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 '=' ctype
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 gentype { LL $ HsOpTy $1 $2 $3 }
1001 | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 }
1003 infixtypedoc :: { LHsType RdrName }
1005 | infixtype docprev { LL $ HsDocTy $1 $2 }
1007 gentypedoc :: { LHsType RdrName }
1010 | infixtypedoc { $1 }
1011 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1012 | btypedoc '->' ctypedoc { LL $ HsFunTy $1 $3 }
1014 ctypedoc :: { LHsType RdrName }
1015 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
1016 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
1017 -- A type of form (context => type) is an *implicit* HsForAllTy
1020 strict_mark :: { Located HsBang }
1021 : '!' { L1 HsStrict }
1022 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
1024 -- A ctype is a for-all type
1025 ctype :: { LHsType RdrName }
1026 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
1027 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
1028 -- A type of form (context => type) is an *implicit* HsForAllTy
1031 -- We parse a context as a btype so that we don't get reduce/reduce
1032 -- errors in ctype. The basic problem is that
1034 -- looks so much like a tuple type. We can't tell until we find the =>
1036 -- We have the t1 ~ t2 form here and in gentype, to permit an individual
1037 -- equational constraint without parenthesis.
1038 context :: { LHsContext RdrName }
1039 : btype '~' btype {% checkContext
1040 (LL $ HsPredTy (HsEqualP $1 $3)) }
1041 | btype {% checkContext $1 }
1043 type :: { LHsType RdrName }
1044 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
1047 gentype :: { LHsType RdrName }
1049 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
1050 | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 }
1051 | btype '->' ctype { LL $ HsFunTy $1 $3 }
1052 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1054 btype :: { LHsType RdrName }
1055 : btype atype { LL $ HsAppTy $1 $2 }
1058 btypedoc :: { LHsType RdrName }
1059 : btype atype docprev { LL $ HsDocTy (L (comb2 $1 $2) (HsAppTy $1 $2)) $3 }
1060 | atype docprev { LL $ HsDocTy $1 $2 }
1062 atype :: { LHsType RdrName }
1063 : gtycon { L1 (HsTyVar (unLoc $1)) }
1064 | tyvar { L1 (HsTyVar (unLoc $1)) }
1065 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
1066 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1067 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1068 | '[' ctype ']' { LL $ HsListTy $2 }
1069 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1070 | '(' ctype ')' { LL $ HsParTy $2 }
1071 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1073 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1075 -- An inst_type is what occurs in the head of an instance decl
1076 -- e.g. (Foo a, Gaz b) => Wibble a b
1077 -- It's kept as a single type, with a MonoDictTy at the right
1078 -- hand corner, for convenience.
1079 inst_type :: { LHsType RdrName }
1080 : sigtype {% checkInstType $1 }
1082 inst_types1 :: { [LHsType RdrName] }
1083 : inst_type { [$1] }
1084 | inst_type ',' inst_types1 { $1 : $3 }
1086 comma_types0 :: { [LHsType RdrName] }
1087 : comma_types1 { $1 }
1088 | {- empty -} { [] }
1090 comma_types1 :: { [LHsType RdrName] }
1092 | ctype ',' comma_types1 { $1 : $3 }
1094 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1095 : tv_bndr tv_bndrs { $1 : $2 }
1096 | {- empty -} { [] }
1098 tv_bndr :: { LHsTyVarBndr RdrName }
1099 : tyvar { L1 (UserTyVar (unLoc $1)) }
1100 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1103 fds :: { Located [Located ([RdrName], [RdrName])] }
1104 : {- empty -} { noLoc [] }
1105 | '|' fds1 { LL (reverse (unLoc $2)) }
1107 fds1 :: { Located [Located ([RdrName], [RdrName])] }
1108 : fds1 ',' fd { LL ($3 : unLoc $1) }
1111 fd :: { Located ([RdrName], [RdrName]) }
1112 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1113 (reverse (unLoc $1), reverse (unLoc $3)) }
1115 varids0 :: { Located [RdrName] }
1116 : {- empty -} { noLoc [] }
1117 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1119 -----------------------------------------------------------------------------
1122 kind :: { Located Kind }
1124 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1126 akind :: { Located Kind }
1127 : '*' { L1 liftedTypeKind }
1128 | '!' { L1 unliftedTypeKind }
1129 | '(' kind ')' { LL (unLoc $2) }
1132 -----------------------------------------------------------------------------
1133 -- Datatype declarations
1135 gadt_constrlist :: { Located [LConDecl RdrName] }
1136 : '{' gadt_constrs '}' { LL (unLoc $2) }
1137 | vocurly gadt_constrs close { $2 }
1139 gadt_constrs :: { Located [LConDecl RdrName] }
1140 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
1141 | gadt_constrs ';' { $1 }
1142 | gadt_constr { L1 [$1] }
1144 -- We allow the following forms:
1145 -- C :: Eq a => a -> T a
1146 -- C :: forall a. Eq a => !a -> T a
1147 -- D { x,y :: a } :: T a
1148 -- forall a. Eq a => D { x,y :: a } :: T a
1150 gadt_constr :: { LConDecl RdrName }
1152 { LL (mkGadtDecl $1 $3) }
1153 -- Syntax: Maybe merge the record stuff with the single-case above?
