2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
12 {-# OPTIONS -Wwarn -w #-}
13 -- The above warning supression flag is a temporary kludge.
14 -- While working on this module you are encouraged to remove it and fix
15 -- any warnings in the module. See
16 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
19 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
21 Careful optimisation of the parser: we don't want to throw everything
22 at it, because that takes too long and doesn't buy much, but we do want
23 to inline certain key external functions, so we instruct GHC not to
24 throw away inlinings as it would normally do in -O0 mode.
27 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
32 import HscTypes ( IsBootInterface, WarningTxt(..) )
35 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
36 unboxedSingletonTyCon, unboxedSingletonDataCon,
37 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
38 import Type ( funTyCon )
39 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
40 CCallConv(..), CCallTarget(..), defaultCCallConv
42 import OccName ( varName, dataName, tcClsName, tvName )
43 import DataCon ( DataCon, dataConName )
44 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
45 SrcSpan, combineLocs, srcLocFile,
48 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
49 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
50 import Coercion ( mkArrowKind )
51 import Class ( FunDep )
58 import Maybes ( orElse )
61 import Control.Monad ( unless )
64 import Control.Monad ( mplus )
68 -----------------------------------------------------------------------------
71 Conflicts: 33 shift/reduce
74 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
75 would think the two should never occur in the same context.
79 -----------------------------------------------------------------------------
82 Conflicts: 34 shift/reduce
85 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
86 would think the two should never occur in the same context.
90 -----------------------------------------------------------------------------
93 Conflicts: 32 shift/reduce
96 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
97 would think the two should never occur in the same context.
101 -----------------------------------------------------------------------------
104 Conflicts: 37 shift/reduce
107 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
108 would think the two should never occur in the same context.
112 -----------------------------------------------------------------------------
113 Conflicts: 38 shift/reduce (1.25)
115 10 for abiguity in 'if x then y else z + 1' [State 178]
116 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
117 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
119 1 for ambiguity in 'if x then y else z :: T' [State 178]
120 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
122 4 for ambiguity in 'if x then y else z -< e' [State 178]
123 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
124 There are four such operators: -<, >-, -<<, >>-
127 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
128 Which of these two is intended?
130 (x::T) -> T -- Rhs is T
133 (x::T -> T) -> .. -- Rhs is ...
135 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
138 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
139 Same duplication between states 11 and 253 as the previous case
141 1 for ambiguity in 'let ?x ...' [State 329]
142 the parser can't tell whether the ?x is the lhs of a normal binding or
143 an implicit binding. Fortunately resolving as shift gives it the only
144 sensible meaning, namely the lhs of an implicit binding.
146 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
147 we don't know whether the '[' starts the activation or not: it
148 might be the start of the declaration with the activation being
149 empty. --SDM 1/4/2002
151 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
152 since 'forall' is a valid variable name, we don't know whether
153 to treat a forall on the input as the beginning of a quantifier
154 or the beginning of the rule itself. Resolving to shift means
155 it's always treated as a quantifier, hence the above is disallowed.
156 This saves explicitly defining a grammar for the rule lhs that
157 doesn't include 'forall'.
159 1 for ambiguity when the source file starts with "-- | doc". We need another
160 token of lookahead to determine if a top declaration or the 'module' keyword
161 follows. Shift parses as if the 'module' keyword follows.
163 -- ---------------------------------------------------------------------------
164 -- Adding location info
166 This is done in a stylised way using the three macros below, L0, L1
167 and LL. Each of these macros can be thought of as having type
169 L0, L1, LL :: a -> Located a
171 They each add a SrcSpan to their argument.
173 L0 adds 'noSrcSpan', used for empty productions
174 -- This doesn't seem to work anymore -=chak
176 L1 for a production with a single token on the lhs. Grabs the SrcSpan
179 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
180 the first and last tokens.
182 These suffice for the majority of cases. However, we must be
183 especially careful with empty productions: LL won't work if the first
184 or last token on the lhs can represent an empty span. In these cases,
185 we have to calculate the span using more of the tokens from the lhs, eg.
187 | 'newtype' tycl_hdr '=' newconstr deriving
189 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
191 We provide comb3 and comb4 functions which are useful in such cases.
193 Be careful: there's no checking that you actually got this right, the
194 only symptom will be that the SrcSpans of your syntax will be
198 * We must expand these macros *before* running Happy, which is why this file is
199 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
201 #define L0 L noSrcSpan
202 #define L1 sL (getLoc $1)
203 #define LL sL (comb2 $1 $>)
205 -- -----------------------------------------------------------------------------
210 '_' { L _ ITunderscore } -- Haskell keywords
212 'case' { L _ ITcase }
213 'class' { L _ ITclass }
214 'data' { L _ ITdata }
215 'default' { L _ ITdefault }
216 'deriving' { L _ ITderiving }
218 'else' { L _ ITelse }
219 'hiding' { L _ IThiding }
221 'import' { L _ ITimport }
223 'infix' { L _ ITinfix }
224 'infixl' { L _ ITinfixl }
225 'infixr' { L _ ITinfixr }
226 'instance' { L _ ITinstance }
228 'module' { L _ ITmodule }
229 'newtype' { L _ ITnewtype }
231 'qualified' { L _ ITqualified }
232 'then' { L _ ITthen }
233 'type' { L _ ITtype }
234 'where' { L _ ITwhere }
235 '_scc_' { L _ ITscc } -- ToDo: remove
237 'forall' { L _ ITforall } -- GHC extension keywords
238 'foreign' { L _ ITforeign }
239 'export' { L _ ITexport }
240 'label' { L _ ITlabel }
241 'dynamic' { L _ ITdynamic }
242 'safe' { L _ ITsafe }
243 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
244 'interruptible' { L _ ITinterruptible }
245 'unsafe' { L _ ITunsafe }
247 'family' { L _ ITfamily }
248 'stdcall' { L _ ITstdcallconv }
249 'ccall' { L _ ITccallconv }
250 'prim' { L _ ITprimcallconv }
251 'proc' { L _ ITproc } -- for arrow notation extension
252 'rec' { L _ ITrec } -- for arrow notation extension
253 'group' { L _ ITgroup } -- for list transform extension
