2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# OPTIONS -Wwarn -w -XNoMonomorphismRestriction #-}
12 -- The NoMonomorphismRestriction deals with a Happy infelicity
13 -- With OutsideIn's more conservativ monomorphism restriction
14 -- we aren't generalising
15 -- notHappyAtAll = error "urk"
16 -- which is terrible. Switching off the restriction allows
17 -- the generalisation. Better would be to make Happy generate
18 -- an appropriate signature.
20 -- The above warning supression flag is a temporary kludge.
21 -- While working on this module you are encouraged to remove it and fix
22 -- any warnings in the module. See
23 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
26 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
28 Careful optimisation of the parser: we don't want to throw everything
29 at it, because that takes too long and doesn't buy much, but we do want
30 to inline certain key external functions, so we instruct GHC not to
31 throw away inlinings as it would normally do in -O0 mode.
34 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
39 import HscTypes ( IsBootInterface, WarningTxt(..) )
42 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
43 unboxedSingletonTyCon, unboxedSingletonDataCon,
44 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
45 import Type ( funTyCon )
46 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
47 CCallConv(..), CCallTarget(..), defaultCCallConv
49 import OccName ( varName, dataName, tcClsName, tvName )
50 import DataCon ( DataCon, dataConName )
51 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
52 SrcSpan, combineLocs, srcLocFile,
55 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
56 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
57 import Coercion ( mkArrowKind )
58 import Class ( FunDep )
59 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
60 Activation(..), RuleMatchInfo(..), defaultInlinePragma )
66 import Maybes ( orElse )
69 import Control.Monad ( unless )
72 import Control.Monad ( mplus )
76 -----------------------------------------------------------------------------
79 Conflicts: 33 shift/reduce
82 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
83 would think the two should never occur in the same context.
87 -----------------------------------------------------------------------------
90 Conflicts: 34 shift/reduce
93 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
94 would think the two should never occur in the same context.
98 -----------------------------------------------------------------------------
101 Conflicts: 32 shift/reduce
104 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
105 would think the two should never occur in the same context.
109 -----------------------------------------------------------------------------
112 Conflicts: 37 shift/reduce
115 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
116 would think the two should never occur in the same context.
120 -----------------------------------------------------------------------------
121 Conflicts: 38 shift/reduce (1.25)
123 10 for abiguity in 'if x then y else z + 1' [State 178]
124 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
125 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
127 1 for ambiguity in 'if x then y else z :: T' [State 178]
128 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
130 4 for ambiguity in 'if x then y else z -< e' [State 178]
131 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
132 There are four such operators: -<, >-, -<<, >>-
135 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
136 Which of these two is intended?
138 (x::T) -> T -- Rhs is T
141 (x::T -> T) -> .. -- Rhs is ...
143 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
146 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
147 Same duplication between states 11 and 253 as the previous case
149 1 for ambiguity in 'let ?x ...' [State 329]
150 the parser can't tell whether the ?x is the lhs of a normal binding or
151 an implicit binding. Fortunately resolving as shift gives it the only
152 sensible meaning, namely the lhs of an implicit binding.
154 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
155 we don't know whether the '[' starts the activation or not: it
156 might be the start of the declaration with the activation being
157 empty. --SDM 1/4/2002
159 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
160 since 'forall' is a valid variable name, we don't know whether
161 to treat a forall on the input as the beginning of a quantifier
162 or the beginning of the rule itself. Resolving to shift means
163 it's always treated as a quantifier, hence the above is disallowed.
164 This saves explicitly defining a grammar for the rule lhs that
165 doesn't include 'forall'.
167 1 for ambiguity when the source file starts with "-- | doc". We need another
168 token of lookahead to determine if a top declaration or the 'module' keyword
169 follows. Shift parses as if the 'module' keyword follows.
171 -- ---------------------------------------------------------------------------
172 -- Adding location info
174 This is done in a stylised way using the three macros below, L0, L1
175 and LL. Each of these macros can be thought of as having type
177 L0, L1, LL :: a -> Located a
179 They each add a SrcSpan to their argument.
181 L0 adds 'noSrcSpan', used for empty productions
182 -- This doesn't seem to work anymore -=chak
184 L1 for a production with a single token on the lhs. Grabs the SrcSpan
187 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
188 the first and last tokens.
190 These suffice for the majority of cases. However, we must be
191 especially careful with empty productions: LL won't work if the first
192 or last token on the lhs can represent an empty span. In these cases,
193 we have to calculate the span using more of the tokens from the lhs, eg.
195 | 'newtype' tycl_hdr '=' newconstr deriving
197 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
199 We provide comb3 and comb4 functions which are useful in such cases.
201 Be careful: there's no checking that you actually got this right, the
202 only symptom will be that the SrcSpans of your syntax will be
206 * We must expand these macros *before* running Happy, which is why this file is
207 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
209 #define L0 L noSrcSpan
210 #define L1 sL (getLoc $1)
211 #define LL sL (comb2 $1 $>)
213 -- -----------------------------------------------------------------------------
218 '_' { L _ ITunderscore } -- Haskell keywords
220 'case' { L _ ITcase }
221 'class' { L _ ITclass }
222 'data' { L _ ITdata }
223 'default' { L _ ITdefault }
224 'deriving' { L _ ITderiving }
226 'else' { L _ ITelse }
227 'hiding' { L _ IThiding }
229 'import' { L _ ITimport }
231 'infix' { L _ ITinfix }
232 'infixl' { L _ ITinfixl }
233 'infixr' { L _ ITinfixr }
234 'instance' { L _ ITinstance }
236 'module' { L _ ITmodule }
237 'newtype' { L _ ITnewtype }
239 'qualified' { L _ ITqualified }
240 'then' { L _ ITthen }
241 'type' { L _ ITtype }
242 'where' { L _ ITwhere }
243 '_scc_' { L _ ITscc } -- ToDo: remove
245 'forall' { L _ ITforall } -- GHC extension keywords
246 'foreign' { L _ ITforeign }
247 'export' { L _ ITexport }
248 'label' { L _ ITlabel }
249 'dynamic' { L _ ITdynamic }
250 'safe' { L _ ITsafe }
251 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
252 'unsafe' { L _ ITunsafe }
254 'family' { L _ ITfamily }
255 'stdcall' { L _ ITstdcallconv }
256 'ccall' { L _ ITccallconv }