1154 -- (to kill the mostly harmless reduce/reduce error)
1155 -- XXX revisit audreyt
1156 | constr_stuff_record '::' sigtype
1157 { let (con,details) = unLoc $1 in
1158 LL (ConDecl con Implicit [] (noLoc []) details (ResTyGADT $3) Nothing) }
1160 | forall context '=>' constr_stuff_record '::' sigtype
1161 { let (con,details) = unLoc $4 in
1162 LL (ConDecl con Implicit (unLoc $1) $2 details (ResTyGADT $6) Nothing ) }
1163 | forall constr_stuff_record '::' sigtype
1164 { let (con,details) = unLoc $2 in
1165 LL (ConDecl con Implicit (unLoc $1) (noLoc []) details (ResTyGADT $4) Nothing) }
1169 constrs :: { Located [LConDecl RdrName] }
1170 : {- empty; a GHC extension -} { noLoc [] }
1171 | maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1173 constrs1 :: { Located [LConDecl RdrName] }
1174 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1175 | constr { L1 [$1] }
1177 constr :: { LConDecl RdrName }
1178 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1179 { let (con,details) = unLoc $5 in
1180 L (comb4 $2 $3 $4 $5) (ConDecl con Explicit (unLoc $2) $3 details ResTyH98 ($1 `mplus` $6)) }
1181 | maybe_docnext forall constr_stuff maybe_docprev
1182 { let (con,details) = unLoc $3 in
1183 L (comb2 $2 $3) (ConDecl con Explicit (unLoc $2) (noLoc []) details ResTyH98 ($1 `mplus` $4)) }
1185 forall :: { Located [LHsTyVarBndr RdrName] }
1186 : 'forall' tv_bndrs '.' { LL $2 }
1187 | {- empty -} { noLoc [] }
1189 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1190 -- We parse the constructor declaration
1192 -- as a btype (treating C as a type constructor) and then convert C to be
1193 -- a data constructor. Reason: it might continue like this:
1195 -- in which case C really would be a type constructor. We can't resolve this
1196 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1197 : btype {% mkPrefixCon $1 [] >>= return.LL }
1198 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
1199 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
1200 | btype conop btype { LL ($2, InfixCon $1 $3) }
1202 constr_stuff_record :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1203 : oqtycon '{' '}' {% mkRecCon $1 [] >>= return.sL (comb2 $1 $>) }
1204 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.sL (comb2 $1 $>) }
1206 fielddecls :: { [([Located RdrName], LBangType RdrName, Maybe (LHsDoc RdrName))] }
1207 : fielddecl maybe_docnext ',' maybe_docprev fielddecls { addFieldDoc (unLoc $1) $4 : addFieldDocs $5 $2 }
1208 | fielddecl { [unLoc $1] }
1210 fielddecl :: { Located ([Located RdrName], LBangType RdrName, Maybe (LHsDoc RdrName)) }
1211 : maybe_docnext sig_vars '::' ctype maybe_docprev { L (comb3 $2 $3 $4) (reverse (unLoc $2), $4, $1 `mplus` $5) }
1213 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1214 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1215 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1216 -- We don't allow a context, but that's sorted out by the type checker.
