list (you can
look these up in the Grammar section of the info file).
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Obviously the state numbers are not stable across modifications to the parser,
the idea is to reproduce enough information on each conflict so you can figure
out what happened if the states were renumbered.  Try not to gratuitously move
productions around in this file.  It's probably less important to keep
the rule annotations up-to-date.
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-------------------------------------------------------------------------------
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state 0 contains 1 shift/reduce conflicts.
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    Conflicts: DOCNEXT (empty missing_module_keyword reduces)
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Ambiguity when the source file starts with "-- | doc". We need another
token of lookahead to determine if a top declaration or the 'module' keyword
follows. Shift parses as if the 'module' keyword follows.
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-------------------------------------------------------------------------------
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state 49 contains 10 shift/reduce conflicts.
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        context -> btype . '~' btype                        (rule 279)
        context -> btype .                                  (rule 280)
    *** type -> btype .                                     (rule 281)
        type -> btype . qtyconop type                       (rule 282)
        type -> btype . tyvarop type                        (rule 283)
        type -> btype . '->' ctype                          (rule 284)
        type -> btype . '~' btype                           (rule 285)
        type -> btype . SIMPLEQUOTE qconop type             (rule 286)
        type -> btype . SIMPLEQUOTE varop type              (rule 287)
        btype -> btype . atype                              (rule 299)
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    Conflicts: '->' '-' '!' '*' '.' '`' VARSYM CONSYM QVARSYM QCONSYM
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Example of ambiguity: 'e :: a `b` c';  does this mean
    (e::a) `b` c, or
    (e :: (a `b` c))
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The case for '->' involves view patterns rather than type operators:
    'case v of { x :: T -> T ... } '
    Which of these two is intended?
          case v of
            (x::T) -> T         -- Rhs is T
    or
          case v of
            (x::T -> T) -> ..   -- Rhs is ...
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-------------------------------------------------------------------------------
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state 118 contains 15 shift/reduce conflicts.
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        exp -> infixexp . '::' sigtype                      (rule 414)
        exp -> infixexp . '-<' exp                          (rule 415)
        exp -> infixexp . '>-' exp                          (rule 416)
        exp -> infixexp . '-<<' exp                         (rule 417)
        exp -> infixexp . '>>-' exp                         (rule 418)
    *** exp -> infixexp .                                   (rule 419)
        infixexp -> infixexp . qop exp10                    (rule 421)
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    Conflicts: ':' '::' '-' '!' '*' '-<' '>-' '-<<' '>>-'
               '.' '`' VARSYM CONSYM QVARSYM QCONSYM
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Examples of ambiguity:
    'if x then y else z -< e'
    'if x then y else z :: T'
    'if x then y else z + 1' (NB: '+' is in VARSYM)
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Shift parses as (per longest-parse rule):
    'if x then y else (z -< T)'
    'if x then y else (z :: T)'
    'if x then y else (z + 1)'
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-------------------------------------------------------------------------------
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state 276 contains 1 shift/reduce conflicts.
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        rule -> STRING . rule_activation rule_forall infixexp '=' exp    (rule 214)
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    Conflict: '[' (empty rule_activation reduces)
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We don't know whether the '[' starts the activation or not: it
might be the start of the declaration with the activation being
empty.  --SDM 1/4/2002
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Example ambiguity:
    '{-# RULE [0] f = ... #-}'
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We parse this as having a [0] rule activation for rewriting 'f', rather
a rule instructing how to rewrite the expression '[0] f'.
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-------------------------------------------------------------------------------
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state 285 contains 10 shift/reduce conflicts.
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    *** type -> btype .                                     (rule 281)
        type -> btype . qtyconop type                       (rule 282)
        type -> btype . tyvarop type                        (rule 283)
        type -> btype . '->' ctype                          (rule 284)
        type -> btype . '~' btype                           (rule 285)
        type -> btype . SIMPLEQUOTE qconop type             (rule 286)
        type -> btype . SIMPLEQUOTE varop type              (rule 287)
        btype -> btype . atype                              (rule 299)
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    Conflicts: [elided]
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Same as State 49, but minus the context productions.
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-------------------------------------------------------------------------------
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state 320 contains 1 shift/reduce conflicts.
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        tup_exprs -> commas . tup_tail                      (rule 502)
        sysdcon -> '(' commas . ')'                         (rule 610)
        commas -> commas . ','                              (rule 724)
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    Conflict: ')' (empty tup_tail reduces)
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A tuple section with NO free variables '(,,)' is indistinguishable
from the Haskell98 data constructor for a tuple.  Shift resolves in
favor of sysdcon, which is good because a tuple section will get rejected
if -XTupleSections is not specified.
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-------------------------------------------------------------------------------
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state 372 contains 1 shift/reduce conflicts.

        tup_exprs -> commas . tup_tail                      (rule 502)
        sysdcon -> '(#' commas . '#)'                       (rule 612)
        commas -> commas . ','                              (rule 724)

    Conflict: '#)' (empty tup_tail reduces)

Same as State 320 for unboxed tuples.

-------------------------------------------------------------------------------

state 400 contains 1 shift/reduce conflicts.

        exp10 -> 'let' binds . 'in' exp                     (rule 423)
        exp10 -> 'let' binds . 'in' error                   (rule 438)
        exp10 -> 'let' binds . error                        (rule 439)
    *** qual -> 'let' binds .                               (rule 576)

    Conflict: error

TODO: Why?

