2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 {-# LANGUAGE BangPatterns #-} -- required for versions of Happy before 1.18.6
12 {-# OPTIONS -Wwarn -w #-}
13 -- The above warning supression flag is a temporary kludge.
14 -- While working on this module you are encouraged to remove it and fix
15 -- any warnings in the module. See
16 -- http://hackage.haskell.org/trac/ghc/wiki/Commentary/CodingStyle#Warnings
19 {-# OPTIONS_GHC -O0 -fno-ignore-interface-pragmas #-}
21 Careful optimisation of the parser: we don't want to throw everything
22 at it, because that takes too long and doesn't buy much, but we do want
23 to inline certain key external functions, so we instruct GHC not to
24 throw away inlinings as it would normally do in -O0 mode.
27 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
32 import HscTypes ( IsBootInterface, WarningTxt(..) )
35 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
36 unboxedSingletonTyCon, unboxedSingletonDataCon,
37 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
38 import Type ( funTyCon )
39 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
40 CCallConv(..), CCallTarget(..), defaultCCallConv
42 import OccName ( varName, varNameDepth, dataName, tcClsName, tvName )
43 import DataCon ( DataCon, dataConName )
44 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
45 SrcSpan, combineLocs, srcLocFile,
48 import StaticFlags ( opt_SccProfilingOn, opt_Hpc )
49 import Type ( Kind, liftedTypeKind, unliftedTypeKind )
50 import Coercion ( mkArrowKind )
51 import Class ( FunDep )
58 import Maybes ( orElse )
61 import Control.Monad ( unless )
64 import Control.Monad ( mplus )
68 -----------------------------------------------------------------------------
71 Conflicts: 33 shift/reduce
74 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
75 would think the two should never occur in the same context.
79 -----------------------------------------------------------------------------
82 Conflicts: 34 shift/reduce
85 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
86 would think the two should never occur in the same context.
90 -----------------------------------------------------------------------------
93 Conflicts: 32 shift/reduce
96 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
97 would think the two should never occur in the same context.
101 -----------------------------------------------------------------------------
104 Conflicts: 37 shift/reduce
107 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
108 would think the two should never occur in the same context.
112 -----------------------------------------------------------------------------
113 Conflicts: 38 shift/reduce (1.25)
115 10 for abiguity in 'if x then y else z + 1' [State 178]
116 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
117 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
119 1 for ambiguity in 'if x then y else z :: T' [State 178]
120 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
122 4 for ambiguity in 'if x then y else z -< e' [State 178]
123 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
124 There are four such operators: -<, >-, -<<, >>-
127 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
128 Which of these two is intended?
130 (x::T) -> T -- Rhs is T
133 (x::T -> T) -> .. -- Rhs is ...
135 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
138 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
139 Same duplication between states 11 and 253 as the previous case
141 1 for ambiguity in 'let ?x ...' [State 329]
142 the parser can't tell whether the ?x is the lhs of a normal binding or
143 an implicit binding. Fortunately resolving as shift gives it the only
144 sensible meaning, namely the lhs of an implicit binding.
146 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
147 we don't know whether the '[' starts the activation or not: it
148 might be the start of the declaration with the activation being
149 empty. --SDM 1/4/2002
151 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
152 since 'forall' is a valid variable name, we don't know whether
153 to treat a forall on the input as the beginning of a quantifier
154 or the beginning of the rule itself. Resolving to shift means
155 it's always treated as a quantifier, hence the above is disallowed.
156 This saves explicitly defining a grammar for the rule lhs that
157 doesn't include 'forall'.
159 1 for ambiguity when the source file starts with "-- | doc". We need another
160 token of lookahead to determine if a top declaration or the 'module' keyword
161 follows. Shift parses as if the 'module' keyword follows.
163 -- ---------------------------------------------------------------------------
164 -- Adding location info
166 This is done in a stylised way using the three macros below, L0, L1
167 and LL. Each of these macros can be thought of as having type
169 L0, L1, LL :: a -> Located a
171 They each add a SrcSpan to their argument.
173 L0 adds 'noSrcSpan', used for empty productions
174 -- This doesn't seem to work anymore -=chak
176 L1 for a production with a single token on the lhs. Grabs the SrcSpan
179 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
180 the first and last tokens.