1217 deriving :: { Located (Maybe [LHsType RdrName]) }
1218 : {- empty -} { noLoc Nothing }
1219 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1220 ; p <- checkInstType (L loc (HsTyVar tv))
1221 ; return (LL (Just [p])) } }
1222 | 'deriving' '(' ')' { LL (Just []) }
1223 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1224 -- Glasgow extension: allow partial
1225 -- applications in derivings
1227 -----------------------------------------------------------------------------
1228 -- Value definitions
1230 {- There's an awkward overlap with a type signature. Consider
1231 f :: Int -> Int = ...rhs...
1232 Then we can't tell whether it's a type signature or a value
1233 definition with a result signature until we see the '='.
1234 So we have to inline enough to postpone reductions until we know.
1238 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1239 instead of qvar, we get another shift/reduce-conflict. Consider the
1242 { (^^) :: Int->Int ; } Type signature; only var allowed
1244 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1245 qvar allowed (because of instance decls)
1247 We can't tell whether to reduce var to qvar until after we've read the signatures.
1250 docdecl :: { LHsDecl RdrName }
1251 : docdecld { L1 (DocD (unLoc $1)) }
1253 docdecld :: { LDocDecl RdrName }
1254 : docnext { L1 (DocCommentNext (unLoc $1)) }
1255 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1256 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1257 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1259 decl :: { Located (OrdList (LHsDecl RdrName)) }
1261 | '!' aexp rhs {% do { pat <- checkPattern $2;
1262 return (LL $ unitOL $ LL $ ValD (
1263 PatBind (LL $ BangPat pat) (unLoc $3)
1264 placeHolderType placeHolderNames)) } }
1265 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1266 let { l = comb2 $1 $> };
1267 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1268 | docdecl { LL $ unitOL $1 }
1270 rhs :: { Located (GRHSs RdrName) }
1271 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1272 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1274 gdrhs :: { Located [LGRHS RdrName] }
1275 : gdrhs gdrh { LL ($2 : unLoc $1) }
1278 gdrh :: { LGRHS RdrName }
1279 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1281 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1282 : infixexp '::' sigtypedoc
1283 {% do s <- checkValSig $1 $3;
1284 return (LL $ unitOL (LL $ SigD s)) }
1285 -- See the above notes for why we need infixexp here
1286 | var ',' sig_vars '::' sigtypedoc
1287 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1288 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1290 | '{-# INLINE' activation qvar '#-}'
1291 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 FunLike (getINLINE $1)))) }
1292 | '{-# INLINE_CONLIKE' activation qvar '#-}'
1293 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 ConLike (getINLINE_CONLIKE $1)))) }
1294 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1295 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlineSpec)
1297 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1298 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlineSpec $2 FunLike (getSPEC_INLINE $1)))
1300 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1301 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1303 -----------------------------------------------------------------------------
1306 exp :: { LHsExpr RdrName }
1307 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1308 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1309 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1310 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1311 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1314 infixexp :: { LHsExpr RdrName }
1316 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1318 exp10 :: { LHsExpr RdrName }
1319 : '\\' apat apats opt_asig '->' exp
1320 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1323 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1324 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1325 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1326 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1328 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1329 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1330 return (L loc (mkHsDo DoExpr stmts body)) }
1331 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1332 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1333 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1334 | scc_annot exp { LL $ if opt_SccProfilingOn
1335 then HsSCC (unLoc $1) $2
1337 | hpc_annot exp { LL $ if opt_Hpc
1338 then HsTickPragma (unLoc $1) $2
1341 | 'proc' aexp '->' exp
1342 {% checkPattern $2 >>= \ p ->
1343 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1344 placeHolderType undefined)) }
1345 -- TODO: is LL right here?
1347 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1348 -- hdaume: core annotation
1351 scc_annot :: { Located FastString }
1352 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1353 ( do scc <- getSCC $2; return $ LL scc ) }
1354 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1356 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1357 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1358 { LL $ (getSTRING $2
1359 ,( fromInteger $ getINTEGER $3
1360 , fromInteger $ getINTEGER $5
1362 ,( fromInteger $ getINTEGER $7
1363 , fromInteger $ getINTEGER $9
1368 fexp :: { LHsExpr RdrName }
1369 : fexp aexp { LL $ HsApp $1 $2 }
1372 aexp :: { LHsExpr RdrName }
1373 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1374 | '~' aexp { LL $ ELazyPat $2 }
1377 aexp1 :: { LHsExpr RdrName }
1378 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1382 -- Here was the syntax for type applications that I was planning
1383 -- but there are difficulties (e.g. what order for type args)
1384 -- so it's not enabled yet.