257 'prim' { L _ ITprimcallconv }
258 'proc' { L _ ITproc } -- for arrow notation extension
259 'rec' { L _ ITrec } -- for arrow notation extension
260 'group' { L _ ITgroup } -- for list transform extension
261 'by' { L _ ITby } -- for list transform extension
262 'using' { L _ ITusing } -- for list transform extension
264 '{-# INLINE' { L _ (ITinline_prag _) }
265 '{-# INLINE_CONLIKE' { L _ (ITinline_conlike_prag _) }
266 '{-# SPECIALISE' { L _ ITspec_prag }
267 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
268 '{-# SOURCE' { L _ ITsource_prag }
269 '{-# RULES' { L _ ITrules_prag }
270 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
271 '{-# SCC' { L _ ITscc_prag }
272 '{-# GENERATED' { L _ ITgenerated_prag }
273 '{-# DEPRECATED' { L _ ITdeprecated_prag }
274 '{-# WARNING' { L _ ITwarning_prag }
275 '{-# UNPACK' { L _ ITunpack_prag }
276 '{-# ANN' { L _ ITann_prag }
277 '#-}' { L _ ITclose_prag }
279 '..' { L _ ITdotdot } -- reserved symbols
281 '::' { L _ ITdcolon }
285 '<-' { L _ ITlarrow }
286 '->' { L _ ITrarrow }
289 '=>' { L _ ITdarrow }
293 '-<' { L _ ITlarrowtail } -- for arrow notation
294 '>-' { L _ ITrarrowtail } -- for arrow notation
295 '-<<' { L _ ITLarrowtail } -- for arrow notation
296 '>>-' { L _ ITRarrowtail } -- for arrow notation
299 '{' { L _ ITocurly } -- special symbols
301 '{|' { L _ ITocurlybar }
302 '|}' { L _ ITccurlybar }
303 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
304 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
307 '[:' { L _ ITopabrack }
308 ':]' { L _ ITcpabrack }
311 '(#' { L _ IToubxparen }
312 '#)' { L _ ITcubxparen }
313 '(|' { L _ IToparenbar }
314 '|)' { L _ ITcparenbar }
317 '`' { L _ ITbackquote }
319 VARID { L _ (ITvarid _) } -- identifiers
320 CONID { L _ (ITconid _) }
321 VARSYM { L _ (ITvarsym _) }
322 CONSYM { L _ (ITconsym _) }
323 QVARID { L _ (ITqvarid _) }
324 QCONID { L _ (ITqconid _) }
325 QVARSYM { L _ (ITqvarsym _) }
326 QCONSYM { L _ (ITqconsym _) }
327 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
328 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
330 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
332 CHAR { L _ (ITchar _) }
333 STRING { L _ (ITstring _) }
334 INTEGER { L _ (ITinteger _) }
335 RATIONAL { L _ (ITrational _) }
337 PRIMCHAR { L _ (ITprimchar _) }
338 PRIMSTRING { L _ (ITprimstring _) }
339 PRIMINTEGER { L _ (ITprimint _) }
340 PRIMWORD { L _ (ITprimword _) }
341 PRIMFLOAT { L _ (ITprimfloat _) }
342 PRIMDOUBLE { L _ (ITprimdouble _) }
344 DOCNEXT { L _ (ITdocCommentNext _) }
345 DOCPREV { L _ (ITdocCommentPrev _) }
346 DOCNAMED { L _ (ITdocCommentNamed _) }
347 DOCSECTION { L _ (ITdocSection _ _) }
350 '[|' { L _ ITopenExpQuote }
351 '[p|' { L _ ITopenPatQuote }
352 '[t|' { L _ ITopenTypQuote }
353 '[d|' { L _ ITopenDecQuote }
354 '|]' { L _ ITcloseQuote }
355 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
356 '$(' { L _ ITparenEscape } -- $( exp )
357 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
358 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
359 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
361 %monad { P } { >>= } { return }
362 %lexer { lexer } { L _ ITeof }
363 %name parseModule module
364 %name parseStmt maybe_stmt
365 %name parseIdentifier identifier
366 %name parseType ctype
367 %partial parseHeader header
368 %tokentype { (Located Token) }
371 -----------------------------------------------------------------------------
372 -- Identifiers; one of the entry points
373 identifier :: { Located RdrName }
378 | '(' '->' ')' { LL $ getRdrName funTyCon }
380 -----------------------------------------------------------------------------
383 -- The place for module deprecation is really too restrictive, but if it
384 -- was allowed at its natural place just before 'module', we get an ugly
385 -- s/r conflict with the second alternative. Another solution would be the
386 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
387 -- either, and DEPRECATED is only expected to be used by people who really
388 -- know what they are doing. :-)
390 module :: { Located (HsModule RdrName) }
391 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
392 {% fileSrcSpan >>= \ loc ->
393 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
396 {% fileSrcSpan >>= \ loc ->
397 return (L loc (HsModule Nothing Nothing
398 (fst $1) (snd $1) Nothing Nothing
401 maybedocheader :: { Maybe LHsDocString }
402 : moduleheader { $1 }
403 | {- empty -} { Nothing }
405 missing_module_keyword :: { () }
406 : {- empty -} {% pushCurrentContext }
408 maybemodwarning :: { Maybe WarningTxt }
409 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
410 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
411 | {- empty -} { Nothing }
413 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
415 | vocurly top close { $2 }
417 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
419 | missing_module_keyword top close { $2 }
421 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
422 : importdecls { (reverse $1,[]) }
423 | importdecls ';' cvtopdecls { (reverse $1,$3) }
424 | cvtopdecls { ([],$1) }
426 cvtopdecls :: { [LHsDecl RdrName] }
427 : topdecls { cvTopDecls $1 }
429 -----------------------------------------------------------------------------
430 -- Module declaration & imports only
432 header :: { Located (HsModule RdrName) }
433 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
434 {% fileSrcSpan >>= \ loc ->
435 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
437 | missing_module_keyword importdecls
438 {% fileSrcSpan >>= \ loc ->
439 return (L loc (HsModule Nothing Nothing $2 [] Nothing
442 header_body :: { [LImportDecl RdrName] }
443 : '{' importdecls { $2 }
444 | vocurly importdecls { $2 }
446 -----------------------------------------------------------------------------
449 maybeexports :: { Maybe [LIE RdrName] }
450 : '(' exportlist ')' { Just $2 }
451 | {- empty -} { Nothing }
453 exportlist :: { [LIE RdrName] }
454 : expdoclist ',' expdoclist { $1 ++ $3 }
457 exportlist1 :: { [LIE RdrName] }
458 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
459 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
462 expdoclist :: { [LIE RdrName] }
463 : exp_doc expdoclist { $1 : $2 }
466 exp_doc :: { LIE RdrName }
467 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
468 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
469 | docnext { L1 (IEDoc (unLoc $1)) }
471 -- No longer allow things like [] and (,,,) to be exported
472 -- They are built in syntax, always available
473 export :: { LIE RdrName }
474 : qvar { L1 (IEVar (unLoc $1)) }
475 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
476 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
477 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
478 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
479 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
481 qcnames :: { [RdrName] }
482 : qcnames ',' qcname_ext { unLoc $3 : $1 }
483 | qcname_ext { [unLoc $1] }
485 qcname_ext :: { Located RdrName } -- Variable or data constructor
486 -- or tagged type constructor
488 | 'type' qcon { sL (comb2 $1 $2)
489 (setRdrNameSpace (unLoc $2)
492 -- Cannot pull into qcname_ext, as qcname is also used in expression.
493 qcname :: { Located RdrName } -- Variable or data constructor
497 -----------------------------------------------------------------------------
498 -- Import Declarations
500 -- import decls can be *empty*, or even just a string of semicolons
501 -- whereas topdecls must contain at least one topdecl.
