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, varNameDepth, 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 )
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 '{-# VECTORISE' { L _ ITvect_prag }
270 '{-# VECTORISE_SCALAR' { L _ ITvect_scalar_prag }
271 '{-# NOVECTORISE' { L _ ITnovect_prag }
272 '#-}' { L _ ITclose_prag }
274 '..' { L _ ITdotdot } -- reserved symbols
276 '::' { L _ ITdcolon }
280 '<-' { L _ ITlarrow }
281 '->' { L _ ITrarrow }
282 '~~>' { L _ ITkappa }
285 '=>' { L _ ITdarrow }
289 '-<' { L _ ITlarrowtail } -- for arrow notation
290 '>-' { L _ ITrarrowtail } -- for arrow notation
291 '-<<' { L _ ITLarrowtail } -- for arrow notation
292 '>>-' { L _ ITRarrowtail } -- for arrow notation
295 '{' { L _ ITocurly } -- special symbols
297 '{|' { L _ ITocurlybar }
298 '|}' { L _ ITccurlybar }
299 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
300 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
303 '[:' { L _ ITopabrack }
304 ':]' { L _ ITcpabrack }
307 '(#' { L _ IToubxparen }
308 '#)' { L _ ITcubxparen }
309 '(|' { L _ IToparenbar }
310 '|)' { L _ ITcparenbar }
311 '<[' { L _ ITopenBrak }
312 ']>' { L _ ITcloseBrak }
313 '<{' { L _ ITopenBrak1 }
314 '}>' { L _ ITcloseBrak1 }
315 '~~' { L _ ITescape }
316 '~~$' { L _ ITescapeDollar }
317 '%%' { L _ ITdoublePercent }
320 '`' { L _ ITbackquote }
322 VARID { L _ (ITvarid _) } -- identifiers
323 CONID { L _ (ITconid _) }
324 VARSYM { L _ (ITvarsym _) }
325 CONSYM { L _ (ITconsym _) }
326 QVARID { L _ (ITqvarid _) }
327 QCONID { L _ (ITqconid _) }
328 QVARSYM { L _ (ITqvarsym _) }
329 QCONSYM { L _ (ITqconsym _) }
330 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
331 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
333 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
335 CHAR { L _ (ITchar _) }
336 STRING { L _ (ITstring _) }
337 INTEGER { L _ (ITinteger _) }
338 RATIONAL { L _ (ITrational _) }
340 PRIMCHAR { L _ (ITprimchar _) }
341 PRIMSTRING { L _ (ITprimstring _) }
342 PRIMINTEGER { L _ (ITprimint _) }
343 PRIMWORD { L _ (ITprimword _) }
344 PRIMFLOAT { L _ (ITprimfloat _) }
345 PRIMDOUBLE { L _ (ITprimdouble _) }
347 DOCNEXT { L _ (ITdocCommentNext _) }
348 DOCPREV { L _ (ITdocCommentPrev _) }
349 DOCNAMED { L _ (ITdocCommentNamed _) }
350 DOCSECTION { L _ (ITdocSection _ _) }
353 '[|' { L _ ITopenExpQuote }
354 '[p|' { L _ ITopenPatQuote }
355 '[t|' { L _ ITopenTypQuote }
356 '[d|' { L _ ITopenDecQuote }
357 '|]' { L _ ITcloseQuote }
358 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
359 '$(' { L _ ITparenEscape } -- $( exp )
360 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
361 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
362 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
364 %monad { P } { >>= } { return }
365 %lexer { lexer } { L _ ITeof }
366 %name parseModule module
367 %name parseStmt maybe_stmt
368 %name parseIdentifier identifier
369 %name parseType ctype
370 %partial parseHeader header
371 %tokentype { (Located Token) }
374 -----------------------------------------------------------------------------
375 -- Identifiers; one of the entry points
376 identifier :: { Located RdrName }
381 | '(' '->' ')' { LL $ getRdrName funTyCon }
383 -----------------------------------------------------------------------------
386 -- The place for module deprecation is really too restrictive, but if it
387 -- was allowed at its natural place just before 'module', we get an ugly
388 -- s/r conflict with the second alternative. Another solution would be the
389 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
390 -- either, and DEPRECATED is only expected to be used by people who really
391 -- know what they are doing. :-)
393 module :: { Located (HsModule RdrName) }
394 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
395 {% fileSrcSpan >>= \ loc ->
396 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
399 {% fileSrcSpan >>= \ loc ->
400 return (L loc (HsModule Nothing Nothing
401 (fst $1) (snd $1) Nothing Nothing
404 maybedocheader :: { Maybe LHsDocString }
405 : moduleheader { $1 }
406 | {- empty -} { Nothing }
408 missing_module_keyword :: { () }
409 : {- empty -} {% pushCurrentContext }
411 maybemodwarning :: { Maybe WarningTxt }
412 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
413 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
414 | {- empty -} { Nothing }
416 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
418 | vocurly top close { $2 }
420 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
422 | missing_module_keyword top close { $2 }
424 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
425 : importdecls { (reverse $1,[]) }
426 | importdecls ';' cvtopdecls { (reverse $1,$3) }
427 | cvtopdecls { ([],$1) }
429 cvtopdecls :: { [LHsDecl RdrName] }
430 : topdecls { cvTopDecls $1 }
432 -----------------------------------------------------------------------------
433 -- Module declaration & imports only
435 header :: { Located (HsModule RdrName) }
436 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
437 {% fileSrcSpan >>= \ loc ->
438 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
440 | missing_module_keyword importdecls
441 {% fileSrcSpan >>= \ loc ->
442 return (L loc (HsModule Nothing Nothing $2 [] Nothing
445 header_body :: { [LImportDecl RdrName] }
446 : '{' importdecls { $2 }
447 | vocurly importdecls { $2 }
449 -----------------------------------------------------------------------------
452 maybeexports :: { Maybe [LIE RdrName] }
453 : '(' exportlist ')' { Just $2 }
454 | {- empty -} { Nothing }
456 exportlist :: { [LIE RdrName] }
457 : expdoclist ',' expdoclist { $1 ++ $3 }
460 exportlist1 :: { [LIE RdrName] }
461 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
462 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
465 expdoclist :: { [LIE RdrName] }
466 : exp_doc expdoclist { $1 : $2 }
469 exp_doc :: { LIE RdrName }
470 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
471 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
472 | docnext { L1 (IEDoc (unLoc $1)) }
474 -- No longer allow things like [] and (,,,) to be exported
475 -- They are built in syntax, always available
476 export :: { LIE RdrName }
477 : qvar { L1 (IEVar (unLoc $1)) }
478 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
479 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
480 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
481 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
482 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
483 | '<[' incdepth export decdepth ']>' { $3 }
484 | '<{' incdepth1 export decdepth '}>' { $3 }
485 qcnames :: { [RdrName] }
486 : qcnames ',' qcname_ext { unLoc $3 : $1 }
487 | qcname_ext { [unLoc $1] }
489 qcname_ext :: { Located RdrName } -- Variable or data constructor
490 -- or tagged type constructor
492 | 'type' qcon { sL (comb2 $1 $2)
493 (setRdrNameSpace (unLoc $2)
496 -- Cannot pull into qcname_ext, as qcname is also used in expression.