254 'by' { L _ ITby } -- for list transform extension
255 'using' { L _ ITusing } -- for list transform extension
257 '{-# INLINE' { L _ (ITinline_prag _ _) }
258 '{-# SPECIALISE' { L _ ITspec_prag }
259 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
260 '{-# SOURCE' { L _ ITsource_prag }
261 '{-# RULES' { L _ ITrules_prag }
262 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
263 '{-# SCC' { L _ ITscc_prag }
264 '{-# GENERATED' { L _ ITgenerated_prag }
265 '{-# DEPRECATED' { L _ ITdeprecated_prag }
266 '{-# WARNING' { L _ ITwarning_prag }
267 '{-# UNPACK' { L _ ITunpack_prag }
268 '{-# ANN' { L _ ITann_prag }
269 '#-}' { L _ ITclose_prag }
271 '..' { L _ ITdotdot } -- reserved symbols
273 '::' { L _ ITdcolon }
277 '<-' { L _ ITlarrow }
278 '->' { L _ ITrarrow }
281 '=>' { L _ ITdarrow }
285 '-<' { L _ ITlarrowtail } -- for arrow notation
286 '>-' { L _ ITrarrowtail } -- for arrow notation
287 '-<<' { L _ ITLarrowtail } -- for arrow notation
288 '>>-' { L _ ITRarrowtail } -- for arrow notation
291 '{' { L _ ITocurly } -- special symbols
293 '{|' { L _ ITocurlybar }
294 '|}' { L _ ITccurlybar }
295 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
296 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
299 '[:' { L _ ITopabrack }
300 ':]' { L _ ITcpabrack }
303 '(#' { L _ IToubxparen }
304 '#)' { L _ ITcubxparen }
305 '(|' { L _ IToparenbar }
306 '|)' { L _ ITcparenbar }
309 '`' { L _ ITbackquote }
311 VARID { L _ (ITvarid _) } -- identifiers
312 CONID { L _ (ITconid _) }
313 VARSYM { L _ (ITvarsym _) }
314 CONSYM { L _ (ITconsym _) }
315 QVARID { L _ (ITqvarid _) }
316 QCONID { L _ (ITqconid _) }
317 QVARSYM { L _ (ITqvarsym _) }
318 QCONSYM { L _ (ITqconsym _) }
319 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
320 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
322 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
324 CHAR { L _ (ITchar _) }
325 STRING { L _ (ITstring _) }
326 INTEGER { L _ (ITinteger _) }
327 RATIONAL { L _ (ITrational _) }
329 PRIMCHAR { L _ (ITprimchar _) }
330 PRIMSTRING { L _ (ITprimstring _) }
331 PRIMINTEGER { L _ (ITprimint _) }
332 PRIMWORD { L _ (ITprimword _) }
333 PRIMFLOAT { L _ (ITprimfloat _) }
334 PRIMDOUBLE { L _ (ITprimdouble _) }
336 DOCNEXT { L _ (ITdocCommentNext _) }
337 DOCPREV { L _ (ITdocCommentPrev _) }
338 DOCNAMED { L _ (ITdocCommentNamed _) }
339 DOCSECTION { L _ (ITdocSection _ _) }
342 '[|' { L _ ITopenExpQuote }
343 '[p|' { L _ ITopenPatQuote }
344 '[t|' { L _ ITopenTypQuote }
345 '[d|' { L _ ITopenDecQuote }
346 '|]' { L _ ITcloseQuote }
347 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
348 '$(' { L _ ITparenEscape } -- $( exp )
349 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
350 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
351 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
353 %monad { P } { >>= } { return }
354 %lexer { lexer } { L _ ITeof }
355 %name parseModule module
356 %name parseStmt maybe_stmt
357 %name parseIdentifier identifier
358 %name parseType ctype
359 %partial parseHeader header
360 %tokentype { (Located Token) }
363 -----------------------------------------------------------------------------
364 -- Identifiers; one of the entry points
365 identifier :: { Located RdrName }
370 | '(' '->' ')' { LL $ getRdrName funTyCon }
372 -----------------------------------------------------------------------------
375 -- The place for module deprecation is really too restrictive, but if it
376 -- was allowed at its natural place just before 'module', we get an ugly
377 -- s/r conflict with the second alternative. Another solution would be the
378 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
379 -- either, and DEPRECATED is only expected to be used by people who really
380 -- know what they are doing. :-)
382 module :: { Located (HsModule RdrName) }
383 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
384 {% fileSrcSpan >>= \ loc ->
385 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
388 {% fileSrcSpan >>= \ loc ->
389 return (L loc (HsModule Nothing Nothing
390 (fst $1) (snd $1) Nothing Nothing
393 maybedocheader :: { Maybe LHsDocString }
394 : moduleheader { $1 }
395 | {- empty -} { Nothing }
397 missing_module_keyword :: { () }
398 : {- empty -} {% pushCurrentContext }
400 maybemodwarning :: { Maybe WarningTxt }
401 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
402 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
403 | {- empty -} { Nothing }
405 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
407 | vocurly top close { $2 }
409 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
411 | missing_module_keyword top close { $2 }
413 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
414 : importdecls { (reverse $1,[]) }
415 | importdecls ';' cvtopdecls { (reverse $1,$3) }
416 | cvtopdecls { ([],$1) }
418 cvtopdecls :: { [LHsDecl RdrName] }
419 : topdecls { cvTopDecls $1 }
421 -----------------------------------------------------------------------------
422 -- Module declaration & imports only
424 header :: { Located (HsModule RdrName) }
425 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
426 {% fileSrcSpan >>= \ loc ->
427 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
429 | missing_module_keyword importdecls
430 {% fileSrcSpan >>= \ loc ->
431 return (L loc (HsModule Nothing Nothing $2 [] Nothing
434 header_body :: { [LImportDecl RdrName] }
435 : '{' importdecls { $2 }
436 | vocurly importdecls { $2 }
438 -----------------------------------------------------------------------------
441 maybeexports :: { Maybe [LIE RdrName] }
442 : '(' exportlist ')' { Just $2 }
443 | {- empty -} { Nothing }
445 exportlist :: { [LIE RdrName] }
446 : expdoclist ',' expdoclist { $1 ++ $3 }
449 exportlist1 :: { [LIE RdrName] }
450 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
451 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
454 expdoclist :: { [LIE RdrName] }
455 : exp_doc expdoclist { $1 : $2 }
458 exp_doc :: { LIE RdrName }
459 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
460 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
461 | docnext { L1 (IEDoc (unLoc $1)) }
463 -- No longer allow things like [] and (,,,) to be exported
464 -- They are built in syntax, always available
465 export :: { LIE RdrName }
466 : qvar { L1 (IEVar (unLoc $1)) }
467 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
468 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
469 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
470 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
471 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
473 qcnames :: { [RdrName] }
474 : qcnames ',' qcname_ext { unLoc $3 : $1 }
475 | qcname_ext { [unLoc $1] }
477 qcname_ext :: { Located RdrName } -- Variable or data constructor
478 -- or tagged type constructor
480 | 'type' qcon { sL (comb2 $1 $2)
481 (setRdrNameSpace (unLoc $2)
484 -- Cannot pull into qcname_ext, as qcname is also used in expression.
485 qcname :: { Located RdrName } -- Variable or data constructor
489 -----------------------------------------------------------------------------
490 -- Import Declarations
492 -- import decls can be *empty*, or even just a string of semicolons
493 -- whereas topdecls must contain at least one topdecl.
