Parser.y.pp 90.3 KB
Newer Older
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1
--                                                              -*-haskell-*-
2 3 4 5 6 7 8 9 10
-- ---------------------------------------------------------------------------
-- (c) The University of Glasgow 1997-2003
---
-- The GHC grammar.
--
-- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
-- ---------------------------------------------------------------------------

{
11
{-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
12
{-# OPTIONS -Wwarn -w #-}
13 14 15 16 17 18
-- 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
--     http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
-- for details

19 20 21 22 23 24 25 26
{-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
{-
Careful optimisation of the parser: we don't want to throw everything
at it, because that takes too long and doesn't buy much, but we do want
to inline certain key external functions, so we instruct GHC not to
throw away inlinings as it would normally do in -O0 mode.
-}

27
module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
28
                parseHeader ) where
29 30 31

import HsSyn
import RdrHsSyn
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
32
import HscTypes         ( IsBootInterface, WarningTxt(..) )
33 34
import Lexer
import RdrName
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
35 36 37 38 39 40 41 42 43 44
import TysPrim          ( eqPrimTyCon )
import TysWiredIn       ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
                          unboxedSingletonTyCon, unboxedSingletonDataCon,
                          listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR, eqTyCon_RDR )
import Type             ( funTyCon )
import ForeignCall      ( Safety(..), CExportSpec(..), CLabelString,
                          CCallConv(..), CCallTarget(..), defaultCCallConv
                        )
import OccName          ( varName, dataName, tcClsName, tvName )
import DataCon          ( DataCon, dataConName )
Ian Lynagh's avatar
Ian Lynagh committed
45
import SrcLoc
46
import Module
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
47 48 49 50
import StaticFlags      ( opt_SccProfilingOn, opt_Hpc )
import Type             ( Kind, liftedTypeKind, unliftedTypeKind )
import Coercion         ( mkArrowKind )
import Class            ( FunDep )
51
import BasicTypes
52
import DynFlags
53
import OrdList
54
import HaddockUtils
55 56

import FastString
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
57
import Maybes           ( orElse )
58
import Outputable
59

60
import Control.Monad    ( unless )
Simon Marlow's avatar
Simon Marlow committed
61
import GHC.Exts
62 63
import Data.Char
import Control.Monad    ( mplus )
64 65 66
}

{-
67 68 69 70 71 72 73 74 75 76 77
-----------------------------------------------------------------------------
24 Februar 2006

Conflicts: 33 shift/reduce
           1 reduce/reduce

The reduce/reduce conflict is weird.  It's between tyconsym and consym, and I
would think the two should never occur in the same context.

  -=chak

78 79 80 81 82 83 84 85 86 87 88
-----------------------------------------------------------------------------
31 December 2006

Conflicts: 34 shift/reduce
           1 reduce/reduce

The reduce/reduce conflict is weird.  It's between tyconsym and consym, and I
would think the two should never occur in the same context.

  -=chak

89 90 91 92 93 94 95 96 97 98 99
-----------------------------------------------------------------------------
6 December 2006

Conflicts: 32 shift/reduce
           1 reduce/reduce

The reduce/reduce conflict is weird.  It's between tyconsym and consym, and I
would think the two should never occur in the same context.

  -=chak

100 101 102 103 104 105 106 107 108 109 110
-----------------------------------------------------------------------------
26 July 2006

Conflicts: 37 shift/reduce
           1 reduce/reduce

The reduce/reduce conflict is weird.  It's between tyconsym and consym, and I
would think the two should never occur in the same context.

  -=chak

111
-----------------------------------------------------------------------------
112
Conflicts: 38 shift/reduce (1.25)
113

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
114 115 116
10 for abiguity in 'if x then y else z + 1'             [State 178]
        (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
        10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
117

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
118 119
1 for ambiguity in 'if x then y else z :: T'            [State 178]
        (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
120

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
121 122 123
4 for ambiguity in 'if x then y else z -< e'            [State 178]
        (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
        There are four such operators: -<, >-, -<<, >>-
124 125


chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
126 127 128 129
2 for ambiguity in 'case v of { x :: T -> T ... } '     [States 11, 253]
        Which of these two is intended?
          case v of
            (x::T) -> T         -- Rhs is T
130
    or
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
131 132
          case v of
            (x::T -> T) -> ..   -- Rhs is ...
133

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
134 135 136
10 for ambiguity in 'e :: a `b` c'.  Does this mean     [States 11, 253]
        (e::a) `b` c, or 
        (e :: (a `b` c))
137
    As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
138
    Same duplication between states 11 and 253 as the previous case
139

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
140 141 142 143
1 for ambiguity in 'let ?x ...'                         [State 329]
        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.
144

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
145 146 147 148
1 for ambiguity in '{-# RULES "name" [ ... #-}          [State 382]
        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
149

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
150 151 152 153 154 155 156
1 for ambiguity in '{-# RULES "name" forall = ... #-}'  [State 474]
        since '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'.
157

158 159 160 161
1 for 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.   

162 163 164 165 166 167 168 169 170 171
-- ---------------------------------------------------------------------------
-- Adding location info

This is done in a stylised way using the three macros below, L0, L1
and LL.  Each of these macros can be thought of as having type

   L0, L1, LL :: a -> Located a

They each add a SrcSpan to their argument.

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
172
   L0   adds 'noSrcSpan', used for empty productions
173
     -- This doesn't seem to work anymore -=chak
174 175

   L1   for a production with a single token on the lhs.  Grabs the SrcSpan
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
176
        from that token.
177 178 179 180 181 182 183 184 185

   LL   for a production with >1 token on the lhs.  Makes up a SrcSpan from
        the first and last tokens.

These suffice for the majority of cases.  However, we must be
especially careful with empty productions: LL won't work if the first
or last token on the lhs can represent an empty span.  In these cases,
we have to calculate the span using more of the tokens from the lhs, eg.

