2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
12 {-# OPTIONS -Wwarn -w #-}
13 -- The above warning supression flag is a temporary kludge.
14 -- While working on this module you are encouraged to remove it and fix
15 -- any warnings in the module. See
16 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
19 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
21 Careful optimisation of the parser: we don't want to throw everything
22 at it, because that takes too long and doesn't buy much, but we do want
23 to inline certain key external functions, so we instruct GHC not to
24 throw away inlinings as it would normally do in -O0 mode.
27 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
32 import HscTypes ( IsBootInterface, WarningTxt(..) )
35 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
36 unboxedSingletonTyCon, unboxedSingletonDataCon,
37 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
38 import Type ( funTyCon )
39 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
40 CCallConv(..), CCallTarget(..), defaultCCallConv
42 import OccName ( varName, dataName, tcClsName, tvName )
43 import DataCon ( DataCon, dataConName )
44 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
45 SrcSpan, combineLocs, srcLocFile,
48 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
49 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
50 import Coercion ( mkArrowKind )
51 import Class ( FunDep )
58 import Maybes ( orElse )
61 import Control.Monad ( unless )
64 import Control.Monad ( mplus )
68 -----------------------------------------------------------------------------
71 Conflicts: 33 shift/reduce
74 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
75 would think the two should never occur in the same context.
79 -----------------------------------------------------------------------------
82 Conflicts: 34 shift/reduce
85 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
86 would think the two should never occur in the same context.
90 -----------------------------------------------------------------------------
93 Conflicts: 32 shift/reduce
96 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
97 would think the two should never occur in the same context.
101 -----------------------------------------------------------------------------
104 Conflicts: 37 shift/reduce
107 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
108 would think the two should never occur in the same context.
112 -----------------------------------------------------------------------------
113 Conflicts: 38 shift/reduce (1.25)
115 10 for abiguity in 'if x then y else z + 1' [State 178]
116 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
117 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
119 1 for ambiguity in 'if x then y else z :: T' [State 178]
120 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
122 4 for ambiguity in 'if x then y else z -< e' [State 178]
123 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
124 There are four such operators: -<, >-, -<<, >>-
127 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
128 Which of these two is intended?
130 (x::T) -> T -- Rhs is T
133 (x::T -> T) -> .. -- Rhs is ...
135 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
138 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
139 Same duplication between states 11 and 253 as the previous case
141 1 for ambiguity in 'let ?x ...' [State 329]
142 the parser can't tell whether the ?x is the lhs of a normal binding or
143 an implicit binding. Fortunately resolving as shift gives it the only
144 sensible meaning, namely the lhs of an implicit binding.
146 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
147 we don't know whether the '[' starts the activation or not: it
148 might be the start of the declaration with the activation being
149 empty. --SDM 1/4/2002
151 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
152 since 'forall' is a valid variable name, we don't know whether
153 to treat a forall on the input as the beginning of a quantifier
154 or the beginning of the rule itself. Resolving to shift means
155 it's always treated as a quantifier, hence the above is disallowed.
156 This saves explicitly defining a grammar for the rule lhs that
157 doesn't include 'forall'.
159 1 for ambiguity when the source file starts with "-- | doc". We need another
160 token of lookahead to determine if a top declaration or the 'module' keyword
161 follows. Shift parses as if the 'module' keyword follows.
163 -- ---------------------------------------------------------------------------
164 -- Adding location info
166 This is done in a stylised way using the three macros below, L0, L1
167 and LL. Each of these macros can be thought of as having type
169 L0, L1, LL :: a -> Located a
171 They each add a SrcSpan to their argument.
173 L0 adds 'noSrcSpan', used for empty productions
174 -- This doesn't seem to work anymore -=chak
176 L1 for a production with a single token on the lhs. Grabs the SrcSpan
179 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
180 the first and last tokens.
182 These suffice for the majority of cases. However, we must be
183 especially careful with empty productions: LL won't work if the first
184 or last token on the lhs can represent an empty span. In these cases,
185 we have to calculate the span using more of the tokens from the lhs, eg.
187 | 'newtype' tycl_hdr '=' newconstr deriving
189 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
191 We provide comb3 and comb4 functions which are useful in such cases.
193 Be careful: there's no checking that you actually got this right, the
194 only symptom will be that the SrcSpans of your syntax will be
198 * We must expand these macros *before* running Happy, which is why this file is
199 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
201 #define L0 L noSrcSpan
202 #define L1 sL (getLoc $1)
203 #define LL sL (comb2 $1 $>)
205 -- -----------------------------------------------------------------------------
210 '_' { L _ ITunderscore } -- Haskell keywords
212 'case' { L _ ITcase }
213 'class' { L _ ITclass }
214 'data' { L _ ITdata }
215 'default' { L _ ITdefault }
216 'deriving' { L _ ITderiving }
218 'else' { L _ ITelse }
219 'generic' { L _ ITgeneric }
220 'hiding' { L _ IThiding }
222 'import' { L _ ITimport }
224 'infix' { L _ ITinfix }
225 'infixl' { L _ ITinfixl }
226 'infixr' { L _ ITinfixr }
227 'instance' { L _ ITinstance }
229 'module' { L _ ITmodule }
230 'newtype' { L _ ITnewtype }
232 'qualified' { L _ ITqualified }
233 'then' { L _ ITthen }
234 'type' { L _ ITtype }
235 'where' { L _ ITwhere }
236 '_scc_' { L _ ITscc } -- ToDo: remove
238 'forall' { L _ ITforall } -- GHC extension keywords
239 'foreign' { L _ ITforeign }
240 'export' { L _ ITexport }
241 'label' { L _ ITlabel }
242 'dynamic' { L _ ITdynamic }
243 'safe' { L _ ITsafe }
244 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
245 'interruptible' { L _ ITinterruptible }
246 'unsafe' { L _ ITunsafe }
248 'family' { L _ ITfamily }
249 'stdcall' { L _ ITstdcallconv }
250 'ccall' { L _ ITccallconv }
251 'prim' { L _ ITprimcallconv }
252 'proc' { L _ ITproc } -- for arrow notation extension
253 'rec' { L _ ITrec } -- for arrow notation extension
254 'group' { L _ ITgroup } -- for list transform extension
255 'by' { L _ ITby } -- for list transform extension
