2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
12 -- The above warning supression flag is a temporary kludge.
13 -- While working on this module you are encouraged to remove it and fix
14 -- any warnings in the module. See
15 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
18 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
20 Careful optimisation of the parser: we don't want to throw everything
21 at it, because that takes too long and doesn't buy much, but we do want
22 to inline certain key external functions, so we instruct GHC not to
23 throw away inlinings as it would normally do in -O0 mode.
26 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
31 import HscTypes ( IsBootInterface, WarningTxt(..) )
34 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
35 unboxedSingletonTyCon, unboxedSingletonDataCon,
36 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
37 import Type ( funTyCon )
38 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
39 CCallConv(..), CCallTarget(..), defaultCCallConv
41 import OccName ( varName, dataName, tcClsName, tvName )
42 import DataCon ( DataCon, dataConName )
43 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
44 SrcSpan, combineLocs, srcLocFile,
47 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
48 import Type ( Kind, mkArrowKind, liftedTypeKind, unliftedTypeKind )
49 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
50 Activation(..), RuleMatchInfo(..), defaultInlineSpec )
54 import {-# SOURCE #-} HaddockLex hiding ( Token )
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 }
244 'unsafe' { L _ ITunsafe }
246 'family' { L _ ITfamily }
247 'stdcall' { L _ ITstdcallconv }
248 'ccall' { L _ ITccallconv }
249 'dotnet' { L _ ITdotnet }
250 'proc' { L _ ITproc } -- for arrow notation extension
251 'rec' { L _ ITrec } -- for arrow notation extension
252 'group' { L _ ITgroup } -- for list transform extension
253 'by' { L _ ITby } -- for list transform extension
254 'using' { L _ ITusing } -- for list transform extension
256 '{-# INLINE' { L _ (ITinline_prag _) }
257 '{-# INLINE_CONLIKE' { L _ (ITinline_conlike_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 -> case $1 of { (info, doc) ->
385 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4
388 {% fileSrcSpan >>= \ loc ->
389 return (L loc (HsModule Nothing Nothing
390 (fst $1) (snd $1) Nothing emptyHaddockModInfo
393 maybedocheader :: { (HaddockModInfo RdrName, Maybe (HsDoc RdrName)) }
394 : moduleheader { $1 }
395 | {- empty -} { (emptyHaddockModInfo, Nothing) }
397 missing_module_keyword :: { () }
398 : {- empty -} {% pushCurrentContext }
400 maybemodwarning :: { Maybe WarningTxt }
401 : '{-# DEPRECATED' STRING '#-}' { Just (DeprecatedTxt (getSTRING $2)) }
402 | '{-# WARNING' STRING '#-}' { Just (WarningTxt (getSTRING $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 -> case $1 of { (info, doc) ->
427 return (L loc (HsModule (Just $3) $5 $7 [] $4
429 | missing_module_keyword importdecls
430 {% fileSrcSpan >>= \ loc ->
431 return (L loc (HsModule Nothing Nothing $2 [] Nothing
432 emptyHaddockModInfo 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 $1 }
569 -- Template Haskell Extension
570 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
571 | TH_ID_SPLICE { unitOL (LL $ SpliceD (SpliceDecl $
572 L1 $ HsVar (mkUnqual varName (getTH_ID_SPLICE $1))
577 cl_decl :: { LTyClDecl RdrName }
578 : 'class' tycl_hdr fds where_cls
579 {% do { let { (binds, sigs, ats, docs) =
580 cvBindsAndSigs (unLoc $4)
581 ; (ctxt, tc, tvs, tparms) = unLoc $2}
582 ; checkTyVars tparms -- only type vars allowed
584 ; return $ L (comb4 $1 $2 $3 $4)
585 (mkClassDecl (ctxt, tc, tvs)
586 (unLoc $3) sigs binds ats docs) } }
588 -- Type declarations (toplevel)
590 ty_decl :: { LTyClDecl RdrName }
591 -- ordinary type synonyms
592 : 'type' type '=' ctypedoc
593 -- Note ctype, not sigtype, on the right of '='
594 -- We allow an explicit for-all but we don't insert one
595 -- in type Foo a = (b,b)
596 -- Instead we just say b is out of scope
598 -- Note the use of type for the head; this allows
599 -- infix type constructors to be declared
600 {% do { (tc, tvs, _) <- checkSynHdr $2 False
601 ; return (L (comb2 $1 $4)
602 (TySynonym tc tvs Nothing $4))
605 -- type family declarations
606 | 'type' 'family' type opt_kind_sig
607 -- Note the use of type for the head; this allows
608 -- infix type constructors to be declared
610 {% do { (tc, tvs, _) <- checkSynHdr $3 False
611 ; return (L (comb3 $1 $3 $4)
612 (TyFamily TypeFamily tc tvs (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
620 {% do { (tc, tvs, typats) <- checkSynHdr $3 True
621 ; return (L (comb2 $1 $5)
622 (TySynonym tc tvs (Just typats) $5))
625 -- ordinary data type or newtype declaration
626 | data_or_newtype tycl_hdr constrs deriving
627 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
628 ; checkTyVars tparms -- no type pattern
630 sL (comb4 $1 $2 $3 $4)
631 -- We need the location on tycl_hdr in case
632 -- constrs and deriving are both empty
633 (mkTyData (unLoc $1) (ctxt, tc, tvs, Nothing)
634 Nothing (reverse (unLoc $3)) (unLoc $4)) } }
636 -- ordinary GADT declaration
637 | data_or_newtype tycl_hdr opt_kind_sig
638 'where' gadt_constrlist
640 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
641 ; checkTyVars tparms -- can have type pats
643 sL (comb4 $1 $2 $4 $5)
644 (mkTyData (unLoc $1) (ctxt, tc, tvs, Nothing)
645 (unLoc $3) (reverse (unLoc $5)) (unLoc $6)) } }
647 -- data/newtype family
648 | 'data' 'family' tycl_hdr opt_kind_sig
649 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $3}
650 ; checkTyVars tparms -- no type pattern
651 ; unless (null (unLoc ctxt)) $ -- and no context
652 parseError (getLoc ctxt)
653 "A family declaration cannot have a context"
656 (TyFamily DataFamily tc tvs (unLoc $4)) } }
658 -- data/newtype instance declaration
659 | data_or_newtype 'instance' tycl_hdr constrs deriving
660 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $3}
661 -- can have type pats
663 L (comb4 $1 $3 $4 $5)
664 -- We need the location on tycl_hdr in case
665 -- constrs and deriving are both empty
666 (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
667 Nothing (reverse (unLoc $4)) (unLoc $5)) } }
669 -- GADT instance declaration
670 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
671 'where' gadt_constrlist
673 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $3}
674 -- can have type pats
676 L (comb4 $1 $3 $6 $7)
677 (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
678 (unLoc $4) (reverse (unLoc $6)) (unLoc $7)) } }
680 -- Associate type family declarations
682 -- * They have a different syntax than on the toplevel (no family special
685 -- * They also need to be separate from instances; otherwise, data family
686 -- declarations without a kind signature cause parsing conflicts with empty
687 -- data declarations.