503 importdecls :: { [LImportDecl RdrName] }
504 : importdecls ';' importdecl { $3 : $1 }
505 | importdecls ';' { $1 }
506 | importdecl { [ $1 ] }
509 importdecl :: { LImportDecl RdrName }
510 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
511 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
513 maybe_src :: { IsBootInterface }
514 : '{-# SOURCE' '#-}' { True }
515 | {- empty -} { False }
517 maybe_pkg :: { Maybe FastString }
518 : STRING { Just (getSTRING $1) }
519 | {- empty -} { Nothing }
521 optqualified :: { Bool }
522 : 'qualified' { True }
523 | {- empty -} { False }
525 maybeas :: { Located (Maybe ModuleName) }
526 : 'as' modid { LL (Just (unLoc $2)) }
527 | {- empty -} { noLoc Nothing }
529 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
530 : impspec { L1 (Just (unLoc $1)) }
531 | {- empty -} { noLoc Nothing }
533 impspec :: { Located (Bool, [LIE RdrName]) }
534 : '(' exportlist ')' { LL (False, $2) }
535 | 'hiding' '(' exportlist ')' { LL (True, $3) }
537 -----------------------------------------------------------------------------
538 -- Fixity Declarations
542 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
544 infix :: { Located FixityDirection }
545 : 'infix' { L1 InfixN }
546 | 'infixl' { L1 InfixL }
547 | 'infixr' { L1 InfixR }
549 ops :: { Located [Located RdrName] }
550 : ops ',' op { LL ($3 : unLoc $1) }
553 -----------------------------------------------------------------------------
554 -- Top-Level Declarations
556 topdecls :: { OrdList (LHsDecl RdrName) }
557 : topdecls ';' topdecl { $1 `appOL` $3 }
558 | topdecls ';' { $1 }
561 topdecl :: { OrdList (LHsDecl RdrName) }
562 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
563 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
564 | 'instance' inst_type where_inst
565 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
567 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
568 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
569 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
570 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
571 | '{-# DEPRECATED' deprecations '#-}' { $2 }
572 | '{-# WARNING' warnings '#-}' { $2 }
573 | '{-# RULES' rules '#-}' { $2 }
574 | annotation { unitOL $1 }
577 -- Template Haskell Extension
578 -- The $(..) form is one possible form of infixexp
579 -- but we treat an arbitrary expression just as if
580 -- it had a $(..) wrapped around it
581 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
585 cl_decl :: { LTyClDecl RdrName }
586 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
588 -- Type declarations (toplevel)
590 ty_decl :: { LTyClDecl RdrName }
591 -- ordinary type synonyms
592 : 'type' type '=' ctypedoc
593 -- Note ctype, not sigtype, on the right of '='
594 -- We allow an explicit for-all but we don't insert one
595 -- in type Foo a = (b,b)
596 -- Instead we just say b is out of scope
598 -- Note the use of type for the head; this allows
599 -- infix type constructors to be declared
600 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
602 -- type family declarations
603 | 'type' 'family' type opt_kind_sig
604 -- Note the use of type for the head; this allows
605 -- infix type constructors to be declared
606 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
608 -- type instance declarations
609 | 'type' 'instance' type '=' ctype
610 -- Note the use of type for the head; this allows
611 -- infix type constructors and type patterns
612 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
614 -- ordinary data type or newtype declaration
615 | data_or_newtype tycl_hdr constrs deriving
616 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
617 Nothing (reverse (unLoc $3)) (unLoc $4) }
618 -- We need the location on tycl_hdr in case
619 -- constrs and deriving are both empty
621 -- ordinary GADT declaration
622 | data_or_newtype tycl_hdr opt_kind_sig
625 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
626 (unLoc $3) (unLoc $4) (unLoc $5) }
627 -- We need the location on tycl_hdr in case
628 -- constrs and deriving are both empty
630 -- data/newtype family
631 | 'data' 'family' type opt_kind_sig
632 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
634 -- data/newtype instance declaration
635 | data_or_newtype 'instance' tycl_hdr constrs deriving
636 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
637 Nothing (reverse (unLoc $4)) (unLoc $5) }
639 -- GADT instance declaration
640 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
643 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
644 (unLoc $4) (unLoc $5) (unLoc $6) }
646 -- Associated type family declarations
648 -- * They have a different syntax than on the toplevel (no family special
651 -- * They also need to be separate from instances; otherwise, data family
652 -- declarations without a kind signature cause parsing conflicts with empty
653 -- data declarations.
655 at_decl_cls :: { LTyClDecl RdrName }
656 -- type family declarations
657 : 'type' type opt_kind_sig
658 -- Note the use of type for the head; this allows
659 -- infix type constructors to be declared
660 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
662 -- default type instance
663 | 'type' type '=' ctype
664 -- Note the use of type for the head; this allows
665 -- infix type constructors and type patterns
666 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
668 -- data/newtype family declaration
669 | 'data' type opt_kind_sig
670 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
672 -- Associated type instances
674 at_decl_inst :: { LTyClDecl RdrName }
675 -- type instance declarations
676 : 'type' type '=' ctype
677 -- Note the use of type for the head; this allows
678 -- infix type constructors and type patterns
679 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
681 -- data/newtype instance declaration
682 | data_or_newtype tycl_hdr constrs deriving
683 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
684 Nothing (reverse (unLoc $3)) (unLoc $4) }
686 -- GADT instance declaration
687 | data_or_newtype tycl_hdr opt_kind_sig
690 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
691 (unLoc $3) (unLoc $4) (unLoc $5) }
693 data_or_newtype :: { Located NewOrData }
694 : 'data' { L1 DataType }
695 | 'newtype' { L1 NewType }
697 opt_kind_sig :: { Located (Maybe Kind) }
699 | '::' kind { LL (Just (unLoc $2)) }
701 -- tycl_hdr parses the header of a class or data type decl,
702 -- which takes the form
705 -- (Eq a, Ord b) => T a b
706 -- T Int [a] -- for associated types
707 -- Rather a lot of inlining here, else we get reduce/reduce errors
708 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
709 : context '=>' type { LL (Just $1, $3) }
710 | type { L1 (Nothing, $1) }
712 -----------------------------------------------------------------------------
713 -- Stand-alone deriving
715 -- Glasgow extension: stand-alone deriving declarations
716 stand_alone_deriving :: { LDerivDecl RdrName }
717 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
719 -----------------------------------------------------------------------------
720 -- Nested declarations
722 -- Declaration in class bodies
724 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
725 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
728 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
729 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
730 | decls_cls ';' { LL (unLoc $1) }
732 | {- empty -} { noLoc nilOL }
736 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
737 : '{' decls_cls '}' { LL (unLoc $2) }
738 | vocurly decls_cls close { $2 }
742 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
743 -- No implicit parameters
744 -- May have type declarations
745 : 'where' decllist_cls { LL (unLoc $2) }
746 | {- empty -} { noLoc nilOL }
748 -- Declarations in instance bodies
750 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
751 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
754 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
755 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
756 | decls_inst ';' { LL (unLoc $1) }
758 | {- empty -} { noLoc nilOL }
761 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
762 : '{' decls_inst '}' { LL (unLoc $2) }
763 | vocurly decls_inst close { $2 }
767 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
768 -- No implicit parameters
769 -- May have type declarations
770 : 'where' decllist_inst { LL (unLoc $2) }
771 | {- empty -} { noLoc nilOL }
773 -- Declarations in binding groups other than classes and instances
775 decls :: { Located (OrdList (LHsDecl RdrName)) }
776 : decls ';' decl { let { this = unLoc $3;
778 these = rest `appOL` this }
779 in rest `seq` this `seq` these `seq`
781 | decls ';' { LL (unLoc $1) }
783 | {- empty -} { noLoc nilOL }