-------------------------------------------------------------------------------

state 432 contains 1 shift/reduce conflicts.

        atype -> SIMPLEQUOTE '[' . comma_types0 ']'         (rule 318)
        sysdcon -> '[' . ']'                                (rule 613)

    Conflict: ']' (empty comma_types0 reudes)

TODO: Why?

-------------------------------------------------------------------------------

state 461 contains 1 shift/reduce conflicts.

    *** strict_mark -> '{-# NOUNPACK' '#-}' .               (rule 268)
        strict_mark -> '{-# NOUNPACK' '#-}' . '!'           (rule 270)

    Conflict: '!'

TODO: Why?

-------------------------------------------------------------------------------

state 462 contains 1 shift/reduce conflicts.

    *** strict_mark -> '{-# UNPACK' '#-}' .                 (rule 267)
        strict_mark -> '{-# UNPACK' '#-}' . '!'             (rule 269)

    Conflict: '!'

Same as State 462

-------------------------------------------------------------------------------

state 493 contains 1 shift/reduce conflicts.

        context -> btype '~' btype .                        (rule 279)
    *** type -> btype '~' btype .                           (rule 285)
        btype -> btype . atype                              (rule 299)

    Conflict: '!'

TODO: Why?

-------------------------------------------------------------------------------

state 628 contains 1 shift/reduce conflicts.

    *** aexp2 -> ipvar .                                    (rule 462)
        dbind -> ipvar . '=' exp                            (rule 587)

    Conflict: '='

Example ambiguity: 'let ?x ...'

The parser can't tell whether the ?x is the lhs of a normal binding or
an implicit binding.  Fortunately, resolving as shift gives it the only
sensible meaning, namely the lhs of an implicit binding.

-------------------------------------------------------------------------------

state 695 contains 1 shift/reduce conflicts.

        rule -> STRING rule_activation . rule_forall infixexp '=' exp    (rule 214)

    Conflict: 'forall' (empty rule_forall reduces)

Example ambiguity: '{-# RULES "name" forall = ... #-}'

'forall' is a valid variable name---we don't know whether
to treat a forall on the input as the beginning of a quantifier
or the beginning of the rule itself.  Resolving to shift means
it's always treated as a quantifier, hence the above is disallowed.
This saves explicitly defining a grammar for the rule lhs that
doesn't include 'forall'.

-------------------------------------------------------------------------------

state 768 contains 1 shift/reduce conflicts.

    *** type -> btype '~' btype .                           (rule 285)
        btype -> btype . atype                              (rule 299)

    Conflict: '!'

TODO: Why?

-------------------------------------------------------------------------------

state 951 contains 1 shift/reduce conflicts.

        transformqual -> 'then' 'group' . 'using' exp       (rule 525)
        transformqual -> 'then' 'group' . 'by' exp 'using' exp    (rule 526)
    *** special_id -> 'group' .                             (rule 700)

    Conflict: 'by'

TODO: Why?

-------------------------------------------------------------------------------

state 1228 contains 1 reduce/reduce conflicts.

    *** tyconsym -> CONSYM .                                (rule 640)
        consym -> CONSYM .                                  (rule 710)

    Conflict: ')'

TODO: Why?  (NB: This one has been around for a while; it's quite puzzling
    because we really shouldn't get confused between tyconsym and consym.
    Trace the state machine, maybe?)
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-- -----------------------------------------------------------------------------
-- API Annotations
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--
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A lot of the productions are now cluttered with calls to
aa,am,ams,amms etc.

These are helper functions to make sure that the locations of the
various keywords such as do / let / in are captured for use by tools
that want to do source to source conversions, such as refactorers or
structured editors.

The helper functions are defined at the bottom of this file.

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See
  https://ghc.haskell.org/trac/ghc/wiki/ApiAnnotations and
  https://ghc.haskell.org/trac/ghc/wiki/GhcAstAnnotations
for some background.
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-- -----------------------------------------------------------------------------

-}

%token
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 '_'            { L _ ITunderscore }            -- Haskell keywords
 'as'           { L _ ITas }
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 'case'         { L _ ITcase }
 'class'        { L _ ITclass }
 'data'         { L _ ITdata }
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 'default'      { L _ ITdefault }
 'deriving'     { L _ ITderiving }
 'do'           { L _ ITdo }
 'else'         { L _ ITelse }
 'hiding'       { L _ IThiding }
 'if'           { L _ ITif }
 'import'       { L _ ITimport }
 'in'           { L _ ITin }
 'infix'        { L _ ITinfix }
 'infixl'       { L _ ITinfixl }
 'infixr'       { L _ ITinfixr }
 'instance'     { L _ ITinstance }
 'let'          { L _ ITlet }
 'module'       { L _ ITmodule }
 'newtype'      { L _ ITnewtype }
 'of'           { L _ ITof }
 'qualified'    { L _ ITqualified }
 'then'         { L _ ITthen }
 'type'         { L _ ITtype }
 'where'        { L _ ITwhere }