689 at_decl_cls :: { LTyClDecl RdrName }
690 -- type family declarations
691 : 'type' type opt_kind_sig
692 -- Note the use of type for the head; this allows
693 -- infix type constructors to be declared
695 {% do { (tc, tvs, _) <- checkSynHdr $2 False
696 ; return (L (comb3 $1 $2 $3)
697 (TyFamily TypeFamily tc tvs (unLoc $3)))
700 -- default type instance
701 | 'type' type '=' ctype
702 -- Note the use of type for the head; this allows
703 -- infix type constructors and type patterns
705 {% do { (tc, tvs, typats) <- checkSynHdr $2 True
706 ; return (L (comb2 $1 $4)
707 (TySynonym tc tvs (Just typats) $4))
710 -- data/newtype family declaration
711 | 'data' tycl_hdr opt_kind_sig
712 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
713 ; checkTyVars tparms -- no type pattern
714 ; unless (null (unLoc ctxt)) $ -- and no context
715 parseError (getLoc ctxt)
716 "A family declaration cannot have a context"
719 (TyFamily DataFamily tc tvs (unLoc $3))
722 -- Associate type instances
724 at_decl_inst :: { LTyClDecl RdrName }
725 -- type instance declarations
726 : 'type' type '=' ctype
727 -- Note the use of type for the head; this allows
728 -- infix type constructors and type patterns
730 {% do { (tc, tvs, typats) <- checkSynHdr $2 True
731 ; return (L (comb2 $1 $4)
732 (TySynonym tc tvs (Just typats) $4))
735 -- data/newtype instance declaration
736 | data_or_newtype tycl_hdr constrs deriving
737 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
738 -- can have type pats
740 L (comb4 $1 $2 $3 $4)
741 -- We need the location on tycl_hdr in case
742 -- constrs and deriving are both empty
743 (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
744 Nothing (reverse (unLoc $3)) (unLoc $4)) } }
746 -- GADT instance declaration
747 | data_or_newtype tycl_hdr opt_kind_sig
748 'where' gadt_constrlist
750 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
751 -- can have type pats
753 L (comb4 $1 $2 $5 $6)
754 (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
755 (unLoc $3) (reverse (unLoc $5)) (unLoc $6)) } }
757 data_or_newtype :: { Located NewOrData }
758 : 'data' { L1 DataType }
759 | 'newtype' { L1 NewType }
761 opt_kind_sig :: { Located (Maybe Kind) }
763 | '::' kind { LL (Just (unLoc $2)) }
765 -- tycl_hdr parses the header of a class or data type decl,
766 -- which takes the form
769 -- (Eq a, Ord b) => T a b
770 -- T Int [a] -- for associated types
771 -- Rather a lot of inlining here, else we get reduce/reduce errors
772 tycl_hdr :: { Located (LHsContext RdrName,
774 [LHsTyVarBndr RdrName],
776 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
777 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
779 -----------------------------------------------------------------------------
780 -- Stand-alone deriving
782 -- Glasgow extension: stand-alone deriving declarations
783 stand_alone_deriving :: { LDerivDecl RdrName }
784 : 'deriving' 'instance' inst_type {% checkDerivDecl (LL (DerivDecl $3)) }
786 -----------------------------------------------------------------------------
787 -- Nested declarations
789 -- Declaration in class bodies
791 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
792 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
795 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
796 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
797 | decls_cls ';' { LL (unLoc $1) }
799 | {- empty -} { noLoc nilOL }
803 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
804 : '{' decls_cls '}' { LL (unLoc $2) }
805 | vocurly decls_cls close { $2 }
809 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
810 -- No implicit parameters
811 -- May have type declarations
812 : 'where' decllist_cls { LL (unLoc $2) }
813 | {- empty -} { noLoc nilOL }
815 -- Declarations in instance bodies
817 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
818 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
821 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
822 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
823 | decls_inst ';' { LL (unLoc $1) }
825 | {- empty -} { noLoc nilOL }
828 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
829 : '{' decls_inst '}' { LL (unLoc $2) }
830 | vocurly decls_inst close { $2 }
834 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
835 -- No implicit parameters
836 -- May have type declarations
837 : 'where' decllist_inst { LL (unLoc $2) }
838 | {- empty -} { noLoc nilOL }
840 -- Declarations in binding groups other than classes and instances
842 decls :: { Located (OrdList (LHsDecl RdrName)) }
843 : decls ';' decl { let { this = unLoc $3;
845 these = rest `appOL` this }
846 in rest `seq` this `seq` these `seq`
848 | decls ';' { LL (unLoc $1) }
850 | {- empty -} { noLoc nilOL }
852 decllist :: { Located (OrdList (LHsDecl RdrName)) }
853 : '{' decls '}' { LL (unLoc $2) }
854 | vocurly decls close { $2 }
856 -- Binding groups other than those of class and instance declarations
858 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
859 -- No type declarations
860 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
861 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
862 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
864 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
865 -- No type declarations
866 : 'where' binds { LL (unLoc $2) }
867 | {- empty -} { noLoc emptyLocalBinds }
870 -----------------------------------------------------------------------------
871 -- Transformation Rules
873 rules :: { OrdList (LHsDecl RdrName) }
874 : rules ';' rule { $1 `snocOL` $3 }
877 | {- empty -} { nilOL }
879 rule :: { LHsDecl RdrName }
880 : STRING activation rule_forall infixexp '=' exp
881 { LL $ RuleD (HsRule (getSTRING $1)
882 ($2 `orElse` AlwaysActive)
883 $3 $4 placeHolderNames $6 placeHolderNames) }
885 activation :: { Maybe Activation }
886 : {- empty -} { Nothing }
887 | explicit_activation { Just $1 }
889 explicit_activation :: { Activation } -- In brackets
890 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
891 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
893 rule_forall :: { [RuleBndr RdrName] }
894 : 'forall' rule_var_list '.' { $2 }
897 rule_var_list :: { [RuleBndr RdrName] }
899 | rule_var rule_var_list { $1 : $2 }
901 rule_var :: { RuleBndr RdrName }
902 : varid { RuleBndr $1 }
903 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
905 -----------------------------------------------------------------------------
906 -- Warnings and deprecations (c.f. rules)
908 warnings :: { OrdList (LHsDecl RdrName) }
909 : warnings ';' warning { $1 `appOL` $3 }
910 | warnings ';' { $1 }
912 | {- empty -} { nilOL }
914 -- SUP: TEMPORARY HACK, not checking for `module Foo'
915 warning :: { OrdList (LHsDecl RdrName) }
917 { toOL [ LL $ WarningD (Warning n (WarningTxt (getSTRING $2)))
