2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# OPTIONS -Wwarn -w -XNoMonomorphismRestriction #-}
12 -- The NoMonomorphismRestriction deals with a Happy infelicity
13 -- With OutsideIn's more conservativ monomorphism restriction
14 -- we aren't generalising
15 -- notHappyAtAll = error "urk"
16 -- which is terrible. Switching off the restriction allows
17 -- the generalisation. Better would be to make Happy generate
18 -- an appropriate signature.
20 -- The above warning supression flag is a temporary kludge.
21 -- While working on this module you are encouraged to remove it and fix
22 -- any warnings in the module. See
23 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
26 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
28 Careful optimisation of the parser: we don't want to throw everything
29 at it, because that takes too long and doesn't buy much, but we do want
30 to inline certain key external functions, so we instruct GHC not to
31 throw away inlinings as it would normally do in -O0 mode.
34 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
39 import HscTypes ( IsBootInterface, WarningTxt(..) )
42 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
43 unboxedSingletonTyCon, unboxedSingletonDataCon,
44 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
45 import Type ( funTyCon )
46 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
47 CCallConv(..), CCallTarget(..), defaultCCallConv
49 import OccName ( varName, dataName, tcClsName, tvName )
50 import DataCon ( DataCon, dataConName )
51 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
52 SrcSpan, combineLocs, srcLocFile,
55 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
56 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
57 import Coercion ( mkArrowKind )
58 import Class ( FunDep )
65 import Maybes ( orElse )
68 import Control.Monad ( unless )
71 import Control.Monad ( mplus )
75 -----------------------------------------------------------------------------
78 Conflicts: 33 shift/reduce
81 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
82 would think the two should never occur in the same context.
86 -----------------------------------------------------------------------------
89 Conflicts: 34 shift/reduce
92 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
93 would think the two should never occur in the same context.
97 -----------------------------------------------------------------------------
100 Conflicts: 32 shift/reduce
103 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
104 would think the two should never occur in the same context.
108 -----------------------------------------------------------------------------
111 Conflicts: 37 shift/reduce
114 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
115 would think the two should never occur in the same context.
119 -----------------------------------------------------------------------------
120 Conflicts: 38 shift/reduce (1.25)
122 10 for abiguity in 'if x then y else z + 1' [State 178]
123 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
124 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
126 1 for ambiguity in 'if x then y else z :: T' [State 178]
127 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
129 4 for ambiguity in 'if x then y else z -< e' [State 178]
130 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
131 There are four such operators: -<, >-, -<<, >>-
134 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
135 Which of these two is intended?
137 (x::T) -> T -- Rhs is T
140 (x::T -> T) -> .. -- Rhs is ...
142 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
145 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
146 Same duplication between states 11 and 253 as the previous case
148 1 for ambiguity in 'let ?x ...' [State 329]
149 the parser can't tell whether the ?x is the lhs of a normal binding or
150 an implicit binding. Fortunately resolving as shift gives it the only
151 sensible meaning, namely the lhs of an implicit binding.
153 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
154 we don't know whether the '[' starts the activation or not: it
155 might be the start of the declaration with the activation being
156 empty. --SDM 1/4/2002
158 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
159 since 'forall' is a valid variable name, we don't know whether
160 to treat a forall on the input as the beginning of a quantifier
161 or the beginning of the rule itself. Resolving to shift means
162 it's always treated as a quantifier, hence the above is disallowed.
163 This saves explicitly defining a grammar for the rule lhs that
164 doesn't include 'forall'.
166 1 for ambiguity when the source file starts with "-- | doc". We need another
167 token of lookahead to determine if a top declaration or the 'module' keyword
168 follows. Shift parses as if the 'module' keyword follows.
170 -- ---------------------------------------------------------------------------
171 -- Adding location info
173 This is done in a stylised way using the three macros below, L0, L1
174 and LL. Each of these macros can be thought of as having type
176 L0, L1, LL :: a -> Located a
178 They each add a SrcSpan to their argument.
180 L0 adds 'noSrcSpan', used for empty productions
181 -- This doesn't seem to work anymore -=chak
183 L1 for a production with a single token on the lhs. Grabs the SrcSpan
186 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
187 the first and last tokens.
189 These suffice for the majority of cases. However, we must be
190 especially careful with empty productions: LL won't work if the first
191 or last token on the lhs can represent an empty span. In these cases,
192 we have to calculate the span using more of the tokens from the lhs, eg.
194 | 'newtype' tycl_hdr '=' newconstr deriving
196 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
198 We provide comb3 and comb4 functions which are useful in such cases.
200 Be careful: there's no checking that you actually got this right, the
201 only symptom will be that the SrcSpans of your syntax will be
205 * We must expand these macros *before* running Happy, which is why this file is
206 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
208 #define L0 L noSrcSpan
209 #define L1 sL (getLoc $1)
210 #define LL sL (comb2 $1 $>)
212 -- -----------------------------------------------------------------------------
217 '_' { L _ ITunderscore } -- Haskell keywords
219 'case' { L _ ITcase }
220 'class' { L _ ITclass }
221 'data' { L _ ITdata }
222 'default' { L _ ITdefault }
223 'deriving' { L _ ITderiving }
225 'else' { L _ ITelse }
226 'hiding' { L _ IThiding }
228 'import' { L _ ITimport }
230 'infix' { L _ ITinfix }
231 'infixl' { L _ ITinfixl }
232 'infixr' { L _ ITinfixr }
233 'instance' { L _ ITinstance }
235 'module' { L _ ITmodule }
236 'newtype' { L _ ITnewtype }
238 'qualified' { L _ ITqualified }
239 'then' { L _ ITthen }
240 'type' { L _ ITtype }
241 'where' { L _ ITwhere }
242 '_scc_' { L _ ITscc } -- ToDo: remove
244 'forall' { L _ ITforall } -- GHC extension keywords
245 'foreign' { L _ ITforeign }
246 'export' { L _ ITexport }
247 'label' { L _ ITlabel }
248 'dynamic' { L _ ITdynamic }
249 'safe' { L _ ITsafe }
250 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
251 'interruptible' { L _ ITinterruptible }
252 'unsafe' { L _ ITunsafe }
254 'family' { L _ ITfamily }
255 'stdcall' { L _ ITstdcallconv }
256 'ccall' { L _ ITccallconv }