1385 -- But this case *is* used for the left hand side of a generic definition,
1386 -- which is parsed as an expression before being munged into a pattern
1387 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1388 (sL (getLoc $3) (HsType $3)) }
1390 aexp2 :: { LHsExpr RdrName }
1391 : ipvar { L1 (HsIPVar $! unLoc $1) }
1392 | qcname { L1 (HsVar $! unLoc $1) }
1393 | literal { L1 (HsLit $! unLoc $1) }
1394 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1395 -- into HsOverLit when -foverloaded-strings is on.
1396 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1397 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1398 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1399 -- N.B.: sections get parsed by these next two productions.
1400 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't correct Haskell98
1401 -- (you'd have to write '((+ 3), (4 -))')
1402 -- but the less cluttered version fell out of having texps.
1403 | '(' texp ')' { LL (HsPar $2) }
1404 | '(' texp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1405 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1406 | '[' list ']' { LL (unLoc $2) }
1407 | '[:' parr ':]' { LL (unLoc $2) }
1408 | '_' { L1 EWildPat }
1410 -- Template Haskell Extension
1411 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1412 (L1 $ HsVar (mkUnqual varName
1413 (getTH_ID_SPLICE $1)))) } -- $x
1414 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1416 | TH_QUASIQUOTE { let { loc = getLoc $1
1417 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1418 ; quoterId = mkUnqual varName quoter
1420 in sL loc $ HsQuasiQuoteE (mkHsQuasiQuote quoterId quoteSpan quote) }
1421 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1422 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1423 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1424 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1425 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1426 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1427 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1428 return (LL $ HsBracket (PatBr p)) }
1429 | '[d|' cvtopbody '|]' {% checkDecBrGroup $2 >>= \g ->
1430 return (LL $ HsBracket (DecBr g)) }
1432 -- arrow notation extension
1433 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $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 -- "texp" is short for tuple expressions:
1451 -- things that can appear unparenthesized as long as they're
1452 -- inside parens or delimitted by commas
1453 texp :: { LHsExpr RdrName }
1456 -- Note [Parsing sections]
1457 -- ~~~~~~~~~~~~~~~~~~~~~~~
1458 -- We include left and right sections here, which isn't
1459 -- technically right according to Haskell 98. For example
1460 -- (3 +, True) isn't legal
1461 -- However, we want to parse bang patterns like
1463 -- and it's convenient to do so here as a section
1464 -- Then when converting expr to pattern we unravel it again
1465 -- Meanwhile, the renamer checks that real sections appear
1467 | infixexp qop { LL $ SectionL $1 $2 }
1468 | qopm infixexp { LL $ SectionR $1 $2 }
1470 -- View patterns get parenthesized above
1471 | exp '->' exp { LL $ EViewPat $1 $3 }
1473 texps :: { [LHsExpr RdrName] }
1474 : texps ',' texp { $3 : $1 }
1478 -----------------------------------------------------------------------------
1481 -- The rules below are little bit contorted to keep lexps left-recursive while
1482 -- avoiding another shift/reduce-conflict.
1484 list :: { LHsExpr RdrName }
1485 : texp { L1 $ ExplicitList placeHolderType [$1] }
1486 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1487 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1488 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1489 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1490 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1491 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1493 lexps :: { Located [LHsExpr RdrName] }
1494 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1495 | texp ',' texp { LL [$3,$1] }
1497 -----------------------------------------------------------------------------
1498 -- List Comprehensions
1500 flattenedpquals :: { Located [LStmt RdrName] }
1501 : pquals { case (unLoc $1) of
1502 ParStmt [(qs, _)] -> L1 qs
1503 -- We just had one thing in our "parallel" list so
1504 -- we simply return that thing directly
1507 -- We actually found some actual parallel lists so
1508 -- we leave them into as a ParStmt
1511 pquals :: { LStmt RdrName }
1512 : pquals1 { L1 (ParStmt [(qs, undefined) | qs <- (reverse (unLoc $1))]) }
1514 pquals1 :: { Located [[LStmt RdrName]] }
1515 : pquals1 '|' squals { LL (unLoc $3 : unLoc $1) }
1516 | squals { L (getLoc $1) [unLoc $1] }
1518 squals :: { Located [LStmt RdrName] }
1519 : squals1 { L (getLoc $1) (reverse (unLoc $1)) }
1521 squals1 :: { Located [LStmt RdrName] }
1522 : transformquals1 { LL (unLoc $1) }
1524 transformquals1 :: { Located [LStmt RdrName] }
1525 : transformquals1 ',' transformqual { LL $ [LL ((unLoc $3) (unLoc $1))] }
1526 | transformquals1 ',' qual { LL ($3 : unLoc $1) }
1527 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1528 | transformqual { LL $ [LL ((unLoc $1) [])] }
1530 -- | '{|' pquals '|}' { L1 [$2] }
1533 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1534 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1535 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1536 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1538 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1539 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt (reverse leftStmts) $2) }
1540 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt (reverse leftStmts) $2 $4) }
1541 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt (reverse leftStmts) $4) }
1542 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt (reverse leftStmts) $4) }
1543 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt (reverse leftStmts) $4 $6) }
1545 -----------------------------------------------------------------------------
1546 -- Parallel array expressions
1548 -- The rules below are little bit contorted; see the list case for details.