497 qcname :: { Located RdrName } -- Variable or data constructor
501 -----------------------------------------------------------------------------
502 -- Import Declarations
504 -- import decls can be *empty*, or even just a string of semicolons
505 -- whereas topdecls must contain at least one topdecl.
507 importdecls :: { [LImportDecl RdrName] }
508 : importdecls ';' importdecl { $3 : $1 }
509 | importdecls ';' { $1 }
510 | importdecl { [ $1 ] }
513 importdecl :: { LImportDecl RdrName }
514 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
515 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
517 maybe_src :: { IsBootInterface }
518 : '{-# SOURCE' '#-}' { True }
519 | {- empty -} { False }
521 maybe_pkg :: { Maybe FastString }
522 : STRING { Just (getSTRING $1) }
523 | {- empty -} { Nothing }
525 optqualified :: { Bool }
526 : 'qualified' { True }
527 | {- empty -} { False }
529 maybeas :: { Located (Maybe ModuleName) }
530 : 'as' modid { LL (Just (unLoc $2)) }
531 | {- empty -} { noLoc Nothing }
533 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
534 : impspec { L1 (Just (unLoc $1)) }
535 | {- empty -} { noLoc Nothing }
537 impspec :: { Located (Bool, [LIE RdrName]) }
538 : '(' exportlist ')' { LL (False, $2) }
539 | 'hiding' '(' exportlist ')' { LL (True, $3) }
541 -----------------------------------------------------------------------------
542 -- Fixity Declarations
546 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
548 infix :: { Located FixityDirection }
549 : 'infix' { L1 InfixN }
550 | 'infixl' { L1 InfixL }
551 | 'infixr' { L1 InfixR }
553 ops :: { Located [Located RdrName] }
554 : ops ',' op { LL ($3 : unLoc $1) }
557 -----------------------------------------------------------------------------
558 -- Top-Level Declarations
560 topdecls :: { OrdList (LHsDecl RdrName) }
561 : topdecls ';' topdecl { $1 `appOL` $3 }
562 | topdecls ';' { $1 }
565 topdecl :: { OrdList (LHsDecl RdrName) }
566 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
567 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
568 | 'instance' inst_type where_inst
569 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
571 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
572 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
573 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
574 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
575 | '{-# DEPRECATED' deprecations '#-}' { $2 }
576 | '{-# WARNING' warnings '#-}' { $2 }
577 | '{-# RULES' rules '#-}' { $2 }
578 | '{-# VECTORISE_SCALAR' qvar '#-}' { unitOL $ LL $ VectD (HsVect $2 Nothing) }
579 | '{-# VECTORISE' qvar '=' exp '#-}' { unitOL $ LL $ VectD (HsVect $2 (Just $4)) }
580 | '{-# NOVECTORISE' qvar '#-}' { unitOL $ LL $ VectD (HsNoVect $2) }
581 | annotation { unitOL $1 }
584 -- Template Haskell Extension
585 -- The $(..) form is one possible form of infixexp
586 -- but we treat an arbitrary expression just as if
587 -- it had a $(..) wrapped around it
588 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
592 cl_decl :: { LTyClDecl RdrName }
593 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
595 -- Type declarations (toplevel)
597 ty_decl :: { LTyClDecl RdrName }
598 -- ordinary type synonyms
599 : 'type' type '=' ctypedoc
600 -- Note ctype, not sigtype, on the right of '='
601 -- We allow an explicit for-all but we don't insert one
602 -- in type Foo a = (b,b)
603 -- Instead we just say b is out of scope
605 -- Note the use of type for the head; this allows
606 -- infix type constructors to be declared
607 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
609 -- type family declarations
610 | 'type' 'family' type opt_kind_sig
611 -- Note the use of type for the head; this allows
612 -- infix type constructors to be declared
613 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
615 -- type instance declarations
616 | 'type' 'instance' type '=' ctype
617 -- Note the use of type for the head; this allows
618 -- infix type constructors and type patterns
619 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
621 -- ordinary data type or newtype declaration
622 | data_or_newtype tycl_hdr constrs deriving
623 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
624 Nothing (reverse (unLoc $3)) (unLoc $4) }
625 -- We need the location on tycl_hdr in case
626 -- constrs and deriving are both empty
628 -- ordinary GADT declaration
629 | data_or_newtype tycl_hdr opt_kind_sig
632 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
633 (unLoc $3) (unLoc $4) (unLoc $5) }
634 -- We need the location on tycl_hdr in case
635 -- constrs and deriving are both empty
637 -- data/newtype family
638 | 'data' 'family' type opt_kind_sig
639 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
641 -- data/newtype instance declaration
642 | data_or_newtype 'instance' tycl_hdr constrs deriving
643 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
644 Nothing (reverse (unLoc $4)) (unLoc $5) }
646 -- GADT instance declaration
647 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
650 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
651 (unLoc $4) (unLoc $5) (unLoc $6) }
653 -- Associated type family declarations
655 -- * They have a different syntax than on the toplevel (no family special
658 -- * They also need to be separate from instances; otherwise, data family
659 -- declarations without a kind signature cause parsing conflicts with empty
660 -- data declarations.