257 'prim' { L _ ITprimcallconv }
258 'proc' { L _ ITproc } -- for arrow notation extension
259 'rec' { L _ ITrec } -- for arrow notation extension
260 'group' { L _ ITgroup } -- for list transform extension
261 'by' { L _ ITby } -- for list transform extension
262 'using' { L _ ITusing } -- for list transform extension
264 '{-# INLINE' { L _ (ITinline_prag _ _) }
265 '{-# SPECIALISE' { L _ ITspec_prag }
266 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
267 '{-# SOURCE' { L _ ITsource_prag }
268 '{-# RULES' { L _ ITrules_prag }
269 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
270 '{-# SCC' { L _ ITscc_prag }
271 '{-# GENERATED' { L _ ITgenerated_prag }
272 '{-# DEPRECATED' { L _ ITdeprecated_prag }
273 '{-# WARNING' { L _ ITwarning_prag }
274 '{-# UNPACK' { L _ ITunpack_prag }
275 '{-# ANN' { L _ ITann_prag }
276 '#-}' { L _ ITclose_prag }
278 '..' { L _ ITdotdot } -- reserved symbols
280 '::' { L _ ITdcolon }
284 '<-' { L _ ITlarrow }
285 '->' { L _ ITrarrow }
288 '=>' { L _ ITdarrow }
292 '-<' { L _ ITlarrowtail } -- for arrow notation
293 '>-' { L _ ITrarrowtail } -- for arrow notation
294 '-<<' { L _ ITLarrowtail } -- for arrow notation
295 '>>-' { L _ ITRarrowtail } -- for arrow notation
298 '{' { L _ ITocurly } -- special symbols
300 '{|' { L _ ITocurlybar }
301 '|}' { L _ ITccurlybar }
302 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
303 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
306 '[:' { L _ ITopabrack }
307 ':]' { L _ ITcpabrack }
310 '(#' { L _ IToubxparen }
311 '#)' { L _ ITcubxparen }
312 '(|' { L _ IToparenbar }
313 '|)' { L _ ITcparenbar }
316 '`' { L _ ITbackquote }
318 VARID { L _ (ITvarid _) } -- identifiers
319 CONID { L _ (ITconid _) }
320 VARSYM { L _ (ITvarsym _) }
321 CONSYM { L _ (ITconsym _) }
322 QVARID { L _ (ITqvarid _) }
323 QCONID { L _ (ITqconid _) }
324 QVARSYM { L _ (ITqvarsym _) }
325 QCONSYM { L _ (ITqconsym _) }
326 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
327 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
329 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
331 CHAR { L _ (ITchar _) }
332 STRING { L _ (ITstring _) }
333 INTEGER { L _ (ITinteger _) }
334 RATIONAL { L _ (ITrational _) }
336 PRIMCHAR { L _ (ITprimchar _) }
337 PRIMSTRING { L _ (ITprimstring _) }
338 PRIMINTEGER { L _ (ITprimint _) }
339 PRIMWORD { L _ (ITprimword _) }
340 PRIMFLOAT { L _ (ITprimfloat _) }
341 PRIMDOUBLE { L _ (ITprimdouble _) }
343 DOCNEXT { L _ (ITdocCommentNext _) }
344 DOCPREV { L _ (ITdocCommentPrev _) }
345 DOCNAMED { L _ (ITdocCommentNamed _) }
346 DOCSECTION { L _ (ITdocSection _ _) }
349 '[|' { L _ ITopenExpQuote }
350 '[p|' { L _ ITopenPatQuote }
351 '[t|' { L _ ITopenTypQuote }
352 '[d|' { L _ ITopenDecQuote }
353 '|]' { L _ ITcloseQuote }
354 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
355 '$(' { L _ ITparenEscape } -- $( exp )
356 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
357 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
358 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
360 %monad { P } { >>= } { return }
361 %lexer { lexer } { L _ ITeof }
362 %name parseModule module
363 %name parseStmt maybe_stmt
364 %name parseIdentifier identifier
365 %name parseType ctype
366 %partial parseHeader header
367 %tokentype { (Located Token) }
370 -----------------------------------------------------------------------------
371 -- Identifiers; one of the entry points
372 identifier :: { Located RdrName }
377 | '(' '->' ')' { LL $ getRdrName funTyCon }
379 -----------------------------------------------------------------------------
382 -- The place for module deprecation is really too restrictive, but if it
383 -- was allowed at its natural place just before 'module', we get an ugly
384 -- s/r conflict with the second alternative. Another solution would be the
385 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
386 -- either, and DEPRECATED is only expected to be used by people who really
387 -- know what they are doing. :-)
389 module :: { Located (HsModule RdrName) }
390 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
391 {% fileSrcSpan >>= \ loc ->
392 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
395 {% fileSrcSpan >>= \ loc ->
396 return (L loc (HsModule Nothing Nothing
397 (fst $1) (snd $1) Nothing Nothing
400 maybedocheader :: { Maybe LHsDocString }
401 : moduleheader { $1 }
402 | {- empty -} { Nothing }
404 missing_module_keyword :: { () }
405 : {- empty -} {% pushCurrentContext }
407 maybemodwarning :: { Maybe WarningTxt }
408 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
409 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
410 | {- empty -} { Nothing }
412 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
414 | vocurly top close { $2 }
416 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
418 | missing_module_keyword top close { $2 }
420 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
421 : importdecls { (reverse $1,[]) }
422 | importdecls ';' cvtopdecls { (reverse $1,$3) }
423 | cvtopdecls { ([],$1) }
425 cvtopdecls :: { [LHsDecl RdrName] }
426 : topdecls { cvTopDecls $1 }
428 -----------------------------------------------------------------------------
429 -- Module declaration & imports only
431 header :: { Located (HsModule RdrName) }
432 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
433 {% fileSrcSpan >>= \ loc ->
434 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
436 | missing_module_keyword importdecls
437 {% fileSrcSpan >>= \ loc ->
438 return (L loc (HsModule Nothing Nothing $2 [] Nothing
441 header_body :: { [LImportDecl RdrName] }
442 : '{' importdecls { $2 }
443 | vocurly importdecls { $2 }
445 -----------------------------------------------------------------------------
448 maybeexports :: { Maybe [LIE RdrName] }
449 : '(' exportlist ')' { Just $2 }
450 | {- empty -} { Nothing }
452 exportlist :: { [LIE RdrName] }
453 : expdoclist ',' expdoclist { $1 ++ $3 }
456 exportlist1 :: { [LIE RdrName] }
457 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
458 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
461 expdoclist :: { [LIE RdrName] }
462 : exp_doc expdoclist { $1 : $2 }
465 exp_doc :: { LIE RdrName }
466 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
467 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
468 | docnext { L1 (IEDoc (unLoc $1)) }
470 -- No longer allow things like [] and (,,,) to be exported
471 -- They are built in syntax, always available
472 export :: { LIE RdrName }
473 : qvar { L1 (IEVar (unLoc $1)) }
474 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
475 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
476 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
477 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
478 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
480 qcnames :: { [RdrName] }
481 : qcnames ',' qcname_ext { unLoc $3 : $1 }
482 | qcname_ext { [unLoc $1] }
484 qcname_ext :: { Located RdrName } -- Variable or data constructor
485 -- or tagged type constructor
487 | 'type' qcon { sL (comb2 $1 $2)
488 (setRdrNameSpace (unLoc $2)
491 -- Cannot pull into qcname_ext, as qcname is also used in expression.
492 qcname :: { Located RdrName } -- Variable or data constructor
496 -----------------------------------------------------------------------------
497 -- Import Declarations
499 -- import decls can be *empty*, or even just a string of semicolons
500 -- whereas topdecls must contain at least one topdecl.
