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 'unsafe' { L _ ITunsafe }
253 'family' { L _ ITfamily }
254 'stdcall' { L _ ITstdcallconv }
255 'ccall' { L _ ITccallconv }
256 'prim' { L _ ITprimcallconv }
257 'proc' { L _ ITproc } -- for arrow notation extension
258 'rec' { L _ ITrec } -- for arrow notation extension
259 'group' { L _ ITgroup } -- for list transform extension
260 'by' { L _ ITby } -- for list transform extension
261 'using' { L _ ITusing } -- for list transform extension
263 '{-# INLINE' { L _ (ITinline_prag _ _) }
264 '{-# SPECIALISE' { L _ ITspec_prag }
265 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
266 '{-# SOURCE' { L _ ITsource_prag }
267 '{-# RULES' { L _ ITrules_prag }
268 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
269 '{-# SCC' { L _ ITscc_prag }
270 '{-# GENERATED' { L _ ITgenerated_prag }
271 '{-# DEPRECATED' { L _ ITdeprecated_prag }
272 '{-# WARNING' { L _ ITwarning_prag }
273 '{-# UNPACK' { L _ ITunpack_prag }
274 '{-# ANN' { L _ ITann_prag }
275 '#-}' { L _ ITclose_prag }
277 '..' { L _ ITdotdot } -- reserved symbols
279 '::' { L _ ITdcolon }
283 '<-' { L _ ITlarrow }
284 '->' { L _ ITrarrow }
287 '=>' { L _ ITdarrow }
291 '-<' { L _ ITlarrowtail } -- for arrow notation
292 '>-' { L _ ITrarrowtail } -- for arrow notation
293 '-<<' { L _ ITLarrowtail } -- for arrow notation
294 '>>-' { L _ ITRarrowtail } -- for arrow notation
297 '{' { L _ ITocurly } -- special symbols
299 '{|' { L _ ITocurlybar }
300 '|}' { L _ ITccurlybar }
301 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
302 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
305 '[:' { L _ ITopabrack }
306 ':]' { L _ ITcpabrack }
309 '(#' { L _ IToubxparen }
310 '#)' { L _ ITcubxparen }
311 '(|' { L _ IToparenbar }
312 '|)' { L _ ITcparenbar }
315 '`' { L _ ITbackquote }
317 VARID { L _ (ITvarid _) } -- identifiers
318 CONID { L _ (ITconid _) }
319 VARSYM { L _ (ITvarsym _) }
320 CONSYM { L _ (ITconsym _) }
321 QVARID { L _ (ITqvarid _) }
322 QCONID { L _ (ITqconid _) }
323 QVARSYM { L _ (ITqvarsym _) }
324 QCONSYM { L _ (ITqconsym _) }
325 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
326 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
328 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
330 CHAR { L _ (ITchar _) }
331 STRING { L _ (ITstring _) }
332 INTEGER { L _ (ITinteger _) }
333 RATIONAL { L _ (ITrational _) }
335 PRIMCHAR { L _ (ITprimchar _) }
336 PRIMSTRING { L _ (ITprimstring _) }
337 PRIMINTEGER { L _ (ITprimint _) }
338 PRIMWORD { L _ (ITprimword _) }
339 PRIMFLOAT { L _ (ITprimfloat _) }
340 PRIMDOUBLE { L _ (ITprimdouble _) }
342 DOCNEXT { L _ (ITdocCommentNext _) }
343 DOCPREV { L _ (ITdocCommentPrev _) }
344 DOCNAMED { L _ (ITdocCommentNamed _) }
345 DOCSECTION { L _ (ITdocSection _ _) }
348 '[|' { L _ ITopenExpQuote }
349 '[p|' { L _ ITopenPatQuote }
350 '[t|' { L _ ITopenTypQuote }
351 '[d|' { L _ ITopenDecQuote }
352 '|]' { L _ ITcloseQuote }
353 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
354 '$(' { L _ ITparenEscape } -- $( exp )
355 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
356 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
357 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
359 %monad { P } { >>= } { return }
360 %lexer { lexer } { L _ ITeof }
361 %name parseModule module
362 %name parseStmt maybe_stmt
363 %name parseIdentifier identifier
364 %name parseType ctype
365 %partial parseHeader header
366 %tokentype { (Located Token) }
369 -----------------------------------------------------------------------------
370 -- Identifiers; one of the entry points
371 identifier :: { Located RdrName }
376 | '(' '->' ')' { LL $ getRdrName funTyCon }
378 -----------------------------------------------------------------------------
381 -- The place for module deprecation is really too restrictive, but if it
382 -- was allowed at its natural place just before 'module', we get an ugly
383 -- s/r conflict with the second alternative. Another solution would be the
384 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
385 -- either, and DEPRECATED is only expected to be used by people who really
386 -- know what they are doing. :-)
388 module :: { Located (HsModule RdrName) }
389 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
390 {% fileSrcSpan >>= \ loc ->
391 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
394 {% fileSrcSpan >>= \ loc ->
395 return (L loc (HsModule Nothing Nothing
396 (fst $1) (snd $1) Nothing Nothing
399 maybedocheader :: { Maybe LHsDocString }
400 : moduleheader { $1 }
401 | {- empty -} { Nothing }
403 missing_module_keyword :: { () }
404 : {- empty -} {% pushCurrentContext }
406 maybemodwarning :: { Maybe WarningTxt }
407 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
408 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
409 | {- empty -} { Nothing }
411 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
413 | vocurly top close { $2 }
415 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
417 | missing_module_keyword top close { $2 }
419 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
420 : importdecls { (reverse $1,[]) }
421 | importdecls ';' cvtopdecls { (reverse $1,$3) }
422 | cvtopdecls { ([],$1) }
424 cvtopdecls :: { [LHsDecl RdrName] }
425 : topdecls { cvTopDecls $1 }
427 -----------------------------------------------------------------------------
428 -- Module declaration & imports only
430 header :: { Located (HsModule RdrName) }
431 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
432 {% fileSrcSpan >>= \ loc ->
433 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
435 | missing_module_keyword importdecls
436 {% fileSrcSpan >>= \ loc ->
437 return (L loc (HsModule Nothing Nothing $2 [] Nothing
440 header_body :: { [LImportDecl RdrName] }
441 : '{' importdecls { $2 }
442 | vocurly importdecls { $2 }
444 -----------------------------------------------------------------------------
447 maybeexports :: { Maybe [LIE RdrName] }
448 : '(' exportlist ')' { Just $2 }
449 | {- empty -} { Nothing }
451 exportlist :: { [LIE RdrName] }
452 : expdoclist ',' expdoclist { $1 ++ $3 }
455 exportlist1 :: { [LIE RdrName] }
456 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
457 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
460 expdoclist :: { [LIE RdrName] }
461 : exp_doc expdoclist { $1 : $2 }
464 exp_doc :: { LIE RdrName }
465 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
466 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
467 | docnext { L1 (IEDoc (unLoc $1)) }
469 -- No longer allow things like [] and (,,,) to be exported
470 -- They are built in syntax, always available
471 export :: { LIE RdrName }
472 : qvar { L1 (IEVar (unLoc $1)) }
473 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
474 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
475 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
476 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
477 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
479 qcnames :: { [RdrName] }
480 : qcnames ',' qcname_ext { unLoc $3 : $1 }
481 | qcname_ext { [unLoc $1] }
483 qcname_ext :: { Located RdrName } -- Variable or data constructor
484 -- or tagged type constructor
486 | 'type' qcon { sL (comb2 $1 $2)
487 (setRdrNameSpace (unLoc $2)
490 -- Cannot pull into qcname_ext, as qcname is also used in expression.