920 deprecations :: { OrdList (LHsDecl RdrName) }
921 : deprecations ';' deprecation { $1 `appOL` $3 }
922 | deprecations ';' { $1 }
924 | {- empty -} { nilOL }
926 -- SUP: TEMPORARY HACK, not checking for `module Foo'
927 deprecation :: { OrdList (LHsDecl RdrName) }
929 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt (getSTRING $2)))
932 -----------------------------------------------------------------------------
934 annotation :: { LHsDecl RdrName }
935 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
936 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
937 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
940 -----------------------------------------------------------------------------
941 -- Foreign import and export declarations
943 fdecl :: { LHsDecl RdrName }
944 fdecl : 'import' callconv safety fspec
945 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
946 | 'import' callconv fspec
947 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
949 | 'export' callconv fspec
950 {% mkExport $2 (unLoc $3) >>= return.LL }
952 callconv :: { CallConv }
953 : 'stdcall' { CCall StdCallConv }
954 | 'ccall' { CCall CCallConv }
955 | 'dotnet' { DNCall }
958 : 'unsafe' { PlayRisky }
959 | 'safe' { PlaySafe False }
960 | 'threadsafe' { PlaySafe True }
962 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
963 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
964 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
965 -- if the entity string is missing, it defaults to the empty string;
966 -- the meaning of an empty entity string depends on the calling
969 -----------------------------------------------------------------------------
972 opt_sig :: { Maybe (LHsType RdrName) }
973 : {- empty -} { Nothing }
974 | '::' sigtype { Just $2 }
976 opt_asig :: { Maybe (LHsType RdrName) }
977 : {- empty -} { Nothing }
978 | '::' atype { Just $2 }
980 sigtypes1 :: { [LHsType RdrName] }
982 | sigtype ',' sigtypes1 { $1 : $3 }
984 sigtype :: { LHsType RdrName }
985 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
986 -- Wrap an Implicit forall if there isn't one there already
988 sigtypedoc :: { LHsType RdrName }
989 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
990 -- Wrap an Implicit forall if there isn't one there already
992 sig_vars :: { Located [Located RdrName] }
993 : sig_vars ',' var { LL ($3 : unLoc $1) }
996 -----------------------------------------------------------------------------
999 infixtype :: { LHsType RdrName }
1000 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1001 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1003 strict_mark :: { Located HsBang }
1004 : '!' { L1 HsStrict }
1005 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
1007 ----------------------
1008 -- Notes for 'ctype'
1009 -- We should probably use 'gentype' rather than 'type' in the LHS of type declarations
1010 -- That would leave the only use of 'type' in 'ctype'; and only one of its occurrences
1011 -- makes sense there too! So it might make sense to inline type there:
1012 -- ctype : 'forall' tv_bndrs '.' ctype
1013 -- | context '=>' ctype
1014 -- | ipvar '::' gentype
1016 -- Which in turn would let us rename gentype to type
1018 -- A ctype is a for-all type
1019 ctype :: { LHsType RdrName }
1020 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
1021 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
1022 -- A type of form (context => type) is an *implicit* HsForAllTy
1023 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
1026 type :: { LHsType RdrName }
1027 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
1030 ----------------------
1031 -- Notes for 'ctypedoc'
1032 -- It would have been nice to simplify the grammar by unifying `ctype` and
1033 -- ctypedoc` into one production, allowing comments on types everywhere (and
1034 -- rejecting them after parsing, where necessary). This is however not possible
1035 -- since it leads to ambiguity. The reason is the support for comments on record
1037 -- data R = R { field :: Int -- ^ comment on the field }
1038 -- If we allow comments on types here, it's not clear if the comment applies
1039 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
1041 ctypedoc :: { LHsType RdrName }
1042 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
1043 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
1044 -- A type of form (context => type) is an *implicit* HsForAllTy
1045 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
1048 typedoc :: { LHsType RdrName }
1049 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
1052 ----------------------
1053 -- Notes for 'context'
1054 -- We parse a context as a btype so that we don't get reduce/reduce
1055 -- errors in ctype. The basic problem is that
1057 -- looks so much like a tuple type. We can't tell until we find the =>
1059 -- We have the t1 ~ t2 form both in 'context' and in type,
1060 -- to permit an individual equational constraint without parenthesis.
1061 -- Thus for some reason we allow f :: a~b => blah
1062 -- but not f :: ?x::Int => blah
1063 context :: { LHsContext RdrName }
1064 : btype '~' btype {% checkContext
1065 (LL $ HsPredTy (HsEqualP $1 $3)) }
1066 | btype {% checkContext $1 }
1068 type :: { LHsType RdrName }
1070 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1071 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1072 | btype '->' ctype { LL $ HsFunTy $1 $3 }
1073 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1075 typedoc :: { LHsType RdrName }
1077 | btype docprev { LL $ HsDocTy $1 $2 }
1078 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1079 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1080 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1081 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1082 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1083 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1084 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1086 btype :: { LHsType RdrName }
1087 : btype atype { LL $ HsAppTy $1 $2 }
1090 atype :: { LHsType RdrName }
1091 : gtycon { L1 (HsTyVar (unLoc $1)) }
1092 | tyvar { L1 (HsTyVar (unLoc $1)) }
1093 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
1094 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1095 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1096 | '[' ctype ']' { LL $ HsListTy $2 }
1097 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1098 | '(' ctype ')' { LL $ HsParTy $2 }
1099 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1101 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1103 -- An inst_type is what occurs in the head of an instance decl
1104 -- e.g. (Foo a, Gaz b) => Wibble a b
1105 -- It's kept as a single type, with a MonoDictTy at the right
1106 -- hand corner, for convenience.