502 importdecls :: { [LImportDecl RdrName] }
503 : importdecls ';' importdecl { $3 : $1 }
504 | importdecls ';' { $1 }
505 | importdecl { [ $1 ] }
508 importdecl :: { LImportDecl RdrName }
509 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
510 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
512 maybe_src :: { IsBootInterface }
513 : '{-# SOURCE' '#-}' { True }
514 | {- empty -} { False }
516 maybe_pkg :: { Maybe FastString }
517 : STRING { Just (getSTRING $1) }
518 | {- empty -} { Nothing }
520 optqualified :: { Bool }
521 : 'qualified' { True }
522 | {- empty -} { False }
524 maybeas :: { Located (Maybe ModuleName) }
525 : 'as' modid { LL (Just (unLoc $2)) }
526 | {- empty -} { noLoc Nothing }
528 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
529 : impspec { L1 (Just (unLoc $1)) }
530 | {- empty -} { noLoc Nothing }
532 impspec :: { Located (Bool, [LIE RdrName]) }
533 : '(' exportlist ')' { LL (False, $2) }
534 | 'hiding' '(' exportlist ')' { LL (True, $3) }
536 -----------------------------------------------------------------------------
537 -- Fixity Declarations
541 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
543 infix :: { Located FixityDirection }
544 : 'infix' { L1 InfixN }
545 | 'infixl' { L1 InfixL }
546 | 'infixr' { L1 InfixR }
548 ops :: { Located [Located RdrName] }
549 : ops ',' op { LL ($3 : unLoc $1) }
552 -----------------------------------------------------------------------------
553 -- Top-Level Declarations
555 topdecls :: { OrdList (LHsDecl RdrName) }
556 : topdecls ';' topdecl { $1 `appOL` $3 }
557 | topdecls ';' { $1 }
560 topdecl :: { OrdList (LHsDecl RdrName) }
561 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
562 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
563 | 'instance' inst_type where_inst
564 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
566 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
567 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
568 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
569 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
570 | '{-# DEPRECATED' deprecations '#-}' { $2 }
571 | '{-# WARNING' warnings '#-}' { $2 }
572 | '{-# RULES' rules '#-}' { $2 }
573 | annotation { unitOL $1 }
576 -- Template Haskell Extension
577 -- The $(..) form is one possible form of infixexp
578 -- but we treat an arbitrary expression just as if
579 -- it had a $(..) wrapped around it
580 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
584 cl_decl :: { LTyClDecl RdrName }
585 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
587 -- Type declarations (toplevel)
589 ty_decl :: { LTyClDecl RdrName }
590 -- ordinary type synonyms
591 : 'type' type '=' ctypedoc
592 -- Note ctype, not sigtype, on the right of '='
593 -- We allow an explicit for-all but we don't insert one
594 -- in type Foo a = (b,b)
595 -- Instead we just say b is out of scope
597 -- Note the use of type for the head; this allows
598 -- infix type constructors to be declared
599 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
601 -- type family declarations
602 | 'type' 'family' type opt_kind_sig
603 -- Note the use of type for the head; this allows
604 -- infix type constructors to be declared
605 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
607 -- type instance declarations
608 | 'type' 'instance' type '=' ctype
609 -- Note the use of type for the head; this allows
610 -- infix type constructors and type patterns
611 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
613 -- ordinary data type or newtype declaration
614 | data_or_newtype tycl_hdr constrs deriving
615 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
616 Nothing (reverse (unLoc $3)) (unLoc $4) }
617 -- We need the location on tycl_hdr in case
618 -- constrs and deriving are both empty
620 -- ordinary GADT declaration
621 | data_or_newtype tycl_hdr opt_kind_sig
624 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
625 (unLoc $3) (unLoc $4) (unLoc $5) }
626 -- We need the location on tycl_hdr in case
627 -- constrs and deriving are both empty
629 -- data/newtype family
630 | 'data' 'family' type opt_kind_sig
631 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
633 -- data/newtype instance declaration
634 | data_or_newtype 'instance' tycl_hdr constrs deriving
635 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
636 Nothing (reverse (unLoc $4)) (unLoc $5) }
638 -- GADT instance declaration
639 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
642 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
643 (unLoc $4) (unLoc $5) (unLoc $6) }
645 -- Associated type family declarations
647 -- * They have a different syntax than on the toplevel (no family special
650 -- * They also need to be separate from instances; otherwise, data family
651 -- declarations without a kind signature cause parsing conflicts with empty
652 -- data declarations.
654 at_decl_cls :: { LTyClDecl RdrName }
655 -- type family declarations
656 : 'type' type opt_kind_sig
657 -- Note the use of type for the head; this allows
658 -- infix type constructors to be declared
659 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
661 -- default type instance
662 | 'type' type '=' ctype
663 -- Note the use of type for the head; this allows
664 -- infix type constructors and type patterns
665 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
667 -- data/newtype family declaration
668 | 'data' type opt_kind_sig
669 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
671 -- Associated type instances
673 at_decl_inst :: { LTyClDecl RdrName }
674 -- type instance declarations
675 : 'type' type '=' ctype
676 -- Note the use of type for the head; this allows
677 -- infix type constructors and type patterns
678 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
680 -- data/newtype instance declaration
681 | data_or_newtype tycl_hdr constrs deriving
682 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
683 Nothing (reverse (unLoc $3)) (unLoc $4) }
685 -- GADT instance declaration
686 | data_or_newtype tycl_hdr opt_kind_sig
689 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
690 (unLoc $3) (unLoc $4) (unLoc $5) }
692 data_or_newtype :: { Located NewOrData }
693 : 'data' { L1 DataType }
694 | 'newtype' { L1 NewType }
696 opt_kind_sig :: { Located (Maybe Kind) }
698 | '::' kind { LL (Just (unLoc $2)) }
700 -- tycl_hdr parses the header of a class or data type decl,
701 -- which takes the form
704 -- (Eq a, Ord b) => T a b
705 -- T Int [a] -- for associated types
706 -- Rather a lot of inlining here, else we get reduce/reduce errors
707 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
708 : context '=>' type { LL (Just $1, $3) }
709 | type { L1 (Nothing, $1) }
711 -----------------------------------------------------------------------------
712 -- Stand-alone deriving
714 -- Glasgow extension: stand-alone deriving declarations
715 stand_alone_deriving :: { LDerivDecl RdrName }
716 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
718 -----------------------------------------------------------------------------
719 -- Nested declarations
721 -- Declaration in class bodies
723 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
724 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
727 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
728 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
729 | decls_cls ';' { LL (unLoc $1) }
731 | {- empty -} { noLoc nilOL }
735 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
736 : '{' decls_cls '}' { LL (unLoc $2) }
737 | vocurly decls_cls close { $2 }
741 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
742 -- No implicit parameters
743 -- May have type declarations
744 : 'where' decllist_cls { LL (unLoc $2) }
745 | {- empty -} { noLoc nilOL }
747 -- Declarations in instance bodies
749 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
750 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
753 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
754 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
755 | decls_inst ';' { LL (unLoc $1) }
757 | {- empty -} { noLoc nilOL }
760 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
761 : '{' decls_inst '}' { LL (unLoc $2) }
762 | vocurly decls_inst close { $2 }
766 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
767 -- No implicit parameters
768 -- May have type declarations
769 : 'where' decllist_inst { LL (unLoc $2) }
770 | {- empty -} { noLoc nilOL }
772 -- Declarations in binding groups other than classes and instances
774 decls :: { Located (OrdList (LHsDecl RdrName)) }
775 : decls ';' decl { let { this = unLoc $3;
777 these = rest `appOL` this }
778 in rest `seq` this `seq` these `seq`
780 | decls ';' { LL (unLoc $1) }
782 | {- empty -} { noLoc nilOL }
784 decllist :: { Located (OrdList (LHsDecl RdrName)) }