662 at_decl_cls :: { LTyClDecl RdrName }
663 -- type family declarations
664 : 'type' type opt_kind_sig
665 -- Note the use of type for the head; this allows
666 -- infix type constructors to be declared
667 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
669 -- default type instance
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 family declaration
676 | 'data' type opt_kind_sig
677 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
679 -- Associated type instances
681 at_decl_inst :: { LTyClDecl RdrName }
682 -- type instance declarations
683 : 'type' type '=' ctype
684 -- Note the use of type for the head; this allows
685 -- infix type constructors and type patterns
686 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
688 -- data/newtype instance declaration
689 | data_or_newtype tycl_hdr constrs deriving
690 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
691 Nothing (reverse (unLoc $3)) (unLoc $4) }
693 -- GADT instance declaration
694 | data_or_newtype tycl_hdr opt_kind_sig
697 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
698 (unLoc $3) (unLoc $4) (unLoc $5) }
700 data_or_newtype :: { Located NewOrData }
701 : 'data' { L1 DataType }
702 | 'newtype' { L1 NewType }
704 opt_kind_sig :: { Located (Maybe Kind) }
706 | '::' kind { LL (Just (unLoc $2)) }
708 -- tycl_hdr parses the header of a class or data type decl,
709 -- which takes the form
712 -- (Eq a, Ord b) => T a b
713 -- T Int [a] -- for associated types
714 -- Rather a lot of inlining here, else we get reduce/reduce errors
715 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
716 : context '=>' type { LL (Just $1, $3) }
717 | type { L1 (Nothing, $1) }
719 -----------------------------------------------------------------------------
720 -- Stand-alone deriving
722 -- Glasgow extension: stand-alone deriving declarations
723 stand_alone_deriving :: { LDerivDecl RdrName }
724 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
726 -----------------------------------------------------------------------------
727 -- Nested declarations
729 -- Declaration in class bodies
731 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
732 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
735 -- A 'default' signature used with the generic-programming extension
736 | 'default' infixexp '::' sigtypedoc
737 {% do { (TypeSig l ty) <- checkValSig $2 $4
738 ; return (LL $ unitOL (LL $ SigD (GenericSig l ty))) } }
740 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
741 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
742 | decls_cls ';' { LL (unLoc $1) }
744 | {- empty -} { noLoc nilOL }
748 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
749 : '{' decls_cls '}' { LL (unLoc $2) }
750 | vocurly decls_cls close { $2 }
754 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
755 -- No implicit parameters
756 -- May have type declarations
757 : 'where' decllist_cls { LL (unLoc $2) }
758 | {- empty -} { noLoc nilOL }
760 -- Declarations in instance bodies
762 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
763 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
766 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
767 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
768 | decls_inst ';' { LL (unLoc $1) }
770 | {- empty -} { noLoc nilOL }
773 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
774 : '{' decls_inst '}' { LL (unLoc $2) }
775 | vocurly decls_inst close { $2 }
779 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
780 -- No implicit parameters
781 -- May have type declarations
782 : 'where' decllist_inst { LL (unLoc $2) }
783 | {- empty -} { noLoc nilOL }
785 -- Declarations in binding groups other than classes and instances
787 decls :: { Located (OrdList (LHsDecl RdrName)) }
788 : decls ';' decl { let { this = unLoc $3;
790 these = rest `appOL` this }
791 in rest `seq` this `seq` these `seq`
793 | decls ';' { LL (unLoc $1) }
795 | {- empty -} { noLoc nilOL }
797 decllist :: { Located (OrdList (LHsDecl RdrName)) }
798 : '{' decls '}' { LL (unLoc $2) }
799 | vocurly decls close { $2 }
801 -- Binding groups other than those of class and instance declarations
803 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
804 -- No type declarations
805 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
806 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
807 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
809 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
810 -- No type declarations
811 : 'where' binds { LL (unLoc $2) }
812 | {- empty -} { noLoc emptyLocalBinds }
815 -----------------------------------------------------------------------------
816 -- Transformation Rules
818 rules :: { OrdList (LHsDecl RdrName) }
819 : rules ';' rule { $1 `snocOL` $3 }
822 | {- empty -} { nilOL }
824 rule :: { LHsDecl RdrName }
825 : STRING activation rule_forall infixexp '=' exp
826 { LL $ RuleD (HsRule (getSTRING $1)
827 ($2 `orElse` AlwaysActive)
828 $3 $4 placeHolderNames $6 placeHolderNames) }
830 activation :: { Maybe Activation }
831 : {- empty -} { Nothing }
832 | explicit_activation { Just $1 }
834 explicit_activation :: { Activation } -- In brackets
835 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
836 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
838 rule_forall :: { [RuleBndr RdrName] }
839 : 'forall' rule_var_list '.' { $2 }
842 rule_var_list :: { [RuleBndr RdrName] }
844 | rule_var rule_var_list { $1 : $2 }
846 rule_var :: { RuleBndr RdrName }
847 : varid { RuleBndr $1 }
848 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
850 -----------------------------------------------------------------------------
851 -- Warnings and deprecations (c.f. rules)
853 warnings :: { OrdList (LHsDecl RdrName) }
854 : warnings ';' warning { $1 `appOL` $3 }
855 | warnings ';' { $1 }
857 | {- empty -} { nilOL }
859 -- SUP: TEMPORARY HACK, not checking for `module Foo'
860 warning :: { OrdList (LHsDecl RdrName) }
862 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
865 deprecations :: { OrdList (LHsDecl RdrName) }
866 : deprecations ';' deprecation { $1 `appOL` $3 }
867 | deprecations ';' { $1 }
869 | {- empty -} { nilOL }
871 -- SUP: TEMPORARY HACK, not checking for `module Foo'
872 deprecation :: { OrdList (LHsDecl RdrName) }
874 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
877 strings :: { Located [FastString] }
878 : STRING { L1 [getSTRING $1] }
879 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
881 stringlist :: { Located (OrdList FastString) }
882 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
883 | STRING { LL (unitOL (getSTRING $1)) }
885 -----------------------------------------------------------------------------
887 annotation :: { LHsDecl RdrName }
888 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
889 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
890 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
893 -----------------------------------------------------------------------------
894 -- Foreign import and export declarations
896 fdecl :: { LHsDecl RdrName }
897 fdecl : 'import' callconv safety fspec
898 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
899 | 'import' callconv fspec
900 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
902 | 'export' callconv fspec
903 {% mkExport $2 (unLoc $3) >>= return.LL }
905 callconv :: { CCallConv }
906 : 'stdcall' { StdCallConv }
907 | 'ccall' { CCallConv }
908 | 'prim' { PrimCallConv}
911 : 'unsafe' { PlayRisky }
912 | 'safe' { PlaySafe False }
913 | 'interruptible' { PlayInterruptible }
914 | 'threadsafe' { PlaySafe True } -- deprecated alias
916 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
917 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
918 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
919 -- if the entity string is missing, it defaults to the empty string;
920 -- the meaning of an empty entity string depends on the calling
923 -----------------------------------------------------------------------------
926 opt_sig :: { Maybe (LHsType RdrName) }
927 : {- empty -} { Nothing }
928 | '::' sigtype { Just $2 }
930 opt_asig :: { Maybe (LHsType RdrName) }
931 : {- empty -} { Nothing }
932 | '::' atype { Just $2 }
934 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
935 -- to tell the renamer where to generalise
936 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
937 -- Wrap an Implicit forall if there isn't one there already
939 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
940 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
941 -- Wrap an Implicit forall if there isn't one there already
943 sig_vars :: { Located [Located RdrName] }
944 : sig_vars ',' var { LL ($3 : unLoc $1) }
947 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
949 | sigtype ',' sigtypes1 { $1 : $3 }
951 -----------------------------------------------------------------------------
954 infixtype :: { LHsType RdrName }
955 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
956 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
958 strict_mark :: { Located HsBang }
959 : '!' { L1 HsStrict }
960 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
962 -- A ctype is a for-all type
963 ctype :: { LHsType RdrName }
964 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
965 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
966 -- A type of form (context => type) is an *implicit* HsForAllTy
967 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
970 ----------------------
971 -- Notes for 'ctypedoc'
972 -- It would have been nice to simplify the grammar by unifying `ctype` and
973 -- ctypedoc` into one production, allowing comments on types everywhere (and
974 -- rejecting them after parsing, where necessary). This is however not possible
975 -- since it leads to ambiguity. The reason is the support for comments on record
977 -- data R = R { field :: Int -- ^ comment on the field }
978 -- If we allow comments on types here, it's not clear if the comment applies
979 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
981 ctypedoc :: { LHsType RdrName }
982 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
983 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
984 -- A type of form (context => type) is an *implicit* HsForAllTy
985 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
988 ----------------------
989 -- Notes for 'context'
990 -- We parse a context as a btype so that we don't get reduce/reduce
991 -- errors in ctype. The basic problem is that
993 -- looks so much like a tuple type. We can't tell until we find the =>
995 -- We have the t1 ~ t2 form both in 'context' and in type,
996 -- to permit an individual equational constraint without parenthesis.