256 'using' { L _ ITusing } -- for list transform extension
258 '{-# INLINE' { L _ (ITinline_prag _ _) }
259 '{-# SPECIALISE' { L _ ITspec_prag }
260 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
261 '{-# SOURCE' { L _ ITsource_prag }
262 '{-# RULES' { L _ ITrules_prag }
263 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
264 '{-# SCC' { L _ ITscc_prag }
265 '{-# GENERATED' { L _ ITgenerated_prag }
266 '{-# DEPRECATED' { L _ ITdeprecated_prag }
267 '{-# WARNING' { L _ ITwarning_prag }
268 '{-# UNPACK' { L _ ITunpack_prag }
269 '{-# ANN' { L _ ITann_prag }
270 '{-# VECTORISE' { L _ ITvect_prag }
271 '{-# VECTORISE_SCALAR' { L _ ITvect_scalar_prag }
272 '#-}' { L _ ITclose_prag }
274 '..' { L _ ITdotdot } -- reserved symbols
276 '::' { L _ ITdcolon }
280 '<-' { L _ ITlarrow }
281 '->' { L _ ITrarrow }
284 '=>' { L _ ITdarrow }
288 '-<' { L _ ITlarrowtail } -- for arrow notation
289 '>-' { L _ ITrarrowtail } -- for arrow notation
290 '-<<' { L _ ITLarrowtail } -- for arrow notation
291 '>>-' { L _ ITRarrowtail } -- for arrow notation
294 '{' { L _ ITocurly } -- special symbols
296 '{|' { L _ ITocurlybar }
297 '|}' { L _ ITccurlybar }
298 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
299 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
302 '[:' { L _ ITopabrack }
303 ':]' { L _ ITcpabrack }
306 '(#' { L _ IToubxparen }
307 '#)' { L _ ITcubxparen }
308 '(|' { L _ IToparenbar }
309 '|)' { L _ ITcparenbar }
312 '`' { L _ ITbackquote }
314 VARID { L _ (ITvarid _) } -- identifiers
315 CONID { L _ (ITconid _) }
316 VARSYM { L _ (ITvarsym _) }
317 CONSYM { L _ (ITconsym _) }
318 QVARID { L _ (ITqvarid _) }
319 QCONID { L _ (ITqconid _) }
320 QVARSYM { L _ (ITqvarsym _) }
321 QCONSYM { L _ (ITqconsym _) }
322 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
323 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
325 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
327 CHAR { L _ (ITchar _) }
328 STRING { L _ (ITstring _) }
329 INTEGER { L _ (ITinteger _) }
330 RATIONAL { L _ (ITrational _) }
332 PRIMCHAR { L _ (ITprimchar _) }
333 PRIMSTRING { L _ (ITprimstring _) }
334 PRIMINTEGER { L _ (ITprimint _) }
335 PRIMWORD { L _ (ITprimword _) }
336 PRIMFLOAT { L _ (ITprimfloat _) }
337 PRIMDOUBLE { L _ (ITprimdouble _) }
339 DOCNEXT { L _ (ITdocCommentNext _) }
340 DOCPREV { L _ (ITdocCommentPrev _) }
341 DOCNAMED { L _ (ITdocCommentNamed _) }
342 DOCSECTION { L _ (ITdocSection _ _) }
345 '[|' { L _ ITopenExpQuote }
346 '[p|' { L _ ITopenPatQuote }
347 '[t|' { L _ ITopenTypQuote }
348 '[d|' { L _ ITopenDecQuote }
349 '|]' { L _ ITcloseQuote }
350 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
351 '$(' { L _ ITparenEscape } -- $( exp )
352 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
353 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
354 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
356 %monad { P } { >>= } { return }
357 %lexer { lexer } { L _ ITeof }
358 %name parseModule module
359 %name parseStmt maybe_stmt
360 %name parseIdentifier identifier
361 %name parseType ctype
362 %partial parseHeader header
363 %tokentype { (Located Token) }
366 -----------------------------------------------------------------------------
367 -- Identifiers; one of the entry points
368 identifier :: { Located RdrName }
373 | '(' '->' ')' { LL $ getRdrName funTyCon }
375 -----------------------------------------------------------------------------
378 -- The place for module deprecation is really too restrictive, but if it
379 -- was allowed at its natural place just before 'module', we get an ugly
380 -- s/r conflict with the second alternative. Another solution would be the
381 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
382 -- either, and DEPRECATED is only expected to be used by people who really
383 -- know what they are doing. :-)
385 module :: { Located (HsModule RdrName) }
386 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
387 {% fileSrcSpan >>= \ loc ->
388 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
391 {% fileSrcSpan >>= \ loc ->
392 return (L loc (HsModule Nothing Nothing
393 (fst $1) (snd $1) Nothing Nothing
396 maybedocheader :: { Maybe LHsDocString }
397 : moduleheader { $1 }
398 | {- empty -} { Nothing }
400 missing_module_keyword :: { () }
401 : {- empty -} {% pushCurrentContext }
403 maybemodwarning :: { Maybe WarningTxt }
404 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
405 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
406 | {- empty -} { Nothing }
408 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
410 | vocurly top close { $2 }
412 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
414 | missing_module_keyword top close { $2 }
416 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
417 : importdecls { (reverse $1,[]) }
418 | importdecls ';' cvtopdecls { (reverse $1,$3) }
419 | cvtopdecls { ([],$1) }
421 cvtopdecls :: { [LHsDecl RdrName] }
422 : topdecls { cvTopDecls $1 }
424 -----------------------------------------------------------------------------
425 -- Module declaration & imports only
427 header :: { Located (HsModule RdrName) }
428 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
429 {% fileSrcSpan >>= \ loc ->
430 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
432 | missing_module_keyword importdecls
433 {% fileSrcSpan >>= \ loc ->
434 return (L loc (HsModule Nothing Nothing $2 [] Nothing
437 header_body :: { [LImportDecl RdrName] }
438 : '{' importdecls { $2 }
439 | vocurly importdecls { $2 }
441 -----------------------------------------------------------------------------
444 maybeexports :: { Maybe [LIE RdrName] }
445 : '(' exportlist ')' { Just $2 }
446 | {- empty -} { Nothing }
448 exportlist :: { [LIE RdrName] }
449 : expdoclist ',' expdoclist { $1 ++ $3 }
452 exportlist1 :: { [LIE RdrName] }
453 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
454 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
457 expdoclist :: { [LIE RdrName] }
458 : exp_doc expdoclist { $1 : $2 }
461 exp_doc :: { LIE RdrName }
462 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
463 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
464 | docnext { L1 (IEDoc (unLoc $1)) }
466 -- No longer allow things like [] and (,,,) to be exported
467 -- They are built in syntax, always available
468 export :: { LIE RdrName }
469 : qvar { L1 (IEVar (unLoc $1)) }
470 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
471 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
472 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
473 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
474 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
476 qcnames :: { [RdrName] }
477 : qcnames ',' qcname_ext { unLoc $3 : $1 }
478 | qcname_ext { [unLoc $1] }
480 qcname_ext :: { Located RdrName } -- Variable or data constructor
481 -- or tagged type constructor
483 | 'type' qcon { sL (comb2 $1 $2)
484 (setRdrNameSpace (unLoc $2)
487 -- Cannot pull into qcname_ext, as qcname is also used in expression.
488 qcname :: { Located RdrName } -- Variable or data constructor
492 -----------------------------------------------------------------------------
493 -- Import Declarations
495 -- import decls can be *empty*, or even just a string of semicolons
496 -- whereas topdecls must contain at least one topdecl.