1549 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1550 -- Moreover, we allow explicit arrays with no element (represented by the nil
1551 -- constructor in the list case).
1553 parr :: { LHsExpr RdrName }
1554 : { noLoc (ExplicitPArr placeHolderType []) }
1555 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1556 | lexps { L1 $ ExplicitPArr placeHolderType
1557 (reverse (unLoc $1)) }
1558 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1559 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1560 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1562 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1564 -----------------------------------------------------------------------------
1567 guardquals :: { Located [LStmt RdrName] }
1568 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1570 guardquals1 :: { Located [LStmt RdrName] }
1571 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1574 -----------------------------------------------------------------------------
1575 -- Case alternatives
1577 altslist :: { Located [LMatch RdrName] }
1578 : '{' alts '}' { LL (reverse (unLoc $2)) }
1579 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1581 alts :: { Located [LMatch RdrName] }
1582 : alts1 { L1 (unLoc $1) }
1583 | ';' alts { LL (unLoc $2) }
1585 alts1 :: { Located [LMatch RdrName] }
1586 : alts1 ';' alt { LL ($3 : unLoc $1) }
1587 | alts1 ';' { LL (unLoc $1) }
1590 alt :: { LMatch RdrName }
1591 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1593 alt_rhs :: { Located (GRHSs RdrName) }
1594 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1596 ralt :: { Located [LGRHS RdrName] }
1597 : '->' exp { LL (unguardedRHS $2) }
1598 | gdpats { L1 (reverse (unLoc $1)) }
1600 gdpats :: { Located [LGRHS RdrName] }
1601 : gdpats gdpat { LL ($2 : unLoc $1) }
1604 gdpat :: { LGRHS RdrName }
1605 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1607 -- 'pat' recognises a pattern, including one with a bang at the top
1608 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1609 -- Bangs inside are parsed as infix operator applications, so that
1610 -- we parse them right when bang-patterns are off
1611 pat :: { LPat RdrName }
1612 pat : exp {% checkPattern $1 }
1613 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1615 apat :: { LPat RdrName }
1616 apat : aexp {% checkPattern $1 }
1617 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1619 apats :: { [LPat RdrName] }
1620 : apat apats { $1 : $2 }
1621 | {- empty -} { [] }
1623 -----------------------------------------------------------------------------
1624 -- Statement sequences
1626 stmtlist :: { Located [LStmt RdrName] }
1627 : '{' stmts '}' { LL (unLoc $2) }
1628 | vocurly stmts close { $2 }
1630 -- do { ;; s ; s ; ; s ;; }
1631 -- The last Stmt should be an expression, but that's hard to enforce
1632 -- here, because we need too much lookahead if we see do { e ; }
1633 -- So we use ExprStmts throughout, and switch the last one over
1634 -- in ParseUtils.checkDo instead
1635 stmts :: { Located [LStmt RdrName] }
1636 : stmt stmts_help { LL ($1 : unLoc $2) }
1637 | ';' stmts { LL (unLoc $2) }
1638 | {- empty -} { noLoc [] }
1640 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1641 : ';' stmts { LL (unLoc $2) }
1642 | {- empty -} { noLoc [] }
1644 -- For typing stmts at the GHCi prompt, where
1645 -- the input may consist of just comments.