495 importdecls :: { [LImportDecl RdrName] }
496 : importdecls ';' importdecl { $3 : $1 }
497 | importdecls ';' { $1 }
498 | importdecl { [ $1 ] }
501 importdecl :: { LImportDecl RdrName }
502 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
503 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
505 maybe_src :: { IsBootInterface }
506 : '{-# SOURCE' '#-}' { True }
507 | {- empty -} { False }
509 maybe_pkg :: { Maybe FastString }
510 : STRING { Just (getSTRING $1) }
511 | {- empty -} { Nothing }
513 optqualified :: { Bool }
514 : 'qualified' { True }
515 | {- empty -} { False }
517 maybeas :: { Located (Maybe ModuleName) }
518 : 'as' modid { LL (Just (unLoc $2)) }
519 | {- empty -} { noLoc Nothing }
521 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
522 : impspec { L1 (Just (unLoc $1)) }
523 | {- empty -} { noLoc Nothing }
525 impspec :: { Located (Bool, [LIE RdrName]) }
526 : '(' exportlist ')' { LL (False, $2) }
527 | 'hiding' '(' exportlist ')' { LL (True, $3) }
529 -----------------------------------------------------------------------------
530 -- Fixity Declarations
534 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
536 infix :: { Located FixityDirection }
537 : 'infix' { L1 InfixN }
538 | 'infixl' { L1 InfixL }
539 | 'infixr' { L1 InfixR }
541 ops :: { Located [Located RdrName] }
542 : ops ',' op { LL ($3 : unLoc $1) }
545 -----------------------------------------------------------------------------
546 -- Top-Level Declarations
548 topdecls :: { OrdList (LHsDecl RdrName) }
549 : topdecls ';' topdecl { $1 `appOL` $3 }
550 | topdecls ';' { $1 }
553 topdecl :: { OrdList (LHsDecl RdrName) }
554 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
555 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
556 | 'instance' inst_type where_inst
557 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
559 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
560 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
561 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
562 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
563 | '{-# DEPRECATED' deprecations '#-}' { $2 }
564 | '{-# WARNING' warnings '#-}' { $2 }
565 | '{-# RULES' rules '#-}' { $2 }
566 | annotation { unitOL $1 }
569 -- Template Haskell Extension
570 -- The $(..) form is one possible form of infixexp
571 -- but we treat an arbitrary expression just as if
572 -- it had a $(..) wrapped around it
573 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
577 cl_decl :: { LTyClDecl RdrName }
578 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
580 -- Type declarations (toplevel)
582 ty_decl :: { LTyClDecl RdrName }
583 -- ordinary type synonyms
584 : 'type' type '=' ctypedoc
585 -- Note ctype, not sigtype, on the right of '='
586 -- We allow an explicit for-all but we don't insert one
587 -- in type Foo a = (b,b)
588 -- Instead we just say b is out of scope
590 -- Note the use of type for the head; this allows
591 -- infix type constructors to be declared
592 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
594 -- type family declarations
595 | 'type' 'family' type opt_kind_sig
596 -- Note the use of type for the head; this allows
597 -- infix type constructors to be declared
598 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
600 -- type instance declarations
601 | 'type' 'instance' type '=' ctype
602 -- Note the use of type for the head; this allows
603 -- infix type constructors and type patterns
604 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
606 -- ordinary data type or newtype declaration
607 | data_or_newtype tycl_hdr constrs deriving
608 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
609 Nothing (reverse (unLoc $3)) (unLoc $4) }
610 -- We need the location on tycl_hdr in case
611 -- constrs and deriving are both empty
613 -- ordinary GADT declaration
614 | data_or_newtype tycl_hdr opt_kind_sig
617 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
618 (unLoc $3) (unLoc $4) (unLoc $5) }
619 -- We need the location on tycl_hdr in case
620 -- constrs and deriving are both empty
622 -- data/newtype family
623 | 'data' 'family' type opt_kind_sig
624 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
626 -- data/newtype instance declaration
627 | data_or_newtype 'instance' tycl_hdr constrs deriving
628 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
629 Nothing (reverse (unLoc $4)) (unLoc $5) }
631 -- GADT instance declaration
632 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
635 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
636 (unLoc $4) (unLoc $5) (unLoc $6) }
638 -- Associated type family declarations
640 -- * They have a different syntax than on the toplevel (no family special
643 -- * They also need to be separate from instances; otherwise, data family
644 -- declarations without a kind signature cause parsing conflicts with empty
645 -- data declarations.
647 at_decl_cls :: { LTyClDecl RdrName }
648 -- type family declarations
649 : 'type' type opt_kind_sig
650 -- Note the use of type for the head; this allows
651 -- infix type constructors to be declared
652 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
654 -- default type instance
655 | 'type' type '=' ctype
656 -- Note the use of type for the head; this allows
657 -- infix type constructors and type patterns
658 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
660 -- data/newtype family declaration
661 | 'data' type opt_kind_sig
662 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
664 -- Associated type instances
666 at_decl_inst :: { LTyClDecl RdrName }
667 -- type instance declarations
668 : 'type' type '=' ctype
669 -- Note the use of type for the head; this allows
670 -- infix type constructors and type patterns
671 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
673 -- data/newtype instance declaration
674 | data_or_newtype tycl_hdr constrs deriving
675 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
676 Nothing (reverse (unLoc $3)) (unLoc $4) }
678 -- GADT instance declaration
679 | data_or_newtype tycl_hdr opt_kind_sig
682 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
683 (unLoc $3) (unLoc $4) (unLoc $5) }
685 data_or_newtype :: { Located NewOrData }
686 : 'data' { L1 DataType }
687 | 'newtype' { L1 NewType }
689 opt_kind_sig :: { Located (Maybe Kind) }
691 | '::' kind { LL (Just (unLoc $2)) }
693 -- tycl_hdr parses the header of a class or data type decl,
694 -- which takes the form
697 -- (Eq a, Ord b) => T a b
698 -- T Int [a] -- for associated types
699 -- Rather a lot of inlining here, else we get reduce/reduce errors
700 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
701 : context '=>' type { LL (Just $1, $3) }
702 | type { L1 (Nothing, $1) }
704 -----------------------------------------------------------------------------
705 -- Stand-alone deriving
707 -- Glasgow extension: stand-alone deriving declarations
708 stand_alone_deriving :: { LDerivDecl RdrName }
709 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
711 -----------------------------------------------------------------------------
712 -- Nested declarations
714 -- Declaration in class bodies
716 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
717 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
720 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
721 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
722 | decls_cls ';' { LL (unLoc $1) }
724 | {- empty -} { noLoc nilOL }
728 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
729 : '{' decls_cls '}' { LL (unLoc $2) }
730 | vocurly decls_cls close { $2 }
734 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
735 -- No implicit parameters
736 -- May have type declarations
737 : 'where' decllist_cls { LL (unLoc $2) }
738 | {- empty -} { noLoc nilOL }
740 -- Declarations in instance bodies
742 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
743 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
746 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
747 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
748 | decls_inst ';' { LL (unLoc $1) }
750 | {- empty -} { noLoc nilOL }
753 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
754 : '{' decls_inst '}' { LL (unLoc $2) }
755 | vocurly decls_inst close { $2 }
759 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
760 -- No implicit parameters
761 -- May have type declarations
762 : 'where' decllist_inst { LL (unLoc $2) }
763 | {- empty -} { noLoc nilOL }
765 -- Declarations in binding groups other than classes and instances
767 decls :: { Located (OrdList (LHsDecl RdrName)) }
768 : decls ';' decl { let { this = unLoc $3;
770 these = rest `appOL` this }
771 in rest `seq` this `seq` these `seq`
773 | decls ';' { LL (unLoc $1) }
775 | {- empty -} { noLoc nilOL }
777 decllist :: { Located (OrdList (LHsDecl RdrName)) }