785 : '{' decls '}' { LL (unLoc $2) }
786 | vocurly decls close { $2 }
788 -- Binding groups other than those of class and instance declarations
790 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
791 -- No type declarations
792 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
793 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
794 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
796 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
797 -- No type declarations
798 : 'where' binds { LL (unLoc $2) }
799 | {- empty -} { noLoc emptyLocalBinds }
802 -----------------------------------------------------------------------------
803 -- Transformation Rules
805 rules :: { OrdList (LHsDecl RdrName) }
806 : rules ';' rule { $1 `snocOL` $3 }
809 | {- empty -} { nilOL }
811 rule :: { LHsDecl RdrName }
812 : STRING activation rule_forall infixexp '=' exp
813 { LL $ RuleD (HsRule (getSTRING $1)
814 ($2 `orElse` AlwaysActive)
815 $3 $4 placeHolderNames $6 placeHolderNames) }
817 activation :: { Maybe Activation }
818 : {- empty -} { Nothing }
819 | explicit_activation { Just $1 }
821 explicit_activation :: { Activation } -- In brackets
822 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
823 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
825 rule_forall :: { [RuleBndr RdrName] }
826 : 'forall' rule_var_list '.' { $2 }
829 rule_var_list :: { [RuleBndr RdrName] }
831 | rule_var rule_var_list { $1 : $2 }
833 rule_var :: { RuleBndr RdrName }
834 : varid { RuleBndr $1 }
835 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
837 -----------------------------------------------------------------------------
838 -- Warnings and deprecations (c.f. rules)
840 warnings :: { OrdList (LHsDecl RdrName) }
841 : warnings ';' warning { $1 `appOL` $3 }
842 | warnings ';' { $1 }
844 | {- empty -} { nilOL }
846 -- SUP: TEMPORARY HACK, not checking for `module Foo'
847 warning :: { OrdList (LHsDecl RdrName) }
849 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
852 deprecations :: { OrdList (LHsDecl RdrName) }
853 : deprecations ';' deprecation { $1 `appOL` $3 }
854 | deprecations ';' { $1 }
856 | {- empty -} { nilOL }
858 -- SUP: TEMPORARY HACK, not checking for `module Foo'
859 deprecation :: { OrdList (LHsDecl RdrName) }
861 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
864 strings :: { Located [FastString] }
865 : STRING { L1 [getSTRING $1] }
866 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
868 stringlist :: { Located (OrdList FastString) }
869 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
870 | STRING { LL (unitOL (getSTRING $1)) }
872 -----------------------------------------------------------------------------
874 annotation :: { LHsDecl RdrName }
875 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
876 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
877 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
880 -----------------------------------------------------------------------------
881 -- Foreign import and export declarations
883 fdecl :: { LHsDecl RdrName }
884 fdecl : 'import' callconv safety fspec
885 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
886 | 'import' callconv fspec
887 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
889 | 'export' callconv fspec
890 {% mkExport $2 (unLoc $3) >>= return.LL }
892 callconv :: { CCallConv }
893 : 'stdcall' { StdCallConv }
894 | 'ccall' { CCallConv }
895 | 'prim' { PrimCallConv}
898 : 'unsafe' { PlayRisky }
899 | 'safe' { PlaySafe False }
900 | 'interruptible' { PlayInterruptible }
901 | 'threadsafe' { PlaySafe True } -- deprecated alias
903 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
904 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
905 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
906 -- if the entity string is missing, it defaults to the empty string;
907 -- the meaning of an empty entity string depends on the calling
910 -----------------------------------------------------------------------------
913 opt_sig :: { Maybe (LHsType RdrName) }
914 : {- empty -} { Nothing }
915 | '::' sigtype { Just $2 }
917 opt_asig :: { Maybe (LHsType RdrName) }
918 : {- empty -} { Nothing }
919 | '::' atype { Just $2 }
921 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
922 -- to tell the renamer where to generalise
923 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
924 -- Wrap an Implicit forall if there isn't one there already
926 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
927 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
928 -- Wrap an Implicit forall if there isn't one there already
930 sig_vars :: { Located [Located RdrName] }
931 : sig_vars ',' var { LL ($3 : unLoc $1) }
934 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
936 | sigtype ',' sigtypes1 { $1 : $3 }
938 -----------------------------------------------------------------------------
941 infixtype :: { LHsType RdrName }
942 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
943 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
945 strict_mark :: { Located HsBang }
946 : '!' { L1 HsStrict }
947 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
949 -- A ctype is a for-all type
950 ctype :: { LHsType RdrName }
951 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
952 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
953 -- A type of form (context => type) is an *implicit* HsForAllTy
954 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
957 ----------------------
958 -- Notes for 'ctypedoc'
959 -- It would have been nice to simplify the grammar by unifying `ctype` and
960 -- ctypedoc` into one production, allowing comments on types everywhere (and
961 -- rejecting them after parsing, where necessary). This is however not possible
962 -- since it leads to ambiguity. The reason is the support for comments on record
964 -- data R = R { field :: Int -- ^ comment on the field }
965 -- If we allow comments on types here, it's not clear if the comment applies
966 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
968 ctypedoc :: { LHsType RdrName }
969 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
970 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
971 -- A type of form (context => type) is an *implicit* HsForAllTy
972 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
975 ----------------------
976 -- Notes for 'context'
977 -- We parse a context as a btype so that we don't get reduce/reduce
978 -- errors in ctype. The basic problem is that
980 -- looks so much like a tuple type. We can't tell until we find the =>
982 -- We have the t1 ~ t2 form both in 'context' and in type,
983 -- to permit an individual equational constraint without parenthesis.
984 -- Thus for some reason we allow f :: a~b => blah
985 -- but not f :: ?x::Int => blah
986 context :: { LHsContext RdrName }
987 : btype '~' btype {% checkContext
988 (LL $ HsPredTy (HsEqualP $1 $3)) }
989 | btype {% checkContext $1 }
991 type :: { LHsType RdrName }
993 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
994 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
995 | btype '->' ctype { LL $ HsFunTy $1 $3 }
996 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
998 typedoc :: { LHsType RdrName }
1000 | btype docprev { LL $ HsDocTy $1 $2 }
1001 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1002 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1003 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1004 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1005 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1006 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1007 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1009 btype :: { LHsType RdrName }
1010 : btype atype { LL $ HsAppTy $1 $2 }
1013 atype :: { LHsType RdrName }
1014 : gtycon { L1 (HsTyVar (unLoc $1)) }
1015 | tyvar { L1 (HsTyVar (unLoc $1)) }
1016 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1017 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1018 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1019 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1020 | '[' ctype ']' { LL $ HsListTy $2 }
1021 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1022 | '(' ctype ')' { LL $ HsParTy $2 }
1023 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1024 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1025 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1026 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1027 mkUnqual varName (getTH_ID_SPLICE $1) }
1029 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1031 -- An inst_type is what occurs in the head of an instance decl
1032 -- e.g. (Foo a, Gaz b) => Wibble a b
1033 -- It's kept as a single type, with a MonoDictTy at the right
1034 -- hand corner, for convenience.
