2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# OPTIONS -Wwarn -w #-}
12 -- The above warning supression flag is a temporary kludge.
13 -- While working on this module you are encouraged to remove it and fix
14 -- any warnings in the module. See
15 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
18 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
20 Careful optimisation of the parser: we don't want to throw everything
21 at it, because that takes too long and doesn't buy much, but we do want
22 to inline certain key external functions, so we instruct GHC not to
23 throw away inlinings as it would normally do in -O0 mode.
26 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
31 import HscTypes ( IsBootInterface, WarningTxt(..) )
34 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
35 unboxedSingletonTyCon, unboxedSingletonDataCon,
36 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
37 import Type ( funTyCon )
38 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
39 CCallConv(..), CCallTarget(..), defaultCCallConv
41 import OccName ( varName, dataName, tcClsName, tvName )
42 import DataCon ( DataCon, dataConName )
43 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
44 SrcSpan, combineLocs, srcLocFile,
47 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
48 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
49 import Coercion ( mkArrowKind )
50 import Class ( FunDep )
51 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
52 Activation(..), RuleMatchInfo(..), defaultInlinePragma )
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 'hiding' { L _ IThiding }
221 'import' { L _ ITimport }
223 'infix' { L _ ITinfix }
224 'infixl' { L _ ITinfixl }
225 'infixr' { L _ ITinfixr }
226 'instance' { L _ ITinstance }
228 'module' { L _ ITmodule }
229 'newtype' { L _ ITnewtype }
231 'qualified' { L _ ITqualified }
232 'then' { L _ ITthen }
233 'type' { L _ ITtype }
234 'where' { L _ ITwhere }
235 '_scc_' { L _ ITscc } -- ToDo: remove
237 'forall' { L _ ITforall } -- GHC extension keywords
238 'foreign' { L _ ITforeign }
239 'export' { L _ ITexport }
240 'label' { L _ ITlabel }
241 'dynamic' { L _ ITdynamic }
242 'safe' { L _ ITsafe }
243 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
244 'unsafe' { L _ ITunsafe }
246 'family' { L _ ITfamily }
247 'stdcall' { L _ ITstdcallconv }
248 'ccall' { L _ ITccallconv }
249 'prim' { L _ ITprimcallconv }
250 'proc' { L _ ITproc } -- for arrow notation extension
251 'rec' { L _ ITrec } -- for arrow notation extension
252 'group' { L _ ITgroup } -- for list transform extension
253 'by' { L _ ITby } -- for list transform extension
254 'using' { L _ ITusing } -- for list transform extension
256 '{-# INLINE' { L _ (ITinline_prag _) }
257 '{-# INLINE_CONLIKE' { L _ (ITinline_conlike_prag _) }
258 '{-# SPECIALISE' { L _ ITspec_prag }
259 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
260 '{-# SOURCE' { L _ ITsource_prag }
261 '{-# RULES' { L _ ITrules_prag }
262 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
263 '{-# SCC' { L _ ITscc_prag }
264 '{-# GENERATED' { L _ ITgenerated_prag }
265 '{-# DEPRECATED' { L _ ITdeprecated_prag }
266 '{-# WARNING' { L _ ITwarning_prag }
267 '{-# UNPACK' { L _ ITunpack_prag }
268 '{-# ANN' { L _ ITann_prag }
269 '#-}' { L _ ITclose_prag }
271 '..' { L _ ITdotdot } -- reserved symbols
273 '::' { L _ ITdcolon }
277 '<-' { L _ ITlarrow }
278 '->' { L _ ITrarrow }
281 '=>' { L _ ITdarrow }
285 '-<' { L _ ITlarrowtail } -- for arrow notation
286 '>-' { L _ ITrarrowtail } -- for arrow notation
287 '-<<' { L _ ITLarrowtail } -- for arrow notation
288 '>>-' { L _ ITRarrowtail } -- for arrow notation
291 '{' { L _ ITocurly } -- special symbols
293 '{|' { L _ ITocurlybar }
294 '|}' { L _ ITccurlybar }
295 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
296 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
299 '[:' { L _ ITopabrack }
300 ':]' { L _ ITcpabrack }
303 '(#' { L _ IToubxparen }
304 '#)' { L _ ITcubxparen }
305 '(|' { L _ IToparenbar }
306 '|)' { L _ ITcparenbar }
309 '`' { L _ ITbackquote }
311 VARID { L _ (ITvarid _) } -- identifiers
312 CONID { L _ (ITconid _) }
313 VARSYM { L _ (ITvarsym _) }
314 CONSYM { L _ (ITconsym _) }
315 QVARID { L _ (ITqvarid _) }
316 QCONID { L _ (ITqconid _) }
317 QVARSYM { L _ (ITqvarsym _) }
318 QCONSYM { L _ (ITqconsym _) }
319 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
320 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
322 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
324 CHAR { L _ (ITchar _) }
325 STRING { L _ (ITstring _) }
326 INTEGER { L _ (ITinteger _) }
327 RATIONAL { L _ (ITrational _) }
329 PRIMCHAR { L _ (ITprimchar _) }
330 PRIMSTRING { L _ (ITprimstring _) }
331 PRIMINTEGER { L _ (ITprimint _) }
332 PRIMWORD { L _ (ITprimword _) }
333 PRIMFLOAT { L _ (ITprimfloat _) }
334 PRIMDOUBLE { L _ (ITprimdouble _) }
336 DOCNEXT { L _ (ITdocCommentNext _) }
337 DOCPREV { L _ (ITdocCommentPrev _) }
338 DOCNAMED { L _ (ITdocCommentNamed _) }
339 DOCSECTION { L _ (ITdocSection _ _) }
342 '[|' { L _ ITopenExpQuote }
343 '[p|' { L _ ITopenPatQuote }
344 '[t|' { L _ ITopenTypQuote }
345 '[d|' { L _ ITopenDecQuote }
346 '|]' { L _ ITcloseQuote }
347 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
348 '$(' { L _ ITparenEscape } -- $( exp )
349 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
350 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
351 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
353 %monad { P } { >>= } { return }
354 %lexer { lexer } { L _ ITeof }
355 %name parseModule module
356 %name parseStmt maybe_stmt
357 %name parseIdentifier identifier
358 %name parseType ctype
359 %partial parseHeader header
360 %tokentype { (Located Token) }
363 -----------------------------------------------------------------------------
364 -- Identifiers; one of the entry points
365 identifier :: { Located RdrName }
370 | '(' '->' ')' { LL $ getRdrName funTyCon }
372 -----------------------------------------------------------------------------
375 -- The place for module deprecation is really too restrictive, but if it
376 -- was allowed at its natural place just before 'module', we get an ugly
377 -- s/r conflict with the second alternative. Another solution would be the
378 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
379 -- either, and DEPRECATED is only expected to be used by people who really
380 -- know what they are doing. :-)
382 module :: { Located (HsModule RdrName) }
383 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
384 {% fileSrcSpan >>= \ loc ->
385 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
388 {% fileSrcSpan >>= \ loc ->
389 return (L loc (HsModule Nothing Nothing
390 (fst $1) (snd $1) Nothing Nothing
393 maybedocheader :: { Maybe LHsDocString }
394 : moduleheader { $1 }
395 | {- empty -} { Nothing }
397 missing_module_keyword :: { () }
398 : {- empty -} {% pushCurrentContext }
400 maybemodwarning :: { Maybe WarningTxt }
401 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
402 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
403 | {- empty -} { Nothing }
405 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
407 | vocurly top close { $2 }
409 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
411 | missing_module_keyword top close { $2 }
413 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
414 : importdecls { (reverse $1,[]) }