785 decllist :: { Located (OrdList (LHsDecl RdrName)) }
786 : '{' decls '}' { LL (unLoc $2) }
787 | vocurly decls close { $2 }
789 -- Binding groups other than those of class and instance declarations
791 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
792 -- No type declarations
793 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
794 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
795 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
797 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
798 -- No type declarations
799 : 'where' binds { LL (unLoc $2) }
800 | {- empty -} { noLoc emptyLocalBinds }
803 -----------------------------------------------------------------------------
804 -- Transformation Rules
806 rules :: { OrdList (LHsDecl RdrName) }
807 : rules ';' rule { $1 `snocOL` $3 }
810 | {- empty -} { nilOL }
812 rule :: { LHsDecl RdrName }
813 : STRING activation rule_forall infixexp '=' exp
814 { LL $ RuleD (HsRule (getSTRING $1)
815 ($2 `orElse` AlwaysActive)
816 $3 $4 placeHolderNames $6 placeHolderNames) }
818 activation :: { Maybe Activation }
819 : {- empty -} { Nothing }
820 | explicit_activation { Just $1 }
822 explicit_activation :: { Activation } -- In brackets
823 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
824 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
826 rule_forall :: { [RuleBndr RdrName] }
827 : 'forall' rule_var_list '.' { $2 }
830 rule_var_list :: { [RuleBndr RdrName] }
832 | rule_var rule_var_list { $1 : $2 }
834 rule_var :: { RuleBndr RdrName }
835 : varid { RuleBndr $1 }
836 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
838 -----------------------------------------------------------------------------
839 -- Warnings and deprecations (c.f. rules)
841 warnings :: { OrdList (LHsDecl RdrName) }
842 : warnings ';' warning { $1 `appOL` $3 }
843 | warnings ';' { $1 }
845 | {- empty -} { nilOL }
847 -- SUP: TEMPORARY HACK, not checking for `module Foo'
848 warning :: { OrdList (LHsDecl RdrName) }
850 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
853 deprecations :: { OrdList (LHsDecl RdrName) }
854 : deprecations ';' deprecation { $1 `appOL` $3 }
855 | deprecations ';' { $1 }
857 | {- empty -} { nilOL }
859 -- SUP: TEMPORARY HACK, not checking for `module Foo'
860 deprecation :: { OrdList (LHsDecl RdrName) }
862 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
865 strings :: { Located [FastString] }
866 : STRING { L1 [getSTRING $1] }
867 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
869 stringlist :: { Located (OrdList FastString) }
870 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
871 | STRING { LL (unitOL (getSTRING $1)) }
873 -----------------------------------------------------------------------------
875 annotation :: { LHsDecl RdrName }
876 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
877 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
878 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
881 -----------------------------------------------------------------------------
882 -- Foreign import and export declarations
884 fdecl :: { LHsDecl RdrName }
885 fdecl : 'import' callconv safety fspec
886 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
887 | 'import' callconv fspec
888 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
890 | 'export' callconv fspec
891 {% mkExport $2 (unLoc $3) >>= return.LL }
893 callconv :: { CCallConv }
894 : 'stdcall' { StdCallConv }
895 | 'ccall' { CCallConv }
896 | 'prim' { PrimCallConv}
899 : 'unsafe' { PlayRisky }
900 | 'safe' { PlaySafe False }
901 | 'threadsafe' { PlaySafe True } -- deprecated alias
903 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
904 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
905 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
906 -- if the entity string is missing, it defaults to the empty string;
907 -- the meaning of an empty entity string depends on the calling
910 -----------------------------------------------------------------------------
913 opt_sig :: { Maybe (LHsType RdrName) }
914 : {- empty -} { Nothing }
915 | '::' sigtype { Just $2 }
917 opt_asig :: { Maybe (LHsType RdrName) }
918 : {- empty -} { Nothing }
919 | '::' atype { Just $2 }
921 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
922 -- to tell the renamer where to generalise
923 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
924 -- Wrap an Implicit forall if there isn't one there already
926 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
927 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
928 -- Wrap an Implicit forall if there isn't one there already
930 sig_vars :: { Located [Located RdrName] }
931 : sig_vars ',' var { LL ($3 : unLoc $1) }
934 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
936 | sigtype ',' sigtypes1 { $1 : $3 }
938 -----------------------------------------------------------------------------
941 infixtype :: { LHsType RdrName }
942 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
943 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
945 strict_mark :: { Located HsBang }
946 : '!' { L1 HsStrict }
947 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
949 -- A ctype is a for-all type
950 ctype :: { LHsType RdrName }
951 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
952 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
953 -- A type of form (context => type) is an *implicit* HsForAllTy
954 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
957 ----------------------
958 -- Notes for 'ctypedoc'
959 -- It would have been nice to simplify the grammar by unifying `ctype` and
960 -- ctypedoc` into one production, allowing comments on types everywhere (and
961 -- rejecting them after parsing, where necessary). This is however not possible
962 -- since it leads to ambiguity. The reason is the support for comments on record
964 -- data R = R { field :: Int -- ^ comment on the field }
965 -- If we allow comments on types here, it's not clear if the comment applies
966 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
968 ctypedoc :: { LHsType RdrName }
969 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
970 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
971 -- A type of form (context => type) is an *implicit* HsForAllTy
972 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
975 ----------------------
976 -- Notes for 'context'
977 -- We parse a context as a btype so that we don't get reduce/reduce
978 -- errors in ctype. The basic problem is that
980 -- looks so much like a tuple type. We can't tell until we find the =>
982 -- We have the t1 ~ t2 form both in 'context' and in type,
983 -- to permit an individual equational constraint without parenthesis.
984 -- Thus for some reason we allow f :: a~b => blah
985 -- but not f :: ?x::Int => blah
986 context :: { LHsContext RdrName }
987 : btype '~' btype {% checkContext
988 (LL $ HsPredTy (HsEqualP $1 $3)) }
989 | btype {% checkContext $1 }
991 type :: { LHsType RdrName }
993 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
994 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
995 | btype '->' ctype { LL $ HsFunTy $1 $3 }
996 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
998 typedoc :: { LHsType RdrName }
1000 | btype docprev { LL $ HsDocTy $1 $2 }
1001 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1002 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1003 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1004 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1005 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1006 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1007 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1009 btype :: { LHsType RdrName }
1010 : btype atype { LL $ HsAppTy $1 $2 }
1013 atype :: { LHsType RdrName }
1014 : gtycon { L1 (HsTyVar (unLoc $1)) }
1015 | tyvar { L1 (HsTyVar (unLoc $1)) }
1016 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1017 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1018 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1019 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1020 | '[' ctype ']' { LL $ HsListTy $2 }
1021 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1022 | '(' ctype ')' { LL $ HsParTy $2 }
1023 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1024 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1025 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1026 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1027 mkUnqual varName (getTH_ID_SPLICE $1) }
1029 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1031 -- An inst_type is what occurs in the head of an instance decl
1032 -- e.g. (Foo a, Gaz b) => Wibble a b
1033 -- It's kept as a single type, with a MonoDictTy at the right
1034 -- hand corner, for convenience.