1107 inst_type :: { LHsType RdrName }
1108 : sigtype {% checkInstType $1 }
1110 inst_types1 :: { [LHsType RdrName] }
1111 : inst_type { [$1] }
1112 | inst_type ',' inst_types1 { $1 : $3 }
1114 comma_types0 :: { [LHsType RdrName] }
1115 : comma_types1 { $1 }
1116 | {- empty -} { [] }
1118 comma_types1 :: { [LHsType RdrName] }
1120 | ctype ',' comma_types1 { $1 : $3 }
1122 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1123 : tv_bndr tv_bndrs { $1 : $2 }
1124 | {- empty -} { [] }
1126 tv_bndr :: { LHsTyVarBndr RdrName }
1127 : tyvar { L1 (UserTyVar (unLoc $1)) }
1128 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1131 fds :: { Located [Located ([RdrName], [RdrName])] }
1132 : {- empty -} { noLoc [] }
1133 | '|' fds1 { LL (reverse (unLoc $2)) }
1135 fds1 :: { Located [Located ([RdrName], [RdrName])] }
1136 : fds1 ',' fd { LL ($3 : unLoc $1) }
1139 fd :: { Located ([RdrName], [RdrName]) }
1140 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1141 (reverse (unLoc $1), reverse (unLoc $3)) }
1143 varids0 :: { Located [RdrName] }
1144 : {- empty -} { noLoc [] }
1145 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1147 -----------------------------------------------------------------------------
1150 kind :: { Located Kind }
1152 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1154 akind :: { Located Kind }
1155 : '*' { L1 liftedTypeKind }
1156 | '!' { L1 unliftedTypeKind }
1157 | '(' kind ')' { LL (unLoc $2) }
1160 -----------------------------------------------------------------------------
1161 -- Datatype declarations
1163 gadt_constrlist :: { Located [LConDecl RdrName] }
1164 : '{' gadt_constrs '}' { LL (unLoc $2) }
1165 | vocurly gadt_constrs close { $2 }
1167 gadt_constrs :: { Located [LConDecl RdrName] }
1168 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
1169 | gadt_constrs ';' { $1 }
1170 | gadt_constr { L1 [$1] }
1172 -- We allow the following forms:
1173 -- C :: Eq a => a -> T a
1174 -- C :: forall a. Eq a => !a -> T a
1175 -- D { x,y :: a } :: T a
1176 -- forall a. Eq a => D { x,y :: a } :: T a
1178 gadt_constr :: { LConDecl RdrName }
1180 { LL (mkGadtDecl $1 $3) }
1181 -- Syntax: Maybe merge the record stuff with the single-case above?
1182 -- (to kill the mostly harmless reduce/reduce error)
1183 -- XXX revisit audreyt
1184 | constr_stuff_record '::' sigtype
1185 { let (con,details) = unLoc $1 in
1186 LL (ConDecl con Implicit [] (noLoc []) details (ResTyGADT $3) Nothing) }
1188 | forall context '=>' constr_stuff_record '::' sigtype
1189 { let (con,details) = unLoc $4 in
1190 LL (ConDecl con Implicit (unLoc $1) $2 details (ResTyGADT $6) Nothing ) }
1191 | forall constr_stuff_record '::' sigtype
1192 { let (con,details) = unLoc $2 in
1193 LL (ConDecl con Implicit (unLoc $1) (noLoc []) details (ResTyGADT $4) Nothing) }
1197 constrs :: { Located [LConDecl RdrName] }
1198 : {- empty; a GHC extension -} { noLoc [] }
1199 | maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1201 constrs1 :: { Located [LConDecl RdrName] }
1202 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1203 | constr { L1 [$1] }
1205 constr :: { LConDecl RdrName }
1206 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1207 { let (con,details) = unLoc $5 in
1208 L (comb4 $2 $3 $4 $5) (ConDecl con Explicit (unLoc $2) $3 details ResTyH98 ($1 `mplus` $6)) }
1209 | maybe_docnext forall constr_stuff maybe_docprev
1210 { let (con,details) = unLoc $3 in
1211 L (comb2 $2 $3) (ConDecl con Explicit (unLoc $2) (noLoc []) details ResTyH98 ($1 `mplus` $4)) }
1213 forall :: { Located [LHsTyVarBndr RdrName] }
1214 : 'forall' tv_bndrs '.' { LL $2 }
1215 | {- empty -} { noLoc [] }
1217 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1218 -- We parse the constructor declaration
1220 -- as a btype (treating C as a type constructor) and then convert C to be
1221 -- a data constructor. Reason: it might continue like this:
1223 -- in which case C really would be a type constructor. We can't resolve this
1224 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1225 : btype {% mkPrefixCon $1 [] >>= return.LL }
1226 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
1227 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
1228 | btype conop btype { LL ($2, InfixCon $1 $3) }
1230 constr_stuff_record :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1231 : oqtycon '{' '}' {% mkRecCon $1 [] >>= return.sL (comb2 $1 $>) }
1232 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.sL (comb2 $1 $>) }
1234 fielddecls :: { [([Located RdrName], LBangType RdrName, Maybe (LHsDoc RdrName))] }
1235 : fielddecl maybe_docnext ',' maybe_docprev fielddecls { addFieldDoc (unLoc $1) $4 : addFieldDocs $5 $2 }
1236 | fielddecl { [unLoc $1] }
1238 fielddecl :: { Located ([Located RdrName], LBangType RdrName, Maybe (LHsDoc RdrName)) }
1239 : maybe_docnext sig_vars '::' ctype maybe_docprev { L (comb3 $2 $3 $4) (reverse (unLoc $2), $4, $1 `mplus` $5) }
1241 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1242 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1243 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1244 -- We don't allow a context, but that's sorted out by the type checker.
1245 deriving :: { Located (Maybe [LHsType RdrName]) }
1246 : {- empty -} { noLoc Nothing }
1247 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1248 ; p <- checkInstType (L loc (HsTyVar tv))
1249 ; return (LL (Just [p])) } }
1250 | 'deriving' '(' ')' { LL (Just []) }
1251 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1252 -- Glasgow extension: allow partial
1253 -- applications in derivings
1255 -----------------------------------------------------------------------------
1256 -- Value definitions
1258 {- There's an awkward overlap with a type signature. Consider
1259 f :: Int -> Int = ...rhs...
1260 Then we can't tell whether it's a type signature or a value
1261 definition with a result signature until we see the '='.