491 qcname :: { Located RdrName } -- Variable or data constructor
495 -----------------------------------------------------------------------------
496 -- Import Declarations
498 -- import decls can be *empty*, or even just a string of semicolons
499 -- whereas topdecls must contain at least one topdecl.
501 importdecls :: { [LImportDecl RdrName] }
502 : importdecls ';' importdecl { $3 : $1 }
503 | importdecls ';' { $1 }
504 | importdecl { [ $1 ] }
507 importdecl :: { LImportDecl RdrName }
508 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
509 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
511 maybe_src :: { IsBootInterface }
512 : '{-# SOURCE' '#-}' { True }
513 | {- empty -} { False }
515 maybe_pkg :: { Maybe FastString }
516 : STRING { Just (getSTRING $1) }
517 | {- empty -} { Nothing }
519 optqualified :: { Bool }
520 : 'qualified' { True }
521 | {- empty -} { False }
523 maybeas :: { Located (Maybe ModuleName) }
524 : 'as' modid { LL (Just (unLoc $2)) }
525 | {- empty -} { noLoc Nothing }
527 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
528 : impspec { L1 (Just (unLoc $1)) }
529 | {- empty -} { noLoc Nothing }
531 impspec :: { Located (Bool, [LIE RdrName]) }
532 : '(' exportlist ')' { LL (False, $2) }
533 | 'hiding' '(' exportlist ')' { LL (True, $3) }
535 -----------------------------------------------------------------------------
536 -- Fixity Declarations
540 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
542 infix :: { Located FixityDirection }
543 : 'infix' { L1 InfixN }
544 | 'infixl' { L1 InfixL }
545 | 'infixr' { L1 InfixR }
547 ops :: { Located [Located RdrName] }
548 : ops ',' op { LL ($3 : unLoc $1) }
551 -----------------------------------------------------------------------------
552 -- Top-Level Declarations
554 topdecls :: { OrdList (LHsDecl RdrName) }
555 : topdecls ';' topdecl { $1 `appOL` $3 }
556 | topdecls ';' { $1 }
559 topdecl :: { OrdList (LHsDecl RdrName) }
560 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
561 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
562 | 'instance' inst_type where_inst
563 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
565 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
566 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
567 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
568 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
569 | '{-# DEPRECATED' deprecations '#-}' { $2 }
570 | '{-# WARNING' warnings '#-}' { $2 }
571 | '{-# RULES' rules '#-}' { $2 }
572 | annotation { unitOL $1 }
575 -- Template Haskell Extension
576 -- The $(..) form is one possible form of infixexp
577 -- but we treat an arbitrary expression just as if
578 -- it had a $(..) wrapped around it
579 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
583 cl_decl :: { LTyClDecl RdrName }
584 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
586 -- Type declarations (toplevel)
588 ty_decl :: { LTyClDecl RdrName }
589 -- ordinary type synonyms
590 : 'type' type '=' ctypedoc
591 -- Note ctype, not sigtype, on the right of '='
592 -- We allow an explicit for-all but we don't insert one
593 -- in type Foo a = (b,b)
594 -- Instead we just say b is out of scope
596 -- Note the use of type for the head; this allows
597 -- infix type constructors to be declared
598 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
600 -- type family declarations
601 | 'type' 'family' type opt_kind_sig
602 -- Note the use of type for the head; this allows
603 -- infix type constructors to be declared
604 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
606 -- type instance declarations
607 | 'type' 'instance' type '=' ctype
608 -- Note the use of type for the head; this allows
609 -- infix type constructors and type patterns
610 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
612 -- ordinary data type or newtype declaration
613 | data_or_newtype tycl_hdr constrs deriving
614 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
615 Nothing (reverse (unLoc $3)) (unLoc $4) }
616 -- We need the location on tycl_hdr in case
617 -- constrs and deriving are both empty
619 -- ordinary GADT declaration
620 | data_or_newtype tycl_hdr opt_kind_sig
623 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
624 (unLoc $3) (unLoc $4) (unLoc $5) }
625 -- We need the location on tycl_hdr in case
626 -- constrs and deriving are both empty
628 -- data/newtype family
629 | 'data' 'family' type opt_kind_sig
630 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
632 -- data/newtype instance declaration
633 | data_or_newtype 'instance' tycl_hdr constrs deriving
634 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
635 Nothing (reverse (unLoc $4)) (unLoc $5) }
637 -- GADT instance declaration
638 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
641 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
642 (unLoc $4) (unLoc $5) (unLoc $6) }
644 -- Associated type family declarations
646 -- * They have a different syntax than on the toplevel (no family special
649 -- * They also need to be separate from instances; otherwise, data family
650 -- declarations without a kind signature cause parsing conflicts with empty
651 -- data declarations.