 'forall'       { L _ ITforall }                -- GHC extension keywords
 'foreign'      { L _ ITforeign }
 'export'       { L _ ITexport }
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 'label'        { L _ ITlabel }
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 'dynamic'      { L _ ITdynamic }
 'safe'         { L _ ITsafe }
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 'interruptible' { L _ ITinterruptible }
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 'unsafe'       { L _ ITunsafe }
 'mdo'          { L _ ITmdo }
 'family'       { L _ ITfamily }
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 'role'         { L _ ITrole }
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 'stdcall'      { L _ ITstdcallconv }
 'ccall'        { L _ ITccallconv }
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 'capi'         { L _ ITcapiconv }
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 'prim'         { L _ ITprimcallconv }
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 'javascript'   { L _ ITjavascriptcallconv }
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 'proc'         { L _ ITproc }          -- for arrow notation extension
 'rec'          { L _ ITrec }           -- for arrow notation extension
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 'group'    { L _ ITgroup }     -- for list transform extension
 'by'       { L _ ITby }        -- for list transform extension
 'using'    { L _ ITusing }     -- for list transform extension
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 'pattern'      { L _ ITpattern } -- for pattern synonyms
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 'static'       { L _ ITstatic }  -- for static pointers extension
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 '{-# INLINE'             { L _ (ITinline_prag _ _ _) }
 '{-# SPECIALISE'         { L _ (ITspec_prag _) }
 '{-# SPECIALISE_INLINE'  { L _ (ITspec_inline_prag _ _) }
 '{-# SOURCE'             { L _ (ITsource_prag _) }
 '{-# RULES'              { L _ (ITrules_prag _) }
 '{-# CORE'               { L _ (ITcore_prag _) }      -- hdaume: annotated core
 '{-# SCC'                { L _ (ITscc_prag _)}
 '{-# GENERATED'          { L _ (ITgenerated_prag _) }
 '{-# DEPRECATED'         { L _ (ITdeprecated_prag _) }
 '{-# WARNING'            { L _ (ITwarning_prag _) }
 '{-# UNPACK'             { L _ (ITunpack_prag _) }
 '{-# NOUNPACK'           { L _ (ITnounpack_prag _) }
 '{-# ANN'                { L _ (ITann_prag _) }
 '{-# VECTORISE'          { L _ (ITvect_prag _) }
 '{-# VECTORISE_SCALAR'   { L _ (ITvect_scalar_prag _) }
 '{-# NOVECTORISE'        { L _ (ITnovect_prag _) }
 '{-# MINIMAL'            { L _ (ITminimal_prag _) }
 '{-# CTYPE'              { L _ (ITctype _) }
 '{-# OVERLAPPING'        { L _ (IToverlapping_prag _) }
 '{-# OVERLAPPABLE'       { L _ (IToverlappable_prag _) }
 '{-# OVERLAPS'           { L _ (IToverlaps_prag _) }
 '{-# INCOHERENT'         { L _ (ITincoherent_prag _) }
 '#-}'                    { L _ ITclose_prag }
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 '..'           { L _ ITdotdot }                        -- reserved symbols
 ':'            { L _ ITcolon }
 '::'           { L _ ITdcolon }
 '='            { L _ ITequal }
 '\\'           { L _ ITlam }
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 'lcase'        { L _ ITlcase }
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 '|'            { L _ ITvbar }
 '<-'           { L _ ITlarrow }
 '->'           { L _ ITrarrow }
 '@'            { L _ ITat }
 '~'            { L _ ITtilde }
 '~#'           { L _ ITtildehsh }
 '=>'           { L _ ITdarrow }
 '-'            { L _ ITminus }
 '!'            { L _ ITbang }
 '*'            { L _ ITstar }
 '-<'           { L _ ITlarrowtail }            -- for arrow notation
 '>-'           { L _ ITrarrowtail }            -- for arrow notation
 '-<<'          { L _ ITLarrowtail }            -- for arrow notation
 '>>-'          { L _ ITRarrowtail }            -- for arrow notation
 '.'            { L _ ITdot }

 '{'            { L _ ITocurly }                        -- special symbols
 '}'            { L _ ITccurly }
 vocurly        { L _ ITvocurly } -- virtual open curly (from layout)
 vccurly        { L _ ITvccurly } -- virtual close curly (from layout)
 '['            { L _ ITobrack }
 ']'            { L _ ITcbrack }
 '[:'           { L _ ITopabrack }
 ':]'           { L _ ITcpabrack }
 '('            { L _ IToparen }
 ')'            { L _ ITcparen }
 '(#'           { L _ IToubxparen }
 '#)'           { L _ ITcubxparen }
 '(|'           { L _ IToparenbar }
 '|)'           { L _ ITcparenbar }
 ';'            { L _ ITsemi }
 ','            { L _ ITcomma }
 '`'            { L _ ITbackquote }
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 SIMPLEQUOTE    { L _ ITsimpleQuote      }     -- 'x
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 VARID          { L _ (ITvarid    _) }          -- identifiers
 CONID          { L _ (ITconid    _) }
 VARSYM         { L _ (ITvarsym   _) }
 CONSYM         { L _ (ITconsym   _) }
 QVARID         { L _ (ITqvarid   _) }
 QCONID         { L _ (ITqconid   _) }
 QVARSYM        { L _ (ITqvarsym  _) }
 QCONSYM        { L _ (ITqconsym  _) }
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 PREFIXQVARSYM  { L _ (ITprefixqvarsym  _) }
 PREFIXQCONSYM  { L _ (ITprefixqconsym  _) }
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 IPDUPVARID     { L _ (ITdupipvarid   _) }              -- GHC extension

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 CHAR           { L _ (ITchar   _ _) }
 STRING         { L _ (ITstring _ _) }
 INTEGER        { L _ (ITinteger _ _) }
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 RATIONAL       { L _ (ITrational _) }
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 PRIMCHAR       { L _ (ITprimchar   _ _) }
 PRIMSTRING     { L _ (ITprimstring _ _) }
 PRIMINTEGER    { L _ (ITprimint    _ _) }
 PRIMWORD       { L _ (ITprimword   _ _) }
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 PRIMFLOAT      { L _ (ITprimfloat  _) }
 PRIMDOUBLE     { L _ (ITprimdouble _) }

