2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
12 {-# OPTIONS -Wwarn -w #-}
13 -- The above warning supression flag is a temporary kludge.
14 -- While working on this module you are encouraged to remove it and fix
15 -- any warnings in the module. See
16 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
19 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
21 Careful optimisation of the parser: we don't want to throw everything
22 at it, because that takes too long and doesn't buy much, but we do want
23 to inline certain key external functions, so we instruct GHC not to
24 throw away inlinings as it would normally do in -O0 mode.
27 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
32 import HscTypes ( IsBootInterface, WarningTxt(..) )
35 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
36 unboxedSingletonTyCon, unboxedSingletonDataCon,
37 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
38 import Type ( funTyCon )
39 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
40 CCallConv(..), CCallTarget(..), defaultCCallConv
42 import OccName ( varName, dataName, tcClsName, tvName )
43 import DataCon ( DataCon, dataConName )
46 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
47 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
48 import Coercion ( mkArrowKind )
49 import Class ( FunDep )
56 import Maybes ( orElse )
59 import Control.Monad ( unless )
62 import Control.Monad ( mplus )
66 -----------------------------------------------------------------------------
69 Conflicts: 33 shift/reduce
72 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
73 would think the two should never occur in the same context.
77 -----------------------------------------------------------------------------
80 Conflicts: 34 shift/reduce
83 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
84 would think the two should never occur in the same context.
88 -----------------------------------------------------------------------------
91 Conflicts: 32 shift/reduce
94 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
95 would think the two should never occur in the same context.
99 -----------------------------------------------------------------------------
102 Conflicts: 37 shift/reduce
105 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
106 would think the two should never occur in the same context.
110 -----------------------------------------------------------------------------
111 Conflicts: 38 shift/reduce (1.25)
113 10 for abiguity in 'if x then y else z + 1' [State 178]
114 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
115 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
117 1 for ambiguity in 'if x then y else z :: T' [State 178]
118 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
120 4 for ambiguity in 'if x then y else z -< e' [State 178]
121 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
122 There are four such operators: -<, >-, -<<, >>-
125 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
126 Which of these two is intended?
128 (x::T) -> T -- Rhs is T
131 (x::T -> T) -> .. -- Rhs is ...
133 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
136 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
137 Same duplication between states 11 and 253 as the previous case
139 1 for ambiguity in 'let ?x ...' [State 329]
140 the parser can't tell whether the ?x is the lhs of a normal binding or
141 an implicit binding. Fortunately resolving as shift gives it the only
142 sensible meaning, namely the lhs of an implicit binding.
144 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
145 we don't know whether the '[' starts the activation or not: it
146 might be the start of the declaration with the activation being
147 empty. --SDM 1/4/2002
149 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
150 since 'forall' is a valid variable name, we don't know whether
151 to treat a forall on the input as the beginning of a quantifier
152 or the beginning of the rule itself. Resolving to shift means
153 it's always treated as a quantifier, hence the above is disallowed.
154 This saves explicitly defining a grammar for the rule lhs that
155 doesn't include 'forall'.
157 1 for ambiguity when the source file starts with "-- | doc". We need another
158 token of lookahead to determine if a top declaration or the 'module' keyword
159 follows. Shift parses as if the 'module' keyword follows.
161 -- ---------------------------------------------------------------------------
162 -- Adding location info
164 This is done in a stylised way using the three macros below, L0, L1
165 and LL. Each of these macros can be thought of as having type
167 L0, L1, LL :: a -> Located a
169 They each add a SrcSpan to their argument.
171 L0 adds 'noSrcSpan', used for empty productions
172 -- This doesn't seem to work anymore -=chak
174 L1 for a production with a single token on the lhs. Grabs the SrcSpan
177 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
178 the first and last tokens.
180 These suffice for the majority of cases. However, we must be
181 especially careful with empty productions: LL won't work if the first
182 or last token on the lhs can represent an empty span. In these cases,
183 we have to calculate the span using more of the tokens from the lhs, eg.
185 | 'newtype' tycl_hdr '=' newconstr deriving
187 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
189 We provide comb3 and comb4 functions which are useful in such cases.
191 Be careful: there's no checking that you actually got this right, the
192 only symptom will be that the SrcSpans of your syntax will be
196 * We must expand these macros *before* running Happy, which is why this file is
197 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
199 #define L0 L noSrcSpan
200 #define L1 sL (getLoc $1)
201 #define LL sL (comb2 $1 $>)
203 -- -----------------------------------------------------------------------------
208 '_' { L _ ITunderscore } -- Haskell keywords
210 'case' { L _ ITcase }
211 'class' { L _ ITclass }
212 'data' { L _ ITdata }
213 'default' { L _ ITdefault }
214 'deriving' { L _ ITderiving }
216 'else' { L _ ITelse }
217 'hiding' { L _ IThiding }
219 'import' { L _ ITimport }
221 'infix' { L _ ITinfix }
222 'infixl' { L _ ITinfixl }
223 'infixr' { L _ ITinfixr }
224 'instance' { L _ ITinstance }
226 'module' { L _ ITmodule }
227 'newtype' { L _ ITnewtype }
229 'qualified' { L _ ITqualified }
230 'then' { L _ ITthen }
231 'type' { L _ ITtype }
232 'where' { L _ ITwhere }
233 '_scc_' { L _ ITscc } -- ToDo: remove
235 'forall' { L _ ITforall } -- GHC extension keywords
236 'foreign' { L _ ITforeign }
237 'export' { L _ ITexport }
238 'label' { L _ ITlabel }
239 'dynamic' { L _ ITdynamic }
240 'safe' { L _ ITsafe }
241 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
242 'interruptible' { L _ ITinterruptible }
243 'unsafe' { L _ ITunsafe }
245 'family' { L _ ITfamily }
246 'stdcall' { L _ ITstdcallconv }
247 'ccall' { L _ ITccallconv }
248 'prim' { L _ ITprimcallconv }
249 'proc' { L _ ITproc } -- for arrow notation extension
250 'rec' { L _ ITrec } -- for arrow notation extension