182 These suffice for the majority of cases. However, we must be
183 especially careful with empty productions: LL won't work if the first
184 or last token on the lhs can represent an empty span. In these cases,
185 we have to calculate the span using more of the tokens from the lhs, eg.
187 | 'newtype' tycl_hdr '=' newconstr deriving
189 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
191 We provide comb3 and comb4 functions which are useful in such cases.
193 Be careful: there's no checking that you actually got this right, the
194 only symptom will be that the SrcSpans of your syntax will be
198 * We must expand these macros *before* running Happy, which is why this file is
199 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
201 #define L0 L noSrcSpan
202 #define L1 sL (getLoc $1)
203 #define LL sL (comb2 $1 $>)
205 -- -----------------------------------------------------------------------------
210 '_' { L _ ITunderscore } -- Haskell keywords
212 'case' { L _ ITcase }
213 'class' { L _ ITclass }
214 'data' { L _ ITdata }
215 'default' { L _ ITdefault }
216 'deriving' { L _ ITderiving }
218 'else' { L _ ITelse }
219 'hiding' { L _ IThiding }
221 'import' { L _ ITimport }
223 'infix' { L _ ITinfix }
224 'infixl' { L _ ITinfixl }
225 'infixr' { L _ ITinfixr }
226 'instance' { L _ ITinstance }
228 'module' { L _ ITmodule }
229 'newtype' { L _ ITnewtype }
231 'qualified' { L _ ITqualified }
232 'then' { L _ ITthen }
233 'type' { L _ ITtype }
234 'where' { L _ ITwhere }
235 '_scc_' { L _ ITscc } -- ToDo: remove
237 'forall' { L _ ITforall } -- GHC extension keywords
238 'foreign' { L _ ITforeign }
239 'export' { L _ ITexport }
240 'label' { L _ ITlabel }
241 'dynamic' { L _ ITdynamic }
242 'safe' { L _ ITsafe }
243 'threadsafe' { L _ ITthreadsafe } -- ToDo: remove deprecated alias
244 'interruptible' { L _ ITinterruptible }
245 'unsafe' { L _ ITunsafe }
247 'family' { L _ ITfamily }
248 'stdcall' { L _ ITstdcallconv }
249 'ccall' { L _ ITccallconv }
250 'prim' { L _ ITprimcallconv }
251 'proc' { L _ ITproc } -- for arrow notation extension
252 'rec' { L _ ITrec } -- for arrow notation extension
253 'group' { L _ ITgroup } -- for list transform extension
254 'by' { L _ ITby } -- for list transform extension
255 'using' { L _ ITusing } -- for list transform extension
257 '{-# INLINE' { L _ (ITinline_prag _ _) }
258 '{-# SPECIALISE' { L _ ITspec_prag }
259 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
260 '{-# SOURCE' { L _ ITsource_prag }
261 '{-# RULES' { L _ ITrules_prag }
262 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
263 '{-# SCC' { L _ ITscc_prag }
264 '{-# GENERATED' { L _ ITgenerated_prag }
265 '{-# DEPRECATED' { L _ ITdeprecated_prag }
266 '{-# WARNING' { L _ ITwarning_prag }
267 '{-# UNPACK' { L _ ITunpack_prag }
268 '{-# ANN' { L _ ITann_prag }
269 '#-}' { L _ ITclose_prag }
271 '..' { L _ ITdotdot } -- reserved symbols
273 '::' { L _ ITdcolon }
277 '<-' { L _ ITlarrow }
278 '->' { L _ ITrarrow }
281 '=>' { L _ ITdarrow }
285 '-<' { L _ ITlarrowtail } -- for arrow notation
286 '>-' { L _ ITrarrowtail } -- for arrow notation
287 '-<<' { L _ ITLarrowtail } -- for arrow notation
288 '>>-' { L _ ITRarrowtail } -- for arrow notation
291 '{' { L _ ITocurly } -- special symbols
293 '{|' { L _ ITocurlybar }
294 '|}' { L _ ITccurlybar }
295 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
296 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
299 '[:' { L _ ITopabrack }
300 ':]' { L _ ITcpabrack }
303 '(#' { L _ IToubxparen }
304 '#)' { L _ ITcubxparen }
305 '(|' { L _ IToparenbar }
306 '|)' { L _ ITcparenbar }
307 '<[' { L _ ITopenBrak }
308 ']>' { L _ ITcloseBrak }