997 -- Thus for some reason we allow f :: a~b => blah
998 -- but not f :: ?x::Int => blah
999 context :: { LHsContext RdrName }
1000 : btype '~' btype {% checkContext
1001 (LL $ HsPredTy (HsEqualP $1 $3)) }
1002 | btype {% checkContext $1 }
1004 type :: { LHsType RdrName }
1006 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1007 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1008 | btype '->' ctype { LL $ HsFunTy $1 $3 }
1009 | btype '~~>' ctype { LL $ HsKappaTy $1 $3 }
1010 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1012 typedoc :: { LHsType RdrName }
1014 | btype docprev { LL $ HsDocTy $1 $2 }
1015 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1016 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1017 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1018 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1019 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1020 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1021 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1023 btype :: { LHsType RdrName }
1024 : btype atype { LL $ HsAppTy $1 $2 }
1027 atype :: { LHsType RdrName }
1028 : gtycon { L1 (HsTyVar (unLoc $1)) }
1029 | tyvar { L1 (HsTyVar (unLoc $1)) }
1030 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1031 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1032 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1033 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1034 | '[' ctype ']' { LL $ HsListTy $2 }
1035 | '<{' ctype '}>' '@' tyvar { LL $ HsModalBoxType (unLoc $5) $2 }
1036 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1037 | '(' ctype ')' { LL $ HsParTy $2 }
1038 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1039 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1040 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1041 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1042 mkUnqual varName (getTH_ID_SPLICE $1) }
1044 -- An inst_type is what occurs in the head of an instance decl
1045 -- e.g. (Foo a, Gaz b) => Wibble a b
1046 -- It's kept as a single type, with a MonoDictTy at the right
1047 -- hand corner, for convenience.
1048 inst_type :: { LHsType RdrName }
1049 : sigtype {% checkInstType $1 }
1051 inst_types1 :: { [LHsType RdrName] }
1052 : inst_type { [$1] }
1053 | inst_type ',' inst_types1 { $1 : $3 }
1055 comma_types0 :: { [LHsType RdrName] }
1056 : comma_types1 { $1 }
1057 | {- empty -} { [] }
1059 comma_types1 :: { [LHsType RdrName] }
1061 | ctype ',' comma_types1 { $1 : $3 }
1063 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1064 : tv_bndr tv_bndrs { $1 : $2 }
1065 | {- empty -} { [] }
1067 tv_bndr :: { LHsTyVarBndr RdrName }
1068 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1069 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1072 fds :: { Located [Located (FunDep RdrName)] }
1073 : {- empty -} { noLoc [] }
1074 | '|' fds1 { LL (reverse (unLoc $2)) }
1076 fds1 :: { Located [Located (FunDep RdrName)] }
1077 : fds1 ',' fd { LL ($3 : unLoc $1) }
1080 fd :: { Located (FunDep RdrName) }
1081 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1082 (reverse (unLoc $1), reverse (unLoc $3)) }
1084 varids0 :: { Located [RdrName] }
1085 : {- empty -} { noLoc [] }
1086 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1088 -----------------------------------------------------------------------------
1091 kind :: { Located Kind }
1093 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1095 akind :: { Located Kind }
1096 : '*' { L1 liftedTypeKind }
1097 | '!' { L1 unliftedTypeKind }
1098 | '(' kind ')' { LL (unLoc $2) }
1101 -----------------------------------------------------------------------------
1102 -- Datatype declarations
1104 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1105 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1106 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1107 | {- empty -} { noLoc [] }
1109 gadt_constrs :: { Located [LConDecl RdrName] }
1110 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1111 | gadt_constr { L (getLoc (head $1)) $1 }
1112 | {- empty -} { noLoc [] }
1114 -- We allow the following forms:
1115 -- C :: Eq a => a -> T a
1116 -- C :: forall a. Eq a => !a -> T a
1117 -- D { x,y :: a } :: T a
1118 -- forall a. Eq a => D { x,y :: a } :: T a
1120 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1121 : con_list '::' sigtype
1122 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1124 -- Deprecated syntax for GADT record declarations
1125 | oqtycon '{' fielddecls '}' '::' sigtype
1126 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1129 constrs :: { Located [LConDecl RdrName] }
1130 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1132 constrs1 :: { Located [LConDecl RdrName] }
1133 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1134 | constr { L1 [$1] }
1136 constr :: { LConDecl RdrName }
1137 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1138 { let (con,details) = unLoc $5 in
1139 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1141 | maybe_docnext forall constr_stuff maybe_docprev
1142 { let (con,details) = unLoc $3 in
1143 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1146 forall :: { Located [LHsTyVarBndr RdrName] }
1147 : 'forall' tv_bndrs '.' { LL $2 }
1148 | {- empty -} { noLoc [] }
1150 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1151 -- We parse the constructor declaration
1153 -- as a btype (treating C as a type constructor) and then convert C to be
1154 -- a data constructor. Reason: it might continue like this:
1156 -- in which case C really would be a type constructor. We can't resolve this
1157 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1158 : btype {% splitCon $1 >>= return.LL }
1159 | btype conop btype { LL ($2, InfixCon $1 $3) }
1161 fielddecls :: { [ConDeclField RdrName] }
1162 : {- empty -} { [] }
1163 | fielddecls1 { $1 }
1165 fielddecls1 :: { [ConDeclField RdrName] }
1166 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1167 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1168 -- This adds the doc $4 to each field separately
1171 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1172 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1173 | fld <- reverse (unLoc $2) ] }
1175 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1176 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1177 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1178 -- We don't allow a context, but that's sorted out by the type checker.
1179 deriving :: { Located (Maybe [LHsType RdrName]) }
1180 : {- empty -} { noLoc Nothing }
1181 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1182 ; p <- checkInstType (L loc (HsTyVar tv))
1183 ; return (LL (Just [p])) } }
1184 | 'deriving' '(' ')' { LL (Just []) }
1185 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1186 -- Glasgow extension: allow partial
1187 -- applications in derivings
1189 -----------------------------------------------------------------------------
1190 -- Value definitions
1192 {- Note [Declaration/signature overlap]
1193 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1194 There's an awkward overlap with a type signature. Consider
1195 f :: Int -> Int = ...rhs...
1196 Then we can't tell whether it's a type signature or a value
1197 definition with a result signature until we see the '='.