498 importdecls :: { [LImportDecl RdrName] }
499 : importdecls ';' importdecl { $3 : $1 }
500 | importdecls ';' { $1 }
501 | importdecl { [ $1 ] }
504 importdecl :: { LImportDecl RdrName }
505 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
506 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
508 maybe_src :: { IsBootInterface }
509 : '{-# SOURCE' '#-}' { True }
510 | {- empty -} { False }
512 maybe_pkg :: { Maybe FastString }
513 : STRING { Just (getSTRING $1) }
514 | {- empty -} { Nothing }
516 optqualified :: { Bool }
517 : 'qualified' { True }
518 | {- empty -} { False }
520 maybeas :: { Located (Maybe ModuleName) }
521 : 'as' modid { LL (Just (unLoc $2)) }
522 | {- empty -} { noLoc Nothing }
524 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
525 : impspec { L1 (Just (unLoc $1)) }
526 | {- empty -} { noLoc Nothing }
528 impspec :: { Located (Bool, [LIE RdrName]) }
529 : '(' exportlist ')' { LL (False, $2) }
530 | 'hiding' '(' exportlist ')' { LL (True, $3) }
532 -----------------------------------------------------------------------------
533 -- Fixity Declarations
537 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
539 infix :: { Located FixityDirection }
540 : 'infix' { L1 InfixN }
541 | 'infixl' { L1 InfixL }
542 | 'infixr' { L1 InfixR }
544 ops :: { Located [Located RdrName] }
545 : ops ',' op { LL ($3 : unLoc $1) }
548 -----------------------------------------------------------------------------
549 -- Top-Level Declarations
551 topdecls :: { OrdList (LHsDecl RdrName) }
552 : topdecls ';' topdecl { $1 `appOL` $3 }
553 | topdecls ';' { $1 }
556 topdecl :: { OrdList (LHsDecl RdrName) }
557 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
558 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
559 | 'instance' inst_type where_inst
560 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
562 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
563 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
564 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
565 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
566 | '{-# DEPRECATED' deprecations '#-}' { $2 }
567 | '{-# WARNING' warnings '#-}' { $2 }
568 | '{-# RULES' rules '#-}' { $2 }
569 | '{-# VECTORISE_SCALAR' qvar '#-}' { unitOL $ LL $ VectD (HsVect $2 Nothing) }
570 | '{-# VECTORISE' qvar '=' exp '#-}' { unitOL $ LL $ VectD (HsVect $2 (Just $4)) }
571 | annotation { unitOL $1 }
574 -- Template Haskell Extension
575 -- The $(..) form is one possible form of infixexp
576 -- but we treat an arbitrary expression just as if
577 -- it had a $(..) wrapped around it
578 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
582 cl_decl :: { LTyClDecl RdrName }
583 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
585 -- Type declarations (toplevel)
587 ty_decl :: { LTyClDecl RdrName }
588 -- ordinary type synonyms
589 : 'type' type '=' ctypedoc
590 -- Note ctype, not sigtype, on the right of '='
591 -- We allow an explicit for-all but we don't insert one
592 -- in type Foo a = (b,b)
593 -- Instead we just say b is out of scope
595 -- Note the use of type for the head; this allows
596 -- infix type constructors to be declared
597 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
599 -- type family declarations
600 | 'type' 'family' type opt_kind_sig
601 -- Note the use of type for the head; this allows
602 -- infix type constructors to be declared
603 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
605 -- type instance declarations
606 | 'type' 'instance' type '=' ctype
607 -- Note the use of type for the head; this allows
608 -- infix type constructors and type patterns
609 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
611 -- ordinary data type or newtype declaration
612 | data_or_newtype tycl_hdr constrs deriving
613 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
614 Nothing (reverse (unLoc $3)) (unLoc $4) }
615 -- We need the location on tycl_hdr in case
616 -- constrs and deriving are both empty
618 -- ordinary GADT declaration
619 | data_or_newtype tycl_hdr opt_kind_sig
622 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
623 (unLoc $3) (unLoc $4) (unLoc $5) }
624 -- We need the location on tycl_hdr in case
625 -- constrs and deriving are both empty
627 -- data/newtype family
628 | 'data' 'family' type opt_kind_sig
629 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
631 -- data/newtype instance declaration
632 | data_or_newtype 'instance' tycl_hdr constrs deriving
633 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
634 Nothing (reverse (unLoc $4)) (unLoc $5) }
636 -- GADT instance declaration
637 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
640 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
641 (unLoc $4) (unLoc $5) (unLoc $6) }
643 -- Associated type family declarations
645 -- * They have a different syntax than on the toplevel (no family special
648 -- * They also need to be separate from instances; otherwise, data family
649 -- declarations without a kind signature cause parsing conflicts with empty
650 -- data declarations.
652 at_decl_cls :: { LTyClDecl RdrName }
653 -- type family declarations
654 : 'type' type opt_kind_sig
655 -- Note the use of type for the head; this allows
656 -- infix type constructors to be declared
657 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
659 -- default type instance
660 | 'type' type '=' ctype
661 -- Note the use of type for the head; this allows
662 -- infix type constructors and type patterns
663 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
665 -- data/newtype family declaration
666 | 'data' type opt_kind_sig
667 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
669 -- Associated type instances
671 at_decl_inst :: { LTyClDecl RdrName }
672 -- type instance declarations
673 : 'type' type '=' ctype
674 -- Note the use of type for the head; this allows
675 -- infix type constructors and type patterns
676 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
678 -- data/newtype instance declaration
679 | data_or_newtype tycl_hdr constrs deriving
680 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
681 Nothing (reverse (unLoc $3)) (unLoc $4) }
683 -- GADT instance declaration
684 | data_or_newtype tycl_hdr opt_kind_sig
687 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
688 (unLoc $3) (unLoc $4) (unLoc $5) }
690 data_or_newtype :: { Located NewOrData }
691 : 'data' { L1 DataType }
692 | 'newtype' { L1 NewType }
694 opt_kind_sig :: { Located (Maybe Kind) }
696 | '::' kind { LL (Just (unLoc $2)) }
698 -- tycl_hdr parses the header of a class or data type decl,
699 -- which takes the form
702 -- (Eq a, Ord b) => T a b
703 -- T Int [a] -- for associated types
704 -- Rather a lot of inlining here, else we get reduce/reduce errors
705 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
706 : context '=>' type { LL (Just $1, $3) }
707 | type { L1 (Nothing, $1) }
709 -----------------------------------------------------------------------------
710 -- Stand-alone deriving
712 -- Glasgow extension: stand-alone deriving declarations
713 stand_alone_deriving :: { LDerivDecl RdrName }
714 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
716 -----------------------------------------------------------------------------
717 -- Nested declarations
719 -- Declaration in class bodies
721 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
722 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
725 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
726 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
727 | decls_cls ';' { LL (unLoc $1) }
729 | {- empty -} { noLoc nilOL }
733 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
734 : '{' decls_cls '}' { LL (unLoc $2) }
735 | vocurly decls_cls close { $2 }
739 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
740 -- No implicit parameters
741 -- May have type declarations
742 : 'where' decllist_cls { LL (unLoc $2) }
743 | {- empty -} { noLoc nilOL }
745 -- Declarations in instance bodies
747 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
748 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
751 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
752 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
753 | decls_inst ';' { LL (unLoc $1) }
755 | {- empty -} { noLoc nilOL }
758 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
759 : '{' decls_inst '}' { LL (unLoc $2) }
760 | vocurly decls_inst close { $2 }
764 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
765 -- No implicit parameters
766 -- May have type declarations
767 : 'where' decllist_inst { LL (unLoc $2) }
768 | {- empty -} { noLoc nilOL }
770 -- Declarations in binding groups other than classes and instances
772 decls :: { Located (OrdList (LHsDecl RdrName)) }
773 : decls ';' decl { let { this = unLoc $3;
775 these = rest `appOL` this }
776 in rest `seq` this `seq` these `seq`
778 | decls ';' { LL (unLoc $1) }