778 : '{' decls '}' { LL (unLoc $2) }
779 | vocurly decls close { $2 }
781 -- Binding groups other than those of class and instance declarations
783 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
784 -- No type declarations
785 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
786 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
787 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
789 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
790 -- No type declarations
791 : 'where' binds { LL (unLoc $2) }
792 | {- empty -} { noLoc emptyLocalBinds }
795 -----------------------------------------------------------------------------
796 -- Transformation Rules
798 rules :: { OrdList (LHsDecl RdrName) }
799 : rules ';' rule { $1 `snocOL` $3 }
802 | {- empty -} { nilOL }
804 rule :: { LHsDecl RdrName }
805 : STRING activation rule_forall infixexp '=' exp
806 { LL $ RuleD (HsRule (getSTRING $1)
807 ($2 `orElse` AlwaysActive)
808 $3 $4 placeHolderNames $6 placeHolderNames) }
810 activation :: { Maybe Activation }
811 : {- empty -} { Nothing }
812 | explicit_activation { Just $1 }
814 explicit_activation :: { Activation } -- In brackets
815 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
816 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
818 rule_forall :: { [RuleBndr RdrName] }
819 : 'forall' rule_var_list '.' { $2 }
822 rule_var_list :: { [RuleBndr RdrName] }
824 | rule_var rule_var_list { $1 : $2 }
826 rule_var :: { RuleBndr RdrName }
827 : varid { RuleBndr $1 }
828 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
830 -----------------------------------------------------------------------------
831 -- Warnings and deprecations (c.f. rules)
833 warnings :: { OrdList (LHsDecl RdrName) }
834 : warnings ';' warning { $1 `appOL` $3 }
835 | warnings ';' { $1 }
837 | {- empty -} { nilOL }
839 -- SUP: TEMPORARY HACK, not checking for `module Foo'
840 warning :: { OrdList (LHsDecl RdrName) }
842 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
845 deprecations :: { OrdList (LHsDecl RdrName) }
846 : deprecations ';' deprecation { $1 `appOL` $3 }
847 | deprecations ';' { $1 }
849 | {- empty -} { nilOL }
851 -- SUP: TEMPORARY HACK, not checking for `module Foo'
852 deprecation :: { OrdList (LHsDecl RdrName) }
854 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
857 strings :: { Located [FastString] }
858 : STRING { L1 [getSTRING $1] }
859 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
861 stringlist :: { Located (OrdList FastString) }
862 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
863 | STRING { LL (unitOL (getSTRING $1)) }
865 -----------------------------------------------------------------------------
867 annotation :: { LHsDecl RdrName }
868 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
869 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
870 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
873 -----------------------------------------------------------------------------
874 -- Foreign import and export declarations
876 fdecl :: { LHsDecl RdrName }
877 fdecl : 'import' callconv safety fspec
878 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
879 | 'import' callconv fspec
880 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
882 | 'export' callconv fspec
883 {% mkExport $2 (unLoc $3) >>= return.LL }
885 callconv :: { CCallConv }
886 : 'stdcall' { StdCallConv }
887 | 'ccall' { CCallConv }
888 | 'prim' { PrimCallConv}
891 : 'unsafe' { PlayRisky }
892 | 'safe' { PlaySafe False }
893 | 'interruptible' { PlayInterruptible }
894 | 'threadsafe' { PlaySafe True } -- deprecated alias
896 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
897 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
898 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
899 -- if the entity string is missing, it defaults to the empty string;
900 -- the meaning of an empty entity string depends on the calling
903 -----------------------------------------------------------------------------
906 opt_sig :: { Maybe (LHsType RdrName) }
907 : {- empty -} { Nothing }
908 | '::' sigtype { Just $2 }
910 opt_asig :: { Maybe (LHsType RdrName) }
911 : {- empty -} { Nothing }
912 | '::' atype { Just $2 }
914 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
915 -- to tell the renamer where to generalise
916 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
917 -- Wrap an Implicit forall if there isn't one there already
919 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
920 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
921 -- Wrap an Implicit forall if there isn't one there already
923 sig_vars :: { Located [Located RdrName] }
924 : sig_vars ',' var { LL ($3 : unLoc $1) }
927 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
929 | sigtype ',' sigtypes1 { $1 : $3 }
931 -----------------------------------------------------------------------------
934 infixtype :: { LHsType RdrName }
935 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
936 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
938 strict_mark :: { Located HsBang }
939 : '!' { L1 HsStrict }
940 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
942 -- A ctype is a for-all type
943 ctype :: { LHsType RdrName }
944 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
945 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
946 -- A type of form (context => type) is an *implicit* HsForAllTy
947 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
950 ----------------------
951 -- Notes for 'ctypedoc'
952 -- It would have been nice to simplify the grammar by unifying `ctype` and
953 -- ctypedoc` into one production, allowing comments on types everywhere (and
954 -- rejecting them after parsing, where necessary). This is however not possible
955 -- since it leads to ambiguity. The reason is the support for comments on record
957 -- data R = R { field :: Int -- ^ comment on the field }
958 -- If we allow comments on types here, it's not clear if the comment applies
959 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
961 ctypedoc :: { LHsType RdrName }
962 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
963 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
964 -- A type of form (context => type) is an *implicit* HsForAllTy
965 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
968 ----------------------
969 -- Notes for 'context'
970 -- We parse a context as a btype so that we don't get reduce/reduce
971 -- errors in ctype. The basic problem is that
973 -- looks so much like a tuple type. We can't tell until we find the =>
975 -- We have the t1 ~ t2 form both in 'context' and in type,
976 -- to permit an individual equational constraint without parenthesis.
977 -- Thus for some reason we allow f :: a~b => blah
978 -- but not f :: ?x::Int => blah
979 context :: { LHsContext RdrName }
980 : btype '~' btype {% checkContext
981 (LL $ HsPredTy (HsEqualP $1 $3)) }
982 | btype {% checkContext $1 }
984 type :: { LHsType RdrName }
986 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
987 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
988 | btype '->' ctype { LL $ HsFunTy $1 $3 }
989 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
991 typedoc :: { LHsType RdrName }
993 | btype docprev { LL $ HsDocTy $1 $2 }
994 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
995 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
996 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
997 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
998 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
999 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1000 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1002 btype :: { LHsType RdrName }
1003 : btype atype { LL $ HsAppTy $1 $2 }
1006 atype :: { LHsType RdrName }
1007 : gtycon { L1 (HsTyVar (unLoc $1)) }
1008 | tyvar { L1 (HsTyVar (unLoc $1)) }
1009 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1010 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1011 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1012 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1013 | '[' ctype ']' { LL $ HsListTy $2 }
1014 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1015 | '(' ctype ')' { LL $ HsParTy $2 }
1016 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1017 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1018 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1019 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1020 mkUnqual varName (getTH_ID_SPLICE $1) }
1022 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1024 -- An inst_type is what occurs in the head of an instance decl
1025 -- e.g. (Foo a, Gaz b) => Wibble a b
1026 -- It's kept as a single type, with a MonoDictTy at the right
1027 -- hand corner, for convenience.