653 at_decl_cls :: { LTyClDecl RdrName }
654 -- type family declarations
655 : 'type' type opt_kind_sig
656 -- Note the use of type for the head; this allows
657 -- infix type constructors to be declared
658 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
660 -- default type instance
661 | 'type' type '=' ctype
662 -- Note the use of type for the head; this allows
663 -- infix type constructors and type patterns
664 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
666 -- data/newtype family declaration
667 | 'data' type opt_kind_sig
668 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
670 -- Associated type instances
672 at_decl_inst :: { LTyClDecl RdrName }
673 -- type instance declarations
674 : 'type' type '=' ctype
675 -- Note the use of type for the head; this allows
676 -- infix type constructors and type patterns
677 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
679 -- data/newtype instance declaration
680 | data_or_newtype tycl_hdr constrs deriving
681 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
682 Nothing (reverse (unLoc $3)) (unLoc $4) }
684 -- GADT instance declaration
685 | data_or_newtype tycl_hdr opt_kind_sig
688 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
689 (unLoc $3) (unLoc $4) (unLoc $5) }
691 data_or_newtype :: { Located NewOrData }
692 : 'data' { L1 DataType }
693 | 'newtype' { L1 NewType }
695 opt_kind_sig :: { Located (Maybe Kind) }
697 | '::' kind { LL (Just (unLoc $2)) }
699 -- tycl_hdr parses the header of a class or data type decl,
700 -- which takes the form
703 -- (Eq a, Ord b) => T a b
704 -- T Int [a] -- for associated types
705 -- Rather a lot of inlining here, else we get reduce/reduce errors
706 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
707 : context '=>' type { LL (Just $1, $3) }
708 | type { L1 (Nothing, $1) }
710 -----------------------------------------------------------------------------
711 -- Stand-alone deriving
713 -- Glasgow extension: stand-alone deriving declarations
714 stand_alone_deriving :: { LDerivDecl RdrName }
715 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
717 -----------------------------------------------------------------------------
718 -- Nested declarations
720 -- Declaration in class bodies
722 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
723 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
726 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
727 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
728 | decls_cls ';' { LL (unLoc $1) }
730 | {- empty -} { noLoc nilOL }
734 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
735 : '{' decls_cls '}' { LL (unLoc $2) }
736 | vocurly decls_cls close { $2 }
740 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
741 -- No implicit parameters
742 -- May have type declarations
743 : 'where' decllist_cls { LL (unLoc $2) }
744 | {- empty -} { noLoc nilOL }
746 -- Declarations in instance bodies
748 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
749 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
752 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
753 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
754 | decls_inst ';' { LL (unLoc $1) }
756 | {- empty -} { noLoc nilOL }
759 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
760 : '{' decls_inst '}' { LL (unLoc $2) }
761 | vocurly decls_inst close { $2 }
765 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
766 -- No implicit parameters
767 -- May have type declarations
768 : 'where' decllist_inst { LL (unLoc $2) }
769 | {- empty -} { noLoc nilOL }
771 -- Declarations in binding groups other than classes and instances
773 decls :: { Located (OrdList (LHsDecl RdrName)) }
774 : decls ';' decl { let { this = unLoc $3;
776 these = rest `appOL` this }
777 in rest `seq` this `seq` these `seq`
779 | decls ';' { LL (unLoc $1) }
781 | {- empty -} { noLoc nilOL }
783 decllist :: { Located (OrdList (LHsDecl RdrName)) }
784 : '{' decls '}' { LL (unLoc $2) }
785 | vocurly decls close { $2 }
787 -- Binding groups other than those of class and instance declarations
789 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
790 -- No type declarations
791 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
792 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
793 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
795 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
796 -- No type declarations
797 : 'where' binds { LL (unLoc $2) }
798 | {- empty -} { noLoc emptyLocalBinds }
801 -----------------------------------------------------------------------------
802 -- Transformation Rules
804 rules :: { OrdList (LHsDecl RdrName) }
805 : rules ';' rule { $1 `snocOL` $3 }
808 | {- empty -} { nilOL }
810 rule :: { LHsDecl RdrName }
811 : STRING activation rule_forall infixexp '=' exp
812 { LL $ RuleD (HsRule (getSTRING $1)
813 ($2 `orElse` AlwaysActive)
814 $3 $4 placeHolderNames $6 placeHolderNames) }
816 activation :: { Maybe Activation }
817 : {- empty -} { Nothing }
818 | explicit_activation { Just $1 }
820 explicit_activation :: { Activation } -- In brackets
821 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
822 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
824 rule_forall :: { [RuleBndr RdrName] }
825 : 'forall' rule_var_list '.' { $2 }
828 rule_var_list :: { [RuleBndr RdrName] }
830 | rule_var rule_var_list { $1 : $2 }
832 rule_var :: { RuleBndr RdrName }
833 : varid { RuleBndr $1 }
834 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
836 -----------------------------------------------------------------------------
837 -- Warnings and deprecations (c.f. rules)
839 warnings :: { OrdList (LHsDecl RdrName) }
840 : warnings ';' warning { $1 `appOL` $3 }
841 | warnings ';' { $1 }
843 | {- empty -} { nilOL }
845 -- SUP: TEMPORARY HACK, not checking for `module Foo'
846 warning :: { OrdList (LHsDecl RdrName) }
848 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
851 deprecations :: { OrdList (LHsDecl RdrName) }
852 : deprecations ';' deprecation { $1 `appOL` $3 }
853 | deprecations ';' { $1 }
855 | {- empty -} { nilOL }
857 -- SUP: TEMPORARY HACK, not checking for `module Foo'
858 deprecation :: { OrdList (LHsDecl RdrName) }
860 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
863 strings :: { Located [FastString] }
864 : STRING { L1 [getSTRING $1] }
865 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
867 stringlist :: { Located (OrdList FastString) }
868 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
869 | STRING { LL (unitOL (getSTRING $1)) }
871 -----------------------------------------------------------------------------
873 annotation :: { LHsDecl RdrName }
874 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
875 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
876 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
879 -----------------------------------------------------------------------------
880 -- Foreign import and export declarations
882 fdecl :: { LHsDecl RdrName }
883 fdecl : 'import' callconv safety fspec
884 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
885 | 'import' callconv fspec
886 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
888 | 'export' callconv fspec
889 {% mkExport $2 (unLoc $3) >>= return.LL }
891 callconv :: { CCallConv }
892 : 'stdcall' { StdCallConv }
893 | 'ccall' { CCallConv }
894 | 'prim' { PrimCallConv}
897 : 'unsafe' { PlayRisky }
898 | 'safe' { PlaySafe False }
899 | 'threadsafe' { PlaySafe True } -- deprecated alias
901 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
902 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
903 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
904 -- if the entity string is missing, it defaults to the empty string;
905 -- the meaning of an empty entity string depends on the calling
908 -----------------------------------------------------------------------------
911 opt_sig :: { Maybe (LHsType RdrName) }
912 : {- empty -} { Nothing }
913 | '::' sigtype { Just $2 }
915 opt_asig :: { Maybe (LHsType RdrName) }
916 : {- empty -} { Nothing }
917 | '::' atype { Just $2 }
919 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
920 -- to tell the renamer where to generalise
921 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
922 -- Wrap an Implicit forall if there isn't one there already
924 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
925 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
926 -- Wrap an Implicit forall if there isn't one there already