 DOCNEXT        { L _ (ITdocCommentNext _) }
 DOCPREV        { L _ (ITdocCommentPrev _) }
 DOCNAMED       { L _ (ITdocCommentNamed _) }
 DOCSECTION     { L _ (ITdocSection _ _) }
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-- Template Haskell
'[|'            { L _ ITopenExpQuote  }
'[p|'           { L _ ITopenPatQuote  }
'[t|'           { L _ ITopenTypQuote  }
'[d|'           { L _ ITopenDecQuote  }
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'|]'            { L _ ITcloseQuote    }
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'[||'           { L _ ITopenTExpQuote   }
'||]'           { L _ ITcloseTExpQuote  }
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TH_ID_SPLICE    { L _ (ITidEscape _)  }     -- $x
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'$('            { L _ ITparenEscape   }     -- $( exp )
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TH_ID_TY_SPLICE { L _ (ITidTyEscape _)  }   -- $$x
'$$('           { L _ ITparenTyEscape   }   -- $$( exp )
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TH_TY_QUOTE     { L _ ITtyQuote       }      -- ''T
TH_QUASIQUOTE   { L _ (ITquasiQuote _) }
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TH_QQUASIQUOTE  { L _ (ITqQuasiQuote _) }
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%monad { P } { >>= } { return }
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%lexer { (lexer True) } { L _ ITeof }
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%tokentype { (Located Token) }

-- Exported parsers
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%name parseModule module
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%name parseImport importdecl
%name parseStatement stmt
%name parseDeclaration topdecl
%name parseExpression exp
%name parseTypeSignature sigdecl
%name parseFullStmt   stmt
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%name parseStmt   maybe_stmt
%name parseIdentifier  identifier
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%name parseType ctype
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%partial parseHeader header
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%%

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-----------------------------------------------------------------------------
-- Identifiers; one of the entry points
identifier :: { Located RdrName }
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        : qvar                          { $1 }
        | qcon                          { $1 }
        | qvarop                        { $1 }
        | qconop                        { $1 }
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    | '(' '->' ')'      {% ams (sLL $1 $> $ getRdrName funTyCon)
                               [mj AnnOpenP $1,mj AnnRarrow $2,mj AnnCloseP $3] }
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-----------------------------------------------------------------------------
-- Module Header

-- The place for module deprecation is really too restrictive, but if it
-- was allowed at its natural place just before 'module', we get an ugly
-- s/r conflict with the second alternative. Another solution would be the
-- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
-- either, and DEPRECATED is only expected to be used by people who really
-- know what they are doing. :-)

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module :: { Located (HsModule RdrName) }
       : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
             {% fileSrcSpan >>= \ loc ->
                ams (L loc (HsModule (Just $3) $5 (fst $ snd $7)
                              (snd $ snd $7) $4 $1)
                    )
                    ([mj AnnModule $2, mj AnnWhere $6] ++ fst $7) }
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        | body2
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                {% fileSrcSpan >>= \ loc ->
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                   ams (L loc (HsModule Nothing Nothing
                               (fst $ snd $1) (snd $ snd $1) Nothing Nothing))
                       (fst $1) }
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maybedocheader :: { Maybe LHsDocString }
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        : moduleheader            { $1 }
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        | {- empty -}             { Nothing }
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missing_module_keyword :: { () }
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        : {- empty -}                           {% pushCurrentContext }
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maybemodwarning :: { Maybe (Located WarningTxt) }
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    : '{-# DEPRECATED' strings '#-}'
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                      {% ajs (Just (sLL $1 $> $ DeprecatedTxt (sL1 $1 (getDEPRECATED_PRAGs $1)) (snd $ unLoc $2)))
                             (mo $1:mc $3: (fst $ unLoc $2)) }
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    | '{-# WARNING' strings '#-}'
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                         {% ajs (Just (sLL $1 $> $ WarningTxt (sL1 $1 (getWARNING_PRAGs $1)) (snd $ unLoc $2)))
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                                (mo $1:mc $3 : (fst $ unLoc $2)) }
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    |  {- empty -}                  { Nothing }
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body    :: { ([AddAnn]
             ,([LImportDecl RdrName], [LHsDecl RdrName])) }
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        :  '{'            top '}'      { (moc $1:mcc $3:(fst $2)
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                                         , snd $2) }
        |      vocurly    top close    { (fst $2, snd $2) }

body2   :: { ([AddAnn]
             ,([LImportDecl RdrName], [LHsDecl RdrName])) }
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        :  '{' top '}'                          { (moc $1:mcc $3
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                                                   :(fst $2), snd $2) }
        |  missing_module_keyword top close     { ([],snd $2) }

top     :: { ([AddAnn]
             ,([LImportDecl RdrName], [LHsDecl RdrName])) }
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        : importdecls                   { (fst $1
                                          ,(reverse $ snd $1,[]))}
        | importdecls ';' cvtopdecls    {% if null (snd $1)
                                             then return ((mj AnnSemi $2:(fst $1))
                                                         ,(reverse $ snd $1,$3))
                                             else do
                                              { addAnnotation (gl $ head $ snd $1)
                                                              AnnSemi (gl $2)
                                              ; return (fst $1
                                                       ,(reverse $ snd $1,$3)) }}
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        | cvtopdecls                    { ([],([],$1)) }
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cvtopdecls :: { [LHsDecl RdrName] }
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        : topdecls                              { cvTopDecls $1 }
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-----------------------------------------------------------------------------
-- Module declaration & imports only