251 'group' { L _ ITgroup } -- for list transform extension
252 'by' { L _ ITby } -- for list transform extension
253 'using' { L _ ITusing } -- for list transform extension
255 '{-# INLINE' { L _ (ITinline_prag _ _) }
256 '{-# SPECIALISE' { L _ ITspec_prag }
257 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
258 '{-# SOURCE' { L _ ITsource_prag }
259 '{-# RULES' { L _ ITrules_prag }
260 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
261 '{-# SCC' { L _ ITscc_prag }
262 '{-# GENERATED' { L _ ITgenerated_prag }
263 '{-# DEPRECATED' { L _ ITdeprecated_prag }
264 '{-# WARNING' { L _ ITwarning_prag }
265 '{-# UNPACK' { L _ ITunpack_prag }
266 '{-# ANN' { L _ ITann_prag }
267 '{-# VECTORISE' { L _ ITvect_prag }
268 '{-# VECTORISE_SCALAR' { L _ ITvect_scalar_prag }
269 '#-}' { L _ ITclose_prag }
271 '..' { L _ ITdotdot } -- reserved symbols
273 '::' { L _ ITdcolon }
277 '<-' { L _ ITlarrow }
278 '->' { L _ ITrarrow }
281 '=>' { L _ ITdarrow }
285 '-<' { L _ ITlarrowtail } -- for arrow notation
286 '>-' { L _ ITrarrowtail } -- for arrow notation
287 '-<<' { L _ ITLarrowtail } -- for arrow notation
288 '>>-' { L _ ITRarrowtail } -- for arrow notation
291 '{' { L _ ITocurly } -- special symbols
293 '{|' { L _ ITocurlybar }
294 '|}' { L _ ITccurlybar }
295 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
296 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
299 '[:' { L _ ITopabrack }
300 ':]' { L _ ITcpabrack }
303 '(#' { L _ IToubxparen }
304 '#)' { L _ ITcubxparen }
305 '(|' { L _ IToparenbar }
306 '|)' { L _ ITcparenbar }
309 '`' { L _ ITbackquote }
311 VARID { L _ (ITvarid _) } -- identifiers
312 CONID { L _ (ITconid _) }
313 VARSYM { L _ (ITvarsym _) }
314 CONSYM { L _ (ITconsym _) }
315 QVARID { L _ (ITqvarid _) }
316 QCONID { L _ (ITqconid _) }
317 QVARSYM { L _ (ITqvarsym _) }
318 QCONSYM { L _ (ITqconsym _) }
319 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
320 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
322 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
324 CHAR { L _ (ITchar _) }
325 STRING { L _ (ITstring _) }
326 INTEGER { L _ (ITinteger _) }
327 RATIONAL { L _ (ITrational _) }
329 PRIMCHAR { L _ (ITprimchar _) }
330 PRIMSTRING { L _ (ITprimstring _) }
331 PRIMINTEGER { L _ (ITprimint _) }
332 PRIMWORD { L _ (ITprimword _) }
333 PRIMFLOAT { L _ (ITprimfloat _) }
334 PRIMDOUBLE { L _ (ITprimdouble _) }
336 DOCNEXT { L _ (ITdocCommentNext _) }
337 DOCPREV { L _ (ITdocCommentPrev _) }
338 DOCNAMED { L _ (ITdocCommentNamed _) }
339 DOCSECTION { L _ (ITdocSection _ _) }
342 '[|' { L _ ITopenExpQuote }
343 '[p|' { L _ ITopenPatQuote }
344 '[t|' { L _ ITopenTypQuote }
345 '[d|' { L _ ITopenDecQuote }
346 '|]' { L _ ITcloseQuote }
347 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
348 '$(' { L _ ITparenEscape } -- $( exp )
349 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
350 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
351 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
353 %monad { P } { >>= } { return }
354 %lexer { lexer } { L _ ITeof }
355 %name parseModule module
356 %name parseStmt maybe_stmt
357 %name parseIdentifier identifier
358 %name parseType ctype
359 %partial parseHeader header
360 %tokentype { (Located Token) }
363 -----------------------------------------------------------------------------
364 -- Identifiers; one of the entry points
365 identifier :: { Located RdrName }
370 | '(' '->' ')' { LL $ getRdrName funTyCon }
372 -----------------------------------------------------------------------------
375 -- The place for module deprecation is really too restrictive, but if it
376 -- was allowed at its natural place just before 'module', we get an ugly
377 -- s/r conflict with the second alternative. Another solution would be the
378 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
379 -- either, and DEPRECATED is only expected to be used by people who really
380 -- know what they are doing. :-)
382 module :: { Located (HsModule RdrName) }
383 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
384 {% fileSrcSpan >>= \ loc ->
385 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
388 {% fileSrcSpan >>= \ loc ->
389 return (L loc (HsModule Nothing Nothing
390 (fst $1) (snd $1) Nothing Nothing
393 maybedocheader :: { Maybe LHsDocString }
394 : moduleheader { $1 }
395 | {- empty -} { Nothing }
397 missing_module_keyword :: { () }
398 : {- empty -} {% pushCurrentContext }
400 maybemodwarning :: { Maybe WarningTxt }
401 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
402 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
403 | {- empty -} { Nothing }
405 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
407 | vocurly top close { $2 }
409 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
411 | missing_module_keyword top close { $2 }
413 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
414 : importdecls { (reverse $1,[]) }
415 | importdecls ';' cvtopdecls { (reverse $1,$3) }
416 | cvtopdecls { ([],$1) }
418 cvtopdecls :: { [LHsDecl RdrName] }
419 : topdecls { cvTopDecls $1 }
421 -----------------------------------------------------------------------------
422 -- Module declaration & imports only
424 header :: { Located (HsModule RdrName) }
425 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
426 {% fileSrcSpan >>= \ loc ->
427 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
429 | missing_module_keyword importdecls
430 {% fileSrcSpan >>= \ loc ->
431 return (L loc (HsModule Nothing Nothing $2 [] Nothing
434 header_body :: { [LImportDecl RdrName] }
435 : '{' importdecls { $2 }
436 | vocurly importdecls { $2 }
438 -----------------------------------------------------------------------------
441 maybeexports :: { Maybe [LIE RdrName] }
442 : '(' exportlist ')' { Just $2 }
443 | {- empty -} { Nothing }
445 exportlist :: { [LIE RdrName] }
446 : expdoclist ',' expdoclist { $1 ++ $3 }
449 exportlist1 :: { [LIE RdrName] }
450 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
451 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
454 expdoclist :: { [LIE RdrName] }
455 : exp_doc expdoclist { $1 : $2 }
458 exp_doc :: { LIE RdrName }
459 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
460 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
461 | docnext { L1 (IEDoc (unLoc $1)) }
463 -- No longer allow things like [] and (,,,) to be exported
464 -- They are built in syntax, always available
465 export :: { LIE RdrName }
466 : qvar { L1 (IEVar (unLoc $1)) }
467 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
468 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
469 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
470 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
471 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
473 qcnames :: { [RdrName] }
474 : qcnames ',' qcname_ext { unLoc $3 : $1 }
475 | qcname_ext { [unLoc $1] }
477 qcname_ext :: { Located RdrName } -- Variable or data constructor
478 -- or tagged type constructor
480 | 'type' qcon { sL (comb2 $1 $2)
481 (setRdrNameSpace (unLoc $2)
484 -- Cannot pull into qcname_ext, as qcname is also used in expression.