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
186 187 188
        | 'newtype' tycl_hdr '=' newconstr deriving
                { L (comb3 $1 $4 $5)
                    (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208

We provide comb3 and comb4 functions which are useful in such cases.

Be careful: there's no checking that you actually got this right, the
only symptom will be that the SrcSpans of your syntax will be
incorrect.

/*
 * We must expand these macros *before* running Happy, which is why this file is
 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
 */
#define L0   L noSrcSpan
#define L1   sL (getLoc $1)
#define LL   sL (comb2 $1 $>)

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

-}

%token
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241
 '_'            { L _ ITunderscore }            -- Haskell keywords
 'as'           { L _ ITas }
 'case'         { L _ ITcase }          
 'class'        { L _ ITclass } 
 'data'         { L _ ITdata } 
 '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 }
 '_scc_'        { L _ ITscc }         -- ToDo: remove

 'forall'       { L _ ITforall }                -- GHC extension keywords
 'foreign'      { L _ ITforeign }
 'export'       { L _ ITexport }
 'label'        { L _ ITlabel } 
 'dynamic'      { L _ ITdynamic }
 'safe'         { L _ ITsafe }
242
 'interruptible' { L _ ITinterruptible }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
243 244 245
 'unsafe'       { L _ ITunsafe }
 'mdo'          { L _ ITmdo }
 'family'       { L _ ITfamily }
246 247
 'stdcall'      { L _ ITstdcallconv }
 'ccall'        { L _ ITccallconv }
248
 'prim'         { L _ ITprimcallconv }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
249 250
 'proc'         { L _ ITproc }          -- for arrow notation extension
 'rec'          { L _ ITrec }           -- for arrow notation extension
251 252 253
 'group'    { L _ ITgroup }     -- for list transform extension
 'by'       { L _ ITby }        -- for list transform extension
 'using'    { L _ ITusing }     -- for list transform extension
254

255 256
 '{-# INLINE'             { L _ (ITinline_prag _ _) }
 '{-# SPECIALISE'         { L _ ITspec_prag }
257
 '{-# SPECIALISE_INLINE'  { L _ (ITspec_inline_prag _) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
258 259 260
 '{-# SOURCE'                                   { L _ ITsource_prag }
 '{-# RULES'                                    { L _ ITrules_prag }
 '{-# CORE'                                     { L _ ITcore_prag }              -- hdaume: annotated core
261 262 263 264 265
 '{-# SCC'                { L _ ITscc_prag }
 '{-# GENERATED'          { L _ ITgenerated_prag }
 '{-# DEPRECATED'         { L _ ITdeprecated_prag }
 '{-# WARNING'            { L _ ITwarning_prag }
 '{-# UNPACK'             { L _ ITunpack_prag }
266
 '{-# NOUNPACK'           { L _ ITnounpack_prag }
267
 '{-# ANN'                { L _ ITann_prag }
268 269
 '{-# VECTORISE'          { L _ ITvect_prag }
 '{-# VECTORISE_SCALAR'   { L _ ITvect_scalar_prag }
270
 '{-# NOVECTORISE'        { L _ ITnovect_prag }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295
 '#-}'                                          { L _ ITclose_prag }

 '..'           { L _ ITdotdot }                        -- reserved symbols
 ':'            { L _ ITcolon }
 '::'           { L _ ITdcolon }
 '='            { L _ ITequal }
 '\\'           { L _ ITlam }
 '|'            { 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 }
296 297
 '{|'           { L _ ITocurlybar }
 '|}'           { L _ ITccurlybar }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321
 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 }

 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  _) }
322 323
 PREFIXQVARSYM  { L _ (ITprefixqvarsym  _) }
 PREFIXQCONSYM  { L _ (ITprefixqconsym  _) }
324

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342
 IPDUPVARID     { L _ (ITdupipvarid   _) }              -- GHC extension

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

 DOCNEXT        { L _ (ITdocCommentNext _) }
 DOCPREV        { L _ (ITdocCommentPrev _) }
 DOCNAMED       { L _ (ITdocCommentNamed _) }
 DOCSECTION     { L _ (ITdocSection _ _) }
343

344 345 346 347 348 349 350
-- Template Haskell 
'[|'            { L _ ITopenExpQuote  }       
'[p|'           { L _ ITopenPatQuote  }      
'[t|'           { L _ ITopenTypQuote  }      
'[d|'           { L _ ITopenDecQuote  }      
'|]'            { L _ ITcloseQuote    }
TH_ID_SPLICE    { L _ (ITidEscape _)  }     -- $x
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
351 352 353 354
'$('            { L _ ITparenEscape   }     -- $( exp )
TH_VAR_QUOTE    { L _ ITvarQuote      }     -- 'x
TH_TY_QUOTE     { L _ ITtyQuote       }      -- ''T
TH_QUASIQUOTE   { L _ (ITquasiQuote _) }
355 356 357 358 359 360

%monad { P } { >>= } { return }
%lexer { lexer } { L _ ITeof }
%name parseModule module
%name parseStmt   maybe_stmt
%name parseIdentifier  identifier
361
%name parseType ctype
362
%partial parseHeader header
363
%tokentype { (Located Token) }
364 365
%%

366 367 368
-----------------------------------------------------------------------------
-- Identifiers; one of the entry points
identifier :: { Located RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
369 370 371 372
        : qvar                          { $1 }
        | qcon                          { $1 }
        | qvarop                        { $1 }
        | qconop                        { $1 }
373
    | '(' '->' ')'      { LL $ getRdrName funTyCon }
374

375 376 377 378 379 380 381 382 383 384
-----------------------------------------------------------------------------
-- 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. :-)