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header  :: { Located (HsModule RdrName) }
        : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
                {% fileSrcSpan >>= \ loc ->
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                   ams (L loc (HsModule (Just $3) $5 $7 [] $4 $1
                          )) [mj AnnModule $2,mj AnnWhere $6] }
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        | header_body2
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                {% fileSrcSpan >>= \ loc ->
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                   return (L loc (HsModule Nothing Nothing $1 [] Nothing
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                          Nothing)) }
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header_body :: { [LImportDecl RdrName] }
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        :  '{'            importdecls           { snd $2 }
        |      vocurly    importdecls           { snd $2 }
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header_body2 :: { [LImportDecl RdrName] }
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        :  '{' importdecls                      { snd $2 }
        |  missing_module_keyword importdecls   { snd $2 }
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-----------------------------------------------------------------------------
-- The Export List

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maybeexports :: { (Maybe (Located [LIE RdrName])) }
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        :  '(' exportlist ')'       {% ams (sLL $1 $> ()) [mop $1,mcp $3] >>
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                                       return (Just (sLL $1 $> (fromOL $2))) }
        |  {- empty -}              { Nothing }
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exportlist :: { OrdList (LIE RdrName) }
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        : expdoclist ',' expdoclist   {% addAnnotation (oll $1) AnnComma (gl $2)
                                         >> return ($1 `appOL` $3) }
        | exportlist1                 { $1 }
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exportlist1 :: { OrdList (LIE RdrName) }
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        : expdoclist export expdoclist ',' exportlist1
                          {% (addAnnotation (oll ($1 `appOL` $2 `appOL` $3))
                                            AnnComma (gl $4) ) >>
                              return ($1 `appOL` $2 `appOL` $3 `appOL` $5) }
        | expdoclist export expdoclist             { $1 `appOL` $2 `appOL` $3 }
        | expdoclist                               { $1 }
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expdoclist :: { OrdList (LIE RdrName) }
        : exp_doc expdoclist                           { $1 `appOL` $2 }
        | {- empty -}                                  { nilOL }
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exp_doc :: { OrdList (LIE RdrName) }
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        : docsection    { unitOL (sL1 $1 (case (unLoc $1) of (n, doc) -> IEGroup n doc)) }
        | docnamed      { unitOL (sL1 $1 (IEDocNamed ((fst . unLoc) $1))) }
        | docnext       { unitOL (sL1 $1 (IEDoc (unLoc $1))) }
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   -- No longer allow things like [] and (,,,) to be exported
   -- They are built in syntax, always available
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export  :: { OrdList (LIE RdrName) }
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        : qcname_ext export_subspec  {% amsu (sLL $1 $> (mkModuleImpExp $1
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                                                    (snd $ unLoc $2)))
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                                             (fst $ unLoc $2) }
        |  'module' modid            {% amsu (sLL $1 $> (IEModuleContents $2))
                                             [mj AnnModule $1] }
        |  'pattern' qcon            {% amsu (sLL $1 $> (IEVar $2))
                                             [mj AnnPattern $1] }

export_subspec :: { Located ([AddAnn],ImpExpSubSpec) }
        : {- empty -}             { sL0 ([],ImpExpAbs) }
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        | '(' '..' ')'            { sLL $1 $> ([mop $1,mcp $3,mj AnnDotdot $2]
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                                       , ImpExpAll) }
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        | '(' ')'                 { sLL $1 $> ([mop $1,mcp $2],ImpExpList []) }
        | '(' qcnames ')'         { sLL $1 $> ([mop $1,mcp $3],ImpExpList (reverse $2)) }
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qcnames :: { [Located RdrName] }     -- A reversed list
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        :  qcnames ',' qcname_ext       {% (aa (head $1) (AnnComma, $2)) >>
                                           return ($3  : $1) }
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        |  qcname_ext                   { [$1]  }
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qcname_ext :: { Located RdrName }       -- Variable or data constructor
                                        -- or tagged type constructor
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        :  qcname                   { $1 }
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        |  'type' qcname            {% amms (mkTypeImpExp (sLL $1 $> (unLoc $2)))
                                            [mj AnnType $1,mj AnnVal $2] }
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-- Cannot pull into qcname_ext, as qcname is also used in expression.
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qcname  :: { Located RdrName }  -- Variable or data constructor
        :  qvar                         { $1 }
        |  qcon                         { $1 }
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-----------------------------------------------------------------------------
-- Import Declarations

-- import decls can be *empty*, or even just a string of semicolons
-- whereas topdecls must contain at least one topdecl.