1646 maybe_stmt :: { Maybe (LStmt RdrName) }
1648 | {- nothing -} { Nothing }
1650 stmt :: { LStmt RdrName }
1652 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1654 qual :: { LStmt RdrName }
1655 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1656 | exp { L1 $ mkExprStmt $1 }
1657 | 'let' binds { LL $ LetStmt (unLoc $2) }
1659 -----------------------------------------------------------------------------
1660 -- Record Field Update/Construction
1662 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1664 | {- empty -} { ([], False) }
1666 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1667 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1668 | fbind { ([$1], False) }
1669 | '..' { ([], True) }
1671 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1672 : qvar '=' exp { HsRecField $1 $3 False }
1673 | qvar { HsRecField $1 (L (getLoc $1) (HsVar (unLoc $1))) True }
1674 -- Here's where we say that plain 'x'
1675 -- means exactly 'x = x'. The pun-flag boolean is
1676 -- there so we can still print it right
1678 -----------------------------------------------------------------------------
1679 -- Implicit Parameter Bindings
1681 dbinds :: { Located [LIPBind RdrName] }
1682 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1683 in rest `seq` this `seq` LL (this : rest) }
1684 | dbinds ';' { LL (unLoc $1) }
1685 | dbind { let this = $1 in this `seq` L1 [this] }
1686 -- | {- empty -} { [] }
1688 dbind :: { LIPBind RdrName }
1689 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1691 ipvar :: { Located (IPName RdrName) }
1692 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1694 -----------------------------------------------------------------------------
1695 -- Warnings and deprecations
1697 namelist :: { Located [RdrName] }
1698 namelist : name_var { L1 [unLoc $1] }
1699 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1701 name_var :: { Located RdrName }
1702 name_var : var { $1 }
1705 -----------------------------------------
1706 -- Data constructors
1707 qcon :: { Located RdrName }
1709 | '(' qconsym ')' { LL (unLoc $2) }
1710 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1711 -- The case of '[:' ':]' is part of the production `parr'
1713 con :: { Located RdrName }
1715 | '(' consym ')' { LL (unLoc $2) }
1716 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1718 sysdcon :: { Located DataCon } -- Wired in data constructors
1719 : '(' ')' { LL unitDataCon }
1720 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1721 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1722 | '(#' commas '#)' { LL $ tupleCon Unboxed $2 }
1723 | '[' ']' { LL nilDataCon }
1725 conop :: { Located RdrName }
1727 | '`' conid '`' { LL (unLoc $2) }
1729 qconop :: { Located RdrName }
1731 | '`' qconid '`' { LL (unLoc $2) }
1733 -----------------------------------------------------------------------------
1734 -- Type constructors
1736 gtycon :: { Located RdrName } -- A "general" qualified tycon
1738 | '(' ')' { LL $ getRdrName unitTyCon }
1739 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1740 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1741 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed $2) }
1742 | '(' '->' ')' { LL $ getRdrName funTyCon }
1743 | '[' ']' { LL $ listTyCon_RDR }
1744 | '[:' ':]' { LL $ parrTyCon_RDR }
1746 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1748 | '(' qtyconsym ')' { LL (unLoc $2) }
1750 qtyconop :: { Located RdrName } -- Qualified or unqualified
1752 | '`' qtycon '`' { LL (unLoc $2) }
1754 qtycon :: { Located RdrName } -- Qualified or unqualified
1755 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1756 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1759 tycon :: { Located RdrName } -- Unqualified
1760 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1762 qtyconsym :: { Located RdrName }
1763 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1766 tyconsym :: { Located RdrName }
1767 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1769 -----------------------------------------------------------------------------
1772 op :: { Located RdrName } -- used in infix decls
1776 varop :: { Located RdrName }
1778 | '`' varid '`' { LL (unLoc $2) }
1780 qop :: { LHsExpr RdrName } -- used in sections
1781 : qvarop { L1 $ HsVar (unLoc $1) }
1782 | qconop { L1 $ HsVar (unLoc $1) }
1784 qopm :: { LHsExpr RdrName } -- used in sections
1785 : qvaropm { L1 $ HsVar (unLoc $1) }
1786 | qconop { L1 $ HsVar (unLoc $1) }
1788 qvarop :: { Located RdrName }
1790 | '`' qvarid '`' { LL (unLoc $2) }
1792 qvaropm :: { Located RdrName }
1793 : qvarsym_no_minus { $1 }
1794 | '`' qvarid '`' { LL (unLoc $2) }
1796 -----------------------------------------------------------------------------
1799 tyvar :: { Located RdrName }
1800 tyvar : tyvarid { $1 }
1801 | '(' tyvarsym ')' { LL (unLoc $2) }
1803 tyvarop :: { Located RdrName }
1804 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1807 tyvarid :: { Located RdrName }
1808 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1809 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1810 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1811 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1812 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1814 tyvarsym :: { Located RdrName }
1815 -- Does not include "!", because that is used for strictness marks
1816 -- or ".", because that separates the quantified type vars from the rest
1817 -- or "*", because that's used for kinds
1818 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1820 -----------------------------------------------------------------------------
1823 var :: { Located RdrName }
1825 | '(' varsym ')' { LL (unLoc $2) }
1827 qvar :: { Located RdrName }
1829 | '(' varsym ')' { LL (unLoc $2) }
1830 | '(' qvarsym1 ')' { LL (unLoc $2) }
1831 -- We've inlined qvarsym here so that the decision about
1832 -- whether it's a qvar or a var can be postponed until
1833 -- *after* we see the close paren.