1035 inst_type :: { LHsType RdrName }
1036 : sigtype {% checkInstType $1 }
1038 inst_types1 :: { [LHsType RdrName] }
1039 : inst_type { [$1] }
1040 | inst_type ',' inst_types1 { $1 : $3 }
1042 comma_types0 :: { [LHsType RdrName] }
1043 : comma_types1 { $1 }
1044 | {- empty -} { [] }
1046 comma_types1 :: { [LHsType RdrName] }
1048 | ctype ',' comma_types1 { $1 : $3 }
1050 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1051 : tv_bndr tv_bndrs { $1 : $2 }
1052 | {- empty -} { [] }
1054 tv_bndr :: { LHsTyVarBndr RdrName }
1055 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1056 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1059 fds :: { Located [Located (FunDep RdrName)] }
1060 : {- empty -} { noLoc [] }
1061 | '|' fds1 { LL (reverse (unLoc $2)) }
1063 fds1 :: { Located [Located (FunDep RdrName)] }
1064 : fds1 ',' fd { LL ($3 : unLoc $1) }
1067 fd :: { Located (FunDep RdrName) }
1068 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1069 (reverse (unLoc $1), reverse (unLoc $3)) }
1071 varids0 :: { Located [RdrName] }
1072 : {- empty -} { noLoc [] }
1073 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1075 -----------------------------------------------------------------------------
1078 kind :: { Located Kind }
1080 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1082 akind :: { Located Kind }
1083 : '*' { L1 liftedTypeKind }
1084 | '!' { L1 unliftedTypeKind }
1085 | '(' kind ')' { LL (unLoc $2) }
1088 -----------------------------------------------------------------------------
1089 -- Datatype declarations
1091 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1092 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1093 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1094 | {- empty -} { noLoc [] }
1096 gadt_constrs :: { Located [LConDecl RdrName] }
1097 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1098 | gadt_constr { L (getLoc (head $1)) $1 }
1099 | {- empty -} { noLoc [] }
1101 -- We allow the following forms:
1102 -- C :: Eq a => a -> T a
1103 -- C :: forall a. Eq a => !a -> T a
1104 -- D { x,y :: a } :: T a
1105 -- forall a. Eq a => D { x,y :: a } :: T a
1107 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1108 : con_list '::' sigtype
1109 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1111 -- Deprecated syntax for GADT record declarations
1112 | oqtycon '{' fielddecls '}' '::' sigtype
1113 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1116 constrs :: { Located [LConDecl RdrName] }
1117 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1119 constrs1 :: { Located [LConDecl RdrName] }
1120 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1121 | constr { L1 [$1] }
1123 constr :: { LConDecl RdrName }
1124 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1125 { let (con,details) = unLoc $5 in
1126 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1128 | maybe_docnext forall constr_stuff maybe_docprev
1129 { let (con,details) = unLoc $3 in
1130 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1133 forall :: { Located [LHsTyVarBndr RdrName] }
1134 : 'forall' tv_bndrs '.' { LL $2 }
1135 | {- empty -} { noLoc [] }
1137 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1138 -- We parse the constructor declaration
1140 -- as a btype (treating C as a type constructor) and then convert C to be
1141 -- a data constructor. Reason: it might continue like this:
1143 -- in which case C really would be a type constructor. We can't resolve this
1144 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1145 : btype {% splitCon $1 >>= return.LL }
1146 | btype conop btype { LL ($2, InfixCon $1 $3) }
1148 fielddecls :: { [ConDeclField RdrName] }
1149 : {- empty -} { [] }
1150 | fielddecls1 { $1 }
1152 fielddecls1 :: { [ConDeclField RdrName] }
1153 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1154 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1155 -- This adds the doc $4 to each field separately
1158 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1159 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1160 | fld <- reverse (unLoc $2) ] }
1162 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1163 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1164 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1165 -- We don't allow a context, but that's sorted out by the type checker.
1166 deriving :: { Located (Maybe [LHsType RdrName]) }
1167 : {- empty -} { noLoc Nothing }
1168 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1169 ; p <- checkInstType (L loc (HsTyVar tv))
1170 ; return (LL (Just [p])) } }
1171 | 'deriving' '(' ')' { LL (Just []) }
1172 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1173 -- Glasgow extension: allow partial
1174 -- applications in derivings
1176 -----------------------------------------------------------------------------
1177 -- Value definitions
1179 {- Note [Declaration/signature overlap]
1180 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1181 There's an awkward overlap with a type signature. Consider
1182 f :: Int -> Int = ...rhs...
1183 Then we can't tell whether it's a type signature or a value
1184 definition with a result signature until we see the '='.
1185 So we have to inline enough to postpone reductions until we know.
1189 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1190 instead of qvar, we get another shift/reduce-conflict. Consider the
1193 { (^^) :: Int->Int ; } Type signature; only var allowed
1195 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1196 qvar allowed (because of instance decls)
1198 We can't tell whether to reduce var to qvar until after we've read the signatures.
1201 docdecl :: { LHsDecl RdrName }
1202 : docdecld { L1 (DocD (unLoc $1)) }
1204 docdecld :: { LDocDecl }
1205 : docnext { L1 (DocCommentNext (unLoc $1)) }
1206 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1207 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1208 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1210 decl :: { Located (OrdList (LHsDecl RdrName)) }
1212 | '!' aexp rhs {% do { pat <- checkPattern $2;
1213 return (LL $ unitOL $ LL $ ValD (
1214 PatBind (LL $ BangPat pat) (unLoc $3)
1215 placeHolderType placeHolderNames)) } }
1216 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1217 let { l = comb2 $1 $> };
1218 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1219 | docdecl { LL $ unitOL $1 }
1221 rhs :: { Located (GRHSs RdrName) }
1222 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1223 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1225 gdrhs :: { Located [LGRHS RdrName] }
1226 : gdrhs gdrh { LL ($2 : unLoc $1) }
1229 gdrh :: { LGRHS RdrName }
1230 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1232 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1233 : infixexp '::' sigtypedoc {% do s <- checkValSig $1 $3
1234 ; return (LL $ unitOL (LL $ SigD s)) }
1235 -- See Note [Declaration/signature overlap] for why we need infixexp here
1236 | var ',' sig_vars '::' sigtypedoc
1237 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1238 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1240 | '{-# INLINE' activation qvar '#-}'
1241 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma (getINLINE $1) $2))) }
1242 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1243 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1245 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1246 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma (getSPEC_INLINE $1) $2))
1248 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1249 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1251 -----------------------------------------------------------------------------
1254 quasiquote :: { Located (HsQuasiQuote RdrName) }
1255 : TH_QUASIQUOTE { let { loc = getLoc $1
1256 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1257 ; quoterId = mkUnqual varName quoter }
1258 in L1 (mkHsQuasiQuote quoterId quoteSpan quote) }
1260 exp :: { LHsExpr RdrName }
1261 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1262 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1263 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1264 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1265 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1268 infixexp :: { LHsExpr RdrName }
1270 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1272 exp10 :: { LHsExpr RdrName }
1273 : '\\' apat apats opt_asig '->' exp
1274 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1277 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1278 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1279 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1280 return (LL $ HsIf $2 $5 $8) }
1281 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1282 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1284 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1285 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1286 return (L loc (mkHsDo DoExpr stmts body)) }
1287 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1288 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1289 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1290 | scc_annot exp { LL $ if opt_SccProfilingOn
1291 then HsSCC (unLoc $1) $2
1293 | hpc_annot exp { LL $ if opt_Hpc
1294 then HsTickPragma (unLoc $1) $2
1297 | 'proc' aexp '->' exp
1298 {% checkPattern $2 >>= \ p ->
1299 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1300 placeHolderType undefined)) }
1301 -- TODO: is LL right here?