1028 inst_type :: { LHsType RdrName }
1029 : sigtype {% checkInstType $1 }
1031 inst_types1 :: { [LHsType RdrName] }
1032 : inst_type { [$1] }
1033 | inst_type ',' inst_types1 { $1 : $3 }
1035 comma_types0 :: { [LHsType RdrName] }
1036 : comma_types1 { $1 }
1037 | {- empty -} { [] }
1039 comma_types1 :: { [LHsType RdrName] }
1041 | ctype ',' comma_types1 { $1 : $3 }
1043 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1044 : tv_bndr tv_bndrs { $1 : $2 }
1045 | {- empty -} { [] }
1047 tv_bndr :: { LHsTyVarBndr RdrName }
1048 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1049 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1052 fds :: { Located [Located (FunDep RdrName)] }
1053 : {- empty -} { noLoc [] }
1054 | '|' fds1 { LL (reverse (unLoc $2)) }
1056 fds1 :: { Located [Located (FunDep RdrName)] }
1057 : fds1 ',' fd { LL ($3 : unLoc $1) }
1060 fd :: { Located (FunDep RdrName) }
1061 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1062 (reverse (unLoc $1), reverse (unLoc $3)) }
1064 varids0 :: { Located [RdrName] }
1065 : {- empty -} { noLoc [] }
1066 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1068 -----------------------------------------------------------------------------
1071 kind :: { Located Kind }
1073 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1075 akind :: { Located Kind }
1076 : '*' { L1 liftedTypeKind }
1077 | '!' { L1 unliftedTypeKind }
1078 | '(' kind ')' { LL (unLoc $2) }
1081 -----------------------------------------------------------------------------
1082 -- Datatype declarations
1084 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1085 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1086 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1087 | {- empty -} { noLoc [] }
1089 gadt_constrs :: { Located [LConDecl RdrName] }
1090 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1091 | gadt_constr { L (getLoc (head $1)) $1 }
1092 | {- empty -} { noLoc [] }
1094 -- We allow the following forms:
1095 -- C :: Eq a => a -> T a
1096 -- C :: forall a. Eq a => !a -> T a
1097 -- D { x,y :: a } :: T a
1098 -- forall a. Eq a => D { x,y :: a } :: T a
1100 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1101 : con_list '::' sigtype
1102 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1104 -- Deprecated syntax for GADT record declarations
1105 | oqtycon '{' fielddecls '}' '::' sigtype
1106 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1109 constrs :: { Located [LConDecl RdrName] }
1110 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1112 constrs1 :: { Located [LConDecl RdrName] }
1113 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1114 | constr { L1 [$1] }
1116 constr :: { LConDecl RdrName }
1117 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1118 { let (con,details) = unLoc $5 in
1119 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1121 | maybe_docnext forall constr_stuff maybe_docprev
1122 { let (con,details) = unLoc $3 in
1123 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1126 forall :: { Located [LHsTyVarBndr RdrName] }
1127 : 'forall' tv_bndrs '.' { LL $2 }
1128 | {- empty -} { noLoc [] }
1130 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1131 -- We parse the constructor declaration
1133 -- as a btype (treating C as a type constructor) and then convert C to be
1134 -- a data constructor. Reason: it might continue like this:
1136 -- in which case C really would be a type constructor. We can't resolve this
1137 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1138 : btype {% splitCon $1 >>= return.LL }
1139 | btype conop btype { LL ($2, InfixCon $1 $3) }
1141 fielddecls :: { [ConDeclField RdrName] }
1142 : {- empty -} { [] }
1143 | fielddecls1 { $1 }
1145 fielddecls1 :: { [ConDeclField RdrName] }
1146 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1147 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1148 -- This adds the doc $4 to each field separately
1151 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1152 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1153 | fld <- reverse (unLoc $2) ] }
1155 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1156 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1157 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1158 -- We don't allow a context, but that's sorted out by the type checker.
1159 deriving :: { Located (Maybe [LHsType RdrName]) }
1160 : {- empty -} { noLoc Nothing }
1161 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1162 ; p <- checkInstType (L loc (HsTyVar tv))
1163 ; return (LL (Just [p])) } }
1164 | 'deriving' '(' ')' { LL (Just []) }
1165 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1166 -- Glasgow extension: allow partial
1167 -- applications in derivings
1169 -----------------------------------------------------------------------------
1170 -- Value definitions
1172 {- Note [Declaration/signature overlap]
1173 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1174 There's an awkward overlap with a type signature. Consider
1175 f :: Int -> Int = ...rhs...
1176 Then we can't tell whether it's a type signature or a value
1177 definition with a result signature until we see the '='.
1178 So we have to inline enough to postpone reductions until we know.
1182 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1183 instead of qvar, we get another shift/reduce-conflict. Consider the
1186 { (^^) :: Int->Int ; } Type signature; only var allowed
1188 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1189 qvar allowed (because of instance decls)
1191 We can't tell whether to reduce var to qvar until after we've read the signatures.
1194 docdecl :: { LHsDecl RdrName }
1195 : docdecld { L1 (DocD (unLoc $1)) }
1197 docdecld :: { LDocDecl }
1198 : docnext { L1 (DocCommentNext (unLoc $1)) }
1199 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1200 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1201 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1203 decl :: { Located (OrdList (LHsDecl RdrName)) }
1206 | '!' aexp rhs {% do { let { e = LL (SectionR (LL (HsVar bang_RDR)) $2) };
1207 pat <- checkPattern e;
1208 return $ LL $ unitOL $ LL $ ValD $
1209 PatBind pat (unLoc $3)
1210 placeHolderType placeHolderNames } }
1211 -- Turn it all into an expression so that
1212 -- checkPattern can check that bangs are enabled
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 $ mkHsIf $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
1288 [L loc (mkRecStmt stmts)]
1290 | scc_annot exp { LL $ if opt_SccProfilingOn
1291 then HsSCC (unLoc $1) $2
1293 | hpc_annot exp { LL $ if opt_Hpc
1294 then HsTickPragma (unLoc $1) $2
1297 | 'proc' aexp '->' exp
1298 {% checkPattern $2 >>= \ p ->
1299 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1300 placeHolderType undefined)) }
1301 -- TODO: is LL right here?