415 | importdecls ';' cvtopdecls { (reverse $1,$3) }
416 | cvtopdecls { ([],$1) }
418 cvtopdecls :: { [LHsDecl RdrName] }
419 : topdecls { cvTopDecls $1 }
421 -----------------------------------------------------------------------------
422 -- Module declaration & imports only
424 header :: { Located (HsModule RdrName) }
425 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
426 {% fileSrcSpan >>= \ loc ->
427 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
429 | missing_module_keyword importdecls
430 {% fileSrcSpan >>= \ loc ->
431 return (L loc (HsModule Nothing Nothing $2 [] Nothing
434 header_body :: { [LImportDecl RdrName] }
435 : '{' importdecls { $2 }
436 | vocurly importdecls { $2 }
438 -----------------------------------------------------------------------------
441 maybeexports :: { Maybe [LIE RdrName] }
442 : '(' exportlist ')' { Just $2 }
443 | {- empty -} { Nothing }
445 exportlist :: { [LIE RdrName] }
446 : expdoclist ',' expdoclist { $1 ++ $3 }
449 exportlist1 :: { [LIE RdrName] }
450 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
451 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
454 expdoclist :: { [LIE RdrName] }
455 : exp_doc expdoclist { $1 : $2 }
458 exp_doc :: { LIE RdrName }
459 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
460 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
461 | docnext { L1 (IEDoc (unLoc $1)) }
463 -- No longer allow things like [] and (,,,) to be exported
464 -- They are built in syntax, always available
465 export :: { LIE RdrName }
466 : qvar { L1 (IEVar (unLoc $1)) }
467 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
468 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
469 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
470 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
471 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
473 qcnames :: { [RdrName] }
474 : qcnames ',' qcname_ext { unLoc $3 : $1 }
475 | qcname_ext { [unLoc $1] }
477 qcname_ext :: { Located RdrName } -- Variable or data constructor
478 -- or tagged type constructor
480 | 'type' qcon { sL (comb2 $1 $2)
481 (setRdrNameSpace (unLoc $2)
484 -- Cannot pull into qcname_ext, as qcname is also used in expression.
485 qcname :: { Located RdrName } -- Variable or data constructor
489 -----------------------------------------------------------------------------
490 -- Import Declarations
492 -- import decls can be *empty*, or even just a string of semicolons
493 -- whereas topdecls must contain at least one topdecl.
495 importdecls :: { [LImportDecl RdrName] }
496 : importdecls ';' importdecl { $3 : $1 }
497 | importdecls ';' { $1 }
498 | importdecl { [ $1 ] }
501 importdecl :: { LImportDecl RdrName }
502 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
503 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
505 maybe_src :: { IsBootInterface }
506 : '{-# SOURCE' '#-}' { True }
507 | {- empty -} { False }
509 maybe_pkg :: { Maybe FastString }
510 : STRING { Just (getSTRING $1) }
511 | {- empty -} { Nothing }
513 optqualified :: { Bool }
514 : 'qualified' { True }
515 | {- empty -} { False }
517 maybeas :: { Located (Maybe ModuleName) }
518 : 'as' modid { LL (Just (unLoc $2)) }
519 | {- empty -} { noLoc Nothing }
521 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
522 : impspec { L1 (Just (unLoc $1)) }
523 | {- empty -} { noLoc Nothing }
525 impspec :: { Located (Bool, [LIE RdrName]) }
526 : '(' exportlist ')' { LL (False, $2) }
527 | 'hiding' '(' exportlist ')' { LL (True, $3) }
529 -----------------------------------------------------------------------------
530 -- Fixity Declarations
534 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
536 infix :: { Located FixityDirection }
537 : 'infix' { L1 InfixN }
538 | 'infixl' { L1 InfixL }
539 | 'infixr' { L1 InfixR }
541 ops :: { Located [Located RdrName] }
542 : ops ',' op { LL ($3 : unLoc $1) }
545 -----------------------------------------------------------------------------
546 -- Top-Level Declarations
548 topdecls :: { OrdList (LHsDecl RdrName) }
549 : topdecls ';' topdecl { $1 `appOL` $3 }
550 | topdecls ';' { $1 }
553 topdecl :: { OrdList (LHsDecl RdrName) }
554 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
555 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
556 | 'instance' inst_type where_inst
557 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
559 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
560 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
561 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
562 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
563 | '{-# DEPRECATED' deprecations '#-}' { $2 }
564 | '{-# WARNING' warnings '#-}' { $2 }
565 | '{-# RULES' rules '#-}' { $2 }
566 | annotation { unitOL $1 }
569 -- Template Haskell Extension
570 -- The $(..) form is one possible form of infixexp
571 -- but we treat an arbitrary expression just as if
572 -- it had a $(..) wrapped around it
573 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
577 cl_decl :: { LTyClDecl RdrName }
578 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
580 -- Type declarations (toplevel)
582 ty_decl :: { LTyClDecl RdrName }
583 -- ordinary type synonyms
584 : 'type' type '=' ctypedoc
585 -- Note ctype, not sigtype, on the right of '='
586 -- We allow an explicit for-all but we don't insert one
587 -- in type Foo a = (b,b)
588 -- Instead we just say b is out of scope
590 -- Note the use of type for the head; this allows
591 -- infix type constructors to be declared
592 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
594 -- type family declarations
595 | 'type' 'family' type opt_kind_sig
596 -- Note the use of type for the head; this allows
597 -- infix type constructors to be declared
598 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
600 -- type instance declarations
601 | 'type' 'instance' type '=' ctype
602 -- Note the use of type for the head; this allows
603 -- infix type constructors and type patterns
604 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
606 -- ordinary data type or newtype declaration
607 | data_or_newtype tycl_hdr constrs deriving
608 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
609 Nothing (reverse (unLoc $3)) (unLoc $4) }
610 -- We need the location on tycl_hdr in case
611 -- constrs and deriving are both empty
613 -- ordinary GADT declaration
614 | data_or_newtype tycl_hdr opt_kind_sig
617 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
618 (unLoc $3) (unLoc $4) (unLoc $5) }
619 -- We need the location on tycl_hdr in case
620 -- constrs and deriving are both empty
622 -- data/newtype family
623 | 'data' 'family' type opt_kind_sig
624 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
626 -- data/newtype instance declaration
627 | data_or_newtype 'instance' tycl_hdr constrs deriving
628 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
629 Nothing (reverse (unLoc $4)) (unLoc $5) }
631 -- GADT instance declaration
632 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
635 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
636 (unLoc $4) (unLoc $5) (unLoc $6) }
638 -- Associated type family declarations
640 -- * They have a different syntax than on the toplevel (no family special
643 -- * They also need to be separate from instances; otherwise, data family
644 -- declarations without a kind signature cause parsing conflicts with empty
645 -- data declarations.