1303 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1304 -- hdaume: core annotation
1309 | {- empty -} { False }
1311 scc_annot :: { Located FastString }
1312 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1313 ( do scc <- getSCC $2; return $ LL scc ) }
1314 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1316 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1317 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1318 { LL $ (getSTRING $2
1319 ,( fromInteger $ getINTEGER $3
1320 , fromInteger $ getINTEGER $5
1322 ,( fromInteger $ getINTEGER $7
1323 , fromInteger $ getINTEGER $9
1328 fexp :: { LHsExpr RdrName }
1329 : fexp aexp { LL $ HsApp $1 $2 }
1332 aexp :: { LHsExpr RdrName }
1333 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1334 | '~' aexp { LL $ ELazyPat $2 }
1337 aexp1 :: { LHsExpr RdrName }
1338 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1342 -- Here was the syntax for type applications that I was planning
1343 -- but there are difficulties (e.g. what order for type args)
1344 -- so it's not enabled yet.
1345 -- But this case *is* used for the left hand side of a generic definition,
1346 -- which is parsed as an expression before being munged into a pattern
1347 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1348 (sL (getLoc $3) (HsType $3)) }
1350 aexp2 :: { LHsExpr RdrName }
1351 : ipvar { L1 (HsIPVar $! unLoc $1) }
1352 | qcname { L1 (HsVar $! unLoc $1) }
1353 | literal { L1 (HsLit $! unLoc $1) }
1354 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1355 -- into HsOverLit when -foverloaded-strings is on.
1356 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1357 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1358 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1360 -- N.B.: sections get parsed by these next two productions.
1361 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
1362 -- (you'd have to write '((+ 3), (4 -))')
1363 -- but the less cluttered version fell out of having texps.
1364 | '(' texp ')' { LL (HsPar $2) }
1365 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1367 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1368 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1370 | '[' list ']' { LL (unLoc $2) }
1371 | '[:' parr ':]' { LL (unLoc $2) }
1372 | '_' { L1 EWildPat }
1374 -- Template Haskell Extension
1375 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1376 (L1 $ HsVar (mkUnqual varName
1377 (getTH_ID_SPLICE $1)))) }
1378 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1381 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1382 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1383 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1384 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1385 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1386 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1387 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1388 return (LL $ HsBracket (PatBr p)) }
1389 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1390 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1392 -- arrow notation extension
1393 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1395 cmdargs :: { [LHsCmdTop RdrName] }
1396 : cmdargs acmd { $2 : $1 }
1397 | {- empty -} { [] }
1399 acmd :: { LHsCmdTop RdrName }
1400 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1402 cvtopbody :: { [LHsDecl RdrName] }
1403 : '{' cvtopdecls0 '}' { $2 }
1404 | vocurly cvtopdecls0 close { $2 }
1406 cvtopdecls0 :: { [LHsDecl RdrName] }
1407 : {- empty -} { [] }
1410 -----------------------------------------------------------------------------
1411 -- Tuple expressions
1413 -- "texp" is short for tuple expressions:
1414 -- things that can appear unparenthesized as long as they're
1415 -- inside parens or delimitted by commas
1416 texp :: { LHsExpr RdrName }
1419 -- Note [Parsing sections]
1420 -- ~~~~~~~~~~~~~~~~~~~~~~~
1421 -- We include left and right sections here, which isn't
1422 -- technically right according to Haskell 98. For example
1423 -- (3 +, True) isn't legal
1424 -- However, we want to parse bang patterns like
1426 -- and it's convenient to do so here as a section
1427 -- Then when converting expr to pattern we unravel it again
1428 -- Meanwhile, the renamer checks that real sections appear
1430 | infixexp qop { LL $ SectionL $1 $2 }
1431 | qopm infixexp { LL $ SectionR $1 $2 }
1433 -- View patterns get parenthesized above
1434 | exp '->' texp { LL $ EViewPat $1 $3 }
1436 -- Always at least one comma
1437 tup_exprs :: { [HsTupArg RdrName] }
1438 : texp commas_tup_tail { Present $1 : $2 }
1439 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1441 -- Always starts with commas; always follows an expr
1442 commas_tup_tail :: { [HsTupArg RdrName] }
1443 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1445 -- Always follows a comma
1446 tup_tail :: { [HsTupArg RdrName] }
1447 : texp commas_tup_tail { Present $1 : $2 }
1448 | texp { [Present $1] }
1449 | {- empty -} { [missingTupArg] }
1451 -----------------------------------------------------------------------------
1454 -- The rules below are little bit contorted to keep lexps left-recursive while
1455 -- avoiding another shift/reduce-conflict.
1457 list :: { LHsExpr RdrName }
1458 : texp { L1 $ ExplicitList placeHolderType [$1] }
1459 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1460 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1461 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1462 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1463 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1464 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1466 lexps :: { Located [LHsExpr RdrName] }
1467 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1468 | texp ',' texp { LL [$3,$1] }
1470 -----------------------------------------------------------------------------
1471 -- List Comprehensions
1473 flattenedpquals :: { Located [LStmt RdrName] }
1474 : pquals { case (unLoc $1) of
1476 -- We just had one thing in our "parallel" list so
1477 -- we simply return that thing directly
1479 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1480 -- We actually found some actual parallel lists so
1481 -- we wrap them into as a ParStmt
1484 pquals :: { Located [[LStmt RdrName]] }
1485 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1486 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1488 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1489 -- one can "grab" the earlier ones
1490 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1491 | squals ',' qual { LL ($3 : unLoc $1) }
1492 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1494 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1495 -- | '{|' pquals '|}' { L1 [$2] }
1498 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1499 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1500 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1501 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1503 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1504 -- Function is applied to a list of stmts *in order*
1505 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1507 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1508 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1510 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1511 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1512 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1513 -- choosing the "group by" variant, which is what we want.
1515 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1516 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1517 -- if /that/ is the group function we conflict with.
1518 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1519 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1521 -----------------------------------------------------------------------------
1522 -- Parallel array expressions
1524 -- The rules below are little bit contorted; see the list case for details.
1525 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1526 -- Moreover, we allow explicit arrays with no element (represented by the nil
1527 -- constructor in the list case).