780 | {- empty -} { noLoc nilOL }
782 decllist :: { Located (OrdList (LHsDecl RdrName)) }
783 : '{' decls '}' { LL (unLoc $2) }
784 | vocurly decls close { $2 }
786 -- Binding groups other than those of class and instance declarations
788 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
789 -- No type declarations
790 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
791 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
792 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
794 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
795 -- No type declarations
796 : 'where' binds { LL (unLoc $2) }
797 | {- empty -} { noLoc emptyLocalBinds }
800 -----------------------------------------------------------------------------
801 -- Transformation Rules
803 rules :: { OrdList (LHsDecl RdrName) }
804 : rules ';' rule { $1 `snocOL` $3 }
807 | {- empty -} { nilOL }
809 rule :: { LHsDecl RdrName }
810 : STRING activation rule_forall infixexp '=' exp
811 { LL $ RuleD (HsRule (getSTRING $1)
812 ($2 `orElse` AlwaysActive)
813 $3 $4 placeHolderNames $6 placeHolderNames) }
815 activation :: { Maybe Activation }
816 : {- empty -} { Nothing }
817 | explicit_activation { Just $1 }
819 explicit_activation :: { Activation } -- In brackets
820 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
821 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
823 rule_forall :: { [RuleBndr RdrName] }
824 : 'forall' rule_var_list '.' { $2 }
827 rule_var_list :: { [RuleBndr RdrName] }
829 | rule_var rule_var_list { $1 : $2 }
831 rule_var :: { RuleBndr RdrName }
832 : varid { RuleBndr $1 }
833 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
835 -----------------------------------------------------------------------------
836 -- Warnings and deprecations (c.f. rules)
838 warnings :: { OrdList (LHsDecl RdrName) }
839 : warnings ';' warning { $1 `appOL` $3 }
840 | warnings ';' { $1 }
842 | {- empty -} { nilOL }
844 -- SUP: TEMPORARY HACK, not checking for `module Foo'
845 warning :: { OrdList (LHsDecl RdrName) }
847 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
850 deprecations :: { OrdList (LHsDecl RdrName) }
851 : deprecations ';' deprecation { $1 `appOL` $3 }
852 | deprecations ';' { $1 }
854 | {- empty -} { nilOL }
856 -- SUP: TEMPORARY HACK, not checking for `module Foo'
857 deprecation :: { OrdList (LHsDecl RdrName) }
859 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
862 strings :: { Located [FastString] }
863 : STRING { L1 [getSTRING $1] }
864 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
866 stringlist :: { Located (OrdList FastString) }
867 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
868 | STRING { LL (unitOL (getSTRING $1)) }
870 -----------------------------------------------------------------------------
872 annotation :: { LHsDecl RdrName }
873 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
874 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
875 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
878 -----------------------------------------------------------------------------
879 -- Foreign import and export declarations
881 fdecl :: { LHsDecl RdrName }
882 fdecl : 'import' callconv safety fspec
883 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
884 | 'import' callconv fspec
885 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
887 | 'export' callconv fspec
888 {% mkExport $2 (unLoc $3) >>= return.LL }
890 callconv :: { CCallConv }
891 : 'stdcall' { StdCallConv }
892 | 'ccall' { CCallConv }
893 | 'prim' { PrimCallConv}
896 : 'unsafe' { PlayRisky }
897 | 'safe' { PlaySafe False }
898 | 'interruptible' { PlayInterruptible }
899 | 'threadsafe' { PlaySafe True } -- deprecated alias
901 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
902 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
903 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
904 -- if the entity string is missing, it defaults to the empty string;
905 -- the meaning of an empty entity string depends on the calling
908 -----------------------------------------------------------------------------
911 opt_sig :: { Maybe (LHsType RdrName) }
912 : {- empty -} { Nothing }
913 | '::' sigtype { Just $2 }
915 opt_asig :: { Maybe (LHsType RdrName) }
916 : {- empty -} { Nothing }
917 | '::' atype { Just $2 }
919 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
920 -- to tell the renamer where to generalise
921 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
922 -- Wrap an Implicit forall if there isn't one there already
924 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
925 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
926 -- Wrap an Implicit forall if there isn't one there already
928 sig_vars :: { Located [Located RdrName] }
929 : sig_vars ',' var { LL ($3 : unLoc $1) }
932 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
934 | sigtype ',' sigtypes1 { $1 : $3 }
936 -----------------------------------------------------------------------------
939 infixtype :: { LHsType RdrName }
940 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
941 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
943 strict_mark :: { Located HsBang }
944 : '!' { L1 HsStrict }
945 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
947 -- A ctype is a for-all type
948 ctype :: { LHsType RdrName }
949 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
950 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
951 -- A type of form (context => type) is an *implicit* HsForAllTy
952 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
955 ----------------------
956 -- Notes for 'ctypedoc'
957 -- It would have been nice to simplify the grammar by unifying `ctype` and
958 -- ctypedoc` into one production, allowing comments on types everywhere (and
959 -- rejecting them after parsing, where necessary). This is however not possible
960 -- since it leads to ambiguity. The reason is the support for comments on record
962 -- data R = R { field :: Int -- ^ comment on the field }
963 -- If we allow comments on types here, it's not clear if the comment applies
964 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
966 ctypedoc :: { LHsType RdrName }
967 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
968 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
969 -- A type of form (context => type) is an *implicit* HsForAllTy
970 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
973 ----------------------
974 -- Notes for 'context'
975 -- We parse a context as a btype so that we don't get reduce/reduce
976 -- errors in ctype. The basic problem is that
978 -- looks so much like a tuple type. We can't tell until we find the =>
980 -- We have the t1 ~ t2 form both in 'context' and in type,
981 -- to permit an individual equational constraint without parenthesis.
982 -- Thus for some reason we allow f :: a~b => blah
983 -- but not f :: ?x::Int => blah
984 context :: { LHsContext RdrName }
985 : btype '~' btype {% checkContext
986 (LL $ HsPredTy (HsEqualP $1 $3)) }
987 | btype {% checkContext $1 }
989 type :: { LHsType RdrName }
991 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
992 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
993 | btype '->' ctype { LL $ HsFunTy $1 $3 }
994 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
996 typedoc :: { LHsType RdrName }
998 | btype docprev { LL $ HsDocTy $1 $2 }
999 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1000 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1001 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1002 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1003 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1004 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1005 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1007 btype :: { LHsType RdrName }
1008 : btype atype { LL $ HsAppTy $1 $2 }
1011 atype :: { LHsType RdrName }
1012 : gtycon { L1 (HsTyVar (unLoc $1)) }
1013 | tyvar { L1 (HsTyVar (unLoc $1)) }
1014 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1015 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1016 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1017 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1018 | '[' ctype ']' { LL $ HsListTy $2 }
1019 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1020 | '(' ctype ')' { LL $ HsParTy $2 }
1021 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1022 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1023 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1024 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1025 mkUnqual varName (getTH_ID_SPLICE $1) }
1027 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1029 -- An inst_type is what occurs in the head of an instance decl
1030 -- e.g. (Foo a, Gaz b) => Wibble a b
1031 -- It's kept as a single type, with a MonoDictTy at the right
1032 -- hand corner, for convenience.