485 qcname :: { Located RdrName } -- Variable or data constructor
489 -----------------------------------------------------------------------------
490 -- Import Declarations
492 -- import decls can be *empty*, or even just a string of semicolons
493 -- whereas topdecls must contain at least one topdecl.
495 importdecls :: { [LImportDecl RdrName] }
496 : importdecls ';' importdecl { $3 : $1 }
497 | importdecls ';' { $1 }
498 | importdecl { [ $1 ] }
501 importdecl :: { LImportDecl RdrName }
502 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
503 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
505 maybe_src :: { IsBootInterface }
506 : '{-# SOURCE' '#-}' { True }
507 | {- empty -} { False }
509 maybe_pkg :: { Maybe FastString }
510 : STRING { Just (getSTRING $1) }
511 | {- empty -} { Nothing }
513 optqualified :: { Bool }
514 : 'qualified' { True }
515 | {- empty -} { False }
517 maybeas :: { Located (Maybe ModuleName) }
518 : 'as' modid { LL (Just (unLoc $2)) }
519 | {- empty -} { noLoc Nothing }
521 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
522 : impspec { L1 (Just (unLoc $1)) }
523 | {- empty -} { noLoc Nothing }
525 impspec :: { Located (Bool, [LIE RdrName]) }
526 : '(' exportlist ')' { LL (False, $2) }
527 | 'hiding' '(' exportlist ')' { LL (True, $3) }
529 -----------------------------------------------------------------------------
530 -- Fixity Declarations
534 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
536 infix :: { Located FixityDirection }
537 : 'infix' { L1 InfixN }
538 | 'infixl' { L1 InfixL }
539 | 'infixr' { L1 InfixR }
541 ops :: { Located [Located RdrName] }
542 : ops ',' op { LL ($3 : unLoc $1) }
545 -----------------------------------------------------------------------------
546 -- Top-Level Declarations
548 topdecls :: { OrdList (LHsDecl RdrName) }
549 : topdecls ';' topdecl { $1 `appOL` $3 }
550 | topdecls ';' { $1 }
553 topdecl :: { OrdList (LHsDecl RdrName) }
554 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
555 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
556 | 'instance' inst_type where_inst
557 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
559 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
560 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
561 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
562 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
563 | '{-# DEPRECATED' deprecations '#-}' { $2 }
564 | '{-# WARNING' warnings '#-}' { $2 }
565 | '{-# RULES' rules '#-}' { $2 }
566 | '{-# VECTORISE_SCALAR' qvar '#-}' { unitOL $ LL $ VectD (HsVect $2 Nothing) }
567 | '{-# VECTORISE' qvar '=' exp '#-}' { unitOL $ LL $ VectD (HsVect $2 (Just $4)) }
568 | annotation { unitOL $1 }
571 -- Template Haskell Extension
572 -- The $(..) form is one possible form of infixexp
573 -- but we treat an arbitrary expression just as if
574 -- it had a $(..) wrapped around it
575 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
579 cl_decl :: { LTyClDecl RdrName }
580 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
582 -- Type declarations (toplevel)
584 ty_decl :: { LTyClDecl RdrName }
585 -- ordinary type synonyms
586 : 'type' type '=' ctypedoc
587 -- Note ctype, not sigtype, on the right of '='
588 -- We allow an explicit for-all but we don't insert one
589 -- in type Foo a = (b,b)
590 -- Instead we just say b is out of scope
592 -- Note the use of type for the head; this allows
593 -- infix type constructors to be declared
594 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
596 -- type family declarations
597 | 'type' 'family' type opt_kind_sig
598 -- Note the use of type for the head; this allows
599 -- infix type constructors to be declared
600 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
602 -- type instance declarations
603 | 'type' 'instance' type '=' ctype
604 -- Note the use of type for the head; this allows
605 -- infix type constructors and type patterns
606 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
608 -- ordinary data type or newtype declaration
609 | data_or_newtype tycl_hdr constrs deriving
610 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
611 Nothing (reverse (unLoc $3)) (unLoc $4) }
612 -- We need the location on tycl_hdr in case
613 -- constrs and deriving are both empty
615 -- ordinary GADT declaration
616 | data_or_newtype tycl_hdr opt_kind_sig
619 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
620 (unLoc $3) (unLoc $4) (unLoc $5) }
621 -- We need the location on tycl_hdr in case
622 -- constrs and deriving are both empty
624 -- data/newtype family
625 | 'data' 'family' type opt_kind_sig
626 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
628 -- data/newtype instance declaration
629 | data_or_newtype 'instance' tycl_hdr constrs deriving
630 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
631 Nothing (reverse (unLoc $4)) (unLoc $5) }
633 -- GADT instance declaration
634 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
637 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
638 (unLoc $4) (unLoc $5) (unLoc $6) }
640 -- Associated type family declarations
642 -- * They have a different syntax than on the toplevel (no family special
645 -- * They also need to be separate from instances; otherwise, data family
646 -- declarations without a kind signature cause parsing conflicts with empty
647 -- data declarations.