309 '~~' { L _ ITescape }
310 '~~$' { L _ ITescapeDollar }
311 '%%' { L _ ITdoublePercent }
314 '`' { L _ ITbackquote }
316 VARID { L _ (ITvarid _) } -- identifiers
317 CONID { L _ (ITconid _) }
318 VARSYM { L _ (ITvarsym _) }
319 CONSYM { L _ (ITconsym _) }
320 QVARID { L _ (ITqvarid _) }
321 QCONID { L _ (ITqconid _) }
322 QVARSYM { L _ (ITqvarsym _) }
323 QCONSYM { L _ (ITqconsym _) }
324 PREFIXQVARSYM { L _ (ITprefixqvarsym _) }
325 PREFIXQCONSYM { L _ (ITprefixqconsym _) }
327 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
329 CHAR { L _ (ITchar _) }
330 STRING { L _ (ITstring _) }
331 INTEGER { L _ (ITinteger _) }
332 RATIONAL { L _ (ITrational _) }
334 PRIMCHAR { L _ (ITprimchar _) }
335 PRIMSTRING { L _ (ITprimstring _) }
336 PRIMINTEGER { L _ (ITprimint _) }
337 PRIMWORD { L _ (ITprimword _) }
338 PRIMFLOAT { L _ (ITprimfloat _) }
339 PRIMDOUBLE { L _ (ITprimdouble _) }
341 DOCNEXT { L _ (ITdocCommentNext _) }
342 DOCPREV { L _ (ITdocCommentPrev _) }
343 DOCNAMED { L _ (ITdocCommentNamed _) }
344 DOCSECTION { L _ (ITdocSection _ _) }
347 '[|' { L _ ITopenExpQuote }
348 '[p|' { L _ ITopenPatQuote }
349 '[t|' { L _ ITopenTypQuote }
350 '[d|' { L _ ITopenDecQuote }
351 '|]' { L _ ITcloseQuote }
352 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
353 '$(' { L _ ITparenEscape } -- $( exp )
354 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
355 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
356 TH_QUASIQUOTE { L _ (ITquasiQuote _) }
358 %monad { P } { >>= } { return }
359 %lexer { lexer } { L _ ITeof }
360 %name parseModule module
361 %name parseStmt maybe_stmt
362 %name parseIdentifier identifier
363 %name parseType ctype
364 %partial parseHeader header
365 %tokentype { (Located Token) }
368 -----------------------------------------------------------------------------
369 -- Identifiers; one of the entry points
370 identifier :: { Located RdrName }
375 | '(' '->' ')' { LL $ getRdrName funTyCon }
377 -----------------------------------------------------------------------------
380 -- The place for module deprecation is really too restrictive, but if it
381 -- was allowed at its natural place just before 'module', we get an ugly
382 -- s/r conflict with the second alternative. Another solution would be the
383 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
384 -- either, and DEPRECATED is only expected to be used by people who really
385 -- know what they are doing. :-)
387 module :: { Located (HsModule RdrName) }
388 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' body
389 {% fileSrcSpan >>= \ loc ->
390 return (L loc (HsModule (Just $3) $5 (fst $7) (snd $7) $4 $1
393 {% fileSrcSpan >>= \ loc ->
394 return (L loc (HsModule Nothing Nothing
395 (fst $1) (snd $1) Nothing Nothing
398 maybedocheader :: { Maybe LHsDocString }
399 : moduleheader { $1 }
400 | {- empty -} { Nothing }
402 missing_module_keyword :: { () }
403 : {- empty -} {% pushCurrentContext }
405 maybemodwarning :: { Maybe WarningTxt }
406 : '{-# DEPRECATED' strings '#-}' { Just (DeprecatedTxt $ unLoc $2) }
407 | '{-# WARNING' strings '#-}' { Just (WarningTxt $ unLoc $2) }
408 | {- empty -} { Nothing }
410 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
412 | vocurly top close { $2 }
414 body2 :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
416 | missing_module_keyword top close { $2 }
418 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
419 : importdecls { (reverse $1,[]) }
420 | importdecls ';' cvtopdecls { (reverse $1,$3) }
421 | cvtopdecls { ([],$1) }
423 cvtopdecls :: { [LHsDecl RdrName] }
424 : topdecls { cvTopDecls $1 }
426 -----------------------------------------------------------------------------