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
385 386 387 388
module  :: { Located (HsModule RdrName) }
        : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
                {% fileSrcSpan >>= \ loc ->
                   return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
389
                          ) )}
390
        | body2
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
391 392
                {% fileSrcSpan >>= \ loc ->
                   return (L loc (HsModule Nothing Nothing
393 394
                          (fst $1) (snd $1) Nothing Nothing
                          )) }
395

396
maybedocheader :: { Maybe LHsDocString }
397
        : moduleheader            { $1 }
398
        | {- empty -}             { Nothing }
399 400

missing_module_keyword :: { () }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
401
        : {- empty -}                           {% pushCurrentContext }
402

Ian Lynagh's avatar
Ian Lynagh committed
403
maybemodwarning :: { Maybe WarningTxt }
404 405
    : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
    | '{-# WARNING' strings '#-}'    { Just (WarningTxt $ unLoc $2) }
Ian Lynagh's avatar
Ian Lynagh committed
406
    |  {- empty -}                  { Nothing }
407

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
408 409 410
body    :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
        :  '{'            top '}'               { $2 }
        |      vocurly    top close             { $2 }
411

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
412 413 414
body2   :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
        :  '{' top '}'                          { $2 }
        |  missing_module_keyword top close     { $2 }
415

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
416 417 418 419
top     :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
        : importdecls                           { (reverse $1,[]) }
        | importdecls ';' cvtopdecls            { (reverse $1,$3) }
        | cvtopdecls                            { ([],$1) }
420 421

cvtopdecls :: { [LHsDecl RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
422
        : topdecls                              { cvTopDecls $1 }
423

424 425 426
-----------------------------------------------------------------------------
-- Module declaration & imports only

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
427 428 429 430
header  :: { Located (HsModule RdrName) }
        : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
                {% fileSrcSpan >>= \ loc ->
                   return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
431
                          ))}
432
        | header_body2
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
433
                {% fileSrcSpan >>= \ loc ->
434
                   return (L loc (HsModule Nothing Nothing $1 [] Nothing
435
                          Nothing)) }
436 437

header_body :: { [LImportDecl RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
438
        :  '{'            importdecls           { $2 }
439 440 441 442 443
        |      vocurly    importdecls           { $2 }

header_body2 :: { [LImportDecl RdrName] }
        :  '{' importdecls                      { $2 }
        |  missing_module_keyword importdecls   { $2 }
444

445 446 447 448
-----------------------------------------------------------------------------
-- The Export List

maybeexports :: { Maybe [LIE RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
449 450
        :  '(' exportlist ')'                   { Just $2 }
        |  {- empty -}                          { Nothing }
451

452
exportlist :: { [LIE RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
453 454
        : expdoclist ',' expdoclist             { $1 ++ $3 }
        | exportlist1                           { $1 }
455 456

exportlist1 :: { [LIE RdrName] }
457
        : expdoclist export expdoclist ',' exportlist  { $1 ++ ($2 : $3) ++ $5 }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
458 459
        | expdoclist export expdoclist                 { $1 ++ ($2 : $3) }
        | expdoclist                                   { $1 }
460 461 462 463 464 465 466 467 468 469

expdoclist :: { [LIE RdrName] }
        : exp_doc expdoclist                           { $1 : $2 }
        | {- empty -}                                  { [] }

exp_doc :: { LIE RdrName }                                                   
        : docsection    { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
        | docnamed      { L1 (IEDocNamed ((fst . unLoc) $1)) } 
        | docnext       { L1 (IEDoc (unLoc $1)) }       
                       
470 471
   -- No longer allow things like [] and (,,,) to be exported
   -- They are built in syntax, always available
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
472 473 474 475 476 477 478
export  :: { LIE RdrName }
        :  qvar                         { L1 (IEVar (unLoc $1)) }
        |  oqtycon                      { L1 (IEThingAbs (unLoc $1)) }
        |  oqtycon '(' '..' ')'         { LL (IEThingAll (unLoc $1)) }
        |  oqtycon '(' ')'              { LL (IEThingWith (unLoc $1) []) }
        |  oqtycon '(' qcnames ')'      { LL (IEThingWith (unLoc $1) (reverse $3)) }
        |  'module' modid               { LL (IEModuleContents (unLoc $2)) }
479 480

qcnames :: { [RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
481 482
        :  qcnames ',' qcname_ext       { unLoc $3 : $1 }
        |  qcname_ext                   { [unLoc $1]  }
483

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
484 485 486 487 488 489
qcname_ext :: { Located RdrName }       -- Variable or data constructor
                                        -- or tagged type constructor
        :  qcname                       { $1 }
        |  'type' qcon                  { sL (comb2 $1 $2) 
                                             (setRdrNameSpace (unLoc $2) 
                                                              tcClsName)  }
490 491

-- Cannot pull into qcname_ext, as qcname is also used in expression.
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
492 493 494
qcname  :: { Located RdrName }  -- Variable or data constructor
        :  qvar                         { $1 }
        |  qcon                         { $1 }
495 496 497 498 499 500 501 502

-----------------------------------------------------------------------------
-- Import Declarations

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

importdecls :: { [LImportDecl RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
503 504 505 506
        : importdecls ';' importdecl            { $3 : $1 }
        | importdecls ';'                       { $1 }
        | importdecl                            { [ $1 ] }
        | {- empty -}                           { [] }
507 508

importdecl :: { LImportDecl RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
509 510
        : 'import' maybe_src maybe_safe optqualified maybe_pkg modid maybeas maybeimpspec 
                { L (comb4 $1 $6 $7 $8) $
511 512 513 514
                  ImportDecl { ideclName = $6, ideclPkgQual = $5
                             , ideclSource = $2, ideclSafe = $3
                             , ideclQualified = $4, ideclImplicit = False
                             , ideclAs = unLoc $7, ideclHiding = unLoc $8 } }
515 516

maybe_src :: { IsBootInterface }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
517 518
        : '{-# SOURCE' '#-}'                    { True }
        | {- empty -}                           { False }
519