928 sig_vars :: { Located [Located RdrName] }
929 : sig_vars ',' var { LL ($3 : unLoc $1) }
932 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
934 | sigtype ',' sigtypes1 { $1 : $3 }
936 -----------------------------------------------------------------------------
939 infixtype :: { LHsType RdrName }
940 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
941 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
943 strict_mark :: { Located HsBang }
944 : '!' { L1 HsStrict }
945 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
947 -- A ctype is a for-all type
948 ctype :: { LHsType RdrName }
949 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
950 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
951 -- A type of form (context => type) is an *implicit* HsForAllTy
952 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
955 ----------------------
956 -- Notes for 'ctypedoc'
957 -- It would have been nice to simplify the grammar by unifying `ctype` and
958 -- ctypedoc` into one production, allowing comments on types everywhere (and
959 -- rejecting them after parsing, where necessary). This is however not possible
960 -- since it leads to ambiguity. The reason is the support for comments on record
962 -- data R = R { field :: Int -- ^ comment on the field }
963 -- If we allow comments on types here, it's not clear if the comment applies
964 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
966 ctypedoc :: { LHsType RdrName }
967 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
968 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
969 -- A type of form (context => type) is an *implicit* HsForAllTy
970 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
973 ----------------------
974 -- Notes for 'context'
975 -- We parse a context as a btype so that we don't get reduce/reduce
976 -- errors in ctype. The basic problem is that
978 -- looks so much like a tuple type. We can't tell until we find the =>
980 -- We have the t1 ~ t2 form both in 'context' and in type,
981 -- to permit an individual equational constraint without parenthesis.
982 -- Thus for some reason we allow f :: a~b => blah
983 -- but not f :: ?x::Int => blah
984 context :: { LHsContext RdrName }
985 : btype '~' btype {% checkContext
986 (LL $ HsPredTy (HsEqualP $1 $3)) }
987 | btype {% checkContext $1 }
989 type :: { LHsType RdrName }
991 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
992 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
993 | btype '->' ctype { LL $ HsFunTy $1 $3 }
994 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
996 typedoc :: { LHsType RdrName }
998 | btype docprev { LL $ HsDocTy $1 $2 }
999 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1000 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1001 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1002 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1003 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1004 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1005 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1007 btype :: { LHsType RdrName }
1008 : btype atype { LL $ HsAppTy $1 $2 }
1011 atype :: { LHsType RdrName }
1012 : gtycon { L1 (HsTyVar (unLoc $1)) }
1013 | tyvar { L1 (HsTyVar (unLoc $1)) }
1014 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1015 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1016 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1017 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1018 | '[' ctype ']' { LL $ HsListTy $2 }
1019 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1020 | '(' ctype ')' { LL $ HsParTy $2 }
1021 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1022 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1023 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1024 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1025 mkUnqual varName (getTH_ID_SPLICE $1) }
1027 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1029 -- An inst_type is what occurs in the head of an instance decl
1030 -- e.g. (Foo a, Gaz b) => Wibble a b
1031 -- It's kept as a single type, with a MonoDictTy at the right
1032 -- hand corner, for convenience.
1033 inst_type :: { LHsType RdrName }
1034 : sigtype {% checkInstType $1 }
1036 inst_types1 :: { [LHsType RdrName] }
1037 : inst_type { [$1] }
1038 | inst_type ',' inst_types1 { $1 : $3 }
1040 comma_types0 :: { [LHsType RdrName] }
1041 : comma_types1 { $1 }
1042 | {- empty -} { [] }
1044 comma_types1 :: { [LHsType RdrName] }
1046 | ctype ',' comma_types1 { $1 : $3 }
1048 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1049 : tv_bndr tv_bndrs { $1 : $2 }
1050 | {- empty -} { [] }
1052 tv_bndr :: { LHsTyVarBndr RdrName }
1053 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1054 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1057 fds :: { Located [Located (FunDep RdrName)] }
1058 : {- empty -} { noLoc [] }
1059 | '|' fds1 { LL (reverse (unLoc $2)) }
1061 fds1 :: { Located [Located (FunDep RdrName)] }
1062 : fds1 ',' fd { LL ($3 : unLoc $1) }
1065 fd :: { Located (FunDep RdrName) }
1066 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1067 (reverse (unLoc $1), reverse (unLoc $3)) }
1069 varids0 :: { Located [RdrName] }
1070 : {- empty -} { noLoc [] }
1071 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1073 -----------------------------------------------------------------------------
1076 kind :: { Located Kind }
1078 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1080 akind :: { Located Kind }
1081 : '*' { L1 liftedTypeKind }
1082 | '!' { L1 unliftedTypeKind }
1083 | '(' kind ')' { LL (unLoc $2) }
1086 -----------------------------------------------------------------------------
1087 -- Datatype declarations
1089 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1090 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1091 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1092 | {- empty -} { noLoc [] }
1094 gadt_constrs :: { Located [LConDecl RdrName] }
1095 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1096 | gadt_constr { L (getLoc (head $1)) $1 }
1097 | {- empty -} { noLoc [] }
1099 -- We allow the following forms:
1100 -- C :: Eq a => a -> T a
1101 -- C :: forall a. Eq a => !a -> T a
1102 -- D { x,y :: a } :: T a
1103 -- forall a. Eq a => D { x,y :: a } :: T a
1105 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1106 : con_list '::' sigtype
1107 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1109 -- Deprecated syntax for GADT record declarations
1110 | oqtycon '{' fielddecls '}' '::' sigtype
1111 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1114 constrs :: { Located [LConDecl RdrName] }
1115 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1117 constrs1 :: { Located [LConDecl RdrName] }
1118 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1119 | constr { L1 [$1] }
1121 constr :: { LConDecl RdrName }
1122 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1123 { let (con,details) = unLoc $5 in
1124 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1126 | maybe_docnext forall constr_stuff maybe_docprev
1127 { let (con,details) = unLoc $3 in
1128 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1131 forall :: { Located [LHsTyVarBndr RdrName] }
1132 : 'forall' tv_bndrs '.' { LL $2 }
1133 | {- empty -} { noLoc [] }
1135 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1136 -- We parse the constructor declaration
1138 -- as a btype (treating C as a type constructor) and then convert C to be
1139 -- a data constructor. Reason: it might continue like this:
1141 -- in which case C really would be a type constructor. We can't resolve this
1142 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1143 : btype {% splitCon $1 >>= return.LL }
1144 | btype conop btype { LL ($2, InfixCon $1 $3) }
1146 fielddecls :: { [ConDeclField RdrName] }
1147 : {- empty -} { [] }
1148 | fielddecls1 { $1 }
1150 fielddecls1 :: { [ConDeclField RdrName] }
1151 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1152 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1153 -- This adds the doc $4 to each field separately
1156 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1157 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1158 | fld <- reverse (unLoc $2) ] }
1160 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1161 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1162 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1163 -- We don't allow a context, but that's sorted out by the type checker.