427 -- Module declaration & imports only
429 header :: { Located (HsModule RdrName) }
430 : maybedocheader 'module' modid maybemodwarning maybeexports 'where' header_body
431 {% fileSrcSpan >>= \ loc ->
432 return (L loc (HsModule (Just $3) $5 $7 [] $4 $1
434 | missing_module_keyword importdecls
435 {% fileSrcSpan >>= \ loc ->
436 return (L loc (HsModule Nothing Nothing $2 [] Nothing
439 header_body :: { [LImportDecl RdrName] }
440 : '{' importdecls { $2 }
441 | vocurly importdecls { $2 }
443 -----------------------------------------------------------------------------
446 maybeexports :: { Maybe [LIE RdrName] }
447 : '(' exportlist ')' { Just $2 }
448 | {- empty -} { Nothing }
450 exportlist :: { [LIE RdrName] }
451 : expdoclist ',' expdoclist { $1 ++ $3 }
454 exportlist1 :: { [LIE RdrName] }
455 : expdoclist export expdoclist ',' exportlist { $1 ++ ($2 : $3) ++ $5 }
456 | expdoclist export expdoclist { $1 ++ ($2 : $3) }
459 expdoclist :: { [LIE RdrName] }
460 : exp_doc expdoclist { $1 : $2 }
463 exp_doc :: { LIE RdrName }
464 : docsection { L1 (case (unLoc $1) of (n, doc) -> IEGroup n doc) }
465 | docnamed { L1 (IEDocNamed ((fst . unLoc) $1)) }
466 | docnext { L1 (IEDoc (unLoc $1)) }
468 -- No longer allow things like [] and (,,,) to be exported
469 -- They are built in syntax, always available
470 export :: { LIE RdrName }
471 : qvar { L1 (IEVar (unLoc $1)) }
472 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
473 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
474 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
475 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
476 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
478 qcnames :: { [RdrName] }
479 : qcnames ',' qcname_ext { unLoc $3 : $1 }
480 | qcname_ext { [unLoc $1] }
482 qcname_ext :: { Located RdrName } -- Variable or data constructor
483 -- or tagged type constructor
485 | 'type' qcon { sL (comb2 $1 $2)
486 (setRdrNameSpace (unLoc $2)
489 -- Cannot pull into qcname_ext, as qcname is also used in expression.
490 qcname :: { Located RdrName } -- Variable or data constructor
494 -----------------------------------------------------------------------------
495 -- Import Declarations
497 -- import decls can be *empty*, or even just a string of semicolons
498 -- whereas topdecls must contain at least one topdecl.
500 importdecls :: { [LImportDecl RdrName] }
501 : importdecls ';' importdecl { $3 : $1 }
502 | importdecls ';' { $1 }
503 | importdecl { [ $1 ] }
506 importdecl :: { LImportDecl RdrName }
507 : 'import' maybe_src optqualified maybe_pkg modid maybeas maybeimpspec
508 { L (comb4 $1 $5 $6 $7) (ImportDecl $5 $4 $2 $3 (unLoc $6) (unLoc $7)) }
510 maybe_src :: { IsBootInterface }
511 : '{-# SOURCE' '#-}' { True }
512 | {- empty -} { False }
514 maybe_pkg :: { Maybe FastString }
515 : STRING { Just (getSTRING $1) }
516 | {- empty -} { Nothing }
518 optqualified :: { Bool }
519 : 'qualified' { True }
520 | {- empty -} { False }
522 maybeas :: { Located (Maybe ModuleName) }
523 : 'as' modid { LL (Just (unLoc $2)) }
524 | {- empty -} { noLoc Nothing }
526 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
527 : impspec { L1 (Just (unLoc $1)) }
528 | {- empty -} { noLoc Nothing }
530 impspec :: { Located (Bool, [LIE RdrName]) }
531 : '(' exportlist ')' { LL (False, $2) }
532 | 'hiding' '(' exportlist ')' { LL (True, $3) }
534 -----------------------------------------------------------------------------
535 -- Fixity Declarations
539 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
541 infix :: { Located FixityDirection }
542 : 'infix' { L1 InfixN }
543 | 'infixl' { L1 InfixL }