647 at_decl_cls :: { LTyClDecl RdrName }
648 -- type family declarations
649 : 'type' type opt_kind_sig
650 -- Note the use of type for the head; this allows
651 -- infix type constructors to be declared
652 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
654 -- default type instance
655 | 'type' type '=' ctype
656 -- Note the use of type for the head; this allows
657 -- infix type constructors and type patterns
658 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
660 -- data/newtype family declaration
661 | 'data' type opt_kind_sig
662 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
664 -- Associated type instances
666 at_decl_inst :: { LTyClDecl RdrName }
667 -- type instance declarations
668 : 'type' type '=' ctype
669 -- Note the use of type for the head; this allows
670 -- infix type constructors and type patterns
671 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
673 -- data/newtype instance declaration
674 | data_or_newtype tycl_hdr constrs deriving
675 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
676 Nothing (reverse (unLoc $3)) (unLoc $4) }
678 -- GADT instance declaration
679 | data_or_newtype tycl_hdr opt_kind_sig
682 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
683 (unLoc $3) (unLoc $4) (unLoc $5) }
685 data_or_newtype :: { Located NewOrData }
686 : 'data' { L1 DataType }
687 | 'newtype' { L1 NewType }
689 opt_kind_sig :: { Located (Maybe Kind) }
691 | '::' kind { LL (Just (unLoc $2)) }
693 -- tycl_hdr parses the header of a class or data type decl,
694 -- which takes the form
697 -- (Eq a, Ord b) => T a b
698 -- T Int [a] -- for associated types
699 -- Rather a lot of inlining here, else we get reduce/reduce errors
700 tycl_hdr :: { Located (LHsContext RdrName, LHsType RdrName) }
701 : context '=>' type { LL ($1, $3) }
702 | type { L1 (noLoc [], $1) }
704 -----------------------------------------------------------------------------
705 -- Stand-alone deriving
707 -- Glasgow extension: stand-alone deriving declarations
708 stand_alone_deriving :: { LDerivDecl RdrName }
709 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
711 -----------------------------------------------------------------------------
712 -- Nested declarations
714 -- Declaration in class bodies
716 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
717 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
720 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
721 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
722 | decls_cls ';' { LL (unLoc $1) }
724 | {- empty -} { noLoc nilOL }
728 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
729 : '{' decls_cls '}' { LL (unLoc $2) }
730 | vocurly decls_cls close { $2 }
734 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
735 -- No implicit parameters
736 -- May have type declarations
737 : 'where' decllist_cls { LL (unLoc $2) }
738 | {- empty -} { noLoc nilOL }
740 -- Declarations in instance bodies
742 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
743 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
746 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
747 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
748 | decls_inst ';' { LL (unLoc $1) }
750 | {- empty -} { noLoc nilOL }
753 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
754 : '{' decls_inst '}' { LL (unLoc $2) }
755 | vocurly decls_inst close { $2 }
759 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
760 -- No implicit parameters
761 -- May have type declarations
762 : 'where' decllist_inst { LL (unLoc $2) }
763 | {- empty -} { noLoc nilOL }
765 -- Declarations in binding groups other than classes and instances
767 decls :: { Located (OrdList (LHsDecl RdrName)) }
768 : decls ';' decl { let { this = unLoc $3;
770 these = rest `appOL` this }
771 in rest `seq` this `seq` these `seq`
773 | decls ';' { LL (unLoc $1) }
775 | {- empty -} { noLoc nilOL }
777 decllist :: { Located (OrdList (LHsDecl RdrName)) }
778 : '{' decls '}' { LL (unLoc $2) }
779 | vocurly decls close { $2 }
781 -- Binding groups other than those of class and instance declarations
783 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
784 -- No type declarations
785 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
786 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
787 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
789 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
790 -- No type declarations
791 : 'where' binds { LL (unLoc $2) }
792 | {- empty -} { noLoc emptyLocalBinds }
795 -----------------------------------------------------------------------------
796 -- Transformation Rules
798 rules :: { OrdList (LHsDecl RdrName) }
799 : rules ';' rule { $1 `snocOL` $3 }
802 | {- empty -} { nilOL }
804 rule :: { LHsDecl RdrName }
805 : STRING activation rule_forall infixexp '=' exp
806 { LL $ RuleD (HsRule (getSTRING $1)
807 ($2 `orElse` AlwaysActive)
808 $3 $4 placeHolderNames $6 placeHolderNames) }
810 activation :: { Maybe Activation }
811 : {- empty -} { Nothing }
812 | explicit_activation { Just $1 }
814 explicit_activation :: { Activation } -- In brackets
815 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
816 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
818 rule_forall :: { [RuleBndr RdrName] }
819 : 'forall' rule_var_list '.' { $2 }
822 rule_var_list :: { [RuleBndr RdrName] }
824 | rule_var rule_var_list { $1 : $2 }
826 rule_var :: { RuleBndr RdrName }
827 : varid { RuleBndr $1 }
828 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
830 -----------------------------------------------------------------------------
831 -- Warnings and deprecations (c.f. rules)
833 warnings :: { OrdList (LHsDecl RdrName) }
834 : warnings ';' warning { $1 `appOL` $3 }
835 | warnings ';' { $1 }
837 | {- empty -} { nilOL }
839 -- SUP: TEMPORARY HACK, not checking for `module Foo'
840 warning :: { OrdList (LHsDecl RdrName) }
842 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
845 deprecations :: { OrdList (LHsDecl RdrName) }
846 : deprecations ';' deprecation { $1 `appOL` $3 }
847 | deprecations ';' { $1 }
849 | {- empty -} { nilOL }
851 -- SUP: TEMPORARY HACK, not checking for `module Foo'
852 deprecation :: { OrdList (LHsDecl RdrName) }
854 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
857 strings :: { Located [FastString] }
858 : STRING { L1 [getSTRING $1] }
859 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
861 stringlist :: { Located (OrdList FastString) }
862 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
863 | STRING { LL (unitOL (getSTRING $1)) }
865 -----------------------------------------------------------------------------
867 annotation :: { LHsDecl RdrName }
868 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
869 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
870 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
873 -----------------------------------------------------------------------------
874 -- Foreign import and export declarations
876 fdecl :: { LHsDecl RdrName }
877 fdecl : 'import' callconv safety fspec
878 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
879 | 'import' callconv fspec
880 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
882 | 'export' callconv fspec
883 {% mkExport $2 (unLoc $3) >>= return.LL }
885 callconv :: { CCallConv }
886 : 'stdcall' { StdCallConv }
887 | 'ccall' { CCallConv }
888 | 'prim' { PrimCallConv}
891 : 'unsafe' { PlayRisky }
892 | 'safe' { PlaySafe False }
893 | 'threadsafe' { PlaySafe True } -- deprecated alias
895 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
896 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
897 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
898 -- if the entity string is missing, it defaults to the empty string;
899 -- the meaning of an empty entity string depends on the calling
902 -----------------------------------------------------------------------------
905 opt_sig :: { Maybe (LHsType RdrName) }
906 : {- empty -} { Nothing }
907 | '::' sigtype { Just $2 }
909 opt_asig :: { Maybe (LHsType RdrName) }
910 : {- empty -} { Nothing }
911 | '::' atype { Just $2 }
913 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
914 -- to tell the renamer where to generalise
915 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
916 -- Wrap an Implicit forall if there isn't one there already
918 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
919 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
920 -- Wrap an Implicit forall if there isn't one there already