1262 So we have to inline enough to postpone reductions until we know.
1266 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1267 instead of qvar, we get another shift/reduce-conflict. Consider the
1270 { (^^) :: Int->Int ; } Type signature; only var allowed
1272 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1273 qvar allowed (because of instance decls)
1275 We can't tell whether to reduce var to qvar until after we've read the signatures.
1278 docdecl :: { LHsDecl RdrName }
1279 : docdecld { L1 (DocD (unLoc $1)) }
1281 docdecld :: { LDocDecl RdrName }
1282 : docnext { L1 (DocCommentNext (unLoc $1)) }
1283 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1284 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1285 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1287 decl :: { Located (OrdList (LHsDecl RdrName)) }
1289 | '!' aexp rhs {% do { pat <- checkPattern $2;
1290 return (LL $ unitOL $ LL $ ValD (
1291 PatBind (LL $ BangPat pat) (unLoc $3)
1292 placeHolderType placeHolderNames)) } }
1293 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1294 let { l = comb2 $1 $> };
1295 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1296 | docdecl { LL $ unitOL $1 }
1298 rhs :: { Located (GRHSs RdrName) }
1299 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1300 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1302 gdrhs :: { Located [LGRHS RdrName] }
1303 : gdrhs gdrh { LL ($2 : unLoc $1) }
1306 gdrh :: { LGRHS RdrName }
1307 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1309 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1310 : infixexp '::' sigtypedoc
1311 {% do s <- checkValSig $1 $3;
1312 return (LL $ unitOL (LL $ SigD s)) }
1313 -- See the above notes for why we need infixexp here
1314 | var ',' sig_vars '::' sigtypedoc
1315 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1316 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1318 | '{-# INLINE' activation qvar '#-}'
1319 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 FunLike (getINLINE $1)))) }
1320 | '{-# INLINE_CONLIKE' activation qvar '#-}'
1321 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 ConLike (getINLINE_CONLIKE $1)))) }
1322 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1323 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlineSpec)
1325 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1326 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlineSpec $2 FunLike (getSPEC_INLINE $1)))
1328 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1329 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1331 -----------------------------------------------------------------------------
1334 exp :: { LHsExpr RdrName }
1335 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1336 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1337 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1338 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1339 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1342 infixexp :: { LHsExpr RdrName }
1344 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1346 exp10 :: { LHsExpr RdrName }
1347 : '\\' apat apats opt_asig '->' exp
1348 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1351 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1352 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1353 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1354 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1356 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1357 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1358 return (L loc (mkHsDo DoExpr stmts body)) }
1359 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1360 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1361 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1362 | scc_annot exp { LL $ if opt_SccProfilingOn
1363 then HsSCC (unLoc $1) $2
1365 | hpc_annot exp { LL $ if opt_Hpc
1366 then HsTickPragma (unLoc $1) $2
1369 | 'proc' aexp '->' exp
1370 {% checkPattern $2 >>= \ p ->
1371 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1372 placeHolderType undefined)) }
1373 -- TODO: is LL right here?
1375 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1376 -- hdaume: core annotation
1379 scc_annot :: { Located FastString }
1380 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1381 ( do scc <- getSCC $2; return $ LL scc ) }
1382 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1384 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1385 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1386 { LL $ (getSTRING $2
1387 ,( fromInteger $ getINTEGER $3
1388 , fromInteger $ getINTEGER $5
1390 ,( fromInteger $ getINTEGER $7
1391 , fromInteger $ getINTEGER $9
1396 fexp :: { LHsExpr RdrName }
1397 : fexp aexp { LL $ HsApp $1 $2 }
1400 aexp :: { LHsExpr RdrName }
1401 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1402 | '~' aexp { LL $ ELazyPat $2 }
1405 aexp1 :: { LHsExpr RdrName }
1406 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1410 -- Here was the syntax for type applications that I was planning
1411 -- but there are difficulties (e.g. what order for type args)
1412 -- so it's not enabled yet.
1413 -- But this case *is* used for the left hand side of a generic definition,
1414 -- which is parsed as an expression before being munged into a pattern
1415 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1416 (sL (getLoc $3) (HsType $3)) }
1418 aexp2 :: { LHsExpr RdrName }
1419 : ipvar { L1 (HsIPVar $! unLoc $1) }
1420 | qcname { L1 (HsVar $! unLoc $1) }
1421 | literal { L1 (HsLit $! unLoc $1) }
1422 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1423 -- into HsOverLit when -foverloaded-strings is on.
1424 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1425 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1426 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1427 -- N.B.: sections get parsed by these next two productions.
1428 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
1429 -- (you'd have to write '((+ 3), (4 -))')
1430 -- but the less cluttered version fell out of having texps.
1431 | '(' texp ')' { LL (HsPar $2) }
1432 | '(' texp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1433 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1434 | '[' list ']' { LL (unLoc $2) }
1435 | '[:' parr ':]' { LL (unLoc $2) }
1436 | '_' { L1 EWildPat }
1438 -- Template Haskell Extension
1439 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1440 (L1 $ HsVar (mkUnqual varName
1441 (getTH_ID_SPLICE $1)))) } -- $x
1442 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1444 | TH_QUASIQUOTE { let { loc = getLoc $1
1445 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1446 ; quoterId = mkUnqual varName quoter
1448 in sL loc $ HsQuasiQuoteE (mkHsQuasiQuote quoterId quoteSpan quote) }
1449 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1450 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1451 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1452 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1453 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1454 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1455 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1456 return (LL $ HsBracket (PatBr p)) }
1457 | '[d|' cvtopbody '|]' {% checkDecBrGroup $2 >>= \g ->
1458 return (LL $ HsBracket (DecBr g)) }
1460 -- arrow notation extension
1461 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1463 cmdargs :: { [LHsCmdTop RdrName] }
1464 : cmdargs acmd { $2 : $1 }
1465 | {- empty -} { [] }
1467 acmd :: { LHsCmdTop RdrName }
1468 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1470 cvtopbody :: { [LHsDecl RdrName] }
1471 : '{' cvtopdecls0 '}' { $2 }
1472 | vocurly cvtopdecls0 close { $2 }
1474 cvtopdecls0 :: { [LHsDecl RdrName] }
1475 : {- empty -} { [] }
1478 -- "texp" is short for tuple expressions:
1479 -- things that can appear unparenthesized as long as they're
1480 -- inside parens or delimitted by commas
1481 texp :: { LHsExpr RdrName }
1484 -- Note [Parsing sections]
1485 -- ~~~~~~~~~~~~~~~~~~~~~~~
1486 -- We include left and right sections here, which isn't
1487 -- technically right according to Haskell 98. For example
1488 -- (3 +, True) isn't legal
1489 -- However, we want to parse bang patterns like
1491 -- and it's convenient to do so here as a section
1492 -- Then when converting expr to pattern we unravel it again
1493 -- Meanwhile, the renamer checks that real sections appear
1495 | infixexp qop { LL $ SectionL $1 $2 }
1496 | qopm infixexp { LL $ SectionR $1 $2 }
1498 -- View patterns get parenthesized above
1499 | exp '->' exp { LL $ EViewPat $1 $3 }
1501 texps :: { [LHsExpr RdrName] }
1502 : texps ',' texp { $3 : $1 }
1506 -----------------------------------------------------------------------------
1509 -- The rules below are little bit contorted to keep lexps left-recursive while
1510 -- avoiding another shift/reduce-conflict.