544 | 'infixr' { L1 InfixR }
546 ops :: { Located [Located RdrName] }
547 : ops ',' op { LL ($3 : unLoc $1) }
550 -----------------------------------------------------------------------------
551 -- Top-Level Declarations
553 topdecls :: { OrdList (LHsDecl RdrName) }
554 : topdecls ';' topdecl { $1 `appOL` $3 }
555 | topdecls ';' { $1 }
558 topdecl :: { OrdList (LHsDecl RdrName) }
559 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
560 | ty_decl { unitOL (L1 (TyClD (unLoc $1))) }
561 | 'instance' inst_type where_inst
562 { let (binds, sigs, ats, _) = cvBindsAndSigs (unLoc $3)
564 unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs ats)))}
565 | stand_alone_deriving { unitOL (LL (DerivD (unLoc $1))) }
566 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
567 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
568 | '{-# DEPRECATED' deprecations '#-}' { $2 }
569 | '{-# WARNING' warnings '#-}' { $2 }
570 | '{-# RULES' rules '#-}' { $2 }
571 | annotation { unitOL $1 }
574 -- Template Haskell Extension
575 -- The $(..) form is one possible form of infixexp
576 -- but we treat an arbitrary expression just as if
577 -- it had a $(..) wrapped around it
578 | infixexp { unitOL (LL $ mkTopSpliceDecl $1) }
582 cl_decl :: { LTyClDecl RdrName }
583 : 'class' tycl_hdr fds where_cls {% mkClassDecl (comb4 $1 $2 $3 $4) $2 $3 $4 }
585 -- Type declarations (toplevel)
587 ty_decl :: { LTyClDecl RdrName }
588 -- ordinary type synonyms
589 : 'type' type '=' ctypedoc
590 -- Note ctype, not sigtype, on the right of '='
591 -- We allow an explicit for-all but we don't insert one
592 -- in type Foo a = (b,b)
593 -- Instead we just say b is out of scope
595 -- Note the use of type for the head; this allows
596 -- infix type constructors to be declared
597 {% mkTySynonym (comb2 $1 $4) False $2 $4 }
599 -- type family declarations
600 | 'type' 'family' type opt_kind_sig
601 -- Note the use of type for the head; this allows
602 -- infix type constructors to be declared
603 {% mkTyFamily (comb3 $1 $3 $4) TypeFamily $3 (unLoc $4) }
605 -- type instance declarations
606 | 'type' 'instance' type '=' ctype
607 -- Note the use of type for the head; this allows
608 -- infix type constructors and type patterns
609 {% mkTySynonym (comb2 $1 $5) True $3 $5 }
611 -- ordinary data type or newtype declaration
612 | data_or_newtype tycl_hdr constrs deriving
613 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) False $2
614 Nothing (reverse (unLoc $3)) (unLoc $4) }
615 -- We need the location on tycl_hdr in case
616 -- constrs and deriving are both empty
618 -- ordinary GADT declaration
619 | data_or_newtype tycl_hdr opt_kind_sig
622 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) False $2
623 (unLoc $3) (unLoc $4) (unLoc $5) }
624 -- We need the location on tycl_hdr in case
625 -- constrs and deriving are both empty
627 -- data/newtype family
628 | 'data' 'family' type opt_kind_sig
629 {% mkTyFamily (comb3 $1 $2 $4) DataFamily $3 (unLoc $4) }
631 -- data/newtype instance declaration
632 | data_or_newtype 'instance' tycl_hdr constrs deriving
633 {% mkTyData (comb4 $1 $3 $4 $5) (unLoc $1) True $3
634 Nothing (reverse (unLoc $4)) (unLoc $5) }
636 -- GADT instance declaration
637 | data_or_newtype 'instance' tycl_hdr opt_kind_sig
640 {% mkTyData (comb4 $1 $3 $5 $6) (unLoc $1) True $3
641 (unLoc $4) (unLoc $5) (unLoc $6) }
643 -- Associated type family declarations
645 -- * They have a different syntax than on the toplevel (no family special
648 -- * They also need to be separate from instances; otherwise, data family
649 -- declarations without a kind signature cause parsing conflicts with empty
650 -- data declarations.