922 sig_vars :: { Located [Located RdrName] }
923 : sig_vars ',' var { LL ($3 : unLoc $1) }
926 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
928 | sigtype ',' sigtypes1 { $1 : $3 }
930 -----------------------------------------------------------------------------
933 infixtype :: { LHsType RdrName }
934 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
935 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
937 strict_mark :: { Located HsBang }
938 : '!' { L1 HsStrict }
939 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
941 -- A ctype is a for-all type
942 ctype :: { LHsType RdrName }
943 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
944 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
945 -- A type of form (context => type) is an *implicit* HsForAllTy
946 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
949 ----------------------
950 -- Notes for 'ctypedoc'
951 -- It would have been nice to simplify the grammar by unifying `ctype` and
952 -- ctypedoc` into one production, allowing comments on types everywhere (and
953 -- rejecting them after parsing, where necessary). This is however not possible
954 -- since it leads to ambiguity. The reason is the support for comments on record
956 -- data R = R { field :: Int -- ^ comment on the field }
957 -- If we allow comments on types here, it's not clear if the comment applies
958 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
960 ctypedoc :: { LHsType RdrName }
961 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
962 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
963 -- A type of form (context => type) is an *implicit* HsForAllTy
964 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
967 ----------------------
968 -- Notes for 'context'
969 -- We parse a context as a btype so that we don't get reduce/reduce
970 -- errors in ctype. The basic problem is that
972 -- looks so much like a tuple type. We can't tell until we find the =>
974 -- We have the t1 ~ t2 form both in 'context' and in type,
975 -- to permit an individual equational constraint without parenthesis.
976 -- Thus for some reason we allow f :: a~b => blah
977 -- but not f :: ?x::Int => blah
978 context :: { LHsContext RdrName }
979 : btype '~' btype {% checkContext
980 (LL $ HsPredTy (HsEqualP $1 $3)) }
981 | btype {% checkContext $1 }
983 type :: { LHsType RdrName }
985 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
986 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
987 | btype '->' ctype { LL $ HsFunTy $1 $3 }
988 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
990 typedoc :: { LHsType RdrName }
992 | btype docprev { LL $ HsDocTy $1 $2 }
993 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
994 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
995 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
996 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
997 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
998 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
999 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1001 btype :: { LHsType RdrName }
1002 : btype atype { LL $ HsAppTy $1 $2 }
1005 atype :: { LHsType RdrName }
1006 : gtycon { L1 (HsTyVar (unLoc $1)) }
1007 | tyvar { L1 (HsTyVar (unLoc $1)) }
1008 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1009 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1010 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1011 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1012 | '[' ctype ']' { LL $ HsListTy $2 }
1013 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1014 | '(' ctype ')' { LL $ HsParTy $2 }
1015 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1016 | '$(' exp ')' { LL $ HsSpliceTy (mkHsSplice $2 ) }
1017 | TH_ID_SPLICE { LL $ HsSpliceTy (mkHsSplice
1018 (L1 $ HsVar (mkUnqual varName
1019 (getTH_ID_SPLICE $1)))) } -- $x
1021 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1023 -- An inst_type is what occurs in the head of an instance decl
1024 -- e.g. (Foo a, Gaz b) => Wibble a b
1025 -- It's kept as a single type, with a MonoDictTy at the right
1026 -- hand corner, for convenience.
1027 inst_type :: { LHsType RdrName }
1028 : sigtype {% checkInstType $1 }
1030 inst_types1 :: { [LHsType RdrName] }
1031 : inst_type { [$1] }
1032 | inst_type ',' inst_types1 { $1 : $3 }
1034 comma_types0 :: { [LHsType RdrName] }
1035 : comma_types1 { $1 }
1036 | {- empty -} { [] }
1038 comma_types1 :: { [LHsType RdrName] }
1040 | ctype ',' comma_types1 { $1 : $3 }
1042 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1043 : tv_bndr tv_bndrs { $1 : $2 }
1044 | {- empty -} { [] }
1046 tv_bndr :: { LHsTyVarBndr RdrName }
1047 : tyvar { L1 (UserTyVar (unLoc $1)) }
1048 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1051 fds :: { Located [Located (FunDep RdrName)] }
1052 : {- empty -} { noLoc [] }
1053 | '|' fds1 { LL (reverse (unLoc $2)) }
1055 fds1 :: { Located [Located (FunDep RdrName)] }
1056 : fds1 ',' fd { LL ($3 : unLoc $1) }
1059 fd :: { Located (FunDep RdrName) }
1060 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1061 (reverse (unLoc $1), reverse (unLoc $3)) }
1063 varids0 :: { Located [RdrName] }
1064 : {- empty -} { noLoc [] }
1065 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1067 -----------------------------------------------------------------------------
1070 kind :: { Located Kind }
1072 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1074 akind :: { Located Kind }
1075 : '*' { L1 liftedTypeKind }
1076 | '!' { L1 unliftedTypeKind }
1077 | '(' kind ')' { LL (unLoc $2) }
1080 -----------------------------------------------------------------------------
1081 -- Datatype declarations
1083 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1084 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1085 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1086 | {- empty -} { noLoc [] }
1088 gadt_constrs :: { Located [LConDecl RdrName] }
1089 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1090 | gadt_constr { L (getLoc (head $1)) $1 }
1091 | {- empty -} { noLoc [] }
1093 -- We allow the following forms:
1094 -- C :: Eq a => a -> T a
1095 -- C :: forall a. Eq a => !a -> T a
1096 -- D { x,y :: a } :: T a
1097 -- forall a. Eq a => D { x,y :: a } :: T a
1099 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1100 : con_list '::' sigtype
1101 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1103 -- Deprecated syntax for GADT record declarations
1104 | oqtycon '{' fielddecls '}' '::' sigtype
1105 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1108 constrs :: { Located [LConDecl RdrName] }
1109 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1111 constrs1 :: { Located [LConDecl RdrName] }
1112 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1113 | constr { L1 [$1] }
1115 constr :: { LConDecl RdrName }
1116 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1117 { let (con,details) = unLoc $5 in
1118 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1120 | maybe_docnext forall constr_stuff maybe_docprev
1121 { let (con,details) = unLoc $3 in
1122 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1125 forall :: { Located [LHsTyVarBndr RdrName] }
1126 : 'forall' tv_bndrs '.' { LL $2 }
1127 | {- empty -} { noLoc [] }
1129 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1130 -- We parse the constructor declaration
1132 -- as a btype (treating C as a type constructor) and then convert C to be
1133 -- a data constructor. Reason: it might continue like this:
1135 -- in which case C really would be a type constructor. We can't resolve this
1136 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1137 : btype {% splitCon $1 >>= return.LL }
1138 | btype conop btype { LL ($2, InfixCon $1 $3) }
1140 fielddecls :: { [ConDeclField RdrName] }
1141 : {- empty -} { [] }
1142 | fielddecls1 { $1 }
1144 fielddecls1 :: { [ConDeclField RdrName] }
1145 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1146 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1147 -- This adds the doc $4 to each field separately
1150 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1151 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1152 | fld <- reverse (unLoc $2) ] }
1154 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1155 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1156 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1157 -- We don't allow a context, but that's sorted out by the type checker.