1303 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1304 -- hdaume: core annotation
1309 | {- empty -} { False }
1311 scc_annot :: { Located FastString }
1312 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1313 ( do scc <- getSCC $2; return $ LL scc ) }
1314 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1316 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1317 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1318 { LL $ (getSTRING $2
1319 ,( fromInteger $ getINTEGER $3
1320 , fromInteger $ getINTEGER $5
1322 ,( fromInteger $ getINTEGER $7
1323 , fromInteger $ getINTEGER $9
1328 fexp :: { LHsExpr RdrName }
1329 : fexp aexp { LL $ HsApp $1 $2 }
1332 aexp :: { LHsExpr RdrName }
1333 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1334 | '~' aexp { LL $ ELazyPat $2 }
1337 aexp1 :: { LHsExpr RdrName }
1338 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1342 -- Here was the syntax for type applications that I was planning
1343 -- but there are difficulties (e.g. what order for type args)
1344 -- so it's not enabled yet.
1345 -- But this case *is* used for the left hand side of a generic definition,
1346 -- which is parsed as an expression before being munged into a pattern
1347 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1348 (sL (getLoc $3) (HsType $3)) }
1350 aexp2 :: { LHsExpr RdrName }
1351 : ipvar { L1 (HsIPVar $! unLoc $1) }
1352 | qcname { L1 (HsVar $! unLoc $1) }
1353 | literal { L1 (HsLit $! unLoc $1) }
1354 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1355 -- into HsOverLit when -foverloaded-strings is on.
1356 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1357 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1358 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1360 -- N.B.: sections get parsed by these next two productions.
1361 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't
1362 -- correct Haskell (you'd have to write '((+ 3), (4 -))')
1363 -- but the less cluttered version fell out of having texps.
1364 | '(' texp ')' { LL (HsPar $2) }
1365 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1367 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1368 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1370 | '[' list ']' { LL (unLoc $2) }
1371 | '[:' parr ':]' { LL (unLoc $2) }
1372 | '_' { L1 EWildPat }
1374 -- Template Haskell Extension
1375 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1376 (L1 $ HsVar (mkUnqual varName
1377 (getTH_ID_SPLICE $1)))) }
1378 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1381 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1382 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1383 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1384 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1385 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1386 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1387 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1388 return (LL $ HsBracket (PatBr p)) }
1389 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1390 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1392 -- arrow notation extension
1393 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1395 cmdargs :: { [LHsCmdTop RdrName] }
1396 : cmdargs acmd { $2 : $1 }
1397 | {- empty -} { [] }
1399 acmd :: { LHsCmdTop RdrName }
1400 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1402 cvtopbody :: { [LHsDecl RdrName] }
1403 : '{' cvtopdecls0 '}' { $2 }
1404 | vocurly cvtopdecls0 close { $2 }
1406 cvtopdecls0 :: { [LHsDecl RdrName] }
1407 : {- empty -} { [] }
1410 -----------------------------------------------------------------------------
1411 -- Tuple expressions
1413 -- "texp" is short for tuple expressions:
1414 -- things that can appear unparenthesized as long as they're
1415 -- inside parens or delimitted by commas
1416 texp :: { LHsExpr RdrName }
1419 -- Note [Parsing sections]
1420 -- ~~~~~~~~~~~~~~~~~~~~~~~
1421 -- We include left and right sections here, which isn't
1422 -- technically right according to the Haskell standard.
1423 -- For example (3 +, True) isn't legal.
1424 -- However, we want to parse bang patterns like
1426 -- and it's convenient to do so here as a section
1427 -- Then when converting expr to pattern we unravel it again
1428 -- Meanwhile, the renamer checks that real sections appear
1430 | infixexp qop { LL $ SectionL $1 $2 }
1431 | qopm infixexp { LL $ SectionR $1 $2 }
1433 -- View patterns get parenthesized above
1434 | exp '->' texp { LL $ EViewPat $1 $3 }
1436 -- Always at least one comma
1437 tup_exprs :: { [HsTupArg RdrName] }
1438 : texp commas_tup_tail { Present $1 : $2 }
1439 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1441 -- Always starts with commas; always follows an expr
1442 commas_tup_tail :: { [HsTupArg RdrName] }
1443 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1445 -- Always follows a comma
1446 tup_tail :: { [HsTupArg RdrName] }
1447 : texp commas_tup_tail { Present $1 : $2 }
1448 | texp { [Present $1] }
1449 | {- empty -} { [missingTupArg] }
1451 -----------------------------------------------------------------------------
1454 -- The rules below are little bit contorted to keep lexps left-recursive while
1455 -- avoiding another shift/reduce-conflict.
1457 list :: { LHsExpr RdrName }
1458 : texp { L1 $ ExplicitList placeHolderType [$1] }
1459 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1460 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1461 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1462 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1463 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1464 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1466 lexps :: { Located [LHsExpr RdrName] }
1467 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1468 | texp ',' texp { LL [$3,$1] }
1470 -----------------------------------------------------------------------------
1471 -- List Comprehensions
1473 flattenedpquals :: { Located [LStmt RdrName] }
1474 : pquals { case (unLoc $1) of
1476 -- We just had one thing in our "parallel" list so
1477 -- we simply return that thing directly
1479 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1480 -- We actually found some actual parallel lists so
1481 -- we wrap them into as a ParStmt
1484 pquals :: { Located [[LStmt RdrName]] }
1485 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1486 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1488 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1489 -- one can "grab" the earlier ones
1490 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1491 | squals ',' qual { LL ($3 : unLoc $1) }
1492 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1494 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1495 -- | '{|' pquals '|}' { L1 [$2] }
1498 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1499 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1500 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1501 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1503 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1504 -- Function is applied to a list of stmts *in order*
1505 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1507 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1508 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1510 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1511 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1512 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1513 -- choosing the "group by" variant, which is what we want.
1515 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1516 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1517 -- if /that/ is the group function we conflict with.
1518 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1519 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1521 -----------------------------------------------------------------------------
1522 -- Parallel array expressions
1524 -- The rules below are little bit contorted; see the list case for details.
1525 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1526 -- Moreover, we allow explicit arrays with no element (represented by the nil
1527 -- constructor in the list case).