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importdecls :: { ([AddAnn],[LImportDecl RdrName]) }
        : importdecls ';' importdecl
                                {% if null (snd $1)
                                     then return (mj AnnSemi $2:fst $1,$3 : snd $1)
                                     else do
                                      { addAnnotation (gl $ head $ snd $1)
                                                      AnnSemi (gl $2)
                                      ; return (fst $1,$3 : snd $1) } }
        | importdecls ';'       {% if null (snd $1)
                                     then return ((mj AnnSemi $2:fst $1),snd $1)
                                     else do
                                       { addAnnotation (gl $ head $ snd $1)
                                                       AnnSemi (gl $2)
                                       ; return $1} }
        | importdecl             { ([],[$1]) }
        | {- empty -}            { ([],[]) }
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importdecl :: { LImportDecl RdrName }
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        : 'import' maybe_src maybe_safe optqualified maybe_pkg modid maybeas maybeimpspec
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                {% ams (L (comb4 $1 $6 (snd $7) $8) $
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                  ImportDecl { ideclSourceSrc = snd $ fst $2
                             , ideclName = $6, ideclPkgQual = snd $5
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                             , ideclSource = snd $2, ideclSafe = snd $3
                             , ideclQualified = snd $4, ideclImplicit = False
                             , ideclAs = unLoc (snd $7)
                             , ideclHiding = unLoc $8 })
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                   ((mj AnnImport $1 : (fst $ fst $2) ++ fst $3 ++ fst $4
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                                    ++ fst $5 ++ fst $7)) }
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maybe_src :: { (([AddAnn],Maybe SourceText),IsBootInterface) }
        : '{-# SOURCE' '#-}'        { (([mo $1,mc $2],Just (getSOURCE_PRAGs $1))
                                      ,True) }
        | {- empty -}               { (([],Nothing),False) }
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maybe_safe :: { ([AddAnn],Bool) }
        : 'safe'                                { ([mj AnnSafe $1],True) }
        | {- empty -}                           { ([],False) }

maybe_pkg :: { ([AddAnn],Maybe FastString) }
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        : STRING  {% let pkgFS = getSTRING $1 in
                     if looksLikePackageName (unpackFS pkgFS)
                        then return ([mj AnnPackageName $1], Just pkgFS)
                        else parseErrorSDoc (getLoc $1) $ vcat [
                             text "parse error" <> colon <+> quotes (ppr pkgFS),
                             text "Version number or non-alphanumeric" <+>
                             text "character in package name"] }
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        | {- empty -}                           { ([],Nothing) }

optqualified :: { ([AddAnn],Bool) }
        : 'qualified'                           { ([mj AnnQualified $1],True)  }
        | {- empty -}                           { ([],False) }

maybeas :: { ([AddAnn],Located (Maybe ModuleName)) }
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        : 'as' modid                           { ([mj AnnAs $1,mj AnnVal $2]
                                                 ,sLL $1 $> (Just (unLoc $2))) }
        | {- empty -}                          { ([],noLoc Nothing) }
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maybeimpspec :: { Located (Maybe (Bool, Located [LIE RdrName])) }
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        : impspec                  { L (gl $1) (Just (unLoc $1)) }
        | {- empty -}              { noLoc Nothing }
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impspec :: { Located (Bool, Located [LIE RdrName]) }
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        :  '(' exportlist ')'               {% ams (sLL $1 $> (False,
                                                      sLL $1 $> $ fromOL $2))
                                                   [mop $1,mcp $3] }
        |  'hiding' '(' exportlist ')'      {% ams (sLL $1 $> (True,
                                                      sLL $1 $> $ fromOL $3))
                                               [mj AnnHiding $1,mop $2,mcp $4] }
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-----------------------------------------------------------------------------
-- Fixity Declarations

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prec    :: { Located Int }
        : {- empty -}           { noLoc 9 }
        | INTEGER
                 {% checkPrecP (sL1 $1 (fromInteger (getINTEGER $1))) }
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infix   :: { Located FixityDirection }
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        : 'infix'                               { sL1 $1 InfixN  }
        | 'infixl'                              { sL1 $1 InfixL  }
        | 'infixr'                              { sL1 $1 InfixR }
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ops     :: { Located (OrdList (Located RdrName)) }
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        : ops ',' op       {% addAnnotation (oll $ unLoc $1) AnnComma (gl $2) >>
                              return (sLL $1 $> ((unLoc $1) `appOL` unitOL $3))}
        | op               { sL1 $1 (unitOL $1) }
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-----------------------------------------------------------------------------
-- Top-Level Declarations

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topdecls :: { OrdList (LHsDecl RdrName) }
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        : topdecls ';' topdecl        {% addAnnotation (oll $1) AnnSemi (gl $2)
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                                         >> return ($1 `appOL` $3) }
        | topdecls ';'                {% addAnnotation (oll $1) AnnSemi (gl $2)
                                         >> return $1 }
        | topdecl                     { $1 }
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topdecl :: { OrdList (LHsDecl RdrName) }
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        : cl_decl                               { unitOL (sL1 $1 (TyClD (unLoc $1))) }
        | ty_decl                               { unitOL (sL1 $1 (TyClD (unLoc $1))) }
        | inst_decl                             { unitOL (sL1 $1 (InstD (unLoc $1))) }
        | stand_alone_deriving                  { unitOL (sLL $1 $> (DerivD (unLoc $1))) }
        | role_annot                            { unitOL (sL1 $1 (RoleAnnotD (unLoc $1))) }
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        | 'default' '(' comma_types0 ')'    {% do { def <- checkValidDefaults $3
                                                  ; amsu (sLL $1 $> (DefD def))
                                                         [mj AnnDefault $1
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                                                         ,mop $2,mcp $4] }}
        | 'foreign' fdecl          {% amsu (sLL $1 $> (snd $ unLoc $2))
                                           (mj AnnForeign $1:(fst $ unLoc $2)) }
        | '{-# DEPRECATED' deprecations '#-}'   {% amsu (sLL $1 $> $ WarningD (Warnings (getDEPRECATED_PRAGs $1) (fromOL $2)))
                                                       [mo $1,mc $3] }
        | '{-# WARNING' warnings '#-}'          {% amsu (sLL $1 $> $ WarningD (Warnings (getWARNING_PRAGs $1) (fromOL $2)))
                                                       [mo $1,mc $3] }
        | '{-# RULES' rules '#-}'               {% amsu (sLL $1 $> $ RuleD (HsRules (getRULES_PRAGs $1) (fromOL $2)))
                                                       [mo $1,mc $3] }
        | '{-# VECTORISE' qvar '=' exp '#-}' {% amsu (sLL $1 $> $ VectD (HsVect (getVECT_PRAGs $1) $2 $4))
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                                                    [mo $1,mj AnnEqual $3
                                                    ,mc $5] }
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        | '{-# NOVECTORISE' qvar '#-}'       {% amsu (sLL $1 $> $ VectD (HsNoVect (getNOVECT_PRAGs $1) $2))
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                                                     [mo $1,mc $3] }
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        | '{-# VECTORISE' 'type' gtycon '#-}'
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                                {% amsu (sLL $1 $> $
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                                    VectD (HsVectTypeIn (getVECT_PRAGs $1) False $3 Nothing))
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                                    [mo $1,mj AnnType $2,mc $4] }