520
maybe_safe :: { Bool }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
521 522
        : 'safe'                                { True }
        | {- empty -}                           { False }
523

524 525 526 527
maybe_pkg :: { Maybe FastString }
        : STRING                                { Just (getSTRING $1) }
        | {- empty -}                           { Nothing }

528
optqualified :: { Bool }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
529 530
        : 'qualified'                           { True  }
        | {- empty -}                           { False }
531

Simon Marlow's avatar
Simon Marlow committed
532
maybeas :: { Located (Maybe ModuleName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
533 534
        : 'as' modid                            { LL (Just (unLoc $2)) }
        | {- empty -}                           { noLoc Nothing }
535 536

maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
537 538
        : impspec                               { L1 (Just (unLoc $1)) }
        | {- empty -}                           { noLoc Nothing }
539 540

impspec :: { Located (Bool, [LIE RdrName]) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
541 542
        :  '(' exportlist ')'                   { LL (False, $2) }
        |  'hiding' '(' exportlist ')'          { LL (True,  $3) }
543 544 545 546

-----------------------------------------------------------------------------
-- Fixity Declarations

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
547 548 549
prec    :: { Int }
        : {- empty -}           { 9 }
        | INTEGER               {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
550

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
551 552 553 554
infix   :: { Located FixityDirection }
        : 'infix'                               { L1 InfixN  }
        | 'infixl'                              { L1 InfixL  }
        | 'infixr'                              { L1 InfixR }
555

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
556 557 558
ops     :: { Located [Located RdrName] }
        : ops ',' op                            { LL ($3 : unLoc $1) }
        | op                                    { L1 [$1] }
559 560 561 562

-----------------------------------------------------------------------------
-- Top-Level Declarations

563
topdecls :: { OrdList (LHsDecl RdrName) }
564 565 566
        : topdecls ';' topdecl                  { $1 `appOL` $3 }
        | topdecls ';'                          { $1 }
        | topdecl                               { $1 }
567

568
topdecl :: { OrdList (LHsDecl RdrName) }
569 570
        : cl_decl                               { unitOL (L1 (TyClD (unLoc $1))) }
        | ty_decl                               { unitOL (L1 (TyClD (unLoc $1))) }
571 572 573 574
        | 'instance' inst_type where_inst
            { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
              in 
              unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
575
        | stand_alone_deriving                  { unitOL (LL (DerivD (unLoc $1))) }
576 577
        | 'default' '(' comma_types0 ')'        { unitOL (LL $ DefD (DefaultDecl $3)) }
        | 'foreign' fdecl                       { unitOL (LL (unLoc $2)) }
578 579
        | '{-# DEPRECATED' deprecations '#-}'   { $2 }
        | '{-# WARNING' warnings '#-}'          { $2 }
580
        | '{-# RULES' rules '#-}'               { $2 }
581 582 583
        | '{-# VECTORISE_SCALAR' qvar '#-}'     { unitOL $ LL $ VectD (HsVect       $2 Nothing) }
        | '{-# VECTORISE' qvar '=' exp '#-}'    { unitOL $ LL $ VectD (HsVect       $2 (Just $4)) }
        | '{-# NOVECTORISE' qvar '#-}'          { unitOL $ LL $ VectD (HsNoVect     $2) }
584 585 586 587 588 589 590 591 592
        | '{-# VECTORISE' 'type' gtycon '#-}'     
                                                { unitOL $ LL $ 
                                                    VectD (HsVectTypeIn False $3 Nothing) }
        | '{-# VECTORISE_SCALAR' 'type' gtycon '#-}'     
                                                { unitOL $ LL $ 
                                                    VectD (HsVectTypeIn True $3 Nothing) }
        | '{-# VECTORISE' 'type' gtycon '=' gtycon '#-}'     
                                                { unitOL $ LL $ 
                                                    VectD (HsVectTypeIn False $3 (Just $5)) }
593 594 595 596 597
        | '{-# VECTORISE' 'class' gtycon '#-}'  { unitOL $ LL $ VectD (HsVectClassIn $3) }
        | '{-# VECTORISE' 'instance' type '#-}'     
                                                { unitOL $ LL $ VectD (HsVectInstIn False $3) }
        | '{-# VECTORISE_SCALAR' 'instance' type '#-}'     
                                                { unitOL $ LL $ VectD (HsVectInstIn True $3) }
598 599 600 601 602 603 604 605
        | annotation { unitOL $1 }
        | decl                                  { unLoc $1 }

        -- Template Haskell Extension
        -- The $(..) form is one possible form of infixexp
        -- but we treat an arbitrary expression just as if 
        -- it had a $(..) wrapped around it
        | infixexp                              { unitOL (LL $ mkTopSpliceDecl $1) } 
606

607 608 609
-- Type classes
--
cl_decl :: { LTyClDecl RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
610
        : 'class' tycl_hdr fds where_cls        {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
611

612
-- Type declarations (toplevel)
613 614
--
ty_decl :: { LTyClDecl RdrName }
615
           -- ordinary type synonyms
616
        : 'type' type '=' ctypedoc
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
617 618 619 620 621 622 623 624
                -- 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
                -- infix type constructors to be declared 
                {% mkTySynonym (comb2 $1 $4) False $2 $4 }
625 626

           -- type family declarations
627
        | 'type' 'family' type opt_kind_sig 
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
628 629 630
                -- Note the use of type for the head; this allows
                -- infix type constructors to be declared
                {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
631 632 633

           -- type instance declarations
        | 'type' 'instance' type '=' ctype
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
634 635 636
                -- Note the use of type for the head; this allows
                -- infix type constructors and type patterns
                {% mkTySynonym (comb2 $1 $5) True $3 $5 }
637