1512 list :: { LHsExpr RdrName }
1513 : texp { L1 $ ExplicitList placeHolderType [$1] }
1514 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1515 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1516 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1517 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1518 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1519 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1521 lexps :: { Located [LHsExpr RdrName] }
1522 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1523 | texp ',' texp { LL [$3,$1] }
1525 -----------------------------------------------------------------------------
1526 -- List Comprehensions
1528 flattenedpquals :: { Located [LStmt RdrName] }
1529 : pquals { case (unLoc $1) of
1530 ParStmt [(qs, _)] -> L1 qs
1531 -- We just had one thing in our "parallel" list so
1532 -- we simply return that thing directly
1535 -- We actually found some actual parallel lists so
1536 -- we leave them into as a ParStmt
1539 pquals :: { LStmt RdrName }
1540 : pquals1 { L1 (ParStmt [(qs, undefined) | qs <- (reverse (unLoc $1))]) }
1542 pquals1 :: { Located [[LStmt RdrName]] }
1543 : pquals1 '|' squals { LL (unLoc $3 : unLoc $1) }
1544 | squals { L (getLoc $1) [unLoc $1] }
1546 squals :: { Located [LStmt RdrName] }
1547 : squals1 { L (getLoc $1) (reverse (unLoc $1)) }
1549 squals1 :: { Located [LStmt RdrName] }
1550 : transformquals1 { LL (unLoc $1) }
1552 transformquals1 :: { Located [LStmt RdrName] }
1553 : transformquals1 ',' transformqual { LL $ [LL ((unLoc $3) (unLoc $1))] }
1554 | transformquals1 ',' qual { LL ($3 : unLoc $1) }
1555 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1556 | transformqual { LL $ [LL ((unLoc $1) [])] }
1558 -- | '{|' pquals '|}' { L1 [$2] }
1561 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1562 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1563 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1564 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1566 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1567 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt (reverse leftStmts) $2) }
1568 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt (reverse leftStmts) $2 $4) }
1569 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt (reverse leftStmts) $4) }
1570 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt (reverse leftStmts) $4) }
1571 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt (reverse leftStmts) $4 $6) }
1573 -----------------------------------------------------------------------------
1574 -- Parallel array expressions
1576 -- The rules below are little bit contorted; see the list case for details.
1577 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1578 -- Moreover, we allow explicit arrays with no element (represented by the nil
1579 -- constructor in the list case).
1581 parr :: { LHsExpr RdrName }
1582 : { noLoc (ExplicitPArr placeHolderType []) }
1583 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1584 | lexps { L1 $ ExplicitPArr placeHolderType
1585 (reverse (unLoc $1)) }
1586 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1587 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1588 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1590 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1592 -----------------------------------------------------------------------------
1595 guardquals :: { Located [LStmt RdrName] }
1596 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1598 guardquals1 :: { Located [LStmt RdrName] }
1599 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1602 -----------------------------------------------------------------------------
1603 -- Case alternatives
1605 altslist :: { Located [LMatch RdrName] }
1606 : '{' alts '}' { LL (reverse (unLoc $2)) }
1607 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1609 alts :: { Located [LMatch RdrName] }
1610 : alts1 { L1 (unLoc $1) }
1611 | ';' alts { LL (unLoc $2) }
1613 alts1 :: { Located [LMatch RdrName] }
1614 : alts1 ';' alt { LL ($3 : unLoc $1) }
1615 | alts1 ';' { LL (unLoc $1) }
1618 alt :: { LMatch RdrName }
1619 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1621 alt_rhs :: { Located (GRHSs RdrName) }
1622 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1624 ralt :: { Located [LGRHS RdrName] }
1625 : '->' exp { LL (unguardedRHS $2) }
1626 | gdpats { L1 (reverse (unLoc $1)) }
1628 gdpats :: { Located [LGRHS RdrName] }
1629 : gdpats gdpat { LL ($2 : unLoc $1) }
1632 gdpat :: { LGRHS RdrName }
1633 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1635 -- 'pat' recognises a pattern, including one with a bang at the top
1636 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1637 -- Bangs inside are parsed as infix operator applications, so that
1638 -- we parse them right when bang-patterns are off
1639 pat :: { LPat RdrName }
1640 pat : exp {% checkPattern $1 }
1641 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1643 apat :: { LPat RdrName }
1644 apat : aexp {% checkPattern $1 }
1645 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1647 apats :: { [LPat RdrName] }
1648 : apat apats { $1 : $2 }
1649 | {- empty -} { [] }
1651 -----------------------------------------------------------------------------
1652 -- Statement sequences
1654 stmtlist :: { Located [LStmt RdrName] }
1655 : '{' stmts '}' { LL (unLoc $2) }
1656 | vocurly stmts close { $2 }
1658 -- do { ;; s ; s ; ; s ;; }
1659 -- The last Stmt should be an expression, but that's hard to enforce
1660 -- here, because we need too much lookahead if we see do { e ; }
1661 -- So we use ExprStmts throughout, and switch the last one over
1662 -- in ParseUtils.checkDo instead
1663 stmts :: { Located [LStmt RdrName] }
1664 : stmt stmts_help { LL ($1 : unLoc $2) }
1665 | ';' stmts { LL (unLoc $2) }
1666 | {- empty -} { noLoc [] }
1668 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1669 : ';' stmts { LL (unLoc $2) }
1670 | {- empty -} { noLoc [] }
1672 -- For typing stmts at the GHCi prompt, where
1673 -- the input may consist of just comments.