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        | '{-# VECTORISE_SCALAR' 'type' gtycon '#-}'
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                                {% amsu (sLL $1 $> $
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                                    VectD (HsVectTypeIn (getVECT_SCALAR_PRAGs $1) True $3 Nothing))
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                                    [mo $1,mj AnnType $2,mc $4] }

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        | '{-# VECTORISE' 'type' gtycon '=' gtycon '#-}'
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                                {% amsu (sLL $1 $> $
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                                    VectD (HsVectTypeIn (getVECT_PRAGs $1) False $3 (Just $5)))
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                                    [mo $1,mj AnnType $2,mj AnnEqual $4,mc $6] }
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        | '{-# VECTORISE_SCALAR' 'type' gtycon '=' gtycon '#-}'
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                                {% amsu (sLL $1 $> $
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                                    VectD (HsVectTypeIn (getVECT_SCALAR_PRAGs $1) True $3 (Just $5)))
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                                    [mo $1,mj AnnType $2,mj AnnEqual $4,mc $6] }

        | '{-# VECTORISE' 'class' gtycon '#-}'
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                                         {% amsu (sLL $1 $>  $ VectD (HsVectClassIn (getVECT_PRAGs $1) $3))
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                                                 [mo $1,mj AnnClass $2,mc $4] }
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        | annotation { unitOL $1 }
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        | decl_no_th                            { unLoc $1 }
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        -- Template Haskell Extension
        -- The $(..) form is one possible form of infixexp
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        -- but we treat an arbitrary expression just as if
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        -- it had a $(..) wrapped around it
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        | infixexp                              { unitOL (sLL $1 $> $ mkSpliceDecl $1) }
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-- Type classes
--
cl_decl :: { LTyClDecl RdrName }
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        : 'class' tycl_hdr fds where_cls
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                {% amms (mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 (snd $ unLoc $4))
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                        (mj AnnClass $1:(fst $ unLoc $3)++(fst $ unLoc $4)) }
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-- Type declarations (toplevel)
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--
ty_decl :: { LTyClDecl RdrName }
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           -- ordinary type synonyms
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        : 'type' type '=' ctypedoc
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                -- Note ctype, not sigtype, on the right of '='
                -- We allow an explicit for-all but we don't insert one
                -- in   type Foo a = (b,b)
                -- Instead we just say b is out of scope
                --
                -- Note the use of type for the head; this allows
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                -- infix type constructors to be declared
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                {% amms (mkTySynonym (comb2 $1 $4) $2 $4)
                        [mj AnnType $1,mj AnnEqual $3] }
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           -- type family declarations
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        | 'type' 'family' type opt_kind_sig where_type_family
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                -- Note the use of type for the head; this allows
                -- infix type constructors to be declared
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                {% amms (mkFamDecl (comb4 $1 $3 $4 $5) (snd $ unLoc $5) $3
                                   (unLoc $4))
                        (mj AnnType $1:mj AnnFamily $2:(fst $ unLoc $5)) }
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          -- ordinary data type or newtype declaration
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        | data_or_newtype capi_ctype tycl_hdr constrs deriving
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                {% amms (mkTyData (comb4 $1 $3 $4 $5) (snd $ unLoc $1) $2 $3
                           Nothing (reverse (snd $ unLoc $4))
                                   (unLoc $5))
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                                   -- We need the location on tycl_hdr in case
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                                   -- constrs and deriving are both empty
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                        ((fst $ unLoc $1):(fst $ unLoc $4)) }
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          -- ordinary GADT declaration
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        | data_or_newtype capi_ctype tycl_hdr opt_kind_sig
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                 gadt_constrlist
                 deriving
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            {% amms (mkTyData (comb4 $1 $3 $5 $6) (snd $ unLoc $1) $2 $3
                            (unLoc $4) (snd $ unLoc $5) (unLoc $6) )
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                                   -- We need the location on tycl_hdr in case
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                                   -- constrs and deriving are both empty
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                    ((fst $ unLoc $1):(fst $ unLoc $5)) }
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          -- data/newtype family
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        | 'data' 'family' type opt_kind_sig
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                {% amms (mkFamDecl (comb3 $1 $2 $4) DataFamily $3 (unLoc $4))
                        [mj AnnData $1,mj AnnFamily $2] }
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inst_decl :: { LInstDecl RdrName }
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        : 'instance' overlap_pragma inst_type where_inst