1158 deriving :: { Located (Maybe [LHsType RdrName]) }
1159 : {- empty -} { noLoc Nothing }
1160 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1161 ; p <- checkInstType (L loc (HsTyVar tv))
1162 ; return (LL (Just [p])) } }
1163 | 'deriving' '(' ')' { LL (Just []) }
1164 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1165 -- Glasgow extension: allow partial
1166 -- applications in derivings
1168 -----------------------------------------------------------------------------
1169 -- Value definitions
1171 {- Note [Declaration/signature overlap]
1172 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1173 There's an awkward overlap with a type signature. Consider
1174 f :: Int -> Int = ...rhs...
1175 Then we can't tell whether it's a type signature or a value
1176 definition with a result signature until we see the '='.
1177 So we have to inline enough to postpone reductions until we know.
1181 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1182 instead of qvar, we get another shift/reduce-conflict. Consider the
1185 { (^^) :: Int->Int ; } Type signature; only var allowed
1187 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1188 qvar allowed (because of instance decls)
1190 We can't tell whether to reduce var to qvar until after we've read the signatures.
1193 docdecl :: { LHsDecl RdrName }
1194 : docdecld { L1 (DocD (unLoc $1)) }
1196 docdecld :: { LDocDecl }
1197 : docnext { L1 (DocCommentNext (unLoc $1)) }
1198 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1199 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1200 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1202 decl :: { Located (OrdList (LHsDecl RdrName)) }
1204 | '!' aexp rhs {% do { pat <- checkPattern $2;
1205 return (LL $ unitOL $ LL $ ValD (
1206 PatBind (LL $ BangPat pat) (unLoc $3)
1207 placeHolderType placeHolderNames)) } }
1208 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1209 let { l = comb2 $1 $> };
1210 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1211 | docdecl { LL $ unitOL $1 }
1213 rhs :: { Located (GRHSs RdrName) }
1214 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1215 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1217 gdrhs :: { Located [LGRHS RdrName] }
1218 : gdrhs gdrh { LL ($2 : unLoc $1) }
1221 gdrh :: { LGRHS RdrName }
1222 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1224 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1225 : infixexp '::' sigtypedoc {% do s <- checkValSig $1 $3
1226 ; return (LL $ unitOL (LL $ SigD s)) }
1227 -- See Note [Declaration/signature overlap] for why we need infixexp here
1228 | var ',' sig_vars '::' sigtypedoc
1229 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1230 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1232 | '{-# INLINE' activation qvar '#-}'
1233 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma $2 FunLike (getINLINE $1)))) }
1234 | '{-# INLINE_CONLIKE' activation qvar '#-}'
1235 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma $2 ConLike (getINLINE_CONLIKE $1)))) }
1236 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1237 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1239 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1240 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma $2 FunLike (getSPEC_INLINE $1)))
1242 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1243 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1245 -----------------------------------------------------------------------------
1248 exp :: { LHsExpr RdrName }
1249 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1250 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1251 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1252 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1253 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1256 infixexp :: { LHsExpr RdrName }
1258 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1260 exp10 :: { LHsExpr RdrName }
1261 : '\\' apat apats opt_asig '->' exp
1262 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1265 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1266 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1267 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1268 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1270 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1271 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1272 return (L loc (mkHsDo DoExpr stmts body)) }
1273 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1274 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1275 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1276 | scc_annot exp { LL $ if opt_SccProfilingOn
1277 then HsSCC (unLoc $1) $2
1279 | hpc_annot exp { LL $ if opt_Hpc
1280 then HsTickPragma (unLoc $1) $2
1283 | 'proc' aexp '->' exp
1284 {% checkPattern $2 >>= \ p ->
1285 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1286 placeHolderType undefined)) }
1287 -- TODO: is LL right here?
1289 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1290 -- hdaume: core annotation
1293 scc_annot :: { Located FastString }
1294 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1295 ( do scc <- getSCC $2; return $ LL scc ) }
1296 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1298 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1299 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1300 { LL $ (getSTRING $2
1301 ,( fromInteger $ getINTEGER $3
1302 , fromInteger $ getINTEGER $5
1304 ,( fromInteger $ getINTEGER $7
1305 , fromInteger $ getINTEGER $9
1310 fexp :: { LHsExpr RdrName }
1311 : fexp aexp { LL $ HsApp $1 $2 }
1314 aexp :: { LHsExpr RdrName }
1315 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1316 | '~' aexp { LL $ ELazyPat $2 }
1319 aexp1 :: { LHsExpr RdrName }
1320 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1324 -- Here was the syntax for type applications that I was planning
1325 -- but there are difficulties (e.g. what order for type args)
1326 -- so it's not enabled yet.
1327 -- But this case *is* used for the left hand side of a generic definition,
1328 -- which is parsed as an expression before being munged into a pattern
1329 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1330 (sL (getLoc $3) (HsType $3)) }
1332 aexp2 :: { LHsExpr RdrName }
1333 : ipvar { L1 (HsIPVar $! unLoc $1) }
1334 | qcname { L1 (HsVar $! unLoc $1) }
1335 | literal { L1 (HsLit $! unLoc $1) }
1336 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1337 -- into HsOverLit when -foverloaded-strings is on.