649 at_decl_cls :: { LTyClDecl RdrName }
650 -- type family declarations
651 : 'type' type opt_kind_sig
652 -- Note the use of type for the head; this allows
653 -- infix type constructors to be declared
654 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
656 -- default type instance
657 | 'type' type '=' ctype
658 -- Note the use of type for the head; this allows
659 -- infix type constructors and type patterns
660 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
662 -- data/newtype family declaration
663 | 'data' type opt_kind_sig
664 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
666 -- Associated type instances
668 at_decl_inst :: { LTyClDecl RdrName }
669 -- type instance declarations
670 : 'type' type '=' ctype
671 -- Note the use of type for the head; this allows
672 -- infix type constructors and type patterns
673 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
675 -- data/newtype instance declaration
676 | data_or_newtype tycl_hdr constrs deriving
677 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
678 Nothing (reverse (unLoc $3)) (unLoc $4) }
680 -- GADT instance declaration
681 | data_or_newtype tycl_hdr opt_kind_sig
684 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
685 (unLoc $3) (unLoc $4) (unLoc $5) }
687 data_or_newtype :: { Located NewOrData }
688 : 'data' { L1 DataType }
689 | 'newtype' { L1 NewType }
691 opt_kind_sig :: { Located (Maybe Kind) }
693 | '::' kind { LL (Just (unLoc $2)) }
695 -- tycl_hdr parses the header of a class or data type decl,
696 -- which takes the form
699 -- (Eq a, Ord b) => T a b
700 -- T Int [a] -- for associated types
701 -- Rather a lot of inlining here, else we get reduce/reduce errors
702 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
703 : context '=>' type { LL (Just $1, $3) }
704 | type { L1 (Nothing, $1) }
706 -----------------------------------------------------------------------------
707 -- Stand-alone deriving
709 -- Glasgow extension: stand-alone deriving declarations
710 stand_alone_deriving :: { LDerivDecl RdrName }
711 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
713 -----------------------------------------------------------------------------
714 -- Nested declarations
716 -- Declaration in class bodies
718 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
719 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
722 -- A 'default' signature used with the generic-programming extension
723 | 'default' infixexp '::' sigtypedoc
724 {% do { (TypeSig l ty) <- checkValSig $2 $4
725 ; return (LL $ unitOL (LL $ SigD (GenericSig l ty))) } }
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 -- An inst_type is what occurs in the head of an instance decl
1030 -- e.g. (Foo a, Gaz b) => Wibble a b
1031 -- It's kept as a single type, with a MonoDictTy at the right
1032 -- hand corner, for convenience.
1033 inst_type :: { LHsType RdrName }
1034 : sigtype {% checkInstType $1 }
1036 inst_types1 :: { [LHsType RdrName] }
1037 : inst_type { [$1] }
1038 | inst_type ',' inst_types1 { $1 : $3 }
1040 comma_types0 :: { [LHsType RdrName] }
1041 : comma_types1 { $1 }
1042 | {- empty -} { [] }
1044 comma_types1 :: { [LHsType RdrName] }
1046 | ctype ',' comma_types1 { $1 : $3 }
1048 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1049 : tv_bndr tv_bndrs { $1 : $2 }
1050 | {- empty -} { [] }
1052 tv_bndr :: { LHsTyVarBndr RdrName }
1053 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1054 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1057 fds :: { Located [Located (FunDep RdrName)] }
1058 : {- empty -} { noLoc [] }
1059 | '|' fds1 { LL (reverse (unLoc $2)) }
1061 fds1 :: { Located [Located (FunDep RdrName)] }
1062 : fds1 ',' fd { LL ($3 : unLoc $1) }
1065 fd :: { Located (FunDep RdrName) }
1066 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1067 (reverse (unLoc $1), reverse (unLoc $3)) }
1069 varids0 :: { Located [RdrName] }
1070 : {- empty -} { noLoc [] }
1071 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1073 -----------------------------------------------------------------------------
1076 kind :: { Located Kind }
1078 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1080 akind :: { Located Kind }
1081 : '*' { L1 liftedTypeKind }
1082 | '!' { L1 unliftedTypeKind }
1083 | '(' kind ')' { LL (unLoc $2) }
1086 -----------------------------------------------------------------------------
1087 -- Datatype declarations
1089 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1090 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1091 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1092 | {- empty -} { noLoc [] }
1094 gadt_constrs :: { Located [LConDecl RdrName] }
1095 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1096 | gadt_constr { L (getLoc (head $1)) $1 }
1097 | {- empty -} { noLoc [] }
1099 -- We allow the following forms:
1100 -- C :: Eq a => a -> T a
1101 -- C :: forall a. Eq a => !a -> T a
1102 -- D { x,y :: a } :: T a
1103 -- forall a. Eq a => D { x,y :: a } :: T a
1105 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1106 : con_list '::' sigtype
1107 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1109 -- Deprecated syntax for GADT record declarations
1110 | oqtycon '{' fielddecls '}' '::' sigtype
1111 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1114 constrs :: { Located [LConDecl RdrName] }
1115 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1117 constrs1 :: { Located [LConDecl RdrName] }
1118 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1119 | constr { L1 [$1] }
1121 constr :: { LConDecl RdrName }
1122 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1123 { let (con,details) = unLoc $5 in
1124 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1126 | maybe_docnext forall constr_stuff maybe_docprev
1127 { let (con,details) = unLoc $3 in
1128 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1131 forall :: { Located [LHsTyVarBndr RdrName] }
1132 : 'forall' tv_bndrs '.' { LL $2 }
1133 | {- empty -} { noLoc [] }
1135 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1136 -- We parse the constructor declaration
1138 -- as a btype (treating C as a type constructor) and then convert C to be
1139 -- a data constructor. Reason: it might continue like this:
1141 -- in which case C really would be a type constructor. We can't resolve this
1142 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1143 : btype {% splitCon $1 >>= return.LL }
1144 | btype conop btype { LL ($2, InfixCon $1 $3) }
1146 fielddecls :: { [ConDeclField RdrName] }
1147 : {- empty -} { [] }
1148 | fielddecls1 { $1 }
1150 fielddecls1 :: { [ConDeclField RdrName] }
1151 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1152 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1153 -- This adds the doc $4 to each field separately
1156 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1157 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1158 | fld <- reverse (unLoc $2) ] }
1160 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1161 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1162 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1163 -- We don't allow a context, but that's sorted out by the type checker.
1164 deriving :: { Located (Maybe [LHsType RdrName]) }
1165 : {- empty -} { noLoc Nothing }
1166 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1167 ; p <- checkInstType (L loc (HsTyVar tv))
1168 ; return (LL (Just [p])) } }
1169 | 'deriving' '(' ')' { LL (Just []) }
1170 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1171 -- Glasgow extension: allow partial
1172 -- applications in derivings
1174 -----------------------------------------------------------------------------
1175 -- Value definitions
1177 {- Note [Declaration/signature overlap]
1178 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1179 There's an awkward overlap with a type signature. Consider
1180 f :: Int -> Int = ...rhs...