1529 parr :: { LHsExpr RdrName }
1530 : { noLoc (ExplicitPArr placeHolderType []) }
1531 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1532 | lexps { L1 $ ExplicitPArr placeHolderType
1533 (reverse (unLoc $1)) }
1534 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1535 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1536 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1538 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1540 -----------------------------------------------------------------------------
1543 guardquals :: { Located [LStmt RdrName] }
1544 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1546 guardquals1 :: { Located [LStmt RdrName] }
1547 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1550 -----------------------------------------------------------------------------
1551 -- Case alternatives
1553 altslist :: { Located [LMatch RdrName] }
1554 : '{' alts '}' { LL (reverse (unLoc $2)) }
1555 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1557 alts :: { Located [LMatch RdrName] }
1558 : alts1 { L1 (unLoc $1) }
1559 | ';' alts { LL (unLoc $2) }
1561 alts1 :: { Located [LMatch RdrName] }
1562 : alts1 ';' alt { LL ($3 : unLoc $1) }
1563 | alts1 ';' { LL (unLoc $1) }
1566 alt :: { LMatch RdrName }
1567 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1569 alt_rhs :: { Located (GRHSs RdrName) }
1570 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1572 ralt :: { Located [LGRHS RdrName] }
1573 : '->' exp { LL (unguardedRHS $2) }
1574 | gdpats { L1 (reverse (unLoc $1)) }
1576 gdpats :: { Located [LGRHS RdrName] }
1577 : gdpats gdpat { LL ($2 : unLoc $1) }
1580 gdpat :: { LGRHS RdrName }
1581 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1583 -- 'pat' recognises a pattern, including one with a bang at the top
1584 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1585 -- Bangs inside are parsed as infix operator applications, so that
1586 -- we parse them right when bang-patterns are off
1587 pat :: { LPat RdrName }
1588 pat : exp {% checkPattern $1 }
1589 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1591 apat :: { LPat RdrName }
1592 apat : aexp {% checkPattern $1 }
1593 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1595 apats :: { [LPat RdrName] }
1596 : apat apats { $1 : $2 }
1597 | {- empty -} { [] }
1599 -----------------------------------------------------------------------------
1600 -- Statement sequences
1602 stmtlist :: { Located [LStmt RdrName] }
1603 : '{' stmts '}' { LL (unLoc $2) }
1604 | vocurly stmts close { $2 }
1606 -- do { ;; s ; s ; ; s ;; }
1607 -- The last Stmt should be an expression, but that's hard to enforce
1608 -- here, because we need too much lookahead if we see do { e ; }
1609 -- So we use ExprStmts throughout, and switch the last one over
1610 -- in ParseUtils.checkDo instead
1611 stmts :: { Located [LStmt RdrName] }
1612 : stmt stmts_help { LL ($1 : unLoc $2) }
1613 | ';' stmts { LL (unLoc $2) }
1614 | {- empty -} { noLoc [] }
1616 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1617 : ';' stmts { LL (unLoc $2) }
1618 | {- empty -} { noLoc [] }
1620 -- For typing stmts at the GHCi prompt, where
1621 -- the input may consist of just comments.
1622 maybe_stmt :: { Maybe (LStmt RdrName) }
1624 | {- nothing -} { Nothing }
1626 stmt :: { LStmt RdrName }
1628 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1630 qual :: { LStmt RdrName }
1631 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1632 | exp { L1 $ mkExprStmt $1 }
1633 | 'let' binds { LL $ LetStmt (unLoc $2) }
1635 -----------------------------------------------------------------------------
1636 -- Record Field Update/Construction
1638 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1640 | {- empty -} { ([], False) }
1642 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1643 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1644 | fbind { ([$1], False) }
1645 | '..' { ([], True) }
1647 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1648 : qvar '=' exp { HsRecField $1 $3 False }
1649 | qvar { HsRecField $1 placeHolderPunRhs True }
1650 -- In the punning case, use a place-holder
1651 -- The renamer fills in the final value
1653 -----------------------------------------------------------------------------
1654 -- Implicit Parameter Bindings
1656 dbinds :: { Located [LIPBind RdrName] }
1657 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1658 in rest `seq` this `seq` LL (this : rest) }
1659 | dbinds ';' { LL (unLoc $1) }
1660 | dbind { let this = $1 in this `seq` L1 [this] }
1661 -- | {- empty -} { [] }
1663 dbind :: { LIPBind RdrName }
1664 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1666 ipvar :: { Located (IPName RdrName) }
1667 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1669 -----------------------------------------------------------------------------
1670 -- Warnings and deprecations
1672 namelist :: { Located [RdrName] }
1673 namelist : name_var { L1 [unLoc $1] }
1674 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1676 name_var :: { Located RdrName }
1677 name_var : var { $1 }
1680 -----------------------------------------
1681 -- Data constructors
1682 qcon :: { Located RdrName }
1684 | '(' qconsym ')' { LL (unLoc $2) }
1685 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1686 -- The case of '[:' ':]' is part of the production `parr'
1688 con :: { Located RdrName }
1690 | '(' consym ')' { LL (unLoc $2) }
1691 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1693 con_list :: { Located [Located RdrName] }
1694 con_list : con { L1 [$1] }
1695 | con ',' con_list { LL ($1 : unLoc $3) }
1697 sysdcon :: { Located DataCon } -- Wired in data constructors
1698 : '(' ')' { LL unitDataCon }
1699 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1700 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1701 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1702 | '[' ']' { LL nilDataCon }
1704 conop :: { Located RdrName }
1706 | '`' conid '`' { LL (unLoc $2) }
1708 qconop :: { Located RdrName }
1710 | '`' qconid '`' { LL (unLoc $2) }
1712 -----------------------------------------------------------------------------
1713 -- Type constructors
1715 gtycon :: { Located RdrName } -- A "general" qualified tycon
1717 | '(' ')' { LL $ getRdrName unitTyCon }
1718 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1719 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1720 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1721 | '(' '->' ')' { LL $ getRdrName funTyCon }
1722 | '[' ']' { LL $ listTyCon_RDR }
1723 | '[:' ':]' { LL $ parrTyCon_RDR }
1725 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1727 | '(' qtyconsym ')' { LL (unLoc $2) }
1729 qtyconop :: { Located RdrName } -- Qualified or unqualified
1731 | '`' qtycon '`' { LL (unLoc $2) }
1733 qtycon :: { Located RdrName } -- Qualified or unqualified
1734 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1735 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1738 tycon :: { Located RdrName } -- Unqualified
1739 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1741 qtyconsym :: { Located RdrName }
1742 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1745 tyconsym :: { Located RdrName }
1746 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1748 -----------------------------------------------------------------------------
1751 op :: { Located RdrName } -- used in infix decls
1755 varop :: { Located RdrName }
1757 | '`' varid '`' { LL (unLoc $2) }
1759 qop :: { LHsExpr RdrName } -- used in sections
1760 : qvarop { L1 $ HsVar (unLoc $1) }
1761 | qconop { L1 $ HsVar (unLoc $1) }
1763 qopm :: { LHsExpr RdrName } -- used in sections
1764 : qvaropm { L1 $ HsVar (unLoc $1) }
1765 | qconop { L1 $ HsVar (unLoc $1) }
1767 qvarop :: { Located RdrName }
1769 | '`' qvarid '`' { LL (unLoc $2) }
1771 qvaropm :: { Located RdrName }
1772 : qvarsym_no_minus { $1 }
1773 | '`' qvarid '`' { LL (unLoc $2) }
1775 -----------------------------------------------------------------------------
1778 tyvar :: { Located RdrName }
1779 tyvar : tyvarid { $1 }
1780 | '(' tyvarsym ')' { LL (unLoc $2) }
1782 tyvarop :: { Located RdrName }
1783 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1785 | '.' {% parseErrorSDoc (getLoc $1)
1786 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1787 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1788 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1791 tyvarid :: { Located RdrName }
1792 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1793 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1794 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1795 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1796 | 'interruptible' { L1 $! mkUnqual tvName (fsLit "interruptible") }
1797 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1799 tyvarsym :: { Located RdrName }
1800 -- Does not include "!", because that is used for strictness marks
1801 -- or ".", because that separates the quantified type vars from the rest
1802 -- or "*", because that's used for kinds
1803 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1805 -----------------------------------------------------------------------------
1808 var :: { Located RdrName }
1810 | '(' varsym ')' { LL (unLoc $2) }
1812 qvar :: { Located RdrName }
1814 | '(' varsym ')' { LL (unLoc $2) }
1815 | '(' qvarsym1 ')' { LL (unLoc $2) }
1816 -- We've inlined qvarsym here so that the decision about
1817 -- whether it's a qvar or a var can be postponed until
1818 -- *after* we see the close paren.