1164 deriving :: { Located (Maybe [LHsType RdrName]) }
1165 : {- empty -} { noLoc Nothing }
1166 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1167 ; p <- checkInstType (L loc (HsTyVar tv))
1168 ; return (LL (Just [p])) } }
1169 | 'deriving' '(' ')' { LL (Just []) }
1170 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1171 -- Glasgow extension: allow partial
1172 -- applications in derivings
1174 -----------------------------------------------------------------------------
1175 -- Value definitions
1177 {- Note [Declaration/signature overlap]
1178 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1179 There's an awkward overlap with a type signature. Consider
1180 f :: Int -> Int = ...rhs...
1181 Then we can't tell whether it's a type signature or a value
1182 definition with a result signature until we see the '='.
1183 So we have to inline enough to postpone reductions until we know.
1187 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1188 instead of qvar, we get another shift/reduce-conflict. Consider the
1191 { (^^) :: Int->Int ; } Type signature; only var allowed
1193 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1194 qvar allowed (because of instance decls)
1196 We can't tell whether to reduce var to qvar until after we've read the signatures.
1199 docdecl :: { LHsDecl RdrName }
1200 : docdecld { L1 (DocD (unLoc $1)) }
1202 docdecld :: { LDocDecl }
1203 : docnext { L1 (DocCommentNext (unLoc $1)) }
1204 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1205 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1206 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1208 decl :: { Located (OrdList (LHsDecl RdrName)) }
1210 | '!' aexp rhs {% do { pat <- checkPattern $2;
1211 return (LL $ unitOL $ LL $ ValD (
1212 PatBind (LL $ BangPat pat) (unLoc $3)
1213 placeHolderType placeHolderNames)) } }
1214 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1215 let { l = comb2 $1 $> };
1216 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1217 | docdecl { LL $ unitOL $1 }
1219 rhs :: { Located (GRHSs RdrName) }
1220 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1221 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1223 gdrhs :: { Located [LGRHS RdrName] }
1224 : gdrhs gdrh { LL ($2 : unLoc $1) }
1227 gdrh :: { LGRHS RdrName }
1228 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1230 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1231 : infixexp '::' sigtypedoc {% do s <- checkValSig $1 $3
1232 ; return (LL $ unitOL (LL $ SigD s)) }
1233 -- See Note [Declaration/signature overlap] for why we need infixexp here
1234 | var ',' sig_vars '::' sigtypedoc
1235 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1236 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1238 | '{-# INLINE' activation qvar '#-}'
1239 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma (getINLINE $1) $2))) }
1240 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1241 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1243 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1244 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma (getSPEC_INLINE $1) $2))
1246 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1247 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1249 -----------------------------------------------------------------------------
1252 quasiquote :: { Located (HsQuasiQuote RdrName) }
1253 : TH_QUASIQUOTE { let { loc = getLoc $1
1254 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1255 ; quoterId = mkUnqual varName quoter }
1256 in L1 (mkHsQuasiQuote quoterId quoteSpan quote) }
1258 exp :: { LHsExpr RdrName }
1259 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1260 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1261 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1262 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1263 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1266 infixexp :: { LHsExpr RdrName }
1268 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1270 exp10 :: { LHsExpr RdrName }
1271 : '\\' apat apats opt_asig '->' exp
1272 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1275 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1276 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1277 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1278 return (LL $ HsIf $2 $5 $8) }
1279 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1280 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1282 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1283 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1284 return (L loc (mkHsDo DoExpr stmts body)) }
1285 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1286 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1287 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1288 | scc_annot exp { LL $ if opt_SccProfilingOn
1289 then HsSCC (unLoc $1) $2
1291 | hpc_annot exp { LL $ if opt_Hpc
1292 then HsTickPragma (unLoc $1) $2
1295 | 'proc' aexp '->' exp
1296 {% checkPattern $2 >>= \ p ->
1297 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1298 placeHolderType undefined)) }
1299 -- TODO: is LL right here?
1301 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1302 -- hdaume: core annotation
1307 | {- empty -} { False }
1309 scc_annot :: { Located FastString }
1310 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1311 ( do scc <- getSCC $2; return $ LL scc ) }
1312 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1314 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1315 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1316 { LL $ (getSTRING $2
1317 ,( fromInteger $ getINTEGER $3
1318 , fromInteger $ getINTEGER $5
1320 ,( fromInteger $ getINTEGER $7
1321 , fromInteger $ getINTEGER $9
1326 fexp :: { LHsExpr RdrName }
1327 : fexp aexp { LL $ HsApp $1 $2 }
1330 aexp :: { LHsExpr RdrName }
1331 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1332 | '~' aexp { LL $ ELazyPat $2 }
1335 aexp1 :: { LHsExpr RdrName }
1336 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1340 -- Here was the syntax for type applications that I was planning
1341 -- but there are difficulties (e.g. what order for type args)
1342 -- so it's not enabled yet.
1343 -- But this case *is* used for the left hand side of a generic definition,
1344 -- which is parsed as an expression before being munged into a pattern
1345 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1346 (sL (getLoc $3) (HsType $3)) }
1348 aexp2 :: { LHsExpr RdrName }
1349 : ipvar { L1 (HsIPVar $! unLoc $1) }
1350 | qcname { L1 (HsVar $! unLoc $1) }
1351 | literal { L1 (HsLit $! unLoc $1) }
1352 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1353 -- into HsOverLit when -foverloaded-strings is on.
1354 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1355 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1356 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1358 -- N.B.: sections get parsed by these next two productions.
1359 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
1360 -- (you'd have to write '((+ 3), (4 -))')
1361 -- but the less cluttered version fell out of having texps.