1835 qvarid :: { Located RdrName }
1837 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1838 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1840 varid :: { Located RdrName }
1841 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1842 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1843 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1844 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1845 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1846 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1847 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1849 qvarsym :: { Located RdrName }
1853 qvarsym_no_minus :: { Located RdrName }
1854 : varsym_no_minus { $1 }
1857 qvarsym1 :: { Located RdrName }
1858 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1860 varsym :: { Located RdrName }
1861 : varsym_no_minus { $1 }
1862 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1864 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1865 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1866 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1869 -- These special_ids are treated as keywords in various places,
1870 -- but as ordinary ids elsewhere. 'special_id' collects all these
1871 -- except 'unsafe', 'forall', and 'family' whose treatment differs
1872 -- depending on context
1873 special_id :: { Located FastString }
1875 : 'as' { L1 (fsLit "as") }
1876 | 'qualified' { L1 (fsLit "qualified") }
1877 | 'hiding' { L1 (fsLit "hiding") }
1878 | 'export' { L1 (fsLit "export") }
1879 | 'label' { L1 (fsLit "label") }
1880 | 'dynamic' { L1 (fsLit "dynamic") }
1881 | 'stdcall' { L1 (fsLit "stdcall") }
1882 | 'ccall' { L1 (fsLit "ccall") }
1884 special_sym :: { Located FastString }
1885 special_sym : '!' { L1 (fsLit "!") }
1886 | '.' { L1 (fsLit ".") }
1887 | '*' { L1 (fsLit "*") }
1889 -----------------------------------------------------------------------------
1890 -- Data constructors
1892 qconid :: { Located RdrName } -- Qualified or unqualified
1894 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1895 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1897 conid :: { Located RdrName }
1898 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1900 qconsym :: { Located RdrName } -- Qualified or unqualified
1902 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1904 consym :: { Located RdrName }
1905 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1907 -- ':' means only list cons
1908 | ':' { L1 $ consDataCon_RDR }
1911 -----------------------------------------------------------------------------
1914 literal :: { Located HsLit }
1915 : CHAR { L1 $ HsChar $ getCHAR $1 }
1916 | STRING { L1 $ HsString $ getSTRING $1 }
1917 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1918 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1919 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1920 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1921 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1922 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1924 -----------------------------------------------------------------------------
1928 : vccurly { () } -- context popped in lexer.