1198 So we have to inline enough to postpone reductions until we know.
1202 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1203 instead of qvar, we get another shift/reduce-conflict. Consider the
1206 { (^^) :: Int->Int ; } Type signature; only var allowed
1208 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1209 qvar allowed (because of instance decls)
1211 We can't tell whether to reduce var to qvar until after we've read the signatures.
1214 docdecl :: { LHsDecl RdrName }
1215 : docdecld { L1 (DocD (unLoc $1)) }
1217 docdecld :: { LDocDecl }
1218 : docnext { L1 (DocCommentNext (unLoc $1)) }
1219 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1220 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1221 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1223 decl :: { Located (OrdList (LHsDecl RdrName)) }
1226 | '!' aexp rhs {% do { let { e = LL (SectionR (LL (HsVar bang_RDR)) $2) };
1227 pat <- checkPattern e;
1228 return $ LL $ unitOL $ LL $ ValD $
1229 PatBind pat (unLoc $3)
1230 placeHolderType placeHolderNames } }
1231 -- Turn it all into an expression so that
1232 -- checkPattern can check that bangs are enabled
1234 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1235 let { l = comb2 $1 $> };
1236 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1238 | docdecl { LL $ unitOL $1 }
1240 rhs :: { Located (GRHSs RdrName) }
1241 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1242 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1244 gdrhs :: { Located [LGRHS RdrName] }
1245 : gdrhs gdrh { LL ($2 : unLoc $1) }
1248 gdrh :: { LGRHS RdrName }
1249 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1251 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1253 -- See Note [Declaration/signature overlap] for why we need infixexp here
1254 infixexp '::' sigtypedoc
1255 {% do s <- checkValSig $1 $3
1256 ; return (LL $ unitOL (LL $ SigD s)) }
1257 | var ',' sig_vars '::' sigtypedoc
1258 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1259 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1261 | '{-# INLINE' activation qvar '#-}'
1262 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma (getINLINE $1) $2))) }
1263 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1264 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1266 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1267 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma (getSPEC_INLINE $1) $2))
1269 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1270 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1272 -----------------------------------------------------------------------------
1275 quasiquote :: { Located (HsQuasiQuote RdrName) }
1276 : TH_QUASIQUOTE { let { loc = getLoc $1
1277 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1278 ; quoterId = mkUnqual varName quoter }
1279 in L1 (mkHsQuasiQuote quoterId (RealSrcSpan quoteSpan) quote) }
1281 incdepth :: { Located () } : {% do { incrBracketDepth ; return $ noLoc () } }
1282 incdepth1 :: { Located () } : {% do { incrBracketDepth1 ; return $ noLoc () } }
1283 decdepth :: { Located () } : {% do { decrBracketDepth ; return $ noLoc () } }
1284 pushdepth :: { Located () } : {% do { pushBracketDepth ; return $ noLoc () } }
1285 popdepth :: { Located () } : {% do { popBracketDepth ; return $ noLoc () } }
1288 exp :: { LHsExpr RdrName }
1289 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1290 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1291 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1292 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1293 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1295 | '~~$' pushdepth exp popdepth {% do { x <- mkHsHetMetEsc placeHolderType placeHolderType $3; return $ sL (comb2 $3 $>) x } }
1297 infixexp :: { LHsExpr RdrName }
1299 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1301 exp10 :: { LHsExpr RdrName }
1302 : '\\' apat apats opt_asig '->' exp
1303 {% do { x <- getParserBrakDepth
1306 KappaFlavor:_ -> LL $ HsKappa (mkMatchGroup[LL $ Match ($2:$3) $4 (unguardedGRHSs $6) ])
1307 _ -> LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4 (unguardedGRHSs $6) ])
1309 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1310 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1311 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1312 return (LL $ mkHsIf $2 $5 $8) }
1313 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1314 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1316 | 'do' stmtlist { L (comb2 $1 $2) (mkHsDo DoExpr (unLoc $2)) }
1317 | 'mdo' stmtlist { L (comb2 $1 $2) (mkHsDo MDoExpr (unLoc $2)) }
1319 | scc_annot exp { LL $ if opt_SccProfilingOn
1320 then HsSCC (unLoc $1) $2
1322 | hpc_annot exp { LL $ if opt_Hpc
1323 then HsTickPragma (unLoc $1) $2
1326 | 'proc' aexp '->' exp
1327 {% checkPattern $2 >>= \ p ->
1328 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1329 placeHolderType undefined)) }
1330 -- TODO: is LL right here?
1332 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1333 -- hdaume: core annotation
1338 | {- empty -} { False }
1340 scc_annot :: { Located FastString }
1341 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1342 ( do scc <- getSCC $2; return $ LL scc ) }
1343 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1345 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1346 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1347 { LL $ (getSTRING $2
1348 ,( fromInteger $ getINTEGER $3
1349 , fromInteger $ getINTEGER $5
1351 ,( fromInteger $ getINTEGER $7
1352 , fromInteger $ getINTEGER $9
1357 fexp :: { LHsExpr RdrName }
1358 : fexp aexp {% do { x <- getParserBrakDepth
1359 ; return $ case x of
1360 [] -> LL $ HsApp $1 $2
1361 LambdaFlavor:_ -> LL $ HsApp $1 $2
1362 KappaFlavor:_ -> LL $ HsKappaApp $1 $2
1366 aexp :: { LHsExpr RdrName }
1367 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1368 | '~' aexp { LL $ ELazyPat $2 }
1371 aexp1 :: { LHsExpr RdrName }
1372 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1376 -- Here was the syntax for type applications that I was planning
1377 -- but there are difficulties (e.g. what order for type args)
1378 -- so it's not enabled yet.
1379 -- But this case *is* used for the left hand side of a generic definition,
1380 -- which is parsed as an expression before being munged into a pattern
1381 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1382 (sL (getLoc $3) (HsType $3)) }
1384 aexp2 :: { LHsExpr RdrName }
1385 : ipvar { L1 (HsIPVar $! unLoc $1) }
1386 | qcname { L1 (HsVar $! unLoc $1) }
1387 | literal { L1 (HsLit $! unLoc $1) }
1388 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1389 -- into HsOverLit when -foverloaded-strings is on.
1390 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1391 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1392 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1394 -- N.B.: sections get parsed by these next two productions.
1395 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't
1396 -- correct Haskell (you'd have to write '((+ 3), (4 -))')
1397 -- but the less cluttered version fell out of having texps.