1181 Then we can't tell whether it's a type signature or a value
1182 definition with a result signature until we see the '='.
1183 So we have to inline enough to postpone reductions until we know.
1187 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1188 instead of qvar, we get another shift/reduce-conflict. Consider the
1191 { (^^) :: Int->Int ; } Type signature; only var allowed
1193 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1194 qvar allowed (because of instance decls)
1196 We can't tell whether to reduce var to qvar until after we've read the signatures.
1199 docdecl :: { LHsDecl RdrName }
1200 : docdecld { L1 (DocD (unLoc $1)) }
1202 docdecld :: { LDocDecl }
1203 : docnext { L1 (DocCommentNext (unLoc $1)) }
1204 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1205 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1206 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1208 decl :: { Located (OrdList (LHsDecl RdrName)) }
1211 | '!' aexp rhs {% do { let { e = LL (SectionR (LL (HsVar bang_RDR)) $2) };
1212 pat <- checkPattern e;
1213 return $ LL $ unitOL $ LL $ ValD $
1214 PatBind pat (unLoc $3)
1215 placeHolderType placeHolderNames } }
1216 -- Turn it all into an expression so that
1217 -- checkPattern can check that bangs are enabled
1219 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1220 let { l = comb2 $1 $> };
1221 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1222 | docdecl { LL $ unitOL $1 }
1224 rhs :: { Located (GRHSs RdrName) }
1225 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1226 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1228 gdrhs :: { Located [LGRHS RdrName] }
1229 : gdrhs gdrh { LL ($2 : unLoc $1) }
1232 gdrh :: { LGRHS RdrName }
1233 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1235 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1237 -- See Note [Declaration/signature overlap] for why we need infixexp here
1238 infixexp '::' sigtypedoc
1239 {% do s <- checkValSig $1 $3
1240 ; return (LL $ unitOL (LL $ SigD s)) }
1241 | var ',' sig_vars '::' sigtypedoc
1242 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1243 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1245 | '{-# INLINE' activation qvar '#-}'
1246 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma (getINLINE $1) $2))) }
1247 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1248 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1250 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1251 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma (getSPEC_INLINE $1) $2))
1253 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1254 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1256 -----------------------------------------------------------------------------
1259 quasiquote :: { Located (HsQuasiQuote RdrName) }
1260 : TH_QUASIQUOTE { let { loc = getLoc $1
1261 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1262 ; quoterId = mkUnqual varName quoter }
1263 in L1 (mkHsQuasiQuote quoterId (RealSrcSpan quoteSpan) quote) }
1265 exp :: { LHsExpr RdrName }
1266 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1267 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1268 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1269 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1270 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1273 infixexp :: { LHsExpr RdrName }
1275 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1277 exp10 :: { LHsExpr RdrName }
1278 : '\\' apat apats opt_asig '->' exp
1279 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1282 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1283 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1284 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1285 return (LL $ mkHsIf $2 $5 $8) }
1286 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1287 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1289 | 'do' stmtlist { L (comb2 $1 $2) (mkHsDo DoExpr (unLoc $2)) }
1290 | 'mdo' stmtlist { L (comb2 $1 $2) (mkHsDo MDoExpr (unLoc $2)) }
1292 | scc_annot exp { LL $ if opt_SccProfilingOn
1293 then HsSCC (unLoc $1) $2
1295 | hpc_annot exp { LL $ if opt_Hpc
1296 then HsTickPragma (unLoc $1) $2
1299 | 'proc' aexp '->' exp
1300 {% checkPattern $2 >>= \ p ->
1301 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1302 placeHolderType undefined)) }
1303 -- TODO: is LL right here?
1305 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1306 -- hdaume: core annotation
1311 | {- empty -} { False }
1313 scc_annot :: { Located FastString }
1314 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1315 ( do scc <- getSCC $2; return $ LL scc ) }
1316 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1318 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1319 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1320 { LL $ (getSTRING $2
1321 ,( fromInteger $ getINTEGER $3
1322 , fromInteger $ getINTEGER $5
1324 ,( fromInteger $ getINTEGER $7
1325 , fromInteger $ getINTEGER $9
1330 fexp :: { LHsExpr RdrName }
1331 : fexp aexp { LL $ HsApp $1 $2 }
1334 aexp :: { LHsExpr RdrName }
1335 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1336 | '~' aexp { LL $ ELazyPat $2 }
1339 aexp1 :: { LHsExpr RdrName }
1340 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1344 -- Here was the syntax for type applications that I was planning
1345 -- but there are difficulties (e.g. what order for type args)
1346 -- so it's not enabled yet.
1347 -- But this case *is* used for the left hand side of a generic definition,
1348 -- which is parsed as an expression before being munged into a pattern
1349 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1350 (sL (getLoc $3) (HsType $3)) }
1352 aexp2 :: { LHsExpr RdrName }
1353 : ipvar { L1 (HsIPVar $! unLoc $1) }
1354 | qcname { L1 (HsVar $! unLoc $1) }
1355 | literal { L1 (HsLit $! unLoc $1) }
1356 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1357 -- into HsOverLit when -foverloaded-strings is on.
1358 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1359 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1360 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1362 -- N.B.: sections get parsed by these next two productions.
1363 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't
1364 -- correct Haskell (you'd have to write '((+ 3), (4 -))')
1365 -- but the less cluttered version fell out of having texps.
1366 | '(' texp ')' { LL (HsPar $2) }
1367 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1369 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1370 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1372 | '[' list ']' { LL (unLoc $2) }
1373 | '[:' parr ':]' { LL (unLoc $2) }
1374 | '_' { L1 EWildPat }
1376 -- Template Haskell Extension
1377 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1378 (L1 $ HsVar (mkUnqual varName
1379 (getTH_ID_SPLICE $1)))) }
1380 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1383 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1384 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1385 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1386 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1387 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1388 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1389 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1390 return (LL $ HsBracket (PatBr p)) }
1391 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1392 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1394 -- arrow notation extension
1395 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1397 cmdargs :: { [LHsCmdTop RdrName] }
1398 : cmdargs acmd { $2 : $1 }
1399 | {- empty -} { [] }
1401 acmd :: { LHsCmdTop RdrName }
1402 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1404 cvtopbody :: { [LHsDecl RdrName] }
1405 : '{' cvtopdecls0 '}' { $2 }
1406 | vocurly cvtopdecls0 close { $2 }
1408 cvtopdecls0 :: { [LHsDecl RdrName] }
1409 : {- empty -} { [] }
1412 -----------------------------------------------------------------------------
1413 -- Tuple expressions
1415 -- "texp" is short for tuple expressions:
1416 -- things that can appear unparenthesized as long as they're
1417 -- inside parens or delimitted by commas
1418 texp :: { LHsExpr RdrName }
1421 -- Note [Parsing sections]
1422 -- ~~~~~~~~~~~~~~~~~~~~~~~
1423 -- We include left and right sections here, which isn't
1424 -- technically right according to the Haskell standard.