1035 inst_type :: { LHsType RdrName }
1036 : sigtype {% checkInstType $1 }
1038 inst_types1 :: { [LHsType RdrName] }
1039 : inst_type { [$1] }
1040 | inst_type ',' inst_types1 { $1 : $3 }
1042 comma_types0 :: { [LHsType RdrName] }
1043 : comma_types1 { $1 }
1044 | {- empty -} { [] }
1046 comma_types1 :: { [LHsType RdrName] }
1048 | ctype ',' comma_types1 { $1 : $3 }
1050 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1051 : tv_bndr tv_bndrs { $1 : $2 }
1052 | {- empty -} { [] }
1054 tv_bndr :: { LHsTyVarBndr RdrName }
1055 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1056 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1059 fds :: { Located [Located (FunDep RdrName)] }
1060 : {- empty -} { noLoc [] }
1061 | '|' fds1 { LL (reverse (unLoc $2)) }
1063 fds1 :: { Located [Located (FunDep RdrName)] }
1064 : fds1 ',' fd { LL ($3 : unLoc $1) }
1067 fd :: { Located (FunDep RdrName) }
1068 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1069 (reverse (unLoc $1), reverse (unLoc $3)) }
1071 varids0 :: { Located [RdrName] }
1072 : {- empty -} { noLoc [] }
1073 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1075 -----------------------------------------------------------------------------
1078 kind :: { Located Kind }
1080 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1082 akind :: { Located Kind }
1083 : '*' { L1 liftedTypeKind }
1084 | '!' { L1 unliftedTypeKind }
1085 | '(' kind ')' { LL (unLoc $2) }
1088 -----------------------------------------------------------------------------
1089 -- Datatype declarations
1091 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1092 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1093 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1094 | {- empty -} { noLoc [] }
1096 gadt_constrs :: { Located [LConDecl RdrName] }
1097 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1098 | gadt_constr { L (getLoc (head $1)) $1 }
1099 | {- empty -} { noLoc [] }
1101 -- We allow the following forms:
1102 -- C :: Eq a => a -> T a
1103 -- C :: forall a. Eq a => !a -> T a
1104 -- D { x,y :: a } :: T a
1105 -- forall a. Eq a => D { x,y :: a } :: T a
1107 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1108 : con_list '::' sigtype
1109 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1111 -- Deprecated syntax for GADT record declarations
1112 | oqtycon '{' fielddecls '}' '::' sigtype
1113 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1116 constrs :: { Located [LConDecl RdrName] }
1117 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1119 constrs1 :: { Located [LConDecl RdrName] }
1120 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1121 | constr { L1 [$1] }
1123 constr :: { LConDecl RdrName }
1124 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1125 { let (con,details) = unLoc $5 in
1126 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1128 | maybe_docnext forall constr_stuff maybe_docprev
1129 { let (con,details) = unLoc $3 in
1130 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1133 forall :: { Located [LHsTyVarBndr RdrName] }
1134 : 'forall' tv_bndrs '.' { LL $2 }
1135 | {- empty -} { noLoc [] }
1137 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1138 -- We parse the constructor declaration
1140 -- as a btype (treating C as a type constructor) and then convert C to be
1141 -- a data constructor. Reason: it might continue like this:
1143 -- in which case C really would be a type constructor. We can't resolve this
1144 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1145 : btype {% splitCon $1 >>= return.LL }
1146 | btype conop btype { LL ($2, InfixCon $1 $3) }
1148 fielddecls :: { [ConDeclField RdrName] }
1149 : {- empty -} { [] }
1150 | fielddecls1 { $1 }
1152 fielddecls1 :: { [ConDeclField RdrName] }
1153 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1154 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1155 -- This adds the doc $4 to each field separately
1158 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1159 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1160 | fld <- reverse (unLoc $2) ] }
1162 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1163 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1164 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1165 -- We don't allow a context, but that's sorted out by the type checker.
1166 deriving :: { Located (Maybe [LHsType RdrName]) }
1167 : {- empty -} { noLoc Nothing }
1168 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1169 ; p <- checkInstType (L loc (HsTyVar tv))
1170 ; return (LL (Just [p])) } }
1171 | 'deriving' '(' ')' { LL (Just []) }
1172 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1173 -- Glasgow extension: allow partial
1174 -- applications in derivings
1176 -----------------------------------------------------------------------------
1177 -- Value definitions
1179 {- Note [Declaration/signature overlap]
1180 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1181 There's an awkward overlap with a type signature. Consider
1182 f :: Int -> Int = ...rhs...
1183 Then we can't tell whether it's a type signature or a value
1184 definition with a result signature until we see the '='.
1185 So we have to inline enough to postpone reductions until we know.
1189 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1190 instead of qvar, we get another shift/reduce-conflict. Consider the
1193 { (^^) :: Int->Int ; } Type signature; only var allowed
1195 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1196 qvar allowed (because of instance decls)
1198 We can't tell whether to reduce var to qvar until after we've read the signatures.
1201 docdecl :: { LHsDecl RdrName }
1202 : docdecld { L1 (DocD (unLoc $1)) }
1204 docdecld :: { LDocDecl }
1205 : docnext { L1 (DocCommentNext (unLoc $1)) }
1206 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1207 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1208 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1210 decl :: { Located (OrdList (LHsDecl RdrName)) }
1212 | '!' aexp rhs {% do { pat <- checkPattern $2;
1213 return (LL $ unitOL $ LL $ ValD (
1214 PatBind (LL $ BangPat pat) (unLoc $3)
1215 placeHolderType placeHolderNames)) } }
1216 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1217 let { l = comb2 $1 $> };
1218 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1219 | docdecl { LL $ unitOL $1 }
1221 rhs :: { Located (GRHSs RdrName) }
1222 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1223 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1225 gdrhs :: { Located [LGRHS RdrName] }
1226 : gdrhs gdrh { LL ($2 : unLoc $1) }
1229 gdrh :: { LGRHS RdrName }
1230 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1232 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1233 : infixexp '::' sigtypedoc {% do s <- checkValSig $1 $3
1234 ; return (LL $ unitOL (LL $ SigD s)) }
1235 -- See Note [Declaration/signature overlap] for why we need infixexp here
1236 | var ',' sig_vars '::' sigtypedoc
1237 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1238 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1240 | '{-# INLINE' activation qvar '#-}'
1241 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma $2 FunLike (getINLINE $1)))) }
1242 | '{-# INLINE_CONLIKE' activation qvar '#-}'
1243 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma $2 ConLike (getINLINE_CONLIKE $1)))) }
1244 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1245 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1247 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1248 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma $2 FunLike (getSPEC_INLINE $1)))
1250 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1251 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1253 -----------------------------------------------------------------------------
1256 quasiquote :: { Located (HsQuasiQuote RdrName) }
1257 : TH_QUASIQUOTE { let { loc = getLoc $1
1258 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1259 ; quoterId = mkUnqual varName quoter }
1260 in L1 (mkHsQuasiQuote quoterId quoteSpan quote) }
1262 exp :: { LHsExpr RdrName }
1263 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1264 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1265 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1266 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1267 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1270 infixexp :: { LHsExpr RdrName }
1272 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1274 exp10 :: { LHsExpr RdrName }
1275 : '\\' apat apats opt_asig '->' exp
1276 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1279 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1280 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1281 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1282 return (LL $ HsIf $2 $5 $8) }
1283 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1284 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1286 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1287 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1288 return (L loc (mkHsDo DoExpr stmts body)) }
1289 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1290 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1291 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1292 | scc_annot exp { LL $ if opt_SccProfilingOn
1293 then HsSCC (unLoc $1) $2
1295 | hpc_annot exp { LL $ if opt_Hpc
1296 then HsTickPragma (unLoc $1) $2
1299 | 'proc' aexp '->' exp
1300 {% checkPattern $2 >>= \ p ->
1301 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1302 placeHolderType undefined)) }
1303 -- TODO: is LL right here?