1398 | '(' texp ')' { LL (HsPar $2) }
1399 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1401 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1402 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1404 | '[' list ']' { LL (unLoc $2) }
1405 | '[:' parr ':]' { LL (unLoc $2) }
1406 | '_' { L1 EWildPat }
1408 -- Template Haskell Extension
1409 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1410 (L1 $ HsVar (mkUnqual varName
1411 (getTH_ID_SPLICE $1)))) }
1412 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1415 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1416 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1417 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1418 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1419 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1420 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1421 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1422 return (LL $ HsBracket (PatBr p)) }
1423 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1424 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1426 -- arrow notation extension
1427 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1429 -- code type notation extension
1430 | '<[' incdepth exp decdepth ']>' { sL (comb2 $3 $>) (HsHetMetBrak placeHolderType $3) }
1431 | '<{' incdepth1 exp decdepth '}>' { sL (comb2 $3 $>) (HsHetMetBrak placeHolderType $3) }
1432 | '~~' pushdepth aexp popdepth {% do { x <- mkHsHetMetEsc placeHolderType placeHolderType $3; return $ sL (comb2 $3 $>) x } }
1433 | '%%' pushdepth aexp popdepth { sL (comb2 $3 $>) (HsHetMetCSP placeHolderType $3) }
1435 cmdargs :: { [LHsCmdTop RdrName] }
1436 : cmdargs acmd { $2 : $1 }
1437 | {- empty -} { [] }
1439 acmd :: { LHsCmdTop RdrName }
1440 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1442 cvtopbody :: { [LHsDecl RdrName] }
1443 : '{' cvtopdecls0 '}' { $2 }
1444 | vocurly cvtopdecls0 close { $2 }
1446 cvtopdecls0 :: { [LHsDecl RdrName] }
1447 : {- empty -} { [] }
1450 -----------------------------------------------------------------------------
1451 -- Tuple expressions
1453 -- "texp" is short for tuple expressions:
1454 -- things that can appear unparenthesized as long as they're
1455 -- inside parens or delimitted by commas
1456 texp :: { LHsExpr RdrName }
1459 -- Note [Parsing sections]
1460 -- ~~~~~~~~~~~~~~~~~~~~~~~
1461 -- We include left and right sections here, which isn't
1462 -- technically right according to the Haskell standard.
1463 -- For example (3 +, True) isn't legal.
1464 -- However, we want to parse bang patterns like
1466 -- and it's convenient to do so here as a section
1467 -- Then when converting expr to pattern we unravel it again
1468 -- Meanwhile, the renamer checks that real sections appear
1470 | infixexp qop { LL $ SectionL $1 $2 }
1471 | qopm infixexp { LL $ SectionR $1 $2 }
1473 -- View patterns get parenthesized above
1474 | exp '->' texp { LL $ EViewPat $1 $3 }
1476 -- Always at least one comma
1477 tup_exprs :: { [HsTupArg RdrName] }
1478 : texp commas_tup_tail { Present $1 : $2 }
1479 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1481 -- Always starts with commas; always follows an expr
1482 commas_tup_tail :: { [HsTupArg RdrName] }
1483 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1485 -- Always follows a comma
1486 tup_tail :: { [HsTupArg RdrName] }
1487 : texp commas_tup_tail { Present $1 : $2 }
1488 | texp { [Present $1] }
1489 | {- empty -} { [missingTupArg] }
1491 -----------------------------------------------------------------------------
1494 -- The rules below are little bit contorted to keep lexps left-recursive while
1495 -- avoiding another shift/reduce-conflict.
1497 list :: { LHsExpr RdrName }
1498 : texp { L1 $ ExplicitList placeHolderType [$1] }
1499 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1500 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1501 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1502 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1503 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1504 | texp '|' flattenedpquals
1505 {% checkMonadComp >>= \ ctxt ->
1506 return (sL (comb2 $1 $>) $
1507 mkHsComp ctxt (unLoc $3) $1) }
1509 lexps :: { Located [LHsExpr RdrName] }
1510 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1511 | texp ',' texp { LL [$3,$1] }
1513 -----------------------------------------------------------------------------
1514 -- List Comprehensions
1516 flattenedpquals :: { Located [LStmt RdrName] }
1517 : pquals { case (unLoc $1) of
1519 -- We just had one thing in our "parallel" list so
1520 -- we simply return that thing directly
1522 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss] noSyntaxExpr noSyntaxExpr noSyntaxExpr]
1523 -- We actually found some actual parallel lists so
1524 -- we wrap them into as a ParStmt
1527 pquals :: { Located [[LStmt RdrName]] }
1528 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1529 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1531 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1532 -- one can "grab" the earlier ones
1533 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1534 | squals ',' qual { LL ($3 : unLoc $1) }
1535 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1537 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1538 -- | '{|' pquals '|}' { L1 [$2] }
1541 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1542 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1545 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1546 -- Function is applied to a list of stmts *in order*
1547 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1549 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1550 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1552 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1553 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1554 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1555 -- choosing the "group by" variant, which is what we want.
1557 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1558 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1559 -- if /that/ is the group function we conflict with.
1560 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1561 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1563 -----------------------------------------------------------------------------
1564 -- Parallel array expressions
1566 -- The rules below are little bit contorted; see the list case for details.
1567 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1568 -- Moreover, we allow explicit arrays with no element (represented by the nil
1569 -- constructor in the list case).
1571 parr :: { LHsExpr RdrName }
1572 : { noLoc (ExplicitPArr placeHolderType []) }
1573 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1574 | lexps { L1 $ ExplicitPArr placeHolderType
1575 (reverse (unLoc $1)) }
1576 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1577 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1578 | texp '|' flattenedpquals { LL $ mkHsComp PArrComp (unLoc $3) $1 }
1580 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1582 -----------------------------------------------------------------------------
1585 guardquals :: { Located [LStmt RdrName] }
1586 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1588 guardquals1 :: { Located [LStmt RdrName] }
1589 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1592 -----------------------------------------------------------------------------
1593 -- Case alternatives
1595 altslist :: { Located [LMatch RdrName] }
1596 : '{' alts '}' { LL (reverse (unLoc $2)) }
1597 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1599 alts :: { Located [LMatch RdrName] }
1600 : alts1 { L1 (unLoc $1) }
1601 | ';' alts { LL (unLoc $2) }
1603 alts1 :: { Located [LMatch RdrName] }
1604 : alts1 ';' alt { LL ($3 : unLoc $1) }
1605 | alts1 ';' { LL (unLoc $1) }
1608 alt :: { LMatch RdrName }
1609 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1611 alt_rhs :: { Located (GRHSs RdrName) }
1612 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1614 ralt :: { Located [LGRHS RdrName] }
1615 : '->' exp { LL (unguardedRHS $2) }
1616 | gdpats { L1 (reverse (unLoc $1)) }
1618 gdpats :: { Located [LGRHS RdrName] }
1619 : gdpats gdpat { LL ($2 : unLoc $1) }
1622 gdpat :: { LGRHS RdrName }
1623 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1625 -- 'pat' recognises a pattern, including one with a bang at the top
1626 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1627 -- Bangs inside are parsed as infix operator applications, so that
1628 -- we parse them right when bang-patterns are off
1629 pat :: { LPat RdrName }
1630 pat : exp {% checkPattern $1 }
1631 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1633 apat :: { LPat RdrName }
1634 apat : aexp {% checkPattern $1 }
1635 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1637 apats :: { [LPat RdrName] }
1638 : apat apats { $1 : $2 }
1639 | {- empty -} { [] }
1641 -----------------------------------------------------------------------------
1642 -- Statement sequences
1644 stmtlist :: { Located [LStmt RdrName] }
1645 : '{' stmts '}' { LL (unLoc $2) }
1646 | vocurly stmts close { $2 }
1648 -- do { ;; s ; s ; ; s ;; }
1649 -- The last Stmt should be an expression, but that's hard to enforce
1650 -- here, because we need too much lookahead if we see do { e ; }
1651 -- So we use ExprStmts throughout, and switch the last one over
1652 -- in ParseUtils.checkDo instead
1653 stmts :: { Located [LStmt RdrName] }
1654 : stmt stmts_help { LL ($1 : unLoc $2) }
1655 | ';' stmts { LL (unLoc $2) }
1656 | {- empty -} { noLoc [] }
1658 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1659 : ';' stmts { LL (unLoc $2) }
1660 | {- empty -} { noLoc [] }
1662 -- For typing stmts at the GHCi prompt, where
1663 -- the input may consist of just comments.