638
          -- ordinary data type or newtype declaration
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
639 640
        | data_or_newtype tycl_hdr constrs deriving
                {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2 
641
                            Nothing (reverse (unLoc $3)) (unLoc $4) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
642 643
                                   -- We need the location on tycl_hdr in case 
                                   -- constrs and deriving are both empty
644

645
          -- ordinary GADT declaration
646
        | data_or_newtype tycl_hdr opt_kind_sig 
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
647 648 649
                 gadt_constrlist
                 deriving
                {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2 
650
                            (unLoc $3) (unLoc $4) (unLoc $5) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
651 652
                                   -- We need the location on tycl_hdr in case 
                                   -- constrs and deriving are both empty
653

654
          -- data/newtype family
655
        | 'data' 'family' type opt_kind_sig
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
656
                {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
657

658
          -- data/newtype instance declaration
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
659 660 661
        | data_or_newtype 'instance' tycl_hdr constrs deriving
                {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
                            Nothing (reverse (unLoc $4)) (unLoc $5) }
662

663
          -- GADT instance declaration
664
        | data_or_newtype 'instance' tycl_hdr opt_kind_sig 
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
665 666 667 668
                 gadt_constrlist
                 deriving
                {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
                            (unLoc $4) (unLoc $5) (unLoc $6) }
669 670

-- Associated type family declarations
671 672 673 674 675 676 677
--
-- * 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
--   data declarations. 
678
--
679
at_decl_cls :: { LTyClDecl RdrName }
680
           -- type family declarations
681
        : 'type' type opt_kind_sig
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
682 683 684
                -- Note the use of type for the head; this allows
                -- infix type constructors to be declared
                {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
685

686 687
           -- default type instance
        | 'type' type '=' ctype
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
688 689 690
                -- Note the use of type for the head; this allows
                -- infix type constructors and type patterns
                {% mkTySynonym (comb2 $1 $4) True $2 $4 }
691

692
          -- data/newtype family declaration
693
        | 'data' type opt_kind_sig
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
694
                {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
695 696

-- Associated type instances
697 698 699 700
--
at_decl_inst :: { LTyClDecl RdrName }
           -- type instance declarations
        : 'type' type '=' ctype
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
701 702 703
                -- Note the use of type for the head; this allows
                -- infix type constructors and type patterns
                {% mkTySynonym (comb2 $1 $4) True $2 $4 }
704 705

        -- data/newtype instance declaration
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
706 707
        | data_or_newtype tycl_hdr constrs deriving
                {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2 
708
                            Nothing (reverse (unLoc $3)) (unLoc $4) }
709 710 711

        -- GADT instance declaration
        | data_or_newtype tycl_hdr opt_kind_sig 
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
712 713 714 715
                 gadt_constrlist
                 deriving
                {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2 
                            (unLoc $3) (unLoc $4) (unLoc $5) }
716

717
data_or_newtype :: { Located NewOrData }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
718 719
        : 'data'        { L1 DataType }
        | 'newtype'     { L1 NewType }
720

721
opt_kind_sig :: { Located (Maybe Kind) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
722 723
        :                               { noLoc Nothing }
        | '::' kind                     { LL (Just (unLoc $2)) }
724

725
-- tycl_hdr parses the header of a class or data type decl,
726
-- which takes the form
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
727 728 729 730
--      T a b
--      Eq a => T a
--      (Eq a, Ord b) => T a b
--      T Int [a]                       -- for associated types
731
-- Rather a lot of inlining here, else we get reduce/reduce errors
732
tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
733 734
        : context '=>' type             { LL (Just $1, $3) }
        | type                          { L1 (Nothing, $1) }
735

736 737 738 739 740
-----------------------------------------------------------------------------
-- Stand-alone deriving

-- Glasgow extension: stand-alone deriving declarations
stand_alone_deriving :: { LDerivDecl RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
741
        : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
742

743 744 745
-----------------------------------------------------------------------------
-- Nested declarations

746
-- Declaration in class bodies
747
--
748
decl_cls  :: { Located (OrdList (LHsDecl RdrName)) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
749 750
decl_cls  : at_decl_cls                 { LL (unitOL (L1 (TyClD (unLoc $1)))) }
          | decl                        { $1 }
751

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
752
          -- A 'default' signature used with the generic-programming extension
753 754 755 756
          | 'default' infixexp '::' sigtypedoc
                    {% do { (TypeSig l ty) <- checkValSig $2 $4
                          ; return (LL $ unitOL (LL $ SigD (GenericSig l ty))) } }

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
757 758 759 760 761
decls_cls :: { Located (OrdList (LHsDecl RdrName)) }    -- Reversed
          : decls_cls ';' decl_cls      { LL (unLoc $1 `appOL` unLoc $3) }
          | decls_cls ';'               { LL (unLoc $1) }
          | decl_cls                    { $1 }
          | {- empty -}                 { noLoc nilOL }
762 763


764
decllist_cls
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
765 766 767
        :: { Located (OrdList (LHsDecl RdrName)) }      -- Reversed
        : '{'         decls_cls '}'     { LL (unLoc $2) }
        |     vocurly decls_cls close   { $2 }
768

769
-- Class body
770
--
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
771 772 773 774 775
where_cls :: { Located (OrdList (LHsDecl RdrName)) }    -- Reversed
                                -- No implicit parameters
                                -- May have type declarations
        : 'where' decllist_cls          { LL (unLoc $2) }
        | {- empty -}                   { noLoc nilOL }
776 777 778 779

-- Declarations in instance bodies
--
decl_inst  :: { Located (OrdList (LHsDecl RdrName)) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
780 781
decl_inst  : at_decl_inst               { LL (unitOL (L1 (TyClD (unLoc $1)))) }
           | decl                       { $1 }
782