1338 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1339 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1340 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1342 -- N.B.: sections get parsed by these next two productions.
1343 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
1344 -- (you'd have to write '((+ 3), (4 -))')
1345 -- but the less cluttered version fell out of having texps.
1346 | '(' texp ')' { LL (HsPar $2) }
1347 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1349 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1350 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1352 | '[' list ']' { LL (unLoc $2) }
1353 | '[:' parr ':]' { LL (unLoc $2) }
1354 | '_' { L1 EWildPat }
1356 -- Template Haskell Extension
1357 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1358 (L1 $ HsVar (mkUnqual varName
1359 (getTH_ID_SPLICE $1)))) } -- $x
1360 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1362 | TH_QUASIQUOTE { let { loc = getLoc $1
1363 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1364 ; quoterId = mkUnqual varName quoter
1366 in sL loc $ HsQuasiQuoteE (mkHsQuasiQuote quoterId quoteSpan quote) }
1367 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1368 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1369 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1370 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1371 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1372 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1373 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1374 return (LL $ HsBracket (PatBr p)) }
1375 | '[d|' cvtopbody '|]' {% checkDecBrGroup $2 >>= \g ->
1376 return (LL $ HsBracket (DecBr g)) }
1378 -- arrow notation extension
1379 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1381 cmdargs :: { [LHsCmdTop RdrName] }
1382 : cmdargs acmd { $2 : $1 }
1383 | {- empty -} { [] }
1385 acmd :: { LHsCmdTop RdrName }
1386 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1388 cvtopbody :: { [LHsDecl RdrName] }
1389 : '{' cvtopdecls0 '}' { $2 }
1390 | vocurly cvtopdecls0 close { $2 }
1392 cvtopdecls0 :: { [LHsDecl RdrName] }
1393 : {- empty -} { [] }
1396 -----------------------------------------------------------------------------
1397 -- Tuple expressions
1399 -- "texp" is short for tuple expressions:
1400 -- things that can appear unparenthesized as long as they're
1401 -- inside parens or delimitted by commas
1402 texp :: { LHsExpr RdrName }
1405 -- Note [Parsing sections]
1406 -- ~~~~~~~~~~~~~~~~~~~~~~~
1407 -- We include left and right sections here, which isn't
1408 -- technically right according to Haskell 98. For example
1409 -- (3 +, True) isn't legal
1410 -- However, we want to parse bang patterns like
1412 -- and it's convenient to do so here as a section
1413 -- Then when converting expr to pattern we unravel it again
1414 -- Meanwhile, the renamer checks that real sections appear
1416 | infixexp qop { LL $ SectionL $1 $2 }
1417 | qopm infixexp { LL $ SectionR $1 $2 }
1419 -- View patterns get parenthesized above
1420 | exp '->' texp { LL $ EViewPat $1 $3 }
1422 -- Always at least one comma
1423 tup_exprs :: { [HsTupArg RdrName] }
1424 : texp commas_tup_tail { Present $1 : $2 }
1425 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1427 -- Always starts with commas; always follows an expr
1428 commas_tup_tail :: { [HsTupArg RdrName] }
1429 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1431 -- Always follows a comma
1432 tup_tail :: { [HsTupArg RdrName] }
1433 : texp commas_tup_tail { Present $1 : $2 }
1434 | texp { [Present $1] }
1435 | {- empty -} { [missingTupArg] }
1437 -----------------------------------------------------------------------------
1440 -- The rules below are little bit contorted to keep lexps left-recursive while
1441 -- avoiding another shift/reduce-conflict.
1443 list :: { LHsExpr RdrName }
1444 : texp { L1 $ ExplicitList placeHolderType [$1] }
1445 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1446 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1447 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1448 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1449 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1450 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1452 lexps :: { Located [LHsExpr RdrName] }
1453 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1454 | texp ',' texp { LL [$3,$1] }
1456 -----------------------------------------------------------------------------
1457 -- List Comprehensions
1459 flattenedpquals :: { Located [LStmt RdrName] }
1460 : pquals { case (unLoc $1) of
1462 -- We just had one thing in our "parallel" list so
1463 -- we simply return that thing directly
1465 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1466 -- We actually found some actual parallel lists so
1467 -- we wrap them into as a ParStmt
1470 pquals :: { Located [[LStmt RdrName]] }
1471 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1472 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1474 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1475 -- one can "grab" the earlier ones
1476 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1477 | squals ',' qual { LL ($3 : unLoc $1) }
1478 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1480 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1481 -- | '{|' pquals '|}' { L1 [$2] }
1484 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1485 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1486 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1487 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1489 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1490 -- Function is applied to a list of stmts *in order*
1491 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1493 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1494 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1496 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1497 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1498 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1499 -- choosing the "group by" variant, which is what we want.
1501 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1502 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1503 -- if /that/ is the group function we conflict with.
1504 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1505 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1507 -----------------------------------------------------------------------------
1508 -- Parallel array expressions
1510 -- The rules below are little bit contorted; see the list case for details.
1511 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1512 -- Moreover, we allow explicit arrays with no element (represented by the nil
1513 -- constructor in the list case).