1664 maybe_stmt :: { Maybe (LStmt RdrName) }
1666 | {- nothing -} { Nothing }
1668 stmt :: { LStmt RdrName }
1670 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1672 qual :: { LStmt RdrName }
1673 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1674 | exp { L1 $ mkExprStmt $1 }
1675 | 'let' binds { LL $ LetStmt (unLoc $2) }
1677 -----------------------------------------------------------------------------
1678 -- Record Field Update/Construction
1680 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1682 | {- empty -} { ([], False) }
1684 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1685 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1686 | fbind { ([$1], False) }
1687 | '..' { ([], True) }
1689 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1690 : qvar '=' exp { HsRecField $1 $3 False }
1691 | qvar { HsRecField $1 placeHolderPunRhs True }
1692 -- In the punning case, use a place-holder
1693 -- The renamer fills in the final value
1695 -----------------------------------------------------------------------------
1696 -- Implicit Parameter Bindings
1698 dbinds :: { Located [LIPBind RdrName] }
1699 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1700 in rest `seq` this `seq` LL (this : rest) }
1701 | dbinds ';' { LL (unLoc $1) }
1702 | dbind { let this = $1 in this `seq` L1 [this] }
1703 -- | {- empty -} { [] }
1705 dbind :: { LIPBind RdrName }
1706 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1708 ipvar :: { Located (IPName RdrName) }
1709 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1711 -----------------------------------------------------------------------------
1712 -- Warnings and deprecations
1714 namelist :: { Located [RdrName] }
1715 namelist : name_var { L1 [unLoc $1] }
1716 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1718 name_var :: { Located RdrName }
1719 name_var : var { $1 }
1722 -----------------------------------------
1723 -- Data constructors
1724 qcon :: { Located RdrName }
1726 | '(' qconsym ')' { LL (unLoc $2) }
1727 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1728 -- The case of '[:' ':]' is part of the production `parr'
1730 con :: { Located RdrName }
1732 | '(' consym ')' { LL (unLoc $2) }
1733 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1735 con_list :: { Located [Located RdrName] }
1736 con_list : con { L1 [$1] }
1737 | con ',' con_list { LL ($1 : unLoc $3) }
1739 sysdcon :: { Located DataCon } -- Wired in data constructors
1740 : '(' ')' { LL unitDataCon }
1741 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1742 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1743 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1744 | '[' ']' { LL nilDataCon }
1746 conop :: { Located RdrName }
1748 | '`' conid '`' { LL (unLoc $2) }
1750 qconop :: { Located RdrName }
1752 | '`' qconid '`' { LL (unLoc $2) }
1754 -----------------------------------------------------------------------------
1755 -- Type constructors
1757 gtycon :: { Located RdrName } -- A "general" qualified tycon
1759 | '(' ')' { LL $ getRdrName unitTyCon }
1760 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1761 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1762 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1763 | '(' '->' ')' { LL $ getRdrName funTyCon }
1764 | '[' ']' { LL $ listTyCon_RDR }
1765 | '[:' ':]' { LL $ parrTyCon_RDR }
1767 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1769 | '(' qtyconsym ')' { LL (unLoc $2) }
1771 qtyconop :: { Located RdrName } -- Qualified or unqualified
1773 | '`' qtycon '`' { LL (unLoc $2) }
1775 qtycon :: { Located RdrName } -- Qualified or unqualified
1776 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1777 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1780 tycon :: { Located RdrName } -- Unqualified
1781 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1783 qtyconsym :: { Located RdrName }
1784 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1787 tyconsym :: { Located RdrName }
1788 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1790 -----------------------------------------------------------------------------
1793 op :: { Located RdrName } -- used in infix decls
1797 varop :: { Located RdrName }
1799 | '`' varid '`' { LL (unLoc $2) }
1801 qop :: { LHsExpr RdrName } -- used in sections
1802 : qvarop { L1 $ HsVar (unLoc $1) }
1803 | qconop { L1 $ HsVar (unLoc $1) }
1805 qopm :: { LHsExpr RdrName } -- used in sections
1806 : qvaropm { L1 $ HsVar (unLoc $1) }
1807 | qconop { L1 $ HsVar (unLoc $1) }
1809 qvarop :: { Located RdrName }
1811 | '`' qvarid '`' { LL (unLoc $2) }
1813 qvaropm :: { Located RdrName }
1814 : qvarsym_no_minus { $1 }
1815 | '`' qvarid '`' { LL (unLoc $2) }
1817 -----------------------------------------------------------------------------
1820 tyvar :: { Located RdrName }
1821 tyvar : tyvarid { $1 }
1822 | '(' tyvarsym ')' { LL (unLoc $2) }
1824 tyvarop :: { Located RdrName }
1825 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1827 | '.' {% parseErrorSDoc (getLoc $1)
1828 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1829 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1830 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1833 tyvarid :: { Located RdrName }
1834 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1835 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1836 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1837 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1838 | 'interruptible' { L1 $! mkUnqual tvName (fsLit "interruptible") }
1839 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1841 tyvarsym :: { Located RdrName }
1842 -- Does not include "!", because that is used for strictness marks
1843 -- or ".", because that separates the quantified type vars from the rest
1844 -- or "*", because that's used for kinds
1845 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1847 -----------------------------------------------------------------------------
1850 var :: { Located RdrName }
1852 | '(' varsym ')' { LL (unLoc $2) }
1854 qvar :: { Located RdrName }
1856 | '(' varsym ')' { LL (unLoc $2) }
1857 | '(' qvarsym1 ')' { LL (unLoc $2) }
1858 -- We've inlined qvarsym here so that the decision about
1859 -- whether it's a qvar or a var can be postponed until
1860 -- *after* we see the close paren.