1305 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1306 -- hdaume: core annotation
1311 | {- empty -} { False }
1313 scc_annot :: { Located FastString }
1314 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1315 ( do scc <- getSCC $2; return $ LL scc ) }
1316 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1318 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1319 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1320 { LL $ (getSTRING $2
1321 ,( fromInteger $ getINTEGER $3
1322 , fromInteger $ getINTEGER $5
1324 ,( fromInteger $ getINTEGER $7
1325 , fromInteger $ getINTEGER $9
1330 fexp :: { LHsExpr RdrName }
1331 : fexp aexp { LL $ HsApp $1 $2 }
1334 aexp :: { LHsExpr RdrName }
1335 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1336 | '~' aexp { LL $ ELazyPat $2 }
1339 aexp1 :: { LHsExpr RdrName }
1340 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1344 -- Here was the syntax for type applications that I was planning
1345 -- but there are difficulties (e.g. what order for type args)
1346 -- so it's not enabled yet.
1347 -- But this case *is* used for the left hand side of a generic definition,
1348 -- which is parsed as an expression before being munged into a pattern
1349 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1350 (sL (getLoc $3) (HsType $3)) }
1352 aexp2 :: { LHsExpr RdrName }
1353 : ipvar { L1 (HsIPVar $! unLoc $1) }
1354 | qcname { L1 (HsVar $! unLoc $1) }
1355 | literal { L1 (HsLit $! unLoc $1) }
1356 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1357 -- into HsOverLit when -foverloaded-strings is on.
1358 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1359 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1360 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1362 -- N.B.: sections get parsed by these next two productions.
1363 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
1364 -- (you'd have to write '((+ 3), (4 -))')
1365 -- but the less cluttered version fell out of having texps.
1366 | '(' texp ')' { LL (HsPar $2) }
1367 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1369 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1370 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1372 | '[' list ']' { LL (unLoc $2) }
1373 | '[:' parr ':]' { LL (unLoc $2) }
1374 | '_' { L1 EWildPat }
1376 -- Template Haskell Extension
1377 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1378 (L1 $ HsVar (mkUnqual varName
1379 (getTH_ID_SPLICE $1)))) }
1380 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1383 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1384 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1385 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1386 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1387 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1388 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1389 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1390 return (LL $ HsBracket (PatBr p)) }
1391 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1392 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1394 -- arrow notation extension
1395 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1397 cmdargs :: { [LHsCmdTop RdrName] }
1398 : cmdargs acmd { $2 : $1 }
1399 | {- empty -} { [] }
1401 acmd :: { LHsCmdTop RdrName }
1402 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1404 cvtopbody :: { [LHsDecl RdrName] }
1405 : '{' cvtopdecls0 '}' { $2 }
1406 | vocurly cvtopdecls0 close { $2 }
1408 cvtopdecls0 :: { [LHsDecl RdrName] }
1409 : {- empty -} { [] }
1412 -----------------------------------------------------------------------------
1413 -- Tuple expressions
1415 -- "texp" is short for tuple expressions:
1416 -- things that can appear unparenthesized as long as they're
1417 -- inside parens or delimitted by commas
1418 texp :: { LHsExpr RdrName }
1421 -- Note [Parsing sections]
1422 -- ~~~~~~~~~~~~~~~~~~~~~~~
1423 -- We include left and right sections here, which isn't
1424 -- technically right according to Haskell 98. For example
1425 -- (3 +, True) isn't legal
1426 -- However, we want to parse bang patterns like
1428 -- and it's convenient to do so here as a section
1429 -- Then when converting expr to pattern we unravel it again
1430 -- Meanwhile, the renamer checks that real sections appear
1432 | infixexp qop { LL $ SectionL $1 $2 }
1433 | qopm infixexp { LL $ SectionR $1 $2 }
1435 -- View patterns get parenthesized above
1436 | exp '->' texp { LL $ EViewPat $1 $3 }
1438 -- Always at least one comma
1439 tup_exprs :: { [HsTupArg RdrName] }
1440 : texp commas_tup_tail { Present $1 : $2 }
1441 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1443 -- Always starts with commas; always follows an expr
1444 commas_tup_tail :: { [HsTupArg RdrName] }
1445 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1447 -- Always follows a comma
1448 tup_tail :: { [HsTupArg RdrName] }
1449 : texp commas_tup_tail { Present $1 : $2 }
1450 | texp { [Present $1] }
1451 | {- empty -} { [missingTupArg] }
1453 -----------------------------------------------------------------------------
1456 -- The rules below are little bit contorted to keep lexps left-recursive while
1457 -- avoiding another shift/reduce-conflict.
1459 list :: { LHsExpr RdrName }
1460 : texp { L1 $ ExplicitList placeHolderType [$1] }
1461 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1462 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1463 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1464 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1465 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1466 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1468 lexps :: { Located [LHsExpr RdrName] }
1469 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1470 | texp ',' texp { LL [$3,$1] }
1472 -----------------------------------------------------------------------------
1473 -- List Comprehensions
1475 flattenedpquals :: { Located [LStmt RdrName] }
1476 : pquals { case (unLoc $1) of
1478 -- We just had one thing in our "parallel" list so
1479 -- we simply return that thing directly
1481 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1482 -- We actually found some actual parallel lists so
1483 -- we wrap them into as a ParStmt
1486 pquals :: { Located [[LStmt RdrName]] }
1487 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1488 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1490 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1491 -- one can "grab" the earlier ones
1492 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1493 | squals ',' qual { LL ($3 : unLoc $1) }
1494 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1496 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1497 -- | '{|' pquals '|}' { L1 [$2] }
1500 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1501 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1502 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1503 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1505 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1506 -- Function is applied to a list of stmts *in order*
1507 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1509 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1510 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1512 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1513 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1514 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1515 -- choosing the "group by" variant, which is what we want.
1517 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1518 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1519 -- if /that/ is the group function we conflict with.
1520 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1521 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1523 -----------------------------------------------------------------------------
1524 -- Parallel array expressions
1526 -- The rules below are little bit contorted; see the list case for details.
1527 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1528 -- Moreover, we allow explicit arrays with no element (represented by the nil
1529 -- constructor in the list case).