652 at_decl_cls :: { LTyClDecl RdrName }
653 -- type family declarations
654 : 'type' type opt_kind_sig
655 -- Note the use of type for the head; this allows
656 -- infix type constructors to be declared
657 {% mkTyFamily (comb3 $1 $2 $3) TypeFamily $2 (unLoc $3) }
659 -- default type instance
660 | 'type' type '=' ctype
661 -- Note the use of type for the head; this allows
662 -- infix type constructors and type patterns
663 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
665 -- data/newtype family declaration
666 | 'data' type opt_kind_sig
667 {% mkTyFamily (comb3 $1 $2 $3) DataFamily $2 (unLoc $3) }
669 -- Associated type instances
671 at_decl_inst :: { LTyClDecl RdrName }
672 -- type instance declarations
673 : 'type' type '=' ctype
674 -- Note the use of type for the head; this allows
675 -- infix type constructors and type patterns
676 {% mkTySynonym (comb2 $1 $4) True $2 $4 }
678 -- data/newtype instance declaration
679 | data_or_newtype tycl_hdr constrs deriving
680 {% mkTyData (comb4 $1 $2 $3 $4) (unLoc $1) True $2
681 Nothing (reverse (unLoc $3)) (unLoc $4) }
683 -- GADT instance declaration
684 | data_or_newtype tycl_hdr opt_kind_sig
687 {% mkTyData (comb4 $1 $2 $4 $5) (unLoc $1) True $2
688 (unLoc $3) (unLoc $4) (unLoc $5) }
690 data_or_newtype :: { Located NewOrData }
691 : 'data' { L1 DataType }
692 | 'newtype' { L1 NewType }
694 opt_kind_sig :: { Located (Maybe Kind) }
696 | '::' kind { LL (Just (unLoc $2)) }
698 -- tycl_hdr parses the header of a class or data type decl,
699 -- which takes the form
702 -- (Eq a, Ord b) => T a b
703 -- T Int [a] -- for associated types
704 -- Rather a lot of inlining here, else we get reduce/reduce errors
705 tycl_hdr :: { Located (Maybe (LHsContext RdrName), LHsType RdrName) }
706 : context '=>' type { LL (Just $1, $3) }
707 | type { L1 (Nothing, $1) }
709 -----------------------------------------------------------------------------
710 -- Stand-alone deriving
712 -- Glasgow extension: stand-alone deriving declarations
713 stand_alone_deriving :: { LDerivDecl RdrName }
714 : 'deriving' 'instance' inst_type { LL (DerivDecl $3) }
716 -----------------------------------------------------------------------------
717 -- Nested declarations
719 -- Declaration in class bodies
721 decl_cls :: { Located (OrdList (LHsDecl RdrName)) }
722 decl_cls : at_decl_cls { LL (unitOL (L1 (TyClD (unLoc $1)))) }
725 decls_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
726 : decls_cls ';' decl_cls { LL (unLoc $1 `appOL` unLoc $3) }
727 | decls_cls ';' { LL (unLoc $1) }
729 | {- empty -} { noLoc nilOL }
733 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
734 : '{' decls_cls '}' { LL (unLoc $2) }
735 | vocurly decls_cls close { $2 }
739 where_cls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
740 -- No implicit parameters
741 -- May have type declarations
742 : 'where' decllist_cls { LL (unLoc $2) }
743 | {- empty -} { noLoc nilOL }
745 -- Declarations in instance bodies
747 decl_inst :: { Located (OrdList (LHsDecl RdrName)) }
748 decl_inst : at_decl_inst { LL (unitOL (L1 (TyClD (unLoc $1)))) }
751 decls_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
752 : decls_inst ';' decl_inst { LL (unLoc $1 `appOL` unLoc $3) }
753 | decls_inst ';' { LL (unLoc $1) }
755 | {- empty -} { noLoc nilOL }
758 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
759 : '{' decls_inst '}' { LL (unLoc $2) }
760 | vocurly decls_inst close { $2 }
764 where_inst :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
765 -- No implicit parameters
766 -- May have type declarations
767 : 'where' decllist_inst { LL (unLoc $2) }
768 | {- empty -} { noLoc nilOL }
770 -- Declarations in binding groups other than classes and instances
772 decls :: { Located (OrdList (LHsDecl RdrName)) }
773 : decls ';' decl { let { this = unLoc $3;
775 these = rest `appOL` this }
776 in rest `seq` this `seq` these `seq`