1820 qvarid :: { Located RdrName }
1822 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1823 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1825 varid :: { Located RdrName }
1826 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1827 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1828 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1829 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1830 | 'interruptible' { L1 $! mkUnqual varName (fsLit "interruptible") }
1831 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1832 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1833 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1835 qvarsym :: { Located RdrName }
1839 qvarsym_no_minus :: { Located RdrName }
1840 : varsym_no_minus { $1 }
1843 qvarsym1 :: { Located RdrName }
1844 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1846 varsym :: { Located RdrName }
1847 : varsym_no_minus { $1 }
1848 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1850 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1851 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1852 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1855 -- These special_ids are treated as keywords in various places,
1856 -- but as ordinary ids elsewhere. 'special_id' collects all these
1857 -- except 'unsafe', 'interruptible', 'forall', and 'family' whose treatment differs
1858 -- depending on context
1859 special_id :: { Located FastString }
1861 : 'as' { L1 (fsLit "as") }
1862 | 'qualified' { L1 (fsLit "qualified") }
1863 | 'hiding' { L1 (fsLit "hiding") }
1864 | 'export' { L1 (fsLit "export") }
1865 | 'label' { L1 (fsLit "label") }
1866 | 'dynamic' { L1 (fsLit "dynamic") }
1867 | 'stdcall' { L1 (fsLit "stdcall") }
1868 | 'ccall' { L1 (fsLit "ccall") }
1869 | 'prim' { L1 (fsLit "prim") }
1870 | 'group' { L1 (fsLit "group") }
1872 special_sym :: { Located FastString }
1873 special_sym : '!' { L1 (fsLit "!") }
1874 | '.' { L1 (fsLit ".") }
1875 | '*' { L1 (fsLit "*") }
1877 -----------------------------------------------------------------------------
1878 -- Data constructors
1880 qconid :: { Located RdrName } -- Qualified or unqualified
1882 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1883 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1885 conid :: { Located RdrName }
1886 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1888 qconsym :: { Located RdrName } -- Qualified or unqualified
1890 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1892 consym :: { Located RdrName }
1893 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1895 -- ':' means only list cons
1896 | ':' { L1 $ consDataCon_RDR }
1899 -----------------------------------------------------------------------------
1902 literal :: { Located HsLit }
1903 : CHAR { L1 $ HsChar $ getCHAR $1 }
1904 | STRING { L1 $ HsString $ getSTRING $1 }
1905 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1906 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1907 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1908 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1909 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1910 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1912 -----------------------------------------------------------------------------
1916 : vccurly { () } -- context popped in lexer.
1917 | error {% popContext }
1919 -----------------------------------------------------------------------------
1920 -- Miscellaneous (mostly renamings)
1922 modid :: { Located ModuleName }
1923 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1924 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1927 (unpackFS mod ++ '.':unpackFS c))
1931 : commas ',' { $1 + 1 }
1934 -----------------------------------------------------------------------------
1935 -- Documentation comments
1937 docnext :: { LHsDocString }
1938 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1940 docprev :: { LHsDocString }
1941 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1943 docnamed :: { Located (String, HsDocString) }
1945 let string = getDOCNAMED $1
1946 (name, rest) = break isSpace string
1947 in return (L1 (name, HsDocString (mkFastString rest))) }
1949 docsection :: { Located (Int, HsDocString) }
1950 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1951 return (L1 (n, HsDocString (mkFastString doc))) }
1953 moduleheader :: { Maybe LHsDocString }
1954 : DOCNEXT {% let string = getDOCNEXT $1 in
1955 return (Just (L1 (HsDocString (mkFastString string)))) }
1957 maybe_docprev :: { Maybe LHsDocString }
1958 : docprev { Just $1 }
1959 | {- empty -} { Nothing }
1961 maybe_docnext :: { Maybe LHsDocString }
1962 : docnext { Just $1 }
1963 | {- empty -} { Nothing }
1967 happyError = srcParseFail
1969 getVARID (L _ (ITvarid x)) = x
1970 getCONID (L _ (ITconid x)) = x
1971 getVARSYM (L _ (ITvarsym x)) = x
1972 getCONSYM (L _ (ITconsym x)) = x
1973 getQVARID (L _ (ITqvarid x)) = x
1974 getQCONID (L _ (ITqconid x)) = x
1975 getQVARSYM (L _ (ITqvarsym x)) = x
1976 getQCONSYM (L _ (ITqconsym x)) = x
1977 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1978 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1979 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1980 getCHAR (L _ (ITchar x)) = x
1981 getSTRING (L _ (ITstring x)) = x
1982 getINTEGER (L _ (ITinteger x)) = x
1983 getRATIONAL (L _ (ITrational x)) = x
1984 getPRIMCHAR (L _ (ITprimchar x)) = x
1985 getPRIMSTRING (L _ (ITprimstring x)) = x
1986 getPRIMINTEGER (L _ (ITprimint x)) = x
1987 getPRIMWORD (L _ (ITprimword x)) = x
1988 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1989 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1990 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1991 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
1992 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
1993 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
1995 getDOCNEXT (L _ (ITdocCommentNext x)) = x
1996 getDOCPREV (L _ (ITdocCommentPrev x)) = x
1997 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
1998 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2000 getSCC :: Located Token -> P FastString
2001 getSCC lt = do let s = getSTRING lt
2002 err = "Spaces are not allowed in SCCs"
2003 -- We probably actually want to be more restrictive than this
2004 if ' ' `elem` unpackFS s
2005 then failSpanMsgP (getLoc lt) (text err)
2008 -- Utilities for combining source spans
2009 comb2 :: Located a -> Located b -> SrcSpan
2010 comb2 a b = a `seq` b `seq` combineLocs a b
2012 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2013 comb3 a b c = a `seq` b `seq` c `seq`
2014 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2016 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2017 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2018 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2019 combineSrcSpans (getLoc c) (getLoc d))
2021 -- strict constructor version:
2023 sL :: SrcSpan -> a -> Located a
2024 sL span a = span `seq` a `seq` L span a
2026 -- Make a source location for the file. We're a bit lazy here and just
2027 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2028 -- try to find the span of the whole file (ToDo).
2029 fileSrcSpan :: P SrcSpan
2032 let loc = mkSrcLoc (srcLocFile l) 1 1;
2033 return (mkSrcSpan loc loc)