1362 | '(' texp ')' { LL (HsPar $2) }
1363 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1365 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1366 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1368 | '[' list ']' { LL (unLoc $2) }
1369 | '[:' parr ':]' { LL (unLoc $2) }
1370 | '_' { L1 EWildPat }
1372 -- Template Haskell Extension
1373 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1374 (L1 $ HsVar (mkUnqual varName
1375 (getTH_ID_SPLICE $1)))) }
1376 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1379 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1380 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1381 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1382 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1383 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1384 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1385 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1386 return (LL $ HsBracket (PatBr p)) }
1387 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1388 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1390 -- arrow notation extension
1391 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1393 cmdargs :: { [LHsCmdTop RdrName] }
1394 : cmdargs acmd { $2 : $1 }
1395 | {- empty -} { [] }
1397 acmd :: { LHsCmdTop RdrName }
1398 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1400 cvtopbody :: { [LHsDecl RdrName] }
1401 : '{' cvtopdecls0 '}' { $2 }
1402 | vocurly cvtopdecls0 close { $2 }
1404 cvtopdecls0 :: { [LHsDecl RdrName] }
1405 : {- empty -} { [] }
1408 -----------------------------------------------------------------------------
1409 -- Tuple expressions
1411 -- "texp" is short for tuple expressions:
1412 -- things that can appear unparenthesized as long as they're
1413 -- inside parens or delimitted by commas
1414 texp :: { LHsExpr RdrName }
1417 -- Note [Parsing sections]
1418 -- ~~~~~~~~~~~~~~~~~~~~~~~
1419 -- We include left and right sections here, which isn't
1420 -- technically right according to Haskell 98. For example
1421 -- (3 +, True) isn't legal
1422 -- However, we want to parse bang patterns like
1424 -- and it's convenient to do so here as a section
1425 -- Then when converting expr to pattern we unravel it again
1426 -- Meanwhile, the renamer checks that real sections appear
1428 | infixexp qop { LL $ SectionL $1 $2 }
1429 | qopm infixexp { LL $ SectionR $1 $2 }
1431 -- View patterns get parenthesized above
1432 | exp '->' texp { LL $ EViewPat $1 $3 }
1434 -- Always at least one comma
1435 tup_exprs :: { [HsTupArg RdrName] }
1436 : texp commas_tup_tail { Present $1 : $2 }
1437 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1439 -- Always starts with commas; always follows an expr
1440 commas_tup_tail :: { [HsTupArg RdrName] }
1441 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1443 -- Always follows a comma
1444 tup_tail :: { [HsTupArg RdrName] }
1445 : texp commas_tup_tail { Present $1 : $2 }
1446 | texp { [Present $1] }
1447 | {- empty -} { [missingTupArg] }
1449 -----------------------------------------------------------------------------
1452 -- The rules below are little bit contorted to keep lexps left-recursive while
1453 -- avoiding another shift/reduce-conflict.
1455 list :: { LHsExpr RdrName }
1456 : texp { L1 $ ExplicitList placeHolderType [$1] }
1457 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1458 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1459 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1460 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1461 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1462 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1464 lexps :: { Located [LHsExpr RdrName] }
1465 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1466 | texp ',' texp { LL [$3,$1] }
1468 -----------------------------------------------------------------------------
1469 -- List Comprehensions
1471 flattenedpquals :: { Located [LStmt RdrName] }
1472 : pquals { case (unLoc $1) of
1474 -- We just had one thing in our "parallel" list so
1475 -- we simply return that thing directly
1477 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1478 -- We actually found some actual parallel lists so
1479 -- we wrap them into as a ParStmt
1482 pquals :: { Located [[LStmt RdrName]] }
1483 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1484 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1486 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1487 -- one can "grab" the earlier ones
1488 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1489 | squals ',' qual { LL ($3 : unLoc $1) }
1490 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1492 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1493 -- | '{|' pquals '|}' { L1 [$2] }
1496 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1497 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1498 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1499 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1501 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1502 -- Function is applied to a list of stmts *in order*
1503 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1505 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1506 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1508 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1509 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1510 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1511 -- choosing the "group by" variant, which is what we want.
1513 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1514 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1515 -- if /that/ is the group function we conflict with.
1516 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1517 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1519 -----------------------------------------------------------------------------
1520 -- Parallel array expressions
1522 -- The rules below are little bit contorted; see the list case for details.
1523 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1524 -- Moreover, we allow explicit arrays with no element (represented by the nil
1525 -- constructor in the list case).
1527 parr :: { LHsExpr RdrName }
1528 : { noLoc (ExplicitPArr placeHolderType []) }
1529 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1530 | lexps { L1 $ ExplicitPArr placeHolderType
1531 (reverse (unLoc $1)) }
1532 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1533 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1534 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1536 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1538 -----------------------------------------------------------------------------
1541 guardquals :: { Located [LStmt RdrName] }
1542 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1544 guardquals1 :: { Located [LStmt RdrName] }
1545 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1548 -----------------------------------------------------------------------------
1549 -- Case alternatives
1551 altslist :: { Located [LMatch RdrName] }
1552 : '{' alts '}' { LL (reverse (unLoc $2)) }
1553 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1555 alts :: { Located [LMatch RdrName] }
1556 : alts1 { L1 (unLoc $1) }
1557 | ';' alts { LL (unLoc $2) }
1559 alts1 :: { Located [LMatch RdrName] }
1560 : alts1 ';' alt { LL ($3 : unLoc $1) }
1561 | alts1 ';' { LL (unLoc $1) }
1564 alt :: { LMatch RdrName }
1565 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1567 alt_rhs :: { Located (GRHSs RdrName) }
1568 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1570 ralt :: { Located [LGRHS RdrName] }
1571 : '->' exp { LL (unguardedRHS $2) }
1572 | gdpats { L1 (reverse (unLoc $1)) }
1574 gdpats :: { Located [LGRHS RdrName] }
1575 : gdpats gdpat { LL ($2 : unLoc $1) }
1578 gdpat :: { LGRHS RdrName }
1579 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1581 -- 'pat' recognises a pattern, including one with a bang at the top
1582 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1583 -- Bangs inside are parsed as infix operator applications, so that
1584 -- we parse them right when bang-patterns are off
1585 pat :: { LPat RdrName }
1586 pat : exp {% checkPattern $1 }
1587 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1589 apat :: { LPat RdrName }
1590 apat : aexp {% checkPattern $1 }
1591 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1593 apats :: { [LPat RdrName] }
1594 : apat apats { $1 : $2 }
1595 | {- empty -} { [] }
1597 -----------------------------------------------------------------------------
1598 -- Statement sequences
1600 stmtlist :: { Located [LStmt RdrName] }
1601 : '{' stmts '}' { LL (unLoc $2) }
1602 | vocurly stmts close { $2 }
1604 -- do { ;; s ; s ; ; s ;; }
1605 -- The last Stmt should be an expression, but that's hard to enforce
1606 -- here, because we need too much lookahead if we see do { e ; }
1607 -- So we use ExprStmts throughout, and switch the last one over
1608 -- in ParseUtils.checkDo instead
1609 stmts :: { Located [LStmt RdrName] }
1610 : stmt stmts_help { LL ($1 : unLoc $2) }
1611 | ';' stmts { LL (unLoc $2) }
1612 | {- empty -} { noLoc [] }
1614 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1615 : ';' stmts { LL (unLoc $2) }
1616 | {- empty -} { noLoc [] }
1618 -- For typing stmts at the GHCi prompt, where
1619 -- the input may consist of just comments.