1425 -- For example (3 +, True) isn't legal.
1426 -- However, we want to parse bang patterns like
1428 -- and it's convenient to do so here as a section
1429 -- Then when converting expr to pattern we unravel it again
1430 -- Meanwhile, the renamer checks that real sections appear
1432 | infixexp qop { LL $ SectionL $1 $2 }
1433 | qopm infixexp { LL $ SectionR $1 $2 }
1435 -- View patterns get parenthesized above
1436 | exp '->' texp { LL $ EViewPat $1 $3 }
1438 -- Always at least one comma
1439 tup_exprs :: { [HsTupArg RdrName] }
1440 : texp commas_tup_tail { Present $1 : $2 }
1441 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1443 -- Always starts with commas; always follows an expr
1444 commas_tup_tail :: { [HsTupArg RdrName] }
1445 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1447 -- Always follows a comma
1448 tup_tail :: { [HsTupArg RdrName] }
1449 : texp commas_tup_tail { Present $1 : $2 }
1450 | texp { [Present $1] }
1451 | {- empty -} { [missingTupArg] }
1453 -----------------------------------------------------------------------------
1456 -- The rules below are little bit contorted to keep lexps left-recursive while
1457 -- avoiding another shift/reduce-conflict.
1459 list :: { LHsExpr RdrName }
1460 : texp { L1 $ ExplicitList placeHolderType [$1] }
1461 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1462 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1463 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1464 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1465 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1466 | texp '|' flattenedpquals
1467 {% checkMonadComp >>= \ ctxt ->
1468 return (sL (comb2 $1 $>) $
1469 mkHsComp ctxt (unLoc $3) $1) }
1471 lexps :: { Located [LHsExpr RdrName] }
1472 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1473 | texp ',' texp { LL [$3,$1] }
1475 -----------------------------------------------------------------------------
1476 -- List Comprehensions
1478 flattenedpquals :: { Located [LStmt RdrName] }
1479 : pquals { case (unLoc $1) of
1481 -- We just had one thing in our "parallel" list so
1482 -- we simply return that thing directly
1484 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss] noSyntaxExpr noSyntaxExpr noSyntaxExpr]
1485 -- We actually found some actual parallel lists so
1486 -- we wrap them into as a ParStmt
1489 pquals :: { Located [[LStmt RdrName]] }
1490 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1491 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1493 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1494 -- one can "grab" the earlier ones
1495 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1496 | squals ',' qual { LL ($3 : unLoc $1) }
1497 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1499 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1500 -- | '{|' pquals '|}' { L1 [$2] }
1503 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1504 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1507 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1508 -- Function is applied to a list of stmts *in order*
1509 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1511 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1512 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1514 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1515 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1516 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1517 -- choosing the "group by" variant, which is what we want.
1519 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1520 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1521 -- if /that/ is the group function we conflict with.
1522 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1523 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1525 -----------------------------------------------------------------------------
1526 -- Parallel array expressions
1528 -- The rules below are little bit contorted; see the list case for details.
1529 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1530 -- Moreover, we allow explicit arrays with no element (represented by the nil
1531 -- constructor in the list case).
1533 parr :: { LHsExpr RdrName }
1534 : { noLoc (ExplicitPArr placeHolderType []) }
1535 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1536 | lexps { L1 $ ExplicitPArr placeHolderType
1537 (reverse (unLoc $1)) }
1538 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1539 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1540 | texp '|' flattenedpquals { LL $ mkHsComp PArrComp (unLoc $3) $1 }
1542 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1544 -----------------------------------------------------------------------------
1547 guardquals :: { Located [LStmt RdrName] }
1548 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1550 guardquals1 :: { Located [LStmt RdrName] }
1551 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1554 -----------------------------------------------------------------------------
1555 -- Case alternatives
1557 altslist :: { Located [LMatch RdrName] }
1558 : '{' alts '}' { LL (reverse (unLoc $2)) }
1559 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1561 alts :: { Located [LMatch RdrName] }
1562 : alts1 { L1 (unLoc $1) }
1563 | ';' alts { LL (unLoc $2) }
1565 alts1 :: { Located [LMatch RdrName] }
1566 : alts1 ';' alt { LL ($3 : unLoc $1) }
1567 | alts1 ';' { LL (unLoc $1) }
1570 alt :: { LMatch RdrName }
1571 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1573 alt_rhs :: { Located (GRHSs RdrName) }
1574 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1576 ralt :: { Located [LGRHS RdrName] }
1577 : '->' exp { LL (unguardedRHS $2) }
1578 | gdpats { L1 (reverse (unLoc $1)) }
1580 gdpats :: { Located [LGRHS RdrName] }
1581 : gdpats gdpat { LL ($2 : unLoc $1) }
1584 gdpat :: { LGRHS RdrName }
1585 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1587 -- 'pat' recognises a pattern, including one with a bang at the top
1588 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1589 -- Bangs inside are parsed as infix operator applications, so that
1590 -- we parse them right when bang-patterns are off
1591 pat :: { LPat RdrName }
1592 pat : exp {% checkPattern $1 }
1593 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1595 apat :: { LPat RdrName }
1596 apat : aexp {% checkPattern $1 }
1597 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1599 apats :: { [LPat RdrName] }
1600 : apat apats { $1 : $2 }
1601 | {- empty -} { [] }
1603 -----------------------------------------------------------------------------
1604 -- Statement sequences
1606 stmtlist :: { Located [LStmt RdrName] }
1607 : '{' stmts '}' { LL (unLoc $2) }
1608 | vocurly stmts close { $2 }
1610 -- do { ;; s ; s ; ; s ;; }
1611 -- The last Stmt should be an expression, but that's hard to enforce
1612 -- here, because we need too much lookahead if we see do { e ; }
1613 -- So we use ExprStmts throughout, and switch the last one over
1614 -- in ParseUtils.checkDo instead
1615 stmts :: { Located [LStmt RdrName] }
1616 : stmt stmts_help { LL ($1 : unLoc $2) }
1617 | ';' stmts { LL (unLoc $2) }
1618 | {- empty -} { noLoc [] }
1620 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1621 : ';' stmts { LL (unLoc $2) }
1622 | {- empty -} { noLoc [] }
1624 -- For typing stmts at the GHCi prompt, where
1625 -- the input may consist of just comments.