1033 inst_type :: { LHsType RdrName }
1034 : sigtype {% checkInstType $1 }
1036 inst_types1 :: { [LHsType RdrName] }
1037 : inst_type { [$1] }
1038 | inst_type ',' inst_types1 { $1 : $3 }
1040 comma_types0 :: { [LHsType RdrName] }
1041 : comma_types1 { $1 }
1042 | {- empty -} { [] }
1044 comma_types1 :: { [LHsType RdrName] }
1046 | ctype ',' comma_types1 { $1 : $3 }
1048 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1049 : tv_bndr tv_bndrs { $1 : $2 }
1050 | {- empty -} { [] }
1052 tv_bndr :: { LHsTyVarBndr RdrName }
1053 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1054 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1057 fds :: { Located [Located (FunDep RdrName)] }
1058 : {- empty -} { noLoc [] }
1059 | '|' fds1 { LL (reverse (unLoc $2)) }
1061 fds1 :: { Located [Located (FunDep RdrName)] }
1062 : fds1 ',' fd { LL ($3 : unLoc $1) }
1065 fd :: { Located (FunDep RdrName) }
1066 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1067 (reverse (unLoc $1), reverse (unLoc $3)) }
1069 varids0 :: { Located [RdrName] }
1070 : {- empty -} { noLoc [] }
1071 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1073 -----------------------------------------------------------------------------
1076 kind :: { Located Kind }
1078 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1080 akind :: { Located Kind }
1081 : '*' { L1 liftedTypeKind }
1082 | '!' { L1 unliftedTypeKind }
1083 | '(' kind ')' { LL (unLoc $2) }
1086 -----------------------------------------------------------------------------
1087 -- Datatype declarations
1089 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1090 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1091 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1092 | {- empty -} { noLoc [] }
1094 gadt_constrs :: { Located [LConDecl RdrName] }
1095 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1096 | gadt_constr { L (getLoc (head $1)) $1 }
1097 | {- empty -} { noLoc [] }
1099 -- We allow the following forms:
1100 -- C :: Eq a => a -> T a
1101 -- C :: forall a. Eq a => !a -> T a
1102 -- D { x,y :: a } :: T a
1103 -- forall a. Eq a => D { x,y :: a } :: T a
1105 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1106 : con_list '::' sigtype
1107 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1109 -- Deprecated syntax for GADT record declarations
1110 | oqtycon '{' fielddecls '}' '::' sigtype
1111 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1114 constrs :: { Located [LConDecl RdrName] }
1115 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1117 constrs1 :: { Located [LConDecl RdrName] }
1118 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1119 | constr { L1 [$1] }
1121 constr :: { LConDecl RdrName }
1122 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1123 { let (con,details) = unLoc $5 in
1124 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1126 | maybe_docnext forall constr_stuff maybe_docprev
1127 { let (con,details) = unLoc $3 in
1128 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1131 forall :: { Located [LHsTyVarBndr RdrName] }
1132 : 'forall' tv_bndrs '.' { LL $2 }
1133 | {- empty -} { noLoc [] }
1135 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1136 -- We parse the constructor declaration
1138 -- as a btype (treating C as a type constructor) and then convert C to be
1139 -- a data constructor. Reason: it might continue like this:
1141 -- in which case C really would be a type constructor. We can't resolve this
1142 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1143 : btype {% splitCon $1 >>= return.LL }
1144 | btype conop btype { LL ($2, InfixCon $1 $3) }
1146 fielddecls :: { [ConDeclField RdrName] }
1147 : {- empty -} { [] }
1148 | fielddecls1 { $1 }
1150 fielddecls1 :: { [ConDeclField RdrName] }
1151 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1152 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1153 -- This adds the doc $4 to each field separately
1156 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1157 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1158 | fld <- reverse (unLoc $2) ] }
1160 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1161 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1162 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1163 -- We don't allow a context, but that's sorted out by the type checker.
1164 deriving :: { Located (Maybe [LHsType RdrName]) }
1165 : {- empty -} { noLoc Nothing }
1166 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1167 ; p <- checkInstType (L loc (HsTyVar tv))
1168 ; return (LL (Just [p])) } }
1169 | 'deriving' '(' ')' { LL (Just []) }
1170 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1171 -- Glasgow extension: allow partial
1172 -- applications in derivings
1174 -----------------------------------------------------------------------------
1175 -- Value definitions
1177 {- Note [Declaration/signature overlap]
1178 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1179 There's an awkward overlap with a type signature. Consider
1180 f :: Int -> Int = ...rhs...
1181 Then we can't tell whether it's a type signature or a value
1182 definition with a result signature until we see the '='.
1183 So we have to inline enough to postpone reductions until we know.
1187 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1188 instead of qvar, we get another shift/reduce-conflict. Consider the
1191 { (^^) :: Int->Int ; } Type signature; only var allowed
1193 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1194 qvar allowed (because of instance decls)
1196 We can't tell whether to reduce var to qvar until after we've read the signatures.
1199 docdecl :: { LHsDecl RdrName }
1200 : docdecld { L1 (DocD (unLoc $1)) }
1202 docdecld :: { LDocDecl }
1203 : docnext { L1 (DocCommentNext (unLoc $1)) }
1204 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1205 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1206 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1208 decl :: { Located (OrdList (LHsDecl RdrName)) }
1211 | '!' aexp rhs {% do { let { e = LL (SectionR (LL (HsVar bang_RDR)) $2) };
1212 pat <- checkPattern e;
1213 return $ LL $ unitOL $ LL $ ValD $
1214 PatBind pat (unLoc $3)
1215 placeHolderType placeHolderNames } }
1216 -- Turn it all into an expression so that
1217 -- checkPattern can check that bangs are enabled
1219 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1220 let { l = comb2 $1 $> };
1221 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1222 | docdecl { LL $ unitOL $1 }
1224 rhs :: { Located (GRHSs RdrName) }
1225 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1226 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1228 gdrhs :: { Located [LGRHS RdrName] }
1229 : gdrhs gdrh { LL ($2 : unLoc $1) }
1232 gdrh :: { LGRHS RdrName }
1233 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1235 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1236 : 'generic' infixexp '::' sigtypedoc
1237 {% do (TypeSig l ty) <- checkValSig $2 $4
1238 ; return (LL $ unitOL (LL $ SigD (GenericSig l ty))) }
1239 -- See Note [Declaration/signature overlap] for why we need infixexp here
1240 | infixexp '::' sigtypedoc
1241 {% do s <- checkValSig $1 $3
1242 ; return (LL $ unitOL (LL $ SigD s)) }
1243 | var ',' sig_vars '::' sigtypedoc
1244 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1245 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1247 | '{-# INLINE' activation qvar '#-}'
1248 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma (getINLINE $1) $2))) }
1249 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1250 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1252 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1253 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma (getSPEC_INLINE $1) $2))
1255 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1256 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1258 -----------------------------------------------------------------------------
1261 quasiquote :: { Located (HsQuasiQuote RdrName) }
1262 : TH_QUASIQUOTE { let { loc = getLoc $1
1263 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1264 ; quoterId = mkUnqual varName quoter }
1265 in L1 (mkHsQuasiQuote quoterId quoteSpan quote) }
1267 exp :: { LHsExpr RdrName }
1268 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1269 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1270 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1271 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1272 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1275 infixexp :: { LHsExpr RdrName }
1277 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1279 exp10 :: { LHsExpr RdrName }
1280 : '\\' apat apats opt_asig '->' exp
1281 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1284 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1285 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1286 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1287 return (LL $ mkHsIf $2 $5 $8) }
1288 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1289 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1291 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1292 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1293 return (L loc (mkHsDo DoExpr stmts body)) }
1294 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1295 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1296 return (L loc (mkHsDo MDoExpr
1297 [L loc (mkRecStmt stmts)]
1299 | scc_annot exp { LL $ if opt_SccProfilingOn
1300 then HsSCC (unLoc $1) $2
1302 | hpc_annot exp { LL $ if opt_Hpc
1303 then HsTickPragma (unLoc $1) $2
1306 | 'proc' aexp '->' exp
1307 {% checkPattern $2 >>= \ p ->
1308 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1309 placeHolderType undefined)) }
1310 -- TODO: is LL right here?