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
783 784 785 786 787
decls_inst :: { Located (OrdList (LHsDecl RdrName)) }   -- Reversed
           : decls_inst ';' decl_inst   { LL (unLoc $1 `appOL` unLoc $3) }
           | decls_inst ';'             { LL (unLoc $1) }
           | decl_inst                  { $1 }
           | {- empty -}                { noLoc nilOL }
788 789

decllist_inst 
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
790 791 792
        :: { Located (OrdList (LHsDecl RdrName)) }      -- Reversed
        : '{'         decls_inst '}'    { LL (unLoc $2) }
        |     vocurly decls_inst close  { $2 }
793 794 795

-- Instance body
--
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
796 797 798 799 800
where_inst :: { Located (OrdList (LHsDecl RdrName)) }   -- Reversed
                                -- No implicit parameters
                                -- May have type declarations
        : 'where' decllist_inst         { LL (unLoc $2) }
        | {- empty -}                   { noLoc nilOL }
801

802 803
-- Declarations in binding groups other than classes and instances
--
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
804 805
decls   :: { Located (OrdList (LHsDecl RdrName)) }      
        : decls ';' decl                { let { this = unLoc $3;
Ian Lynagh's avatar
Ian Lynagh committed
806
                                    rest = unLoc $1;
Ian Lynagh's avatar
Ian Lynagh committed
807
                                    these = rest `appOL` this }
Ian Lynagh's avatar
Ian Lynagh committed
808 809
                              in rest `seq` this `seq` these `seq`
                                    LL these }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
810 811 812
        | decls ';'                     { LL (unLoc $1) }
        | decl                          { $1 }
        | {- empty -}                   { noLoc nilOL }
813

814
decllist :: { Located (OrdList (LHsDecl RdrName)) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
815 816
        : '{'            decls '}'      { LL (unLoc $2) }
        |     vocurly    decls close    { $2 }
817

818 819
-- Binding groups other than those of class and instance declarations
--
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
820 821 822 823 824
binds   ::  { Located (HsLocalBinds RdrName) }          -- May have implicit parameters
                                                -- No type declarations
        : decllist                      { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
        | '{'            dbinds '}'     { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
        |     vocurly    dbinds close   { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
825

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
826 827 828 829
wherebinds :: { Located (HsLocalBinds RdrName) }        -- May have implicit parameters
                                                -- No type declarations
        : 'where' binds                 { LL (unLoc $2) }
        | {- empty -}                   { noLoc emptyLocalBinds }
830 831 832 833 834


-----------------------------------------------------------------------------
-- Transformation Rules

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
835 836 837 838 839
rules   :: { OrdList (LHsDecl RdrName) }
        :  rules ';' rule                       { $1 `snocOL` $3 }
        |  rules ';'                            { $1 }
        |  rule                                 { unitOL $1 }
        |  {- empty -}                          { nilOL }
840

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
841 842 843 844 845
rule    :: { LHsDecl RdrName }
        : STRING activation rule_forall infixexp '=' exp
             { LL $ RuleD (HsRule (getSTRING $1) 
                                  ($2 `orElse` AlwaysActive) 
                                  $3 $4 placeHolderNames $6 placeHolderNames) }
846

847 848 849
activation :: { Maybe Activation } 
        : {- empty -}                           { Nothing }
        | explicit_activation                   { Just $1 }
850 851

explicit_activation :: { Activation }  -- In brackets
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
852 853
        : '[' INTEGER ']'               { ActiveAfter  (fromInteger (getINTEGER $2)) }
        | '[' '~' INTEGER ']'           { ActiveBefore (fromInteger (getINTEGER $3)) }
854 855

rule_forall :: { [RuleBndr RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
856 857
        : 'forall' rule_var_list '.'            { $2 }
        | {- empty -}                           { [] }
858 859

rule_var_list :: { [RuleBndr RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
860 861
        : rule_var                              { [$1] }
        | rule_var rule_var_list                { $1 : $2 }
862 863

rule_var :: { RuleBndr RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
864 865
        : varid                                 { RuleBndr $1 }
        | '(' varid '::' ctype ')'              { RuleBndrSig $2 $4 }
866 867

-----------------------------------------------------------------------------
Ian Lynagh's avatar
Ian Lynagh committed
868 869 870
-- Warnings and deprecations (c.f. rules)

warnings :: { OrdList (LHsDecl RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
871 872 873 874
        : warnings ';' warning          { $1 `appOL` $3 }
        | warnings ';'                  { $1 }
        | warning                               { $1 }
        | {- empty -}                           { nilOL }
Ian Lynagh's avatar
Ian Lynagh committed
875 876 877

-- SUP: TEMPORARY HACK, not checking for `module Foo'
warning :: { OrdList (LHsDecl RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
878 879 880
        : namelist strings
                { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
                       | n <- unLoc $1 ] }
881

882
deprecations :: { OrdList (LHsDecl RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
883 884 885 886
        : deprecations ';' deprecation          { $1 `appOL` $3 }
        | deprecations ';'                      { $1 }
        | deprecation                           { $1 }
        | {- empty -}                           { nilOL }
887 888

-- SUP: TEMPORARY HACK, not checking for `module Foo'
889
deprecation :: { OrdList (LHsDecl RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
890 891 892
        : namelist strings
                { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
                       | n <- unLoc $1 ] }
893

894 895 896 897 898 899 900 901
strings :: { Located [FastString] }
    : STRING { L1 [getSTRING $1] }
    | '[' stringlist ']' { LL $ fromOL (unLoc $2) }

stringlist :: { Located (OrdList FastString) }
    : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
    | STRING                { LL (unitOL (getSTRING $1)) }

902 903 904 905 906 907 908
-----------------------------------------------------------------------------
-- Annotations
annotation :: { LHsDecl RdrName }
    : '{-# ANN' name_var aexp '#-}'      { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
    | '{-# ANN' 'type' tycon aexp '#-}'  { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
    | '{-# ANN' 'module' aexp '#-}'      { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }

909 910 911 912 913

-----------------------------------------------------------------------------
-- Foreign import and export declarations

fdecl :: { LHsDecl RdrName }
Simon Marlow's avatar
Simon Marlow committed
914
fdecl : 'import' callconv safety fspec
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
915 916 917 918
                {% mkImport $2 $3 (unLoc $4) >>= return.LL }
      | 'import' callconv        fspec          
                {% do { d <- mkImport $2 PlaySafe (unLoc $3);
                        return (LL d) } }
919
      | 'export' callconv fspec
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
920
                {% mkExport $2 (unLoc $3) >>= return.LL }
921

922
callconv :: { CCallConv }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
923 924 925
          : 'stdcall'                   { StdCallConv }
          | 'ccall'                     { CCallConv   }
          | 'prim'                      { PrimCallConv}
926 927

safety :: { Safety }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
928 929 930
        : 'unsafe'                      { PlayRisky }
        | 'safe'                        { PlaySafe }
        | 'interruptible'               { PlayInterruptible }
931 932

fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
933 934
       : STRING var '::' sigtypedoc     { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
       |        var '::' sigtypedoc     { LL (noLoc nilFS, $1, $3) }
935 936 937 938 939 940 941 942
         -- if the entity string is missing, it defaults to the empty string;
         -- the meaning of an empty entity string depends on the calling
         -- convention

-----------------------------------------------------------------------------
-- Type signatures

opt_sig :: { Maybe (LHsType RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
943 944
        : {- empty -}                   { Nothing }
        | '::' sigtype                  { Just $2 }
945 946

opt_asig :: { Maybe (LHsType RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
947 948
        : {- empty -}                   { Nothing }
        | '::' atype                    { Just $2 }
949

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
950
sigtype :: { LHsType RdrName }          -- Always a HsForAllTy,
951
                                        -- to tell the renamer where to generalise
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
952 953
        : ctype                         { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
        -- Wrap an Implicit forall if there isn't one there already
954

955
sigtypedoc :: { LHsType RdrName }       -- Always a HsForAllTy
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
956 957
        : ctypedoc                      { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
        -- Wrap an Implicit forall if there isn't one there already
958

959
sig_vars :: { Located [Located RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
960 961
         : sig_vars ',' var             { LL ($3 : unLoc $1) }
         | var                          { L1 [$1] }
962

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
963 964 965
sigtypes1 :: { [LHsType RdrName] }      -- Always HsForAllTys
        : sigtype                       { [ $1 ] }
        | sigtype ',' sigtypes1         { $1 : $3 }
966

967 968 969
-----------------------------------------------------------------------------
-- Types

970
infixtype :: { LHsType RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
971 972
        : btype qtyconop type         { LL $ HsOpTy $1 $2 $3 }
        | btype tyvarop  type    { LL $ HsOpTy $1 $2 $3 }
973

974
strict_mark :: { Located HsBang }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
975 976
        : '!'                           { L1 HsStrict }
        | '{-# UNPACK' '#-}' '!'        { LL HsUnpack }
977
        | '{-# NOUNPACK' '#-}' '!'      { LL HsNoUnpack }
978

979
-- A ctype is a for-all type
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
980 981 982 983 984 985
ctype   :: { LHsType RdrName }
        : 'forall' tv_bndrs '.' ctype   { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
        | context '=>' ctype            { LL $ mkImplicitHsForAllTy   $1 $3 }
        -- A type of form (context => type) is an *implicit* HsForAllTy
        | ipvar '::' type               { LL (HsIParamTy (unLoc $1) $3) }
        | type                          { $1 }
986

987 988 989 990 991 992 993 994 995 996 997
----------------------
-- Notes for 'ctypedoc'
-- It would have been nice to simplify the grammar by unifying `ctype` and 
-- ctypedoc` into one production, allowing comments on types everywhere (and
-- rejecting them after parsing, where necessary).  This is however not possible
-- since it leads to ambiguity. The reason is the support for comments on record
-- fields: 
--         data R = R { field :: Int -- ^ comment on the field }
-- If we allow comments on types here, it's not clear if the comment applies
-- to 'field' or to 'Int'. So we must use `ctype` to describe the type.

998
ctypedoc :: { LHsType RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
999 1000 1001 1002 1003
        : 'forall' tv_bndrs '.' ctypedoc        { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
        | context '=>' ctypedoc         { LL $ mkImplicitHsForAllTy   $1 $3 }
        -- A type of form (context => type) is an *implicit* HsForAllTy
        | ipvar '::' type               { LL (HsIParamTy (unLoc $1) $3) }
        | typedoc                       { $1 }
1004

1005 1006
----------------------
-- Notes for 'context'
1007 1008
-- We parse a context as a btype so that we don't get reduce/reduce
-- errors in ctype.  The basic problem is that
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1009
--      (Eq a, Ord a)
1010
-- looks so much like a tuple type.  We can't tell until we find the =>
1011

waern's avatar
waern committed
1012
-- We have the t1 ~ t2 form both in 'context' and in type, 
1013 1014
-- to permit an individual equational constraint without parenthesis.
-- Thus for some reason we allow    f :: a~b => blah
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1015
-- but not                          f :: ?x::Int => blah
1016
context :: { LHsContext RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1017 1018 1019
        : btype '~'      btype          {% checkContext
                                             (LL $ HsEqTy $1 $3) }
        | btype                         {% checkContext $1 }
1020

waern's avatar
waern committed
1021
type :: { LHsType RdrName }
1022
        : btype                         { $1 }
simonpj@microsoft.com's avatar
simonpj@microsoft.com committed
1023
        | btype qtyconop type           { LL $ HsOpTy $1 $2 $3 }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1024 1025 1026
        | btype tyvarop  type           { LL $ HsOpTy $1 $2 $3 }
        | btype '->'     ctype          { LL $ HsFunTy $1 $3 }
        | btype '~'      btype          { LL $ HsEqTy $1 $3 }
1027

waern's avatar
waern committed
1028
typedoc :: { LHsType RdrName }
1029 1030
        : btype                          { $1 }
        | btype docprev                  { LL $ HsDocTy $1 $2 }
waern's avatar
waern committed
1031 1032 1033 1034
        | btype qtyconop type            { LL $ HsOpTy $1 $2 $3 }
        | btype qtyconop type docprev    { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
        | btype tyvarop  type            { LL $ HsOpTy $1 $2 $3 }
        | btype tyvarop  type docprev    { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1035 1036
        | btype '->'     ctypedoc        { LL $ HsFunTy $1 $3 }
        | btype docprev '->' ctypedoc    { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
batterseapower's avatar
batterseapower committed
1037
        | btype '~'      btype           { LL $ HsEqTy $1 $3 }
1038