1626 maybe_stmt :: { Maybe (LStmt RdrName) }
1628 | {- nothing -} { Nothing }
1630 stmt :: { LStmt RdrName }
1632 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1634 qual :: { LStmt RdrName }
1635 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1636 | exp { L1 $ mkExprStmt $1 }
1637 | 'let' binds { LL $ LetStmt (unLoc $2) }
1639 -----------------------------------------------------------------------------
1640 -- Record Field Update/Construction
1642 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1644 | {- empty -} { ([], False) }
1646 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1647 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1648 | fbind { ([$1], False) }
1649 | '..' { ([], True) }
1651 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1652 : qvar '=' exp { HsRecField $1 $3 False }
1653 | qvar { HsRecField $1 placeHolderPunRhs True }
1654 -- In the punning case, use a place-holder
1655 -- The renamer fills in the final value
1657 -----------------------------------------------------------------------------
1658 -- Implicit Parameter Bindings
1660 dbinds :: { Located [LIPBind RdrName] }
1661 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1662 in rest `seq` this `seq` LL (this : rest) }
1663 | dbinds ';' { LL (unLoc $1) }
1664 | dbind { let this = $1 in this `seq` L1 [this] }
1665 -- | {- empty -} { [] }
1667 dbind :: { LIPBind RdrName }
1668 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1670 ipvar :: { Located (IPName RdrName) }
1671 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1673 -----------------------------------------------------------------------------
1674 -- Warnings and deprecations
1676 namelist :: { Located [RdrName] }
1677 namelist : name_var { L1 [unLoc $1] }
1678 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1680 name_var :: { Located RdrName }
1681 name_var : var { $1 }
1684 -----------------------------------------
1685 -- Data constructors
1686 qcon :: { Located RdrName }
1688 | '(' qconsym ')' { LL (unLoc $2) }
1689 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1690 -- The case of '[:' ':]' is part of the production `parr'
1692 con :: { Located RdrName }
1694 | '(' consym ')' { LL (unLoc $2) }
1695 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1697 con_list :: { Located [Located RdrName] }
1698 con_list : con { L1 [$1] }
1699 | con ',' con_list { LL ($1 : unLoc $3) }
1701 sysdcon :: { Located DataCon } -- Wired in data constructors
1702 : '(' ')' { LL unitDataCon }
1703 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1704 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1705 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1706 | '[' ']' { LL nilDataCon }
1708 conop :: { Located RdrName }
1710 | '`' conid '`' { LL (unLoc $2) }
1712 qconop :: { Located RdrName }
1714 | '`' qconid '`' { LL (unLoc $2) }
1716 -----------------------------------------------------------------------------
1717 -- Type constructors
1719 gtycon :: { Located RdrName } -- A "general" qualified tycon
1721 | '(' ')' { LL $ getRdrName unitTyCon }
1722 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1723 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1724 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1725 | '(' '->' ')' { LL $ getRdrName funTyCon }
1726 | '[' ']' { LL $ listTyCon_RDR }
1727 | '[:' ':]' { LL $ parrTyCon_RDR }
1729 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1731 | '(' qtyconsym ')' { LL (unLoc $2) }
1733 qtyconop :: { Located RdrName } -- Qualified or unqualified
1735 | '`' qtycon '`' { LL (unLoc $2) }
1737 qtycon :: { Located RdrName } -- Qualified or unqualified
1738 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1739 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1742 tycon :: { Located RdrName } -- Unqualified
1743 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1745 qtyconsym :: { Located RdrName }
1746 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1749 tyconsym :: { Located RdrName }
1750 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1752 -----------------------------------------------------------------------------
1755 op :: { Located RdrName } -- used in infix decls
1759 varop :: { Located RdrName }
1761 | '`' varid '`' { LL (unLoc $2) }
1763 qop :: { LHsExpr RdrName } -- used in sections
1764 : qvarop { L1 $ HsVar (unLoc $1) }
1765 | qconop { L1 $ HsVar (unLoc $1) }
1767 qopm :: { LHsExpr RdrName } -- used in sections
1768 : qvaropm { L1 $ HsVar (unLoc $1) }
1769 | qconop { L1 $ HsVar (unLoc $1) }
1771 qvarop :: { Located RdrName }
1773 | '`' qvarid '`' { LL (unLoc $2) }
1775 qvaropm :: { Located RdrName }
1776 : qvarsym_no_minus { $1 }
1777 | '`' qvarid '`' { LL (unLoc $2) }
1779 -----------------------------------------------------------------------------
1782 tyvar :: { Located RdrName }
1783 tyvar : tyvarid { $1 }
1784 | '(' tyvarsym ')' { LL (unLoc $2) }
1786 tyvarop :: { Located RdrName }
1787 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1789 | '.' {% parseErrorSDoc (getLoc $1)
1790 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1791 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1792 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1795 tyvarid :: { Located RdrName }
1796 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1797 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1798 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1799 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1800 | 'interruptible' { L1 $! mkUnqual tvName (fsLit "interruptible") }
1801 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1803 tyvarsym :: { Located RdrName }
1804 -- Does not include "!", because that is used for strictness marks
1805 -- or ".", because that separates the quantified type vars from the rest
1806 -- or "*", because that's used for kinds
1807 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1809 -----------------------------------------------------------------------------
1812 var :: { Located RdrName }
1814 | '(' varsym ')' { LL (unLoc $2) }
1816 qvar :: { Located RdrName }
1818 | '(' varsym ')' { LL (unLoc $2) }
1819 | '(' qvarsym1 ')' { LL (unLoc $2) }
1820 -- We've inlined qvarsym here so that the decision about
1821 -- whether it's a qvar or a var can be postponed until
1822 -- *after* we see the close paren.