1529 parr :: { LHsExpr RdrName }
1530 : { noLoc (ExplicitPArr placeHolderType []) }
1531 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1532 | lexps { L1 $ ExplicitPArr placeHolderType
1533 (reverse (unLoc $1)) }
1534 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1535 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1536 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1538 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1540 -----------------------------------------------------------------------------
1543 guardquals :: { Located [LStmt RdrName] }
1544 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1546 guardquals1 :: { Located [LStmt RdrName] }
1547 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1550 -----------------------------------------------------------------------------
1551 -- Case alternatives
1553 altslist :: { Located [LMatch RdrName] }
1554 : '{' alts '}' { LL (reverse (unLoc $2)) }
1555 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1557 alts :: { Located [LMatch RdrName] }
1558 : alts1 { L1 (unLoc $1) }
1559 | ';' alts { LL (unLoc $2) }
1561 alts1 :: { Located [LMatch RdrName] }
1562 : alts1 ';' alt { LL ($3 : unLoc $1) }
1563 | alts1 ';' { LL (unLoc $1) }
1566 alt :: { LMatch RdrName }
1567 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1569 alt_rhs :: { Located (GRHSs RdrName) }
1570 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1572 ralt :: { Located [LGRHS RdrName] }
1573 : '->' exp { LL (unguardedRHS $2) }
1574 | gdpats { L1 (reverse (unLoc $1)) }
1576 gdpats :: { Located [LGRHS RdrName] }
1577 : gdpats gdpat { LL ($2 : unLoc $1) }
1580 gdpat :: { LGRHS RdrName }
1581 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1583 -- 'pat' recognises a pattern, including one with a bang at the top
1584 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1585 -- Bangs inside are parsed as infix operator applications, so that
1586 -- we parse them right when bang-patterns are off
1587 pat :: { LPat RdrName }
1588 pat : exp {% checkPattern $1 }
1589 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1591 apat :: { LPat RdrName }
1592 apat : aexp {% checkPattern $1 }
1593 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1595 apats :: { [LPat RdrName] }
1596 : apat apats { $1 : $2 }
1597 | {- empty -} { [] }
1599 -----------------------------------------------------------------------------
1600 -- Statement sequences
1602 stmtlist :: { Located [LStmt RdrName] }
1603 : '{' stmts '}' { LL (unLoc $2) }
1604 | vocurly stmts close { $2 }
1606 -- do { ;; s ; s ; ; s ;; }
1607 -- The last Stmt should be an expression, but that's hard to enforce
1608 -- here, because we need too much lookahead if we see do { e ; }
1609 -- So we use ExprStmts throughout, and switch the last one over
1610 -- in ParseUtils.checkDo instead
1611 stmts :: { Located [LStmt RdrName] }
1612 : stmt stmts_help { LL ($1 : unLoc $2) }
1613 | ';' stmts { LL (unLoc $2) }
1614 | {- empty -} { noLoc [] }
1616 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1617 : ';' stmts { LL (unLoc $2) }
1618 | {- empty -} { noLoc [] }
1620 -- For typing stmts at the GHCi prompt, where
1621 -- the input may consist of just comments.
1622 maybe_stmt :: { Maybe (LStmt RdrName) }
1624 | {- nothing -} { Nothing }
1626 stmt :: { LStmt RdrName }
1628 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1630 qual :: { LStmt RdrName }
1631 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1632 | exp { L1 $ mkExprStmt $1 }
1633 | 'let' binds { LL $ LetStmt (unLoc $2) }
1635 -----------------------------------------------------------------------------
1636 -- Record Field Update/Construction
1638 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1640 | {- empty -} { ([], False) }
1642 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1643 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1644 | fbind { ([$1], False) }
1645 | '..' { ([], True) }
1647 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1648 : qvar '=' exp { HsRecField $1 $3 False }
1649 | qvar { HsRecField $1 placeHolderPunRhs True }
1650 -- In the punning case, use a place-holder
1651 -- The renamer fills in the final value
1653 -----------------------------------------------------------------------------
1654 -- Implicit Parameter Bindings
1656 dbinds :: { Located [LIPBind RdrName] }
1657 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1658 in rest `seq` this `seq` LL (this : rest) }
1659 | dbinds ';' { LL (unLoc $1) }
1660 | dbind { let this = $1 in this `seq` L1 [this] }
1661 -- | {- empty -} { [] }
1663 dbind :: { LIPBind RdrName }
1664 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1666 ipvar :: { Located (IPName RdrName) }
1667 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1669 -----------------------------------------------------------------------------
1670 -- Warnings and deprecations
1672 namelist :: { Located [RdrName] }
1673 namelist : name_var { L1 [unLoc $1] }
1674 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1676 name_var :: { Located RdrName }
1677 name_var : var { $1 }
1680 -----------------------------------------
1681 -- Data constructors
1682 qcon :: { Located RdrName }
1684 | '(' qconsym ')' { LL (unLoc $2) }
1685 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1686 -- The case of '[:' ':]' is part of the production `parr'
1688 con :: { Located RdrName }
1690 | '(' consym ')' { LL (unLoc $2) }
1691 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1693 con_list :: { Located [Located RdrName] }
1694 con_list : con { L1 [$1] }
1695 | con ',' con_list { LL ($1 : unLoc $3) }
1697 sysdcon :: { Located DataCon } -- Wired in data constructors
1698 : '(' ')' { LL unitDataCon }
1699 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1700 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1701 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1702 | '[' ']' { LL nilDataCon }
1704 conop :: { Located RdrName }
1706 | '`' conid '`' { LL (unLoc $2) }
1708 qconop :: { Located RdrName }
1710 | '`' qconid '`' { LL (unLoc $2) }
1712 -----------------------------------------------------------------------------
1713 -- Type constructors
1715 gtycon :: { Located RdrName } -- A "general" qualified tycon
1717 | '(' ')' { LL $ getRdrName unitTyCon }
1718 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1719 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1720 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1721 | '(' '->' ')' { LL $ getRdrName funTyCon }
1722 | '[' ']' { LL $ listTyCon_RDR }
1723 | '[:' ':]' { LL $ parrTyCon_RDR }
1725 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1727 | '(' qtyconsym ')' { LL (unLoc $2) }
1729 qtyconop :: { Located RdrName } -- Qualified or unqualified
1731 | '`' qtycon '`' { LL (unLoc $2) }
1733 qtycon :: { Located RdrName } -- Qualified or unqualified
1734 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1735 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1738 tycon :: { Located RdrName } -- Unqualified
1739 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1741 qtyconsym :: { Located RdrName }
1742 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1745 tyconsym :: { Located RdrName }
1746 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1748 -----------------------------------------------------------------------------
1751 op :: { Located RdrName } -- used in infix decls
1755 varop :: { Located RdrName }
1757 | '`' varid '`' { LL (unLoc $2) }
1759 qop :: { LHsExpr RdrName } -- used in sections
1760 : qvarop { L1 $ HsVar (unLoc $1) }
1761 | qconop { L1 $ HsVar (unLoc $1) }
1763 qopm :: { LHsExpr RdrName } -- used in sections
1764 : qvaropm { L1 $ HsVar (unLoc $1) }
1765 | qconop { L1 $ HsVar (unLoc $1) }
1767 qvarop :: { Located RdrName }
1769 | '`' qvarid '`' { LL (unLoc $2) }
1771 qvaropm :: { Located RdrName }
1772 : qvarsym_no_minus { $1 }
1773 | '`' qvarid '`' { LL (unLoc $2) }
1775 -----------------------------------------------------------------------------
1778 tyvar :: { Located RdrName }
1779 tyvar : tyvarid { $1 }
1780 | '(' tyvarsym ')' { LL (unLoc $2) }
1782 tyvarop :: { Located RdrName }
1783 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1785 | '.' {% parseErrorSDoc (getLoc $1)
1786 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1787 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1788 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1791 tyvarid :: { Located RdrName }
1792 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1793 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1794 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1795 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1796 | 'interruptible' { L1 $! mkUnqual tvName (fsLit "interruptible") }
1797 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1799 tyvarsym :: { Located RdrName }
1800 -- Does not include "!", because that is used for strictness marks
1801 -- or ".", because that separates the quantified type vars from the rest
1802 -- or "*", because that's used for kinds
1803 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1805 -----------------------------------------------------------------------------
1808 var :: { Located RdrName }
1810 | '(' varsym ')' { LL (unLoc $2) }
1812 qvar :: { Located RdrName }
1814 | '(' varsym ')' { LL (unLoc $2) }
1815 | '(' qvarsym1 ')' { LL (unLoc $2) }
1816 -- We've inlined qvarsym here so that the decision about
1817 -- whether it's a qvar or a var can be postponed until
1818 -- *after* we see the close paren.