1515 parr :: { LHsExpr RdrName }
1516 : { noLoc (ExplicitPArr placeHolderType []) }
1517 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1518 | lexps { L1 $ ExplicitPArr placeHolderType
1519 (reverse (unLoc $1)) }
1520 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1521 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1522 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1524 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1526 -----------------------------------------------------------------------------
1529 guardquals :: { Located [LStmt RdrName] }
1530 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1532 guardquals1 :: { Located [LStmt RdrName] }
1533 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1536 -----------------------------------------------------------------------------
1537 -- Case alternatives
1539 altslist :: { Located [LMatch RdrName] }
1540 : '{' alts '}' { LL (reverse (unLoc $2)) }
1541 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1543 alts :: { Located [LMatch RdrName] }
1544 : alts1 { L1 (unLoc $1) }
1545 | ';' alts { LL (unLoc $2) }
1547 alts1 :: { Located [LMatch RdrName] }
1548 : alts1 ';' alt { LL ($3 : unLoc $1) }
1549 | alts1 ';' { LL (unLoc $1) }
1552 alt :: { LMatch RdrName }
1553 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1555 alt_rhs :: { Located (GRHSs RdrName) }
1556 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1558 ralt :: { Located [LGRHS RdrName] }
1559 : '->' exp { LL (unguardedRHS $2) }
1560 | gdpats { L1 (reverse (unLoc $1)) }
1562 gdpats :: { Located [LGRHS RdrName] }
1563 : gdpats gdpat { LL ($2 : unLoc $1) }
1566 gdpat :: { LGRHS RdrName }
1567 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1569 -- 'pat' recognises a pattern, including one with a bang at the top
1570 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1571 -- Bangs inside are parsed as infix operator applications, so that
1572 -- we parse them right when bang-patterns are off
1573 pat :: { LPat RdrName }
1574 pat : exp {% checkPattern $1 }
1575 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1577 apat :: { LPat RdrName }
1578 apat : aexp {% checkPattern $1 }
1579 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1581 apats :: { [LPat RdrName] }
1582 : apat apats { $1 : $2 }
1583 | {- empty -} { [] }
1585 -----------------------------------------------------------------------------
1586 -- Statement sequences
1588 stmtlist :: { Located [LStmt RdrName] }
1589 : '{' stmts '}' { LL (unLoc $2) }
1590 | vocurly stmts close { $2 }
1592 -- do { ;; s ; s ; ; s ;; }
1593 -- The last Stmt should be an expression, but that's hard to enforce
1594 -- here, because we need too much lookahead if we see do { e ; }
1595 -- So we use ExprStmts throughout, and switch the last one over
1596 -- in ParseUtils.checkDo instead
1597 stmts :: { Located [LStmt RdrName] }
1598 : stmt stmts_help { LL ($1 : unLoc $2) }
1599 | ';' stmts { LL (unLoc $2) }
1600 | {- empty -} { noLoc [] }
1602 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1603 : ';' stmts { LL (unLoc $2) }
1604 | {- empty -} { noLoc [] }
1606 -- For typing stmts at the GHCi prompt, where
1607 -- the input may consist of just comments.
1608 maybe_stmt :: { Maybe (LStmt RdrName) }
1610 | {- nothing -} { Nothing }
1612 stmt :: { LStmt RdrName }
1614 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1616 qual :: { LStmt RdrName }
1617 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1618 | exp { L1 $ mkExprStmt $1 }
1619 | 'let' binds { LL $ LetStmt (unLoc $2) }
1621 -----------------------------------------------------------------------------
1622 -- Record Field Update/Construction
1624 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1626 | {- empty -} { ([], False) }
1628 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1629 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1630 | fbind { ([$1], False) }
1631 | '..' { ([], True) }
1633 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1634 : qvar '=' exp { HsRecField $1 $3 False }
1635 | qvar { HsRecField $1 (L (getLoc $1) placeHolderPunRhs) True }
1636 -- Here's where we say that plain 'x'
1637 -- means exactly 'x = x'. The pun-flag boolean is
1638 -- there so we can still print it right
1640 -----------------------------------------------------------------------------
1641 -- Implicit Parameter Bindings
1643 dbinds :: { Located [LIPBind RdrName] }
1644 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1645 in rest `seq` this `seq` LL (this : rest) }
1646 | dbinds ';' { LL (unLoc $1) }
1647 | dbind { let this = $1 in this `seq` L1 [this] }
1648 -- | {- empty -} { [] }
1650 dbind :: { LIPBind RdrName }
1651 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1653 ipvar :: { Located (IPName RdrName) }
1654 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1656 -----------------------------------------------------------------------------
1657 -- Warnings and deprecations
1659 namelist :: { Located [RdrName] }
1660 namelist : name_var { L1 [unLoc $1] }
1661 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1663 name_var :: { Located RdrName }
1664 name_var : var { $1 }
1667 -----------------------------------------
1668 -- Data constructors
1669 qcon :: { Located RdrName }
1671 | '(' qconsym ')' { LL (unLoc $2) }
1672 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1673 -- The case of '[:' ':]' is part of the production `parr'
1675 con :: { Located RdrName }
1677 | '(' consym ')' { LL (unLoc $2) }
1678 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1680 con_list :: { Located [Located RdrName] }
1681 con_list : con { L1 [$1] }
1682 | con ',' con_list { LL ($1 : unLoc $3) }
1684 sysdcon :: { Located DataCon } -- Wired in data constructors
1685 : '(' ')' { LL unitDataCon }
1686 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1687 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1688 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1689 | '[' ']' { LL nilDataCon }
1691 conop :: { Located RdrName }
1693 | '`' conid '`' { LL (unLoc $2) }
1695 qconop :: { Located RdrName }
1697 | '`' qconid '`' { LL (unLoc $2) }
1699 -----------------------------------------------------------------------------
1700 -- Type constructors
1702 gtycon :: { Located RdrName } -- A "general" qualified tycon
1704 | '(' ')' { LL $ getRdrName unitTyCon }
1705 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1706 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1707 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1708 | '(' '->' ')' { LL $ getRdrName funTyCon }
1709 | '[' ']' { LL $ listTyCon_RDR }
1710 | '[:' ':]' { LL $ parrTyCon_RDR }
1712 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1714 | '(' qtyconsym ')' { LL (unLoc $2) }
1716 qtyconop :: { Located RdrName } -- Qualified or unqualified
1718 | '`' qtycon '`' { LL (unLoc $2) }
1720 qtycon :: { Located RdrName } -- Qualified or unqualified
1721 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1722 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1725 tycon :: { Located RdrName } -- Unqualified
1726 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1728 qtyconsym :: { Located RdrName }
1729 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1732 tyconsym :: { Located RdrName }
1733 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1735 -----------------------------------------------------------------------------
1738 op :: { Located RdrName } -- used in infix decls
1742 varop :: { Located RdrName }
1744 | '`' varid '`' { LL (unLoc $2) }
1746 qop :: { LHsExpr RdrName } -- used in sections
1747 : qvarop { L1 $ HsVar (unLoc $1) }
1748 | qconop { L1 $ HsVar (unLoc $1) }
1750 qopm :: { LHsExpr RdrName } -- used in sections
1751 : qvaropm { L1 $ HsVar (unLoc $1) }
1752 | qconop { L1 $ HsVar (unLoc $1) }
1754 qvarop :: { Located RdrName }
1756 | '`' qvarid '`' { LL (unLoc $2) }
1758 qvaropm :: { Located RdrName }
1759 : qvarsym_no_minus { $1 }
1760 | '`' qvarid '`' { LL (unLoc $2) }
1762 -----------------------------------------------------------------------------
1765 tyvar :: { Located RdrName }
1766 tyvar : tyvarid { $1 }
1767 | '(' tyvarsym ')' { LL (unLoc $2) }
1769 tyvarop :: { Located RdrName }
1770 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1772 | '.' {% parseErrorSDoc (getLoc $1)
1773 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1774 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1775 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1778 tyvarid :: { Located RdrName }
1779 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1780 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1781 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1782 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1783 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1785 tyvarsym :: { Located RdrName }
1786 -- Does not include "!", because that is used for strictness marks
1787 -- or ".", because that separates the quantified type vars from the rest
1788 -- or "*", because that's used for kinds
1789 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1791 -----------------------------------------------------------------------------
1794 var :: { Located RdrName }
1796 | '(' varsym ')' { LL (unLoc $2) }
1798 qvar :: { Located RdrName }
1800 | '(' varsym ')' { LL (unLoc $2) }
1801 | '(' qvarsym1 ')' { LL (unLoc $2) }
1802 -- We've inlined qvarsym here so that the decision about
1803 -- whether it's a qvar or a var can be postponed until
1804 -- *after* we see the close paren.