1312 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1313 -- hdaume: core annotation
1318 | {- empty -} { False }
1320 scc_annot :: { Located FastString }
1321 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1322 ( do scc <- getSCC $2; return $ LL scc ) }
1323 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1325 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1326 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1327 { LL $ (getSTRING $2
1328 ,( fromInteger $ getINTEGER $3
1329 , fromInteger $ getINTEGER $5
1331 ,( fromInteger $ getINTEGER $7
1332 , fromInteger $ getINTEGER $9
1337 fexp :: { LHsExpr RdrName }
1338 : fexp aexp { LL $ HsApp $1 $2 }
1341 aexp :: { LHsExpr RdrName }
1342 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1343 | '~' aexp { LL $ ELazyPat $2 }
1346 aexp1 :: { LHsExpr RdrName }
1347 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1351 -- Here was the syntax for type applications that I was planning
1352 -- but there are difficulties (e.g. what order for type args)
1353 -- so it's not enabled yet.
1354 -- But this case *is* used for the left hand side of a generic definition,
1355 -- which is parsed as an expression before being munged into a pattern
1356 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1357 (sL (getLoc $3) (HsType $3)) }
1359 aexp2 :: { LHsExpr RdrName }
1360 : ipvar { L1 (HsIPVar $! unLoc $1) }
1361 | qcname { L1 (HsVar $! unLoc $1) }
1362 | literal { L1 (HsLit $! unLoc $1) }
1363 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1364 -- into HsOverLit when -foverloaded-strings is on.
1365 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1366 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1367 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1369 -- N.B.: sections get parsed by these next two productions.
1370 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't
1371 -- correct Haskell (you'd have to write '((+ 3), (4 -))')
1372 -- but the less cluttered version fell out of having texps.
1373 | '(' texp ')' { LL (HsPar $2) }
1374 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1376 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1377 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1379 | '[' list ']' { LL (unLoc $2) }
1380 | '[:' parr ':]' { LL (unLoc $2) }
1381 | '_' { L1 EWildPat }
1383 -- Template Haskell Extension
1384 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1385 (L1 $ HsVar (mkUnqual varName
1386 (getTH_ID_SPLICE $1)))) }
1387 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1390 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1391 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1392 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1393 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1394 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1395 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1396 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1397 return (LL $ HsBracket (PatBr p)) }
1398 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1399 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1401 -- arrow notation extension
1402 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1404 cmdargs :: { [LHsCmdTop RdrName] }
1405 : cmdargs acmd { $2 : $1 }
1406 | {- empty -} { [] }
1408 acmd :: { LHsCmdTop RdrName }
1409 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1411 cvtopbody :: { [LHsDecl RdrName] }
1412 : '{' cvtopdecls0 '}' { $2 }
1413 | vocurly cvtopdecls0 close { $2 }
1415 cvtopdecls0 :: { [LHsDecl RdrName] }
1416 : {- empty -} { [] }
1419 -----------------------------------------------------------------------------
1420 -- Tuple expressions
1422 -- "texp" is short for tuple expressions:
1423 -- things that can appear unparenthesized as long as they're
1424 -- inside parens or delimitted by commas
1425 texp :: { LHsExpr RdrName }
1428 -- Note [Parsing sections]
1429 -- ~~~~~~~~~~~~~~~~~~~~~~~
1430 -- We include left and right sections here, which isn't
1431 -- technically right according to the Haskell standard.
1432 -- For example (3 +, True) isn't legal.
1433 -- However, we want to parse bang patterns like
1435 -- and it's convenient to do so here as a section
1436 -- Then when converting expr to pattern we unravel it again
1437 -- Meanwhile, the renamer checks that real sections appear
1439 | infixexp qop { LL $ SectionL $1 $2 }
1440 | qopm infixexp { LL $ SectionR $1 $2 }
1442 -- View patterns get parenthesized above
1443 | exp '->' texp { LL $ EViewPat $1 $3 }
1445 -- Always at least one comma
1446 tup_exprs :: { [HsTupArg RdrName] }
1447 : texp commas_tup_tail { Present $1 : $2 }
1448 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1450 -- Always starts with commas; always follows an expr
1451 commas_tup_tail :: { [HsTupArg RdrName] }
1452 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1454 -- Always follows a comma
1455 tup_tail :: { [HsTupArg RdrName] }
1456 : texp commas_tup_tail { Present $1 : $2 }
1457 | texp { [Present $1] }
1458 | {- empty -} { [missingTupArg] }
1460 -----------------------------------------------------------------------------
1463 -- The rules below are little bit contorted to keep lexps left-recursive while
1464 -- avoiding another shift/reduce-conflict.
1466 list :: { LHsExpr RdrName }
1467 : texp { L1 $ ExplicitList placeHolderType [$1] }
1468 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1469 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1470 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1471 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1472 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1473 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1475 lexps :: { Located [LHsExpr RdrName] }
1476 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1477 | texp ',' texp { LL [$3,$1] }
1479 -----------------------------------------------------------------------------
1480 -- List Comprehensions
1482 flattenedpquals :: { Located [LStmt RdrName] }
1483 : pquals { case (unLoc $1) of
1485 -- We just had one thing in our "parallel" list so
1486 -- we simply return that thing directly
1488 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1489 -- We actually found some actual parallel lists so
1490 -- we wrap them into as a ParStmt
1493 pquals :: { Located [[LStmt RdrName]] }
1494 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1495 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1497 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1498 -- one can "grab" the earlier ones
1499 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1500 | squals ',' qual { LL ($3 : unLoc $1) }
1501 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1503 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1504 -- | '{|' pquals '|}' { L1 [$2] }
1507 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1508 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1509 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1510 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1512 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1513 -- Function is applied to a list of stmts *in order*
1514 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1516 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1517 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1519 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1520 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1521 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1522 -- choosing the "group by" variant, which is what we want.
1524 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1525 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1526 -- if /that/ is the group function we conflict with.
1527 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1528 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1530 -----------------------------------------------------------------------------
1531 -- Parallel array expressions
1533 -- The rules below are little bit contorted; see the list case for details.
1534 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1535 -- Moreover, we allow explicit arrays with no element (represented by the nil
1536 -- constructor in the list case).