1824 qvarid :: { Located RdrName }
1826 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1827 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1829 varid :: { Located RdrName }
1830 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1831 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1832 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1833 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1834 | 'interruptible' { L1 $! mkUnqual varName (fsLit "interruptible") }
1835 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1836 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1837 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1839 qvarsym :: { Located RdrName }
1843 qvarsym_no_minus :: { Located RdrName }
1844 : varsym_no_minus { $1 }
1847 qvarsym1 :: { Located RdrName }
1848 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1850 varsym :: { Located RdrName }
1851 : varsym_no_minus { $1 }
1852 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1854 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1855 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1856 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1859 -- These special_ids are treated as keywords in various places,
1860 -- but as ordinary ids elsewhere. 'special_id' collects all these
1861 -- except 'unsafe', 'interruptible', 'forall', and 'family' whose treatment differs
1862 -- depending on context
1863 special_id :: { Located FastString }
1865 : 'as' { L1 (fsLit "as") }
1866 | 'qualified' { L1 (fsLit "qualified") }
1867 | 'hiding' { L1 (fsLit "hiding") }
1868 | 'export' { L1 (fsLit "export") }
1869 | 'label' { L1 (fsLit "label") }
1870 | 'dynamic' { L1 (fsLit "dynamic") }
1871 | 'stdcall' { L1 (fsLit "stdcall") }
1872 | 'ccall' { L1 (fsLit "ccall") }
1873 | 'prim' { L1 (fsLit "prim") }
1874 | 'group' { L1 (fsLit "group") }
1876 special_sym :: { Located FastString }
1877 special_sym : '!' { L1 (fsLit "!") }
1878 | '.' { L1 (fsLit ".") }
1879 | '*' { L1 (fsLit "*") }
1881 -----------------------------------------------------------------------------
1882 -- Data constructors
1884 qconid :: { Located RdrName } -- Qualified or unqualified
1886 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1887 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1889 conid :: { Located RdrName }
1890 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1892 qconsym :: { Located RdrName } -- Qualified or unqualified
1894 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1896 consym :: { Located RdrName }
1897 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1899 -- ':' means only list cons
1900 | ':' { L1 $ consDataCon_RDR }
1903 -----------------------------------------------------------------------------
1906 literal :: { Located HsLit }
1907 : CHAR { L1 $ HsChar $ getCHAR $1 }
1908 | STRING { L1 $ HsString $ getSTRING $1 }
1909 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1910 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1911 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1912 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1913 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1914 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1916 -----------------------------------------------------------------------------
1920 : vccurly { () } -- context popped in lexer.
1921 | error {% popContext }
1923 -----------------------------------------------------------------------------
1924 -- Miscellaneous (mostly renamings)
1926 modid :: { Located ModuleName }
1927 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1928 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1931 (unpackFS mod ++ '.':unpackFS c))
1935 : commas ',' { $1 + 1 }
1938 -----------------------------------------------------------------------------
1939 -- Documentation comments
1941 docnext :: { LHsDocString }
1942 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1944 docprev :: { LHsDocString }
1945 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1947 docnamed :: { Located (String, HsDocString) }
1949 let string = getDOCNAMED $1
1950 (name, rest) = break isSpace string
1951 in return (L1 (name, HsDocString (mkFastString rest))) }
1953 docsection :: { Located (Int, HsDocString) }
1954 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1955 return (L1 (n, HsDocString (mkFastString doc))) }
1957 moduleheader :: { Maybe LHsDocString }
1958 : DOCNEXT {% let string = getDOCNEXT $1 in
1959 return (Just (L1 (HsDocString (mkFastString string)))) }
1961 maybe_docprev :: { Maybe LHsDocString }
1962 : docprev { Just $1 }
1963 | {- empty -} { Nothing }
1965 maybe_docnext :: { Maybe LHsDocString }
1966 : docnext { Just $1 }
1967 | {- empty -} { Nothing }
1971 happyError = srcParseFail
1973 getVARID (L _ (ITvarid x)) = x
1974 getCONID (L _ (ITconid x)) = x
1975 getVARSYM (L _ (ITvarsym x)) = x
1976 getCONSYM (L _ (ITconsym x)) = x
1977 getQVARID (L _ (ITqvarid x)) = x
1978 getQCONID (L _ (ITqconid x)) = x
1979 getQVARSYM (L _ (ITqvarsym x)) = x
1980 getQCONSYM (L _ (ITqconsym x)) = x
1981 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1982 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1983 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1984 getCHAR (L _ (ITchar x)) = x
1985 getSTRING (L _ (ITstring x)) = x
1986 getINTEGER (L _ (ITinteger x)) = x
1987 getRATIONAL (L _ (ITrational x)) = x
1988 getPRIMCHAR (L _ (ITprimchar x)) = x
1989 getPRIMSTRING (L _ (ITprimstring x)) = x
1990 getPRIMINTEGER (L _ (ITprimint x)) = x
1991 getPRIMWORD (L _ (ITprimword x)) = x
1992 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1993 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1994 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1995 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
1996 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
1997 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
1999 getDOCNEXT (L _ (ITdocCommentNext x)) = x
2000 getDOCPREV (L _ (ITdocCommentPrev x)) = x
2001 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
2002 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2004 getSCC :: Located Token -> P FastString
2005 getSCC lt = do let s = getSTRING lt
2006 err = "Spaces are not allowed in SCCs"
2007 -- We probably actually want to be more restrictive than this
2008 if ' ' `elem` unpackFS s
2009 then failSpanMsgP (getLoc lt) (text err)
2012 -- Utilities for combining source spans
2013 comb2 :: Located a -> Located b -> SrcSpan
2014 comb2 a b = a `seq` b `seq` combineLocs a b
2016 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2017 comb3 a b c = a `seq` b `seq` c `seq`
2018 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2020 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2021 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2022 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2023 combineSrcSpans (getLoc c) (getLoc d))
2025 -- strict constructor version:
2027 sL :: SrcSpan -> a -> Located a
2028 sL span a = span `seq` a `seq` L span a
2030 -- Make a source location for the file. We're a bit lazy here and just
2031 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2032 -- try to find the span of the whole file (ToDo).
2033 fileSrcSpan :: P SrcSpan
2036 let loc = mkSrcLoc (srcLocFile l) 1 1;
2037 return (mkSrcSpan loc loc)