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       {% do { (binds, sigs, _, ats, adts, _) <- cvBindsAndSigs (snd $ unLoc $4)
             ; let cid = ClsInstDecl { cid_poly_ty = $3, cid_binds = binds
                                     , cid_sigs = sigs, cid_tyfam_insts = ats
                                     , cid_overlap_mode = $2
                                     , cid_datafam_insts = adts }
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             ; let err = text "In instance head:" <+> ppr $3
             ; checkNoPartialType err $3
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             ; sequence_ [ checkNoPartialType err ty
                         | sig@(L _ (TypeSig _ ty _ )) <- sigs
                         , let err = text "in instance signature" <> colon
                                     <+> quotes (ppr sig) ]
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             ; ams (L (comb3 $1 $3 $4) (ClsInstD { cid_inst = cid }))
                   (mj AnnInstance $1 : (fst $ unLoc $4)) } }
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           -- type instance declarations
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        | 'type' 'instance' ty_fam_inst_eqn
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                {% amms (mkTyFamInst (comb2 $1 $3) $3)
                    [mj AnnType $1,mj AnnInstance $2] }
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          -- data/newtype instance declaration
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        | data_or_newtype 'instance' capi_ctype tycl_hdr constrs deriving
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            {% amms (mkDataFamInst (comb4 $1 $4 $5 $6) (snd $ unLoc $1) $3 $4
                                      Nothing (reverse (snd  $ unLoc $5))
                                              (unLoc $6))
                    ((fst $ unLoc $1):mj AnnInstance $2:(fst $ unLoc $5)) }
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          -- GADT instance declaration
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        | data_or_newtype 'instance' capi_ctype tycl_hdr opt_kind_sig
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                 gadt_constrlist
                 deriving
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            {% amms (mkDataFamInst (comb4 $1 $4 $6 $7) (snd $ unLoc $1) $3 $4
                                   (unLoc $5) (snd $ unLoc $6) (unLoc $7))
                    ((fst $ unLoc $1):mj AnnInstance $2
                       :(fst $ unLoc $6)) }
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overlap_pragma :: { Maybe (Located OverlapMode) }
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  : '{-# OVERLAPPABLE'    '#-}' {% ajs (Just (sLL $1 $> (Overlappable (getOVERLAPPABLE_PRAGs $1))))
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                                       [mo $1,mc $2] }
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  | '{-# OVERLAPPING'     '#-}' {% ajs (Just (sLL $1 $> (Overlapping (getOVERLAPPING_PRAGs $1))))
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                                       [mo $1,mc $2] }
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  | '{-# OVERLAPS'        '#-}' {% ajs (Just (sLL $1 $> (Overlaps (getOVERLAPS_PRAGs $1))))
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                                       [mo $1,mc $2] }
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  | '{-# INCOHERENT'      '#-}' {% ajs (Just (sLL $1 $> (Incoherent (getINCOHERENT_PRAGs $1))))
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                                       [mo $1,mc $2] }
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  | {- empty -}                 { Nothing }
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-- Closed type families

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where_type_family :: { Located ([AddAnn],FamilyInfo RdrName) }
        : {- empty -}                      { noLoc ([],OpenTypeFamily) }
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        | 'where' ty_fam_inst_eqn_list
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               { sLL $1 $> (mj AnnWhere $1:(fst $ unLoc $2)
                    ,ClosedTypeFamily (reverse (snd $ unLoc $2))) }

ty_fam_inst_eqn_list :: { Located ([AddAnn],[LTyFamInstEqn RdrName]) }
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        :     '{' ty_fam_inst_eqns '}'     { sLL $1 $> ([moc $1,mcc $3]
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                                                ,unLoc $2) }
        | vocurly ty_fam_inst_eqns close   { let L loc _ = $2 in
                                             L loc ([],unLoc $2) }
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        |     '{' '..' '}'                 { sLL $1 $> ([moc $1,mj AnnDotdot $2
                                                 ,mcc $3],[]) }
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        | vocurly '..' close               { let L loc _ = $2 in
                                             L loc ([mj AnnDotdot $2],[]) }
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ty_fam_inst_eqns :: { Located [LTyFamInstEqn RdrName] }
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        : ty_fam_inst_eqns ';' ty_fam_inst_eqn
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                                      {% asl (unLoc $1) $2 $3
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                                         >> return (sLL $1 $> ($3 : unLoc $1)) }
        | ty_fam_inst_eqns ';'        {% addAnnotation (gl $1) AnnSemi (gl $2)
                                         >> return (sLL $1 $>  (unLoc $1)) }
        | ty_fam_inst_eqn             { sLL $1 $> [$1] }
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ty_fam_inst_eqn :: { LTyFamInstEqn RdrName }
        : type '=' ctype
                -- Note the use of type for the head; this allows
                -- infix type constructors and type patterns
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              {% do { (eqn,ann) <- mkTyFamInstEqn $1 $3
                    ; ams (sLL $1 $> eqn) (mj AnnEqual $2:ann) } }
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-- Associated type family declarations
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--
-- * They have a different syntax than on the toplevel (no family special
--   identifier).
--
-- * They also need to be separate from instances; otherwise, data family
--   declarations without a kind signature cause parsing conflicts with empty
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--   data declarations.
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--