1674 maybe_stmt :: { Maybe (LStmt RdrName) }
1676 | {- nothing -} { Nothing }
1678 stmt :: { LStmt RdrName }
1680 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1682 qual :: { LStmt RdrName }
1683 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1684 | exp { L1 $ mkExprStmt $1 }
1685 | 'let' binds { LL $ LetStmt (unLoc $2) }
1687 -----------------------------------------------------------------------------
1688 -- Record Field Update/Construction
1690 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1692 | {- empty -} { ([], False) }
1694 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1695 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1696 | fbind { ([$1], False) }
1697 | '..' { ([], True) }
1699 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1700 : qvar '=' exp { HsRecField $1 $3 False }
1701 | qvar { HsRecField $1 (L (getLoc $1) (HsVar (unLoc $1))) True }
1702 -- Here's where we say that plain 'x'
1703 -- means exactly 'x = x'. The pun-flag boolean is
1704 -- there so we can still print it right
1706 -----------------------------------------------------------------------------
1707 -- Implicit Parameter Bindings
1709 dbinds :: { Located [LIPBind RdrName] }
1710 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1711 in rest `seq` this `seq` LL (this : rest) }
1712 | dbinds ';' { LL (unLoc $1) }
1713 | dbind { let this = $1 in this `seq` L1 [this] }
1714 -- | {- empty -} { [] }
1716 dbind :: { LIPBind RdrName }
1717 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1719 ipvar :: { Located (IPName RdrName) }
1720 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1722 -----------------------------------------------------------------------------
1723 -- Warnings and deprecations
1725 namelist :: { Located [RdrName] }
1726 namelist : name_var { L1 [unLoc $1] }
1727 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1729 name_var :: { Located RdrName }
1730 name_var : var { $1 }
1733 -----------------------------------------
1734 -- Data constructors
1735 qcon :: { Located RdrName }
1737 | '(' qconsym ')' { LL (unLoc $2) }
1738 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1739 -- The case of '[:' ':]' is part of the production `parr'
1741 con :: { Located RdrName }
1743 | '(' consym ')' { LL (unLoc $2) }
1744 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1746 sysdcon :: { Located DataCon } -- Wired in data constructors
1747 : '(' ')' { LL unitDataCon }
1748 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1749 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1750 | '(#' commas '#)' { LL $ tupleCon Unboxed $2 }
1751 | '[' ']' { LL nilDataCon }
1753 conop :: { Located RdrName }
1755 | '`' conid '`' { LL (unLoc $2) }
1757 qconop :: { Located RdrName }
1759 | '`' qconid '`' { LL (unLoc $2) }
1761 -----------------------------------------------------------------------------
1762 -- Type constructors
1764 gtycon :: { Located RdrName } -- A "general" qualified tycon
1766 | '(' ')' { LL $ getRdrName unitTyCon }
1767 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1768 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1769 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed $2) }
1770 | '(' '->' ')' { LL $ getRdrName funTyCon }
1771 | '[' ']' { LL $ listTyCon_RDR }
1772 | '[:' ':]' { LL $ parrTyCon_RDR }
1774 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1776 | '(' qtyconsym ')' { LL (unLoc $2) }
1778 qtyconop :: { Located RdrName } -- Qualified or unqualified
1780 | '`' qtycon '`' { LL (unLoc $2) }
1782 qtycon :: { Located RdrName } -- Qualified or unqualified
1783 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1784 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1787 tycon :: { Located RdrName } -- Unqualified
1788 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1790 qtyconsym :: { Located RdrName }
1791 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1794 tyconsym :: { Located RdrName }
1795 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1797 -----------------------------------------------------------------------------
1800 op :: { Located RdrName } -- used in infix decls
1804 varop :: { Located RdrName }
1806 | '`' varid '`' { LL (unLoc $2) }
1808 qop :: { LHsExpr RdrName } -- used in sections
1809 : qvarop { L1 $ HsVar (unLoc $1) }
1810 | qconop { L1 $ HsVar (unLoc $1) }
1812 qopm :: { LHsExpr RdrName } -- used in sections
1813 : qvaropm { L1 $ HsVar (unLoc $1) }
1814 | qconop { L1 $ HsVar (unLoc $1) }
1816 qvarop :: { Located RdrName }
1818 | '`' qvarid '`' { LL (unLoc $2) }
1820 qvaropm :: { Located RdrName }
1821 : qvarsym_no_minus { $1 }
1822 | '`' qvarid '`' { LL (unLoc $2) }
1824 -----------------------------------------------------------------------------
1827 tyvar :: { Located RdrName }
1828 tyvar : tyvarid { $1 }
1829 | '(' tyvarsym ')' { LL (unLoc $2) }
1831 tyvarop :: { Located RdrName }
1832 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1834 | '.' {% parseErrorSDoc (getLoc $1)
1835 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1836 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1837 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1840 tyvarid :: { Located RdrName }
1841 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1842 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1843 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1844 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1845 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1847 tyvarsym :: { Located RdrName }
1848 -- Does not include "!", because that is used for strictness marks
1849 -- or ".", because that separates the quantified type vars from the rest
1850 -- or "*", because that's used for kinds
1851 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1853 -----------------------------------------------------------------------------
1856 var :: { Located RdrName }
1858 | '(' varsym ')' { LL (unLoc $2) }
1860 qvar :: { Located RdrName }
1862 | '(' varsym ')' { LL (unLoc $2) }
1863 | '(' qvarsym1 ')' { LL (unLoc $2) }
1864 -- We've inlined qvarsym here so that the decision about
1865 -- whether it's a qvar or a var can be postponed until
1866 -- *after* we see the close paren.