1039
btype :: { LHsType RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1040 1041
        : btype atype                   { LL $ HsAppTy $1 $2 }
        | atype                         { $1 }
1042 1043

atype :: { LHsType RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057
        : gtycon                        { L1 (HsTyVar (unLoc $1)) }
        | tyvar                         { L1 (HsTyVar (unLoc $1)) }
        | strict_mark atype             { LL (HsBangTy (unLoc $1) $2) }  -- Constructor sigs only
        | '{' fielddecls '}'            {% checkRecordSyntax (LL $ HsRecTy $2) } -- Constructor sigs only
        | '(' ctype ',' comma_types1 ')'  { LL $ HsTupleTy (HsBoxyTuple placeHolderKind)  ($2:$4) }
        | '(#' comma_types1 '#)'        { LL $ HsTupleTy HsUnboxedTuple $2     }
        | '[' ctype ']'                 { LL $ HsListTy  $2 }
        | '[:' ctype ':]'               { LL $ HsPArrTy  $2 }
        | '(' ctype ')'                 { LL $ HsParTy   $2 }
        | '(' ctype '::' kind ')'       { LL $ HsKindSig $2 (unLoc $4) }
        | quasiquote                    { L1 (HsQuasiQuoteTy (unLoc $1)) }
        | '$(' exp ')'                  { LL $ mkHsSpliceTy $2 }
        | TH_ID_SPLICE                  { LL $ mkHsSpliceTy $ L1 $ HsVar $ 
                                          mkUnqual varName (getTH_ID_SPLICE $1) }
1058 1059

-- An inst_type is what occurs in the head of an instance decl
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1060
--      e.g.  (Foo a, Gaz b) => Wibble a b
1061 1062 1063
-- It's kept as a single type, with a MonoDictTy at the right
-- hand corner, for convenience.
inst_type :: { LHsType RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1064
        : sigtype                       { $1 }
1065

1066
inst_types1 :: { [LHsType RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1067 1068
        : inst_type                     { [$1] }
        | inst_type ',' inst_types1     { $1 : $3 }
1069

1070
comma_types0  :: { [LHsType RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1071 1072
        : comma_types1                  { $1 }
        | {- empty -}                   { [] }
1073

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1074 1075 1076
comma_types1    :: { [LHsType RdrName] }
        : ctype                         { [$1] }
        | ctype  ',' comma_types1       { $1 : $3 }
1077 1078

tv_bndrs :: { [LHsTyVarBndr RdrName] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1079 1080
         : tv_bndr tv_bndrs             { $1 : $2 }
         | {- empty -}                  { [] }
1081 1082

tv_bndr :: { LHsTyVarBndr RdrName }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1083 1084 1085
        : tyvar                         { L1 (UserTyVar (unLoc $1) placeHolderKind) }
        | '(' tyvar '::' kind ')'       { LL (KindedTyVar (unLoc $2) 
                                                          (unLoc $4)) }
1086

1087
fds :: { Located [Located (FunDep RdrName)] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1088 1089
        : {- empty -}                   { noLoc [] }
        | '|' fds1                      { LL (reverse (unLoc $2)) }
1090

1091
fds1 :: { Located [Located (FunDep RdrName)] }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1092 1093
        : fds1 ',' fd                   { LL ($3 : unLoc $1) }
        | fd                            { L1 [$1] }
1094

1095
fd :: { Located (FunDep RdrName) }
chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1096 1097
        : varids0 '->' varids0          { L (comb3 $1 $2 $3)
                                           (reverse (unLoc $1), reverse (unLoc $3)) }
1098

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1099 1100 1101
varids0 :: { Located [RdrName] }
        : {- empty -}                   { noLoc [] }
        | varids0 tyvar                 { LL (unLoc $2 : unLoc $1) }
1102 1103 1104 1105

-----------------------------------------------------------------------------
-- Kinds

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1106 1107 1108
kind    :: { Located Kind }
        : akind                 { $1 }
        | akind '->' kind       { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1109

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1110 1111 1112 1113 1114
akind   :: { Located Kind }
        : '*'                   { L1 liftedTypeKind }
        | '!'                   { L1 unliftedTypeKind }
        | CONID                 {% checkKindName (L1 (getCONID $1)) }
        | '(' kind ')'          { LL (unLoc $2) }
1115 1116 1117 1118 1119


-----------------------------------------------------------------------------
-- Datatype declarations

chak@cse.unsw.edu.au.'s avatar
chak@cse.unsw.edu.au. committed
1120 1121 1122 1123
gadt_constrlist :: { Located [LConDecl RdrName] }       -- Returned in order
        : 'where' '{'        gadt_constrs '}'      { L (comb2 $1 $3) (unLoc $3) }
        | 'where' vocurly    gadt_constrs close    { L (comb2 $1 $3) (unLoc $3) }
        | {- empty -}                              { noLoc [] }
1124 1125

gadt_constrs :: { Located [LConDecl RdrName] }
1126 1127
        : gadt_constr ';' gadt_constrs  { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
        | gadt_constr                   { L (getLoc (head $1)) $1 }