778 | decls ';' { LL (unLoc $1) }
780 | {- empty -} { noLoc nilOL }
782 decllist :: { Located (OrdList (LHsDecl RdrName)) }
783 : '{' decls '}' { LL (unLoc $2) }
784 | vocurly decls close { $2 }
786 -- Binding groups other than those of class and instance declarations
788 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
789 -- No type declarations
790 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
791 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
792 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyTcEvBinds)) }
794 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
795 -- No type declarations
796 : 'where' binds { LL (unLoc $2) }
797 | {- empty -} { noLoc emptyLocalBinds }
800 -----------------------------------------------------------------------------
801 -- Transformation Rules
803 rules :: { OrdList (LHsDecl RdrName) }
804 : rules ';' rule { $1 `snocOL` $3 }
807 | {- empty -} { nilOL }
809 rule :: { LHsDecl RdrName }
810 : STRING activation rule_forall infixexp '=' exp
811 { LL $ RuleD (HsRule (getSTRING $1)
812 ($2 `orElse` AlwaysActive)
813 $3 $4 placeHolderNames $6 placeHolderNames) }
815 activation :: { Maybe Activation }
816 : {- empty -} { Nothing }
817 | explicit_activation { Just $1 }
819 explicit_activation :: { Activation } -- In brackets
820 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
821 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
823 rule_forall :: { [RuleBndr RdrName] }
824 : 'forall' rule_var_list '.' { $2 }
827 rule_var_list :: { [RuleBndr RdrName] }
829 | rule_var rule_var_list { $1 : $2 }
831 rule_var :: { RuleBndr RdrName }
832 : varid { RuleBndr $1 }
833 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
835 -----------------------------------------------------------------------------
836 -- Warnings and deprecations (c.f. rules)
838 warnings :: { OrdList (LHsDecl RdrName) }
839 : warnings ';' warning { $1 `appOL` $3 }
840 | warnings ';' { $1 }
842 | {- empty -} { nilOL }
844 -- SUP: TEMPORARY HACK, not checking for `module Foo'
845 warning :: { OrdList (LHsDecl RdrName) }
847 { toOL [ LL $ WarningD (Warning n (WarningTxt $ unLoc $2))
850 deprecations :: { OrdList (LHsDecl RdrName) }
851 : deprecations ';' deprecation { $1 `appOL` $3 }
852 | deprecations ';' { $1 }
854 | {- empty -} { nilOL }
856 -- SUP: TEMPORARY HACK, not checking for `module Foo'
857 deprecation :: { OrdList (LHsDecl RdrName) }
859 { toOL [ LL $ WarningD (Warning n (DeprecatedTxt $ unLoc $2))
862 strings :: { Located [FastString] }
863 : STRING { L1 [getSTRING $1] }
864 | '[' stringlist ']' { LL $ fromOL (unLoc $2) }
866 stringlist :: { Located (OrdList FastString) }
867 : stringlist ',' STRING { LL (unLoc $1 `snocOL` getSTRING $3) }
868 | STRING { LL (unitOL (getSTRING $1)) }
870 -----------------------------------------------------------------------------
872 annotation :: { LHsDecl RdrName }
873 : '{-# ANN' name_var aexp '#-}' { LL (AnnD $ HsAnnotation (ValueAnnProvenance (unLoc $2)) $3) }
874 | '{-# ANN' 'type' tycon aexp '#-}' { LL (AnnD $ HsAnnotation (TypeAnnProvenance (unLoc $3)) $4) }
875 | '{-# ANN' 'module' aexp '#-}' { LL (AnnD $ HsAnnotation ModuleAnnProvenance $3) }
878 -----------------------------------------------------------------------------
879 -- Foreign import and export declarations
881 fdecl :: { LHsDecl RdrName }
882 fdecl : 'import' callconv safety fspec
883 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
884 | 'import' callconv fspec
885 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
887 | 'export' callconv fspec
888 {% mkExport $2 (unLoc $3) >>= return.LL }
890 callconv :: { CCallConv }
891 : 'stdcall' { StdCallConv }
892 | 'ccall' { CCallConv }
893 | 'prim' { PrimCallConv}
896 : 'unsafe' { PlayRisky }
897 | 'safe' { PlaySafe False }
898 | 'interruptible' { PlayInterruptible }
899 | 'threadsafe' { PlaySafe True } -- deprecated alias
901 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