1820 qvarid :: { Located RdrName }
1822 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1823 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1825 varid :: { Located RdrName }
1826 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1827 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1828 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1829 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1830 | 'interruptible' { L1 $! mkUnqual varName (fsLit "interruptible") }
1831 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1832 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1833 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1835 qvarsym :: { Located RdrName }
1839 qvarsym_no_minus :: { Located RdrName }
1840 : varsym_no_minus { $1 }
1843 qvarsym1 :: { Located RdrName }
1844 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1846 varsym :: { Located RdrName }
1847 : varsym_no_minus { $1 }
1848 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1850 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1851 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1852 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1855 -- These special_ids are treated as keywords in various places,
1856 -- but as ordinary ids elsewhere. 'special_id' collects all these
1857 -- except 'unsafe', 'interruptible', 'forall', and 'family' whose treatment differs
1858 -- depending on context
1859 special_id :: { Located FastString }
1861 : 'as' { L1 (fsLit "as") }
1862 | 'qualified' { L1 (fsLit "qualified") }
1863 | 'hiding' { L1 (fsLit "hiding") }
1864 | 'export' { L1 (fsLit "export") }
1865 | 'label' { L1 (fsLit "label") }
1866 | 'dynamic' { L1 (fsLit "dynamic") }
1867 | 'stdcall' { L1 (fsLit "stdcall") }
1868 | 'ccall' { L1 (fsLit "ccall") }
1869 | 'prim' { L1 (fsLit "prim") }
1870 | 'group' { L1 (fsLit "group") }
1872 special_sym :: { Located FastString }
1873 special_sym : '!' { L1 (fsLit "!") }
1874 | '.' { L1 (fsLit ".") }
1875 | '*' { L1 (fsLit "*") }
1877 -----------------------------------------------------------------------------
1878 -- Data constructors
1880 qconid :: { Located RdrName } -- Qualified or unqualified
1882 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1883 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1885 conid :: { Located RdrName }
1886 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1888 qconsym :: { Located RdrName } -- Qualified or unqualified
1890 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1892 consym :: { Located RdrName }
1893 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1895 -- ':' means only list cons
1896 | ':' { L1 $ consDataCon_RDR }
1899 -----------------------------------------------------------------------------
1902 literal :: { Located HsLit }
1903 : CHAR { L1 $ HsChar $ getCHAR $1 }
1904 | STRING { L1 $ HsString $ getSTRING $1 }
1905 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1906 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1907 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1908 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1909 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1910 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1912 -----------------------------------------------------------------------------
1916 : vccurly { () } -- context popped in lexer.
1917 | error {% popContext }
1919 -----------------------------------------------------------------------------
1920 -- Miscellaneous (mostly renamings)
1922 modid :: { Located ModuleName }
1923 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1924 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1927 (unpackFS mod ++ '.':unpackFS c))
1931 : commas ',' { $1 + 1 }
1934 -----------------------------------------------------------------------------
1935 -- Documentation comments
1937 docnext :: { LHsDocString }
1938 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1940 docprev :: { LHsDocString }
1941 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1943 docnamed :: { Located (String, HsDocString) }
1945 let string = getDOCNAMED $1
1946 (name, rest) = break isSpace string
1947 in return (L1 (name, HsDocString (mkFastString rest))) }
1949 docsection :: { Located (Int, HsDocString) }
1950 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1951 return (L1 (n, HsDocString (mkFastString doc))) }
1953 moduleheader :: { Maybe LHsDocString }
1954 : DOCNEXT {% let string = getDOCNEXT $1 in
1955 return (Just (L1 (HsDocString (mkFastString string)))) }
1957 maybe_docprev :: { Maybe LHsDocString }
1958 : docprev { Just $1 }
1959 | {- empty -} { Nothing }
1961 maybe_docnext :: { Maybe LHsDocString }
1962 : docnext { Just $1 }
1963 | {- empty -} { Nothing }
1967 happyError = srcParseFail
1969 getVARID (L _ (ITvarid x)) = x
1970 getCONID (L _ (ITconid x)) = x
1971 getVARSYM (L _ (ITvarsym x)) = x
1972 getCONSYM (L _ (ITconsym x)) = x
1973 getQVARID (L _ (ITqvarid x)) = x
1974 getQCONID (L _ (ITqconid x)) = x
1975 getQVARSYM (L _ (ITqvarsym x)) = x
1976 getQCONSYM (L _ (ITqconsym x)) = x
1977 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1978 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1979 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1980 getCHAR (L _ (ITchar x)) = x
1981 getSTRING (L _ (ITstring x)) = x
1982 getINTEGER (L _ (ITinteger x)) = x
1983 getRATIONAL (L _ (ITrational x)) = x
1984 getPRIMCHAR (L _ (ITprimchar x)) = x
1985 getPRIMSTRING (L _ (ITprimstring x)) = x
1986 getPRIMINTEGER (L _ (ITprimint x)) = x
1987 getPRIMWORD (L _ (ITprimword x)) = x
1988 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1989 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1990 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1991 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
1992 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
1993 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
1995 getDOCNEXT (L _ (ITdocCommentNext x)) = x
1996 getDOCPREV (L _ (ITdocCommentPrev x)) = x
1997 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
1998 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2000 getSCC :: Located Token -> P FastString
2001 getSCC lt = do let s = getSTRING lt
2002 err = "Spaces are not allowed in SCCs"
2003 -- We probably actually want to be more restrictive than this
2004 if ' ' `elem` unpackFS s
2005 then failSpanMsgP (getLoc lt) (text err)
2008 -- Utilities for combining source spans
2009 comb2 :: Located a -> Located b -> SrcSpan
2010 comb2 a b = a `seq` b `seq` combineLocs a b
2012 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2013 comb3 a b c = a `seq` b `seq` c `seq`
2014 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2016 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2017 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2018 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2019 combineSrcSpans (getLoc c) (getLoc d))
2021 -- strict constructor version:
2023 sL :: SrcSpan -> a -> Located a
2024 sL span a = span `seq` a `seq` L span a
2026 -- Make a source location for the file. We're a bit lazy here and just
2027 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2028 -- try to find the span of the whole file (ToDo).
2029 fileSrcSpan :: P SrcSpan
2032 let loc = mkSrcLoc (srcLocFile l) 1 1;
2033 return (mkSrcSpan loc loc)