1929 | error {% popContext }
1931 -----------------------------------------------------------------------------
1932 -- Miscellaneous (mostly renamings)
1934 modid :: { Located ModuleName }
1935 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1936 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1939 (unpackFS mod ++ '.':unpackFS c))
1943 : commas ',' { $1 + 1 }
1946 -----------------------------------------------------------------------------
1947 -- Documentation comments
1949 docnext :: { LHsDoc RdrName }
1950 : DOCNEXT {% case parseHaddockParagraphs (tokenise (getDOCNEXT $1)) of {
1951 MyLeft err -> parseError (getLoc $1) err;
1952 MyRight doc -> return (L1 doc) } }
1954 docprev :: { LHsDoc RdrName }
1955 : DOCPREV {% case parseHaddockParagraphs (tokenise (getDOCPREV $1)) of {
1956 MyLeft err -> parseError (getLoc $1) err;
1957 MyRight doc -> return (L1 doc) } }
1959 docnamed :: { Located (String, (HsDoc RdrName)) }
1961 let string = getDOCNAMED $1
1962 (name, rest) = break isSpace string
1963 in case parseHaddockParagraphs (tokenise rest) of {
1964 MyLeft err -> parseError (getLoc $1) err;
1965 MyRight doc -> return (L1 (name, doc)) } }
1967 docsection :: { Located (Int, HsDoc RdrName) }
1968 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1969 case parseHaddockString (tokenise doc) of {
1970 MyLeft err -> parseError (getLoc $1) err;
1971 MyRight doc -> return (L1 (n, doc)) } }
1973 moduleheader :: { (HaddockModInfo RdrName, Maybe (HsDoc RdrName)) }
1974 : DOCNEXT {% let string = getDOCNEXT $1 in
1975 case parseModuleHeader string of {
1976 Right (str, info) ->
1977 case parseHaddockParagraphs (tokenise str) of {
1978 MyLeft err -> parseError (getLoc $1) err;
1979 MyRight doc -> return (info, Just doc);
1981 Left err -> parseError (getLoc $1) err
1984 maybe_docprev :: { Maybe (LHsDoc RdrName) }
1985 : docprev { Just $1 }
1986 | {- empty -} { Nothing }
1988 maybe_docnext :: { Maybe (LHsDoc RdrName) }
1989 : docnext { Just $1 }
1990 | {- empty -} { Nothing }
1994 happyError = srcParseFail
1996 getVARID (L _ (ITvarid x)) = x
1997 getCONID (L _ (ITconid x)) = x
1998 getVARSYM (L _ (ITvarsym x)) = x
1999 getCONSYM (L _ (ITconsym x)) = x
2000 getQVARID (L _ (ITqvarid x)) = x
2001 getQCONID (L _ (ITqconid x)) = x
2002 getQVARSYM (L _ (ITqvarsym x)) = x
2003 getQCONSYM (L _ (ITqconsym x)) = x
2004 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
2005 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
2006 getIPDUPVARID (L _ (ITdupipvarid x)) = x
2007 getCHAR (L _ (ITchar x)) = x
2008 getSTRING (L _ (ITstring x)) = x
2009 getINTEGER (L _ (ITinteger x)) = x
2010 getRATIONAL (L _ (ITrational x)) = x
2011 getPRIMCHAR (L _ (ITprimchar x)) = x
2012 getPRIMSTRING (L _ (ITprimstring x)) = x
2013 getPRIMINTEGER (L _ (ITprimint x)) = x
2014 getPRIMWORD (L _ (ITprimword x)) = x
2015 getPRIMFLOAT (L _ (ITprimfloat x)) = x
2016 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
2017 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
2018 getINLINE (L _ (ITinline_prag b)) = b
2019 getINLINE_CONLIKE (L _ (ITinline_conlike_prag b)) = b
2020 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
2022 getDOCNEXT (L _ (ITdocCommentNext x)) = x
2023 getDOCPREV (L _ (ITdocCommentPrev x)) = x
2024 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
2025 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2027 getSCC :: Located Token -> P FastString
2028 getSCC lt = do let s = getSTRING lt
2029 err = "Spaces are not allowed in SCCs"
2030 -- We probably actually want to be more restrictive than this
2031 if ' ' `elem` unpackFS s
2032 then failSpanMsgP (getLoc lt) (text err)
2035 -- Utilities for combining source spans
2036 comb2 :: Located a -> Located b -> SrcSpan
2037 comb2 a b = a `seq` b `seq` combineLocs a b
2039 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2040 comb3 a b c = a `seq` b `seq` c `seq`
2041 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2043 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2044 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2045 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2046 combineSrcSpans (getLoc c) (getLoc d))
2048 -- strict constructor version:
2050 sL :: SrcSpan -> a -> Located a
2051 sL span a = span `seq` a `seq` L span a
2053 -- Make a source location for the file. We're a bit lazy here and just
2054 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2055 -- try to find the span of the whole file (ToDo).
2056 fileSrcSpan :: P SrcSpan
2059 let loc = mkSrcLoc (srcLocFile l) 1 0;
2060 return (mkSrcSpan loc loc)