1620 maybe_stmt :: { Maybe (LStmt RdrName) }
1622 | {- nothing -} { Nothing }
1624 stmt :: { LStmt RdrName }
1626 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1628 qual :: { LStmt RdrName }
1629 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1630 | exp { L1 $ mkExprStmt $1 }
1631 | 'let' binds { LL $ LetStmt (unLoc $2) }
1633 -----------------------------------------------------------------------------
1634 -- Record Field Update/Construction
1636 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1638 | {- empty -} { ([], False) }
1640 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1641 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1642 | fbind { ([$1], False) }
1643 | '..' { ([], True) }
1645 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1646 : qvar '=' exp { HsRecField $1 $3 False }
1647 | qvar { HsRecField $1 placeHolderPunRhs True }
1648 -- In the punning case, use a place-holder
1649 -- The renamer fills in the final value
1651 -----------------------------------------------------------------------------
1652 -- Implicit Parameter Bindings
1654 dbinds :: { Located [LIPBind RdrName] }
1655 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1656 in rest `seq` this `seq` LL (this : rest) }
1657 | dbinds ';' { LL (unLoc $1) }
1658 | dbind { let this = $1 in this `seq` L1 [this] }
1659 -- | {- empty -} { [] }
1661 dbind :: { LIPBind RdrName }
1662 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1664 ipvar :: { Located (IPName RdrName) }
1665 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1667 -----------------------------------------------------------------------------
1668 -- Warnings and deprecations
1670 namelist :: { Located [RdrName] }
1671 namelist : name_var { L1 [unLoc $1] }
1672 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1674 name_var :: { Located RdrName }
1675 name_var : var { $1 }
1678 -----------------------------------------
1679 -- Data constructors
1680 qcon :: { Located RdrName }
1682 | '(' qconsym ')' { LL (unLoc $2) }
1683 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1684 -- The case of '[:' ':]' is part of the production `parr'
1686 con :: { Located RdrName }
1688 | '(' consym ')' { LL (unLoc $2) }
1689 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1691 con_list :: { Located [Located RdrName] }
1692 con_list : con { L1 [$1] }
1693 | con ',' con_list { LL ($1 : unLoc $3) }
1695 sysdcon :: { Located DataCon } -- Wired in data constructors
1696 : '(' ')' { LL unitDataCon }
1697 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1698 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1699 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1700 | '[' ']' { LL nilDataCon }
1702 conop :: { Located RdrName }
1704 | '`' conid '`' { LL (unLoc $2) }
1706 qconop :: { Located RdrName }
1708 | '`' qconid '`' { LL (unLoc $2) }
1710 -----------------------------------------------------------------------------
1711 -- Type constructors
1713 gtycon :: { Located RdrName } -- A "general" qualified tycon
1715 | '(' ')' { LL $ getRdrName unitTyCon }
1716 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1717 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1718 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1719 | '(' '->' ')' { LL $ getRdrName funTyCon }
1720 | '[' ']' { LL $ listTyCon_RDR }
1721 | '[:' ':]' { LL $ parrTyCon_RDR }
1723 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1725 | '(' qtyconsym ')' { LL (unLoc $2) }
1727 qtyconop :: { Located RdrName } -- Qualified or unqualified
1729 | '`' qtycon '`' { LL (unLoc $2) }
1731 qtycon :: { Located RdrName } -- Qualified or unqualified
1732 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1733 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1736 tycon :: { Located RdrName } -- Unqualified
1737 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1739 qtyconsym :: { Located RdrName }
1740 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1743 tyconsym :: { Located RdrName }
1744 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1746 -----------------------------------------------------------------------------
1749 op :: { Located RdrName } -- used in infix decls
1753 varop :: { Located RdrName }
1755 | '`' varid '`' { LL (unLoc $2) }
1757 qop :: { LHsExpr RdrName } -- used in sections
1758 : qvarop { L1 $ HsVar (unLoc $1) }
1759 | qconop { L1 $ HsVar (unLoc $1) }
1761 qopm :: { LHsExpr RdrName } -- used in sections
1762 : qvaropm { L1 $ HsVar (unLoc $1) }
1763 | qconop { L1 $ HsVar (unLoc $1) }
1765 qvarop :: { Located RdrName }
1767 | '`' qvarid '`' { LL (unLoc $2) }
1769 qvaropm :: { Located RdrName }
1770 : qvarsym_no_minus { $1 }
1771 | '`' qvarid '`' { LL (unLoc $2) }
1773 -----------------------------------------------------------------------------
1776 tyvar :: { Located RdrName }
1777 tyvar : tyvarid { $1 }
1778 | '(' tyvarsym ')' { LL (unLoc $2) }
1780 tyvarop :: { Located RdrName }
1781 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1783 | '.' {% parseErrorSDoc (getLoc $1)
1784 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1785 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1786 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1789 tyvarid :: { Located RdrName }
1790 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1791 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1792 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1793 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1794 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1796 tyvarsym :: { Located RdrName }
1797 -- Does not include "!", because that is used for strictness marks
1798 -- or ".", because that separates the quantified type vars from the rest
1799 -- or "*", because that's used for kinds
1800 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1802 -----------------------------------------------------------------------------
1805 var :: { Located RdrName }
1807 | '(' varsym ')' { LL (unLoc $2) }
1809 qvar :: { Located RdrName }
1811 | '(' varsym ')' { LL (unLoc $2) }
1812 | '(' qvarsym1 ')' { LL (unLoc $2) }
1813 -- We've inlined qvarsym here so that the decision about
1814 -- whether it's a qvar or a var can be postponed until
1815 -- *after* we see the close paren.