1538 parr :: { LHsExpr RdrName }
1539 : { noLoc (ExplicitPArr placeHolderType []) }
1540 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1541 | lexps { L1 $ ExplicitPArr placeHolderType
1542 (reverse (unLoc $1)) }
1543 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1544 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1545 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1547 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1549 -----------------------------------------------------------------------------
1552 guardquals :: { Located [LStmt RdrName] }
1553 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1555 guardquals1 :: { Located [LStmt RdrName] }
1556 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1559 -----------------------------------------------------------------------------
1560 -- Case alternatives
1562 altslist :: { Located [LMatch RdrName] }
1563 : '{' alts '}' { LL (reverse (unLoc $2)) }
1564 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1566 alts :: { Located [LMatch RdrName] }
1567 : alts1 { L1 (unLoc $1) }
1568 | ';' alts { LL (unLoc $2) }
1570 alts1 :: { Located [LMatch RdrName] }
1571 : alts1 ';' alt { LL ($3 : unLoc $1) }
1572 | alts1 ';' { LL (unLoc $1) }
1575 alt :: { LMatch RdrName }
1576 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1578 alt_rhs :: { Located (GRHSs RdrName) }
1579 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1581 ralt :: { Located [LGRHS RdrName] }
1582 : '->' exp { LL (unguardedRHS $2) }
1583 | gdpats { L1 (reverse (unLoc $1)) }
1585 gdpats :: { Located [LGRHS RdrName] }
1586 : gdpats gdpat { LL ($2 : unLoc $1) }
1589 gdpat :: { LGRHS RdrName }
1590 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1592 -- 'pat' recognises a pattern, including one with a bang at the top
1593 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1594 -- Bangs inside are parsed as infix operator applications, so that
1595 -- we parse them right when bang-patterns are off
1596 pat :: { LPat RdrName }
1597 pat : exp {% checkPattern $1 }
1598 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1600 apat :: { LPat RdrName }
1601 apat : aexp {% checkPattern $1 }
1602 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1604 apats :: { [LPat RdrName] }
1605 : apat apats { $1 : $2 }
1606 | {- empty -} { [] }
1608 -----------------------------------------------------------------------------
1609 -- Statement sequences
1611 stmtlist :: { Located [LStmt RdrName] }
1612 : '{' stmts '}' { LL (unLoc $2) }
1613 | vocurly stmts close { $2 }
1615 -- do { ;; s ; s ; ; s ;; }
1616 -- The last Stmt should be an expression, but that's hard to enforce
1617 -- here, because we need too much lookahead if we see do { e ; }
1618 -- So we use ExprStmts throughout, and switch the last one over
1619 -- in ParseUtils.checkDo instead
1620 stmts :: { Located [LStmt RdrName] }
1621 : stmt stmts_help { LL ($1 : unLoc $2) }
1622 | ';' stmts { LL (unLoc $2) }
1623 | {- empty -} { noLoc [] }
1625 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1626 : ';' stmts { LL (unLoc $2) }
1627 | {- empty -} { noLoc [] }
1629 -- For typing stmts at the GHCi prompt, where
1630 -- the input may consist of just comments.
1631 maybe_stmt :: { Maybe (LStmt RdrName) }
1633 | {- nothing -} { Nothing }
1635 stmt :: { LStmt RdrName }
1637 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1639 qual :: { LStmt RdrName }
1640 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1641 | exp { L1 $ mkExprStmt $1 }
1642 | 'let' binds { LL $ LetStmt (unLoc $2) }
1644 -----------------------------------------------------------------------------
1645 -- Record Field Update/Construction
1647 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1649 | {- empty -} { ([], False) }
1651 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1652 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1653 | fbind { ([$1], False) }
1654 | '..' { ([], True) }
1656 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1657 : qvar '=' exp { HsRecField $1 $3 False }
1658 | qvar { HsRecField $1 placeHolderPunRhs True }
1659 -- In the punning case, use a place-holder
1660 -- The renamer fills in the final value
1662 -----------------------------------------------------------------------------
1663 -- Implicit Parameter Bindings
1665 dbinds :: { Located [LIPBind RdrName] }
1666 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1667 in rest `seq` this `seq` LL (this : rest) }
1668 | dbinds ';' { LL (unLoc $1) }
1669 | dbind { let this = $1 in this `seq` L1 [this] }
1670 -- | {- empty -} { [] }
1672 dbind :: { LIPBind RdrName }
1673 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1675 ipvar :: { Located (IPName RdrName) }
1676 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1678 -----------------------------------------------------------------------------
1679 -- Warnings and deprecations
1681 namelist :: { Located [RdrName] }
1682 namelist : name_var { L1 [unLoc $1] }
1683 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1685 name_var :: { Located RdrName }
1686 name_var : var { $1 }
1689 -----------------------------------------
1690 -- Data constructors
1691 qcon :: { Located RdrName }
1693 | '(' qconsym ')' { LL (unLoc $2) }
1694 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1695 -- The case of '[:' ':]' is part of the production `parr'
1697 con :: { Located RdrName }
1699 | '(' consym ')' { LL (unLoc $2) }
1700 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1702 con_list :: { Located [Located RdrName] }
1703 con_list : con { L1 [$1] }
1704 | con ',' con_list { LL ($1 : unLoc $3) }
1706 sysdcon :: { Located DataCon } -- Wired in data constructors
1707 : '(' ')' { LL unitDataCon }
1708 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1709 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1710 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1711 | '[' ']' { LL nilDataCon }
1713 conop :: { Located RdrName }
1715 | '`' conid '`' { LL (unLoc $2) }
1717 qconop :: { Located RdrName }
1719 | '`' qconid '`' { LL (unLoc $2) }
1721 -----------------------------------------------------------------------------
1722 -- Type constructors
1724 gtycon :: { Located RdrName } -- A "general" qualified tycon
1726 | '(' ')' { LL $ getRdrName unitTyCon }
1727 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1728 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1729 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1730 | '(' '->' ')' { LL $ getRdrName funTyCon }
1731 | '[' ']' { LL $ listTyCon_RDR }
1732 | '[:' ':]' { LL $ parrTyCon_RDR }
1734 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1736 | '(' qtyconsym ')' { LL (unLoc $2) }
1738 qtyconop :: { Located RdrName } -- Qualified or unqualified
1740 | '`' qtycon '`' { LL (unLoc $2) }
1742 qtycon :: { Located RdrName } -- Qualified or unqualified
1743 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1744 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1747 tycon :: { Located RdrName } -- Unqualified
1748 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1750 qtyconsym :: { Located RdrName }
1751 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1754 tyconsym :: { Located RdrName }
1755 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1757 -----------------------------------------------------------------------------
1760 op :: { Located RdrName } -- used in infix decls
1764 varop :: { Located RdrName }
1766 | '`' varid '`' { LL (unLoc $2) }
1768 qop :: { LHsExpr RdrName } -- used in sections
1769 : qvarop { L1 $ HsVar (unLoc $1) }
1770 | qconop { L1 $ HsVar (unLoc $1) }
1772 qopm :: { LHsExpr RdrName } -- used in sections
1773 : qvaropm { L1 $ HsVar (unLoc $1) }
1774 | qconop { L1 $ HsVar (unLoc $1) }
1776 qvarop :: { Located RdrName }
1778 | '`' qvarid '`' { LL (unLoc $2) }
1780 qvaropm :: { Located RdrName }
1781 : qvarsym_no_minus { $1 }
1782 | '`' qvarid '`' { LL (unLoc $2) }
1784 -----------------------------------------------------------------------------
1787 tyvar :: { Located RdrName }
1788 tyvar : tyvarid { $1 }
1789 | '(' tyvarsym ')' { LL (unLoc $2) }
1791 tyvarop :: { Located RdrName }
1792 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1794 | '.' {% parseErrorSDoc (getLoc $1)
1795 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1796 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1797 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1800 tyvarid :: { Located RdrName }
1801 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1802 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1803 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1804 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1805 | 'interruptible' { L1 $! mkUnqual tvName (fsLit "interruptible") }
1806 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1808 tyvarsym :: { Located RdrName }
1809 -- Does not include "!", because that is used for strictness marks
1810 -- or ".", because that separates the quantified type vars from the rest
1811 -- or "*", because that's used for kinds
1812 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1814 -----------------------------------------------------------------------------
1817 var :: { Located RdrName }
1819 | '(' varsym ')' { LL (unLoc $2) }
1821 qvar :: { Located RdrName }
1823 | '(' varsym ')' { LL (unLoc $2) }
1824 | '(' qvarsym1 ')' { LL (unLoc $2) }
1825 -- We've inlined qvarsym here so that the decision about
1826 -- whether it's a qvar or a var can be postponed until
1827 -- *after* we see the close paren.