1868 qvarid :: { Located RdrName }
1870 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1871 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1873 varid :: { Located RdrName }
1874 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1875 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1876 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1877 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1878 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1879 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1880 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1882 qvarsym :: { Located RdrName }
1886 qvarsym_no_minus :: { Located RdrName }
1887 : varsym_no_minus { $1 }
1890 qvarsym1 :: { Located RdrName }
1891 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1893 varsym :: { Located RdrName }
1894 : varsym_no_minus { $1 }
1895 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1897 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1898 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1899 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1902 -- These special_ids are treated as keywords in various places,
1903 -- but as ordinary ids elsewhere. 'special_id' collects all these
1904 -- except 'unsafe', 'forall', and 'family' whose treatment differs
1905 -- depending on context
1906 special_id :: { Located FastString }
1908 : 'as' { L1 (fsLit "as") }
1909 | 'qualified' { L1 (fsLit "qualified") }
1910 | 'hiding' { L1 (fsLit "hiding") }
1911 | 'export' { L1 (fsLit "export") }
1912 | 'label' { L1 (fsLit "label") }
1913 | 'dynamic' { L1 (fsLit "dynamic") }
1914 | 'stdcall' { L1 (fsLit "stdcall") }
1915 | 'ccall' { L1 (fsLit "ccall") }
1917 special_sym :: { Located FastString }
1918 special_sym : '!' { L1 (fsLit "!") }
1919 | '.' { L1 (fsLit ".") }
1920 | '*' { L1 (fsLit "*") }
1922 -----------------------------------------------------------------------------
1923 -- Data constructors
1925 qconid :: { Located RdrName } -- Qualified or unqualified
1927 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1928 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1930 conid :: { Located RdrName }
1931 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1933 qconsym :: { Located RdrName } -- Qualified or unqualified
1935 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1937 consym :: { Located RdrName }
1938 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1940 -- ':' means only list cons
1941 | ':' { L1 $ consDataCon_RDR }
1944 -----------------------------------------------------------------------------
1947 literal :: { Located HsLit }
1948 : CHAR { L1 $ HsChar $ getCHAR $1 }
1949 | STRING { L1 $ HsString $ getSTRING $1 }
1950 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1951 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1952 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1953 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1954 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1955 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1957 -----------------------------------------------------------------------------
1961 : vccurly { () } -- context popped in lexer.
1962 | error {% popContext }
1964 -----------------------------------------------------------------------------
1965 -- Miscellaneous (mostly renamings)
1967 modid :: { Located ModuleName }
1968 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1969 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1972 (unpackFS mod ++ '.':unpackFS c))
1976 : commas ',' { $1 + 1 }
1979 -----------------------------------------------------------------------------
1980 -- Documentation comments
1982 docnext :: { LHsDoc RdrName }
1983 : DOCNEXT {% case parseHaddockParagraphs (tokenise (getDOCNEXT $1)) of {
1984 MyLeft err -> parseError (getLoc $1) err;
1985 MyRight doc -> return (L1 doc) } }
1987 docprev :: { LHsDoc RdrName }
1988 : DOCPREV {% case parseHaddockParagraphs (tokenise (getDOCPREV $1)) of {
1989 MyLeft err -> parseError (getLoc $1) err;
1990 MyRight doc -> return (L1 doc) } }
1992 docnamed :: { Located (String, (HsDoc RdrName)) }
1994 let string = getDOCNAMED $1
1995 (name, rest) = break isSpace string
1996 in case parseHaddockParagraphs (tokenise rest) of {
1997 MyLeft err -> parseError (getLoc $1) err;
1998 MyRight doc -> return (L1 (name, doc)) } }
2000 docsection :: { Located (Int, HsDoc RdrName) }
2001 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
2002 case parseHaddockString (tokenise doc) of {
2003 MyLeft err -> parseError (getLoc $1) err;
2004 MyRight doc -> return (L1 (n, doc)) } }
2006 moduleheader :: { (HaddockModInfo RdrName, Maybe (HsDoc RdrName)) }
2007 : DOCNEXT {% let string = getDOCNEXT $1 in
2008 case parseModuleHeader string of {
2009 Right (str, info) ->
2010 case parseHaddockParagraphs (tokenise str) of {
2011 MyLeft err -> parseError (getLoc $1) err;
2012 MyRight doc -> return (info, Just doc);
2014 Left err -> parseError (getLoc $1) err
2017 maybe_docprev :: { Maybe (LHsDoc RdrName) }
2018 : docprev { Just $1 }
2019 | {- empty -} { Nothing }
2021 maybe_docnext :: { Maybe (LHsDoc RdrName) }
2022 : docnext { Just $1 }
2023 | {- empty -} { Nothing }
2027 happyError = srcParseFail
2029 getVARID (L _ (ITvarid x)) = x
2030 getCONID (L _ (ITconid x)) = x
2031 getVARSYM (L _ (ITvarsym x)) = x
2032 getCONSYM (L _ (ITconsym x)) = x
2033 getQVARID (L _ (ITqvarid x)) = x
2034 getQCONID (L _ (ITqconid x)) = x
2035 getQVARSYM (L _ (ITqvarsym x)) = x
2036 getQCONSYM (L _ (ITqconsym x)) = x
2037 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
2038 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
2039 getIPDUPVARID (L _ (ITdupipvarid x)) = x
2040 getCHAR (L _ (ITchar x)) = x
2041 getSTRING (L _ (ITstring x)) = x
2042 getINTEGER (L _ (ITinteger x)) = x
2043 getRATIONAL (L _ (ITrational x)) = x
2044 getPRIMCHAR (L _ (ITprimchar x)) = x
2045 getPRIMSTRING (L _ (ITprimstring x)) = x
2046 getPRIMINTEGER (L _ (ITprimint x)) = x
2047 getPRIMWORD (L _ (ITprimword x)) = x
2048 getPRIMFLOAT (L _ (ITprimfloat x)) = x
2049 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
2050 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
2051 getINLINE (L _ (ITinline_prag b)) = b
2052 getINLINE_CONLIKE (L _ (ITinline_conlike_prag b)) = b
2053 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
2055 getDOCNEXT (L _ (ITdocCommentNext x)) = x
2056 getDOCPREV (L _ (ITdocCommentPrev x)) = x
2057 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
2058 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2060 getSCC :: Located Token -> P FastString
2061 getSCC lt = do let s = getSTRING lt
2062 err = "Spaces are not allowed in SCCs"
2063 -- We probably actually want to be more restrictive than this
2064 if ' ' `elem` unpackFS s
2065 then failSpanMsgP (getLoc lt) (text err)
2068 -- Utilities for combining source spans
2069 comb2 :: Located a -> Located b -> SrcSpan
2070 comb2 a b = a `seq` b `seq` combineLocs a b
2072 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2073 comb3 a b c = a `seq` b `seq` c `seq`
2074 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2076 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2077 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2078 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2079 combineSrcSpans (getLoc c) (getLoc d))
2081 -- strict constructor version:
2083 sL :: SrcSpan -> a -> Located a
2084 sL span a = span `seq` a `seq` L span a
2086 -- Make a source location for the file. We're a bit lazy here and just
2087 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2088 -- try to find the span of the whole file (ToDo).
2089 fileSrcSpan :: P SrcSpan
2092 let loc = mkSrcLoc (srcLocFile l) 1 0;
2093 return (mkSrcSpan loc loc)