1806 qvarid :: { Located RdrName }
1808 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1809 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1811 varid :: { Located RdrName }
1812 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1813 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1814 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1815 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1816 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1817 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1818 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1820 qvarsym :: { Located RdrName }
1824 qvarsym_no_minus :: { Located RdrName }
1825 : varsym_no_minus { $1 }
1828 qvarsym1 :: { Located RdrName }
1829 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1831 varsym :: { Located RdrName }
1832 : varsym_no_minus { $1 }
1833 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1835 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1836 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1837 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1840 -- These special_ids are treated as keywords in various places,
1841 -- but as ordinary ids elsewhere. 'special_id' collects all these
1842 -- except 'unsafe', 'forall', and 'family' whose treatment differs
1843 -- depending on context
1844 special_id :: { Located FastString }
1846 : 'as' { L1 (fsLit "as") }
1847 | 'qualified' { L1 (fsLit "qualified") }
1848 | 'hiding' { L1 (fsLit "hiding") }
1849 | 'export' { L1 (fsLit "export") }
1850 | 'label' { L1 (fsLit "label") }
1851 | 'dynamic' { L1 (fsLit "dynamic") }
1852 | 'stdcall' { L1 (fsLit "stdcall") }
1853 | 'ccall' { L1 (fsLit "ccall") }
1854 | 'prim' { L1 (fsLit "prim") }
1855 | 'group' { L1 (fsLit "group") }
1857 special_sym :: { Located FastString }
1858 special_sym : '!' { L1 (fsLit "!") }
1859 | '.' { L1 (fsLit ".") }
1860 | '*' { L1 (fsLit "*") }
1862 -----------------------------------------------------------------------------
1863 -- Data constructors
1865 qconid :: { Located RdrName } -- Qualified or unqualified
1867 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1868 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1870 conid :: { Located RdrName }
1871 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1873 qconsym :: { Located RdrName } -- Qualified or unqualified
1875 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1877 consym :: { Located RdrName }
1878 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1880 -- ':' means only list cons
1881 | ':' { L1 $ consDataCon_RDR }
1884 -----------------------------------------------------------------------------
1887 literal :: { Located HsLit }
1888 : CHAR { L1 $ HsChar $ getCHAR $1 }
1889 | STRING { L1 $ HsString $ getSTRING $1 }
1890 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1891 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1892 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1893 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1894 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1895 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1897 -----------------------------------------------------------------------------
1901 : vccurly { () } -- context popped in lexer.
1902 | error {% popContext }
1904 -----------------------------------------------------------------------------
1905 -- Miscellaneous (mostly renamings)
1907 modid :: { Located ModuleName }
1908 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1909 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1912 (unpackFS mod ++ '.':unpackFS c))
1916 : commas ',' { $1 + 1 }
1919 -----------------------------------------------------------------------------
1920 -- Documentation comments
1922 docnext :: { LHsDocString }
1923 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1925 docprev :: { LHsDocString }
1926 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1928 docnamed :: { Located (String, HsDocString) }
1930 let string = getDOCNAMED $1
1931 (name, rest) = break isSpace string
1932 in return (L1 (name, HsDocString (mkFastString rest))) }
1934 docsection :: { Located (Int, HsDocString) }
1935 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1936 return (L1 (n, HsDocString (mkFastString doc))) }
1938 moduleheader :: { Maybe LHsDocString }
1939 : DOCNEXT {% let string = getDOCNEXT $1 in
1940 return (Just (L1 (HsDocString (mkFastString string)))) }
1942 maybe_docprev :: { Maybe LHsDocString }
1943 : docprev { Just $1 }
1944 | {- empty -} { Nothing }
1946 maybe_docnext :: { Maybe LHsDocString }
1947 : docnext { Just $1 }
1948 | {- empty -} { Nothing }
1952 happyError = srcParseFail
1954 getVARID (L _ (ITvarid x)) = x
1955 getCONID (L _ (ITconid x)) = x
1956 getVARSYM (L _ (ITvarsym x)) = x
1957 getCONSYM (L _ (ITconsym x)) = x
1958 getQVARID (L _ (ITqvarid x)) = x
1959 getQCONID (L _ (ITqconid x)) = x
1960 getQVARSYM (L _ (ITqvarsym x)) = x
1961 getQCONSYM (L _ (ITqconsym x)) = x
1962 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1963 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1964 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1965 getCHAR (L _ (ITchar x)) = x
1966 getSTRING (L _ (ITstring x)) = x
1967 getINTEGER (L _ (ITinteger x)) = x
1968 getRATIONAL (L _ (ITrational x)) = x
1969 getPRIMCHAR (L _ (ITprimchar x)) = x
1970 getPRIMSTRING (L _ (ITprimstring x)) = x
1971 getPRIMINTEGER (L _ (ITprimint x)) = x
1972 getPRIMWORD (L _ (ITprimword x)) = x
1973 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1974 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1975 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1976 getINLINE (L _ (ITinline_prag b)) = b
1977 getINLINE_CONLIKE (L _ (ITinline_conlike_prag b)) = b
1978 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
1980 getDOCNEXT (L _ (ITdocCommentNext x)) = x
1981 getDOCPREV (L _ (ITdocCommentPrev x)) = x
1982 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
1983 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
1985 getSCC :: Located Token -> P FastString
1986 getSCC lt = do let s = getSTRING lt
1987 err = "Spaces are not allowed in SCCs"
1988 -- We probably actually want to be more restrictive than this
1989 if ' ' `elem` unpackFS s
1990 then failSpanMsgP (getLoc lt) (text err)
1993 -- Utilities for combining source spans
1994 comb2 :: Located a -> Located b -> SrcSpan
1995 comb2 a b = a `seq` b `seq` combineLocs a b
1997 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1998 comb3 a b c = a `seq` b `seq` c `seq`
1999 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2001 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2002 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2003 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2004 combineSrcSpans (getLoc c) (getLoc d))
2006 -- strict constructor version:
2008 sL :: SrcSpan -> a -> Located a
2009 sL span a = span `seq` a `seq` L span a
2011 -- Make a source location for the file. We're a bit lazy here and just
2012 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2013 -- try to find the span of the whole file (ToDo).
2014 fileSrcSpan :: P SrcSpan
2017 let loc = mkSrcLoc (srcLocFile l) 1 1;
2018 return (mkSrcSpan loc loc)