1531 parr :: { LHsExpr RdrName }
1532 : { noLoc (ExplicitPArr placeHolderType []) }
1533 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1534 | lexps { L1 $ ExplicitPArr placeHolderType
1535 (reverse (unLoc $1)) }
1536 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1537 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1538 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1540 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1542 -----------------------------------------------------------------------------
1545 guardquals :: { Located [LStmt RdrName] }
1546 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1548 guardquals1 :: { Located [LStmt RdrName] }
1549 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1552 -----------------------------------------------------------------------------
1553 -- Case alternatives
1555 altslist :: { Located [LMatch RdrName] }
1556 : '{' alts '}' { LL (reverse (unLoc $2)) }
1557 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1559 alts :: { Located [LMatch RdrName] }
1560 : alts1 { L1 (unLoc $1) }
1561 | ';' alts { LL (unLoc $2) }
1563 alts1 :: { Located [LMatch RdrName] }
1564 : alts1 ';' alt { LL ($3 : unLoc $1) }
1565 | alts1 ';' { LL (unLoc $1) }
1568 alt :: { LMatch RdrName }
1569 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1571 alt_rhs :: { Located (GRHSs RdrName) }
1572 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1574 ralt :: { Located [LGRHS RdrName] }
1575 : '->' exp { LL (unguardedRHS $2) }
1576 | gdpats { L1 (reverse (unLoc $1)) }
1578 gdpats :: { Located [LGRHS RdrName] }
1579 : gdpats gdpat { LL ($2 : unLoc $1) }
1582 gdpat :: { LGRHS RdrName }
1583 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1585 -- 'pat' recognises a pattern, including one with a bang at the top
1586 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1587 -- Bangs inside are parsed as infix operator applications, so that
1588 -- we parse them right when bang-patterns are off
1589 pat :: { LPat RdrName }
1590 pat : exp {% checkPattern $1 }
1591 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1593 apat :: { LPat RdrName }
1594 apat : aexp {% checkPattern $1 }
1595 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1597 apats :: { [LPat RdrName] }
1598 : apat apats { $1 : $2 }
1599 | {- empty -} { [] }
1601 -----------------------------------------------------------------------------
1602 -- Statement sequences
1604 stmtlist :: { Located [LStmt RdrName] }
1605 : '{' stmts '}' { LL (unLoc $2) }
1606 | vocurly stmts close { $2 }
1608 -- do { ;; s ; s ; ; s ;; }
1609 -- The last Stmt should be an expression, but that's hard to enforce
1610 -- here, because we need too much lookahead if we see do { e ; }
1611 -- So we use ExprStmts throughout, and switch the last one over
1612 -- in ParseUtils.checkDo instead
1613 stmts :: { Located [LStmt RdrName] }
1614 : stmt stmts_help { LL ($1 : unLoc $2) }
1615 | ';' stmts { LL (unLoc $2) }
1616 | {- empty -} { noLoc [] }
1618 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1619 : ';' stmts { LL (unLoc $2) }
1620 | {- empty -} { noLoc [] }
1622 -- For typing stmts at the GHCi prompt, where
1623 -- the input may consist of just comments.
1624 maybe_stmt :: { Maybe (LStmt RdrName) }
1626 | {- nothing -} { Nothing }
1628 stmt :: { LStmt RdrName }
1630 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1632 qual :: { LStmt RdrName }
1633 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1634 | exp { L1 $ mkExprStmt $1 }
1635 | 'let' binds { LL $ LetStmt (unLoc $2) }
1637 -----------------------------------------------------------------------------
1638 -- Record Field Update/Construction
1640 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1642 | {- empty -} { ([], False) }
1644 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1645 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1646 | fbind { ([$1], False) }
1647 | '..' { ([], True) }
1649 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1650 : qvar '=' exp { HsRecField $1 $3 False }
1651 | qvar { HsRecField $1 placeHolderPunRhs True }
1652 -- In the punning case, use a place-holder
1653 -- The renamer fills in the final value
1655 -----------------------------------------------------------------------------
1656 -- Implicit Parameter Bindings
1658 dbinds :: { Located [LIPBind RdrName] }
1659 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1660 in rest `seq` this `seq` LL (this : rest) }
1661 | dbinds ';' { LL (unLoc $1) }
1662 | dbind { let this = $1 in this `seq` L1 [this] }
1663 -- | {- empty -} { [] }
1665 dbind :: { LIPBind RdrName }
1666 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1668 ipvar :: { Located (IPName RdrName) }
1669 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1671 -----------------------------------------------------------------------------
1672 -- Warnings and deprecations
1674 namelist :: { Located [RdrName] }
1675 namelist : name_var { L1 [unLoc $1] }
1676 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1678 name_var :: { Located RdrName }
1679 name_var : var { $1 }
1682 -----------------------------------------
1683 -- Data constructors
1684 qcon :: { Located RdrName }
1686 | '(' qconsym ')' { LL (unLoc $2) }
1687 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1688 -- The case of '[:' ':]' is part of the production `parr'
1690 con :: { Located RdrName }
1692 | '(' consym ')' { LL (unLoc $2) }
1693 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1695 con_list :: { Located [Located RdrName] }
1696 con_list : con { L1 [$1] }
1697 | con ',' con_list { LL ($1 : unLoc $3) }
1699 sysdcon :: { Located DataCon } -- Wired in data constructors
1700 : '(' ')' { LL unitDataCon }
1701 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1702 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1703 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1704 | '[' ']' { LL nilDataCon }
1706 conop :: { Located RdrName }
1708 | '`' conid '`' { LL (unLoc $2) }
1710 qconop :: { Located RdrName }
1712 | '`' qconid '`' { LL (unLoc $2) }
1714 -----------------------------------------------------------------------------
1715 -- Type constructors
1717 gtycon :: { Located RdrName } -- A "general" qualified tycon
1719 | '(' ')' { LL $ getRdrName unitTyCon }
1720 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1721 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1722 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1723 | '(' '->' ')' { LL $ getRdrName funTyCon }
1724 | '[' ']' { LL $ listTyCon_RDR }
1725 | '[:' ':]' { LL $ parrTyCon_RDR }
1727 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1729 | '(' qtyconsym ')' { LL (unLoc $2) }
1731 qtyconop :: { Located RdrName } -- Qualified or unqualified
1733 | '`' qtycon '`' { LL (unLoc $2) }
1735 qtycon :: { Located RdrName } -- Qualified or unqualified
1736 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1737 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1740 tycon :: { Located RdrName } -- Unqualified
1741 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1743 qtyconsym :: { Located RdrName }
1744 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1747 tyconsym :: { Located RdrName }
1748 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1750 -----------------------------------------------------------------------------
1753 op :: { Located RdrName } -- used in infix decls
1757 varop :: { Located RdrName }
1759 | '`' varid '`' { LL (unLoc $2) }
1761 qop :: { LHsExpr RdrName } -- used in sections
1762 : qvarop { L1 $ HsVar (unLoc $1) }
1763 | qconop { L1 $ HsVar (unLoc $1) }
1765 qopm :: { LHsExpr RdrName } -- used in sections
1766 : qvaropm { L1 $ HsVar (unLoc $1) }
1767 | qconop { L1 $ HsVar (unLoc $1) }
1769 qvarop :: { Located RdrName }
1771 | '`' qvarid '`' { LL (unLoc $2) }
1773 qvaropm :: { Located RdrName }
1774 : qvarsym_no_minus { $1 }
1775 | '`' qvarid '`' { LL (unLoc $2) }
1777 -----------------------------------------------------------------------------
1780 tyvar :: { Located RdrName }
1781 tyvar : tyvarid { $1 }
1782 | '(' tyvarsym ')' { LL (unLoc $2) }
1784 tyvarop :: { Located RdrName }
1785 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1787 | '.' {% parseErrorSDoc (getLoc $1)
1788 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1789 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1790 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1793 tyvarid :: { Located RdrName }
1794 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1795 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1796 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1797 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1798 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1800 tyvarsym :: { Located RdrName }
1801 -- Does not include "!", because that is used for strictness marks
1802 -- or ".", because that separates the quantified type vars from the rest
1803 -- or "*", because that's used for kinds
1804 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1806 -----------------------------------------------------------------------------
1809 var :: { Located RdrName }
1811 | '(' varsym ')' { LL (unLoc $2) }
1813 qvar :: { Located RdrName }
1815 | '(' varsym ')' { LL (unLoc $2) }
1816 | '(' qvarsym1 ')' { LL (unLoc $2) }
1817 -- We've inlined qvarsym here so that the decision about
1818 -- whether it's a qvar or a var can be postponed until
1819 -- *after* we see the close paren.