1829 qvarid :: { Located RdrName }
1831 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1832 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1834 varid :: { Located RdrName }
1835 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1836 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1837 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1838 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1839 | 'interruptible' { L1 $! mkUnqual varName (fsLit "interruptible") }
1840 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1841 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1842 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1844 qvarsym :: { Located RdrName }
1848 qvarsym_no_minus :: { Located RdrName }
1849 : varsym_no_minus { $1 }
1852 qvarsym1 :: { Located RdrName }
1853 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1855 varsym :: { Located RdrName }
1856 : varsym_no_minus { $1 }
1857 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1859 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1860 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1861 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1864 -- These special_ids are treated as keywords in various places,
1865 -- but as ordinary ids elsewhere. 'special_id' collects all these
1866 -- except 'unsafe', 'interruptible', 'forall', and 'family' whose treatment differs
1867 -- depending on context
1868 special_id :: { Located FastString }
1870 : 'as' { L1 (fsLit "as") }
1871 | 'qualified' { L1 (fsLit "qualified") }
1872 | 'hiding' { L1 (fsLit "hiding") }
1873 | 'export' { L1 (fsLit "export") }
1874 | 'label' { L1 (fsLit "label") }
1875 | 'dynamic' { L1 (fsLit "dynamic") }
1876 | 'stdcall' { L1 (fsLit "stdcall") }
1877 | 'ccall' { L1 (fsLit "ccall") }
1878 | 'prim' { L1 (fsLit "prim") }
1879 | 'group' { L1 (fsLit "group") }
1881 special_sym :: { Located FastString }
1882 special_sym : '!' { L1 (fsLit "!") }
1883 | '.' { L1 (fsLit ".") }
1884 | '*' { L1 (fsLit "*") }
1886 -----------------------------------------------------------------------------
1887 -- Data constructors
1889 qconid :: { Located RdrName } -- Qualified or unqualified
1891 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1892 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1894 conid :: { Located RdrName }
1895 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1897 qconsym :: { Located RdrName } -- Qualified or unqualified
1899 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1901 consym :: { Located RdrName }
1902 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1904 -- ':' means only list cons
1905 | ':' { L1 $ consDataCon_RDR }
1908 -----------------------------------------------------------------------------
1911 literal :: { Located HsLit }
1912 : CHAR { L1 $ HsChar $ getCHAR $1 }
1913 | STRING { L1 $ HsString $ getSTRING $1 }
1914 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1915 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1916 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1917 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1918 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1919 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1921 -----------------------------------------------------------------------------
1925 : vccurly { () } -- context popped in lexer.
1926 | error {% popContext }
1928 -----------------------------------------------------------------------------
1929 -- Miscellaneous (mostly renamings)
1931 modid :: { Located ModuleName }
1932 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1933 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1936 (unpackFS mod ++ '.':unpackFS c))
1940 : commas ',' { $1 + 1 }
1943 -----------------------------------------------------------------------------
1944 -- Documentation comments
1946 docnext :: { LHsDocString }
1947 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1949 docprev :: { LHsDocString }
1950 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1952 docnamed :: { Located (String, HsDocString) }
1954 let string = getDOCNAMED $1
1955 (name, rest) = break isSpace string
1956 in return (L1 (name, HsDocString (mkFastString rest))) }
1958 docsection :: { Located (Int, HsDocString) }
1959 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1960 return (L1 (n, HsDocString (mkFastString doc))) }
1962 moduleheader :: { Maybe LHsDocString }
1963 : DOCNEXT {% let string = getDOCNEXT $1 in
1964 return (Just (L1 (HsDocString (mkFastString string)))) }
1966 maybe_docprev :: { Maybe LHsDocString }
1967 : docprev { Just $1 }
1968 | {- empty -} { Nothing }
1970 maybe_docnext :: { Maybe LHsDocString }
1971 : docnext { Just $1 }
1972 | {- empty -} { Nothing }
1976 happyError = srcParseFail
1978 getVARID (L _ (ITvarid x)) = x
1979 getCONID (L _ (ITconid x)) = x
1980 getVARSYM (L _ (ITvarsym x)) = x
1981 getCONSYM (L _ (ITconsym x)) = x
1982 getQVARID (L _ (ITqvarid x)) = x
1983 getQCONID (L _ (ITqconid x)) = x
1984 getQVARSYM (L _ (ITqvarsym x)) = x
1985 getQCONSYM (L _ (ITqconsym x)) = x
1986 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1987 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1988 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1989 getCHAR (L _ (ITchar x)) = x
1990 getSTRING (L _ (ITstring x)) = x
1991 getINTEGER (L _ (ITinteger x)) = x
1992 getRATIONAL (L _ (ITrational x)) = x
1993 getPRIMCHAR (L _ (ITprimchar x)) = x
1994 getPRIMSTRING (L _ (ITprimstring x)) = x
1995 getPRIMINTEGER (L _ (ITprimint x)) = x
1996 getPRIMWORD (L _ (ITprimword x)) = x
1997 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1998 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1999 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
2000 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
2001 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
2002 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
2004 getDOCNEXT (L _ (ITdocCommentNext x)) = x
2005 getDOCPREV (L _ (ITdocCommentPrev x)) = x
2006 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
2007 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2009 getSCC :: Located Token -> P FastString
2010 getSCC lt = do let s = getSTRING lt
2011 err = "Spaces are not allowed in SCCs"
2012 -- We probably actually want to be more restrictive than this
2013 if ' ' `elem` unpackFS s
2014 then failSpanMsgP (getLoc lt) (text err)
2017 -- Utilities for combining source spans
2018 comb2 :: Located a -> Located b -> SrcSpan
2019 comb2 a b = a `seq` b `seq` combineLocs a b
2021 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2022 comb3 a b c = a `seq` b `seq` c `seq`
2023 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2025 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2026 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2027 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2028 combineSrcSpans (getLoc c) (getLoc d))
2030 -- strict constructor version:
2032 sL :: SrcSpan -> a -> Located a
2033 sL span a = span `seq` a `seq` L span a
2035 -- Make a source location for the file. We're a bit lazy here and just
2036 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2037 -- try to find the span of the whole file (ToDo).
2038 fileSrcSpan :: P SrcSpan
2041 let loc = mkSrcLoc (srcLocFile l) 1 1;
2042 return (mkSrcSpan loc loc)