1862 qvarid :: { Located RdrName }
1864 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1865 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1867 varid :: { Located RdrName }
1868 : VARID {% do { depth <- getParserBrakDepth ; return (L1 $! mkUnqual (varNameDepth $ length depth) (getVARID $1)) } }
1869 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1870 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1871 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1872 | 'interruptible' { L1 $! mkUnqual varName (fsLit "interruptible") }
1873 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1874 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1875 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1877 qvarsym :: { Located RdrName }
1881 qvarsym_no_minus :: { Located RdrName }
1882 : varsym_no_minus { $1 }
1885 qvarsym1 :: { Located RdrName }
1886 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1888 varsym :: { Located RdrName }
1889 : varsym_no_minus { $1 }
1890 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1892 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1893 : VARSYM {% do { depth <- getParserBrakDepth
1894 ; return (L1 $! mkUnqual (varNameDepth $ length depth) (getVARSYM $1)) } }
1895 | special_sym {% do { depth <- getParserBrakDepth
1896 ; return (L1 $! mkUnqual (varNameDepth $ length depth) (unLoc $1)) } }
1898 -- These special_ids are treated as keywords in various places,
1899 -- but as ordinary ids elsewhere. 'special_id' collects all these
1900 -- except 'unsafe', 'interruptible', 'forall', and 'family' whose treatment differs
1901 -- depending on context
1902 special_id :: { Located FastString }
1904 : 'as' { L1 (fsLit "as") }
1905 | 'qualified' { L1 (fsLit "qualified") }
1906 | 'hiding' { L1 (fsLit "hiding") }
1907 | 'export' { L1 (fsLit "export") }
1908 | 'label' { L1 (fsLit "label") }
1909 | 'dynamic' { L1 (fsLit "dynamic") }
1910 | 'stdcall' { L1 (fsLit "stdcall") }
1911 | 'ccall' { L1 (fsLit "ccall") }
1912 | 'prim' { L1 (fsLit "prim") }
1913 | 'group' { L1 (fsLit "group") }
1915 special_sym :: { Located FastString }
1916 special_sym : '!' { L1 (fsLit "!") }
1917 | '.' { L1 (fsLit ".") }
1918 | '*' { L1 (fsLit "*") }
1920 -----------------------------------------------------------------------------
1921 -- Data constructors
1923 qconid :: { Located RdrName } -- Qualified or unqualified
1925 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1926 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1928 conid :: { Located RdrName }
1929 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1931 qconsym :: { Located RdrName } -- Qualified or unqualified
1933 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1935 consym :: { Located RdrName }
1936 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1938 -- ':' means only list cons
1939 | ':' { L1 $ consDataCon_RDR }
1942 -----------------------------------------------------------------------------
1945 literal :: { Located HsLit }
1946 : CHAR { L1 $ HsChar $ getCHAR $1 }
1947 | STRING { L1 $ HsString $ getSTRING $1 }
1948 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1949 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1950 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1951 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1952 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1953 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1955 -----------------------------------------------------------------------------
1959 : vccurly { () } -- context popped in lexer.
1960 | error {% popContext }
1962 -----------------------------------------------------------------------------
1963 -- Miscellaneous (mostly renamings)
1965 modid :: { Located ModuleName }
1966 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1967 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1970 (unpackFS mod ++ '.':unpackFS c))
1974 : commas ',' { $1 + 1 }
1977 -----------------------------------------------------------------------------
1978 -- Documentation comments
1980 docnext :: { LHsDocString }
1981 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1983 docprev :: { LHsDocString }
1984 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1986 docnamed :: { Located (String, HsDocString) }
1988 let string = getDOCNAMED $1
1989 (name, rest) = break isSpace string
1990 in return (L1 (name, HsDocString (mkFastString rest))) }
1992 docsection :: { Located (Int, HsDocString) }
1993 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1994 return (L1 (n, HsDocString (mkFastString doc))) }
1996 moduleheader :: { Maybe LHsDocString }
1997 : DOCNEXT {% let string = getDOCNEXT $1 in
1998 return (Just (L1 (HsDocString (mkFastString string)))) }
2000 maybe_docprev :: { Maybe LHsDocString }
2001 : docprev { Just $1 }
2002 | {- empty -} { Nothing }
2004 maybe_docnext :: { Maybe LHsDocString }
2005 : docnext { Just $1 }
2006 | {- empty -} { Nothing }
2010 happyError = srcParseFail
2012 getVARID (L _ (ITvarid x)) = x
2013 getCONID (L _ (ITconid x)) = x
2014 getVARSYM (L _ (ITvarsym x)) = x
2015 getCONSYM (L _ (ITconsym x)) = x
2016 getQVARID (L _ (ITqvarid x)) = x
2017 getQCONID (L _ (ITqconid x)) = x
2018 getQVARSYM (L _ (ITqvarsym x)) = x
2019 getQCONSYM (L _ (ITqconsym x)) = x
2020 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
2021 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
2022 getIPDUPVARID (L _ (ITdupipvarid x)) = x
2023 getCHAR (L _ (ITchar x)) = x
2024 getSTRING (L _ (ITstring x)) = x
2025 getINTEGER (L _ (ITinteger x)) = x
2026 getRATIONAL (L _ (ITrational x)) = x
2027 getPRIMCHAR (L _ (ITprimchar x)) = x
2028 getPRIMSTRING (L _ (ITprimstring x)) = x
2029 getPRIMINTEGER (L _ (ITprimint x)) = x
2030 getPRIMWORD (L _ (ITprimword x)) = x
2031 getPRIMFLOAT (L _ (ITprimfloat x)) = x
2032 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
2033 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
2034 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
2035 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
2036 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
2038 getDOCNEXT (L _ (ITdocCommentNext x)) = x
2039 getDOCPREV (L _ (ITdocCommentPrev x)) = x
2040 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
2041 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2043 getSCC :: Located Token -> P FastString
2044 getSCC lt = do let s = getSTRING lt
2045 err = "Spaces are not allowed in SCCs"
2046 -- We probably actually want to be more restrictive than this
2047 if ' ' `elem` unpackFS s
2048 then failSpanMsgP (getLoc lt) (text err)
2051 -- Utilities for combining source spans
2052 comb2 :: Located a -> Located b -> SrcSpan
2053 comb2 a b = a `seq` b `seq` combineLocs a b
2055 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2056 comb3 a b c = a `seq` b `seq` c `seq`
2057 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2059 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2060 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2061 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2062 combineSrcSpans (getLoc c) (getLoc d))
2064 -- strict constructor version:
2066 sL :: SrcSpan -> a -> Located a
2067 sL span a = span `seq` a `seq` L span a
2069 -- Make a source location for the file. We're a bit lazy here and just
2070 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2071 -- try to find the span of the whole file (ToDo).
2072 fileSrcSpan :: P SrcSpan
2075 let loc = mkSrcLoc (srcLocFile l) 1 1;
2076 return (mkSrcSpan loc loc)
2078 mkHsHetMetEsc a b c = do { depth <- getParserBrakDepth
2079 ; return $ case head depth of
2080 { LambdaFlavor -> HsHetMetEsc a b c
2081 ; KappaFlavor -> HsHetMetEsc a b c