1817 qvarid :: { Located RdrName }
1819 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1820 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1822 varid :: { Located RdrName }
1823 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1824 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1825 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1826 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1827 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1828 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1829 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1831 qvarsym :: { Located RdrName }
1835 qvarsym_no_minus :: { Located RdrName }
1836 : varsym_no_minus { $1 }
1839 qvarsym1 :: { Located RdrName }
1840 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1842 varsym :: { Located RdrName }
1843 : varsym_no_minus { $1 }
1844 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1846 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1847 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1848 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1851 -- These special_ids are treated as keywords in various places,
1852 -- but as ordinary ids elsewhere. 'special_id' collects all these
1853 -- except 'unsafe', 'forall', and 'family' whose treatment differs
1854 -- depending on context
1855 special_id :: { Located FastString }
1857 : 'as' { L1 (fsLit "as") }
1858 | 'qualified' { L1 (fsLit "qualified") }
1859 | 'hiding' { L1 (fsLit "hiding") }
1860 | 'export' { L1 (fsLit "export") }
1861 | 'label' { L1 (fsLit "label") }
1862 | 'dynamic' { L1 (fsLit "dynamic") }
1863 | 'stdcall' { L1 (fsLit "stdcall") }
1864 | 'ccall' { L1 (fsLit "ccall") }
1865 | 'prim' { L1 (fsLit "prim") }
1866 | 'group' { L1 (fsLit "group") }
1868 special_sym :: { Located FastString }
1869 special_sym : '!' { L1 (fsLit "!") }
1870 | '.' { L1 (fsLit ".") }
1871 | '*' { L1 (fsLit "*") }
1873 -----------------------------------------------------------------------------
1874 -- Data constructors
1876 qconid :: { Located RdrName } -- Qualified or unqualified
1878 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1879 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1881 conid :: { Located RdrName }
1882 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1884 qconsym :: { Located RdrName } -- Qualified or unqualified
1886 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1888 consym :: { Located RdrName }
1889 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1891 -- ':' means only list cons
1892 | ':' { L1 $ consDataCon_RDR }
1895 -----------------------------------------------------------------------------
1898 literal :: { Located HsLit }
1899 : CHAR { L1 $ HsChar $ getCHAR $1 }
1900 | STRING { L1 $ HsString $ getSTRING $1 }
1901 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1902 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1903 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1904 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1905 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1906 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1908 -----------------------------------------------------------------------------
1912 : vccurly { () } -- context popped in lexer.
1913 | error {% popContext }
1915 -----------------------------------------------------------------------------
1916 -- Miscellaneous (mostly renamings)
1918 modid :: { Located ModuleName }
1919 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1920 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1923 (unpackFS mod ++ '.':unpackFS c))
1927 : commas ',' { $1 + 1 }
1930 -----------------------------------------------------------------------------
1931 -- Documentation comments
1933 docnext :: { LHsDocString }
1934 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1936 docprev :: { LHsDocString }
1937 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1939 docnamed :: { Located (String, HsDocString) }
1941 let string = getDOCNAMED $1
1942 (name, rest) = break isSpace string
1943 in return (L1 (name, HsDocString (mkFastString rest))) }
1945 docsection :: { Located (Int, HsDocString) }
1946 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1947 return (L1 (n, HsDocString (mkFastString doc))) }
1949 moduleheader :: { Maybe LHsDocString }
1950 : DOCNEXT {% let string = getDOCNEXT $1 in
1951 return (Just (L1 (HsDocString (mkFastString string)))) }
1953 maybe_docprev :: { Maybe LHsDocString }
1954 : docprev { Just $1 }
1955 | {- empty -} { Nothing }
1957 maybe_docnext :: { Maybe LHsDocString }
1958 : docnext { Just $1 }
1959 | {- empty -} { Nothing }
1963 happyError = srcParseFail
1965 getVARID (L _ (ITvarid x)) = x
1966 getCONID (L _ (ITconid x)) = x
1967 getVARSYM (L _ (ITvarsym x)) = x
1968 getCONSYM (L _ (ITconsym x)) = x
1969 getQVARID (L _ (ITqvarid x)) = x
1970 getQCONID (L _ (ITqconid x)) = x
1971 getQVARSYM (L _ (ITqvarsym x)) = x
1972 getQCONSYM (L _ (ITqconsym x)) = x
1973 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1974 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1975 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1976 getCHAR (L _ (ITchar x)) = x
1977 getSTRING (L _ (ITstring x)) = x
1978 getINTEGER (L _ (ITinteger x)) = x
1979 getRATIONAL (L _ (ITrational x)) = x
1980 getPRIMCHAR (L _ (ITprimchar x)) = x
1981 getPRIMSTRING (L _ (ITprimstring x)) = x
1982 getPRIMINTEGER (L _ (ITprimint x)) = x
1983 getPRIMWORD (L _ (ITprimword x)) = x
1984 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1985 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1986 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1987 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
1988 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
1989 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
1991 getDOCNEXT (L _ (ITdocCommentNext x)) = x
1992 getDOCPREV (L _ (ITdocCommentPrev x)) = x
1993 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
1994 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
1996 getSCC :: Located Token -> P FastString
1997 getSCC lt = do let s = getSTRING lt
1998 err = "Spaces are not allowed in SCCs"
1999 -- We probably actually want to be more restrictive than this
2000 if ' ' `elem` unpackFS s
2001 then failSpanMsgP (getLoc lt) (text err)
2004 -- Utilities for combining source spans
2005 comb2 :: Located a -> Located b -> SrcSpan
2006 comb2 a b = a `seq` b `seq` combineLocs a b
2008 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2009 comb3 a b c = a `seq` b `seq` c `seq`
2010 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2012 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2013 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2014 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2015 combineSrcSpans (getLoc c) (getLoc d))
2017 -- strict constructor version:
2019 sL :: SrcSpan -> a -> Located a
2020 sL span a = span `seq` a `seq` L span a
2022 -- Make a source location for the file. We're a bit lazy here and just
2023 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2024 -- try to find the span of the whole file (ToDo).
2025 fileSrcSpan :: P SrcSpan
2028 let loc = mkSrcLoc (srcLocFile l) 1 1;
2029 return (mkSrcSpan loc loc)