1821 qvarid :: { Located RdrName }
1823 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1824 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1826 varid :: { Located RdrName }
1827 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1828 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1829 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1830 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1831 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1832 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1833 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1835 qvarsym :: { Located RdrName }
1839 qvarsym_no_minus :: { Located RdrName }
1840 : varsym_no_minus { $1 }
1843 qvarsym1 :: { Located RdrName }
1844 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1846 varsym :: { Located RdrName }
1847 : varsym_no_minus { $1 }
1848 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1850 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1851 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1852 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1855 -- These special_ids are treated as keywords in various places,
1856 -- but as ordinary ids elsewhere. 'special_id' collects all these
1857 -- except 'unsafe', 'forall', and 'family' whose treatment differs
1858 -- depending on context
1859 special_id :: { Located FastString }
1861 : 'as' { L1 (fsLit "as") }
1862 | 'qualified' { L1 (fsLit "qualified") }
1863 | 'hiding' { L1 (fsLit "hiding") }
1864 | 'export' { L1 (fsLit "export") }
1865 | 'label' { L1 (fsLit "label") }
1866 | 'dynamic' { L1 (fsLit "dynamic") }
1867 | 'stdcall' { L1 (fsLit "stdcall") }
1868 | 'ccall' { L1 (fsLit "ccall") }
1869 | 'prim' { L1 (fsLit "prim") }
1870 | 'group' { L1 (fsLit "group") }
1872 special_sym :: { Located FastString }
1873 special_sym : '!' { L1 (fsLit "!") }
1874 | '.' { L1 (fsLit ".") }
1875 | '*' { L1 (fsLit "*") }
1877 -----------------------------------------------------------------------------
1878 -- Data constructors
1880 qconid :: { Located RdrName } -- Qualified or unqualified
1882 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1883 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1885 conid :: { Located RdrName }
1886 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1888 qconsym :: { Located RdrName } -- Qualified or unqualified
1890 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1892 consym :: { Located RdrName }
1893 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1895 -- ':' means only list cons
1896 | ':' { L1 $ consDataCon_RDR }
1899 -----------------------------------------------------------------------------
1902 literal :: { Located HsLit }
1903 : CHAR { L1 $ HsChar $ getCHAR $1 }
1904 | STRING { L1 $ HsString $ getSTRING $1 }
1905 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1906 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1907 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1908 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1909 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1910 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1912 -----------------------------------------------------------------------------
1916 : vccurly { () } -- context popped in lexer.
1917 | error {% popContext }
1919 -----------------------------------------------------------------------------
1920 -- Miscellaneous (mostly renamings)
1922 modid :: { Located ModuleName }
1923 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1924 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1927 (unpackFS mod ++ '.':unpackFS c))
1931 : commas ',' { $1 + 1 }
1934 -----------------------------------------------------------------------------
1935 -- Documentation comments
1937 docnext :: { LHsDocString }
1938 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1940 docprev :: { LHsDocString }
1941 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1943 docnamed :: { Located (String, HsDocString) }
1945 let string = getDOCNAMED $1
1946 (name, rest) = break isSpace string
1947 in return (L1 (name, HsDocString (mkFastString rest))) }
1949 docsection :: { Located (Int, HsDocString) }
1950 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1951 return (L1 (n, HsDocString (mkFastString doc))) }
1953 moduleheader :: { Maybe LHsDocString }
1954 : DOCNEXT {% let string = getDOCNEXT $1 in
1955 return (Just (L1 (HsDocString (mkFastString string)))) }
1957 maybe_docprev :: { Maybe LHsDocString }
1958 : docprev { Just $1 }
1959 | {- empty -} { Nothing }
1961 maybe_docnext :: { Maybe LHsDocString }
1962 : docnext { Just $1 }
1963 | {- empty -} { Nothing }
1967 happyError = srcParseFail
1969 getVARID (L _ (ITvarid x)) = x
1970 getCONID (L _ (ITconid x)) = x
1971 getVARSYM (L _ (ITvarsym x)) = x
1972 getCONSYM (L _ (ITconsym x)) = x
1973 getQVARID (L _ (ITqvarid x)) = x
1974 getQCONID (L _ (ITqconid x)) = x
1975 getQVARSYM (L _ (ITqvarsym x)) = x
1976 getQCONSYM (L _ (ITqconsym x)) = x
1977 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1978 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1979 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1980 getCHAR (L _ (ITchar x)) = x
1981 getSTRING (L _ (ITstring x)) = x
1982 getINTEGER (L _ (ITinteger x)) = x
1983 getRATIONAL (L _ (ITrational x)) = x
1984 getPRIMCHAR (L _ (ITprimchar x)) = x
1985 getPRIMSTRING (L _ (ITprimstring x)) = x
1986 getPRIMINTEGER (L _ (ITprimint x)) = x
1987 getPRIMWORD (L _ (ITprimword x)) = x
1988 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1989 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1990 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1991 getINLINE (L _ (ITinline_prag b)) = b
1992 getINLINE_CONLIKE (L _ (ITinline_conlike_prag b)) = b
1993 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
1995 getDOCNEXT (L _ (ITdocCommentNext x)) = x
1996 getDOCPREV (L _ (ITdocCommentPrev x)) = x
1997 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
1998 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2000 getSCC :: Located Token -> P FastString
2001 getSCC lt = do let s = getSTRING lt
2002 err = "Spaces are not allowed in SCCs"
2003 -- We probably actually want to be more restrictive than this
2004 if ' ' `elem` unpackFS s
2005 then failSpanMsgP (getLoc lt) (text err)
2008 -- Utilities for combining source spans
2009 comb2 :: Located a -> Located b -> SrcSpan
2010 comb2 a b = a `seq` b `seq` combineLocs a b
2012 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2013 comb3 a b c = a `seq` b `seq` c `seq`
2014 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2016 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2017 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2018 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2019 combineSrcSpans (getLoc c) (getLoc d))
2021 -- strict constructor version:
2023 sL :: SrcSpan -> a -> Located a
2024 sL span a = span `seq` a `seq` L span a
2026 -- Make a source location for the file. We're a bit lazy here and just
2027 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2028 -- try to find the span of the whole file (ToDo).
2029 fileSrcSpan :: P SrcSpan
2032 let loc = mkSrcLoc (srcLocFile l) 1 1;
2033 return (mkSrcSpan loc loc)