902 : STRING var '::' sigtypedoc { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
903 | var '::' sigtypedoc { LL (noLoc nilFS, $1, $3) }
904 -- if the entity string is missing, it defaults to the empty string;
905 -- the meaning of an empty entity string depends on the calling
908 -----------------------------------------------------------------------------
911 opt_sig :: { Maybe (LHsType RdrName) }
912 : {- empty -} { Nothing }
913 | '::' sigtype { Just $2 }
915 opt_asig :: { Maybe (LHsType RdrName) }
916 : {- empty -} { Nothing }
917 | '::' atype { Just $2 }
919 sigtype :: { LHsType RdrName } -- Always a HsForAllTy,
920 -- to tell the renamer where to generalise
921 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
922 -- Wrap an Implicit forall if there isn't one there already
924 sigtypedoc :: { LHsType RdrName } -- Always a HsForAllTy
925 : ctypedoc { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
926 -- Wrap an Implicit forall if there isn't one there already
928 sig_vars :: { Located [Located RdrName] }
929 : sig_vars ',' var { LL ($3 : unLoc $1) }
932 sigtypes1 :: { [LHsType RdrName] } -- Always HsForAllTys
934 | sigtype ',' sigtypes1 { $1 : $3 }
936 -----------------------------------------------------------------------------
939 infixtype :: { LHsType RdrName }
940 : btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
941 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
943 strict_mark :: { Located HsBang }
944 : '!' { L1 HsStrict }
945 | '{-# UNPACK' '#-}' '!' { LL HsUnpack }
947 -- A ctype is a for-all type
948 ctype :: { LHsType RdrName }
949 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
950 | context '=>' ctype { LL $ mkImplicitHsForAllTy $1 $3 }
951 -- A type of form (context => type) is an *implicit* HsForAllTy
952 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
955 ----------------------
956 -- Notes for 'ctypedoc'
957 -- It would have been nice to simplify the grammar by unifying `ctype` and
958 -- ctypedoc` into one production, allowing comments on types everywhere (and
959 -- rejecting them after parsing, where necessary). This is however not possible
960 -- since it leads to ambiguity. The reason is the support for comments on record
962 -- data R = R { field :: Int -- ^ comment on the field }
963 -- If we allow comments on types here, it's not clear if the comment applies
964 -- to 'field' or to 'Int'. So we must use `ctype` to describe the type.
966 ctypedoc :: { LHsType RdrName }
967 : 'forall' tv_bndrs '.' ctypedoc { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
968 | context '=>' ctypedoc { LL $ mkImplicitHsForAllTy $1 $3 }
969 -- A type of form (context => type) is an *implicit* HsForAllTy
970 | ipvar '::' type { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
973 ----------------------
974 -- Notes for 'context'
975 -- We parse a context as a btype so that we don't get reduce/reduce
976 -- errors in ctype. The basic problem is that
978 -- looks so much like a tuple type. We can't tell until we find the =>
980 -- We have the t1 ~ t2 form both in 'context' and in type,
981 -- to permit an individual equational constraint without parenthesis.
982 -- Thus for some reason we allow f :: a~b => blah
983 -- but not f :: ?x::Int => blah
984 context :: { LHsContext RdrName }
985 : btype '~' btype {% checkContext
986 (LL $ HsPredTy (HsEqualP $1 $3)) }
987 | btype {% checkContext $1 }
989 type :: { LHsType RdrName }
991 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
992 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
993 | btype '->' ctype { LL $ HsFunTy $1 $3 }
994 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
996 typedoc :: { LHsType RdrName }
998 | btype docprev { LL $ HsDocTy $1 $2 }
999 | btype qtyconop type { LL $ HsOpTy $1 $2 $3 }
1000 | btype qtyconop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1001 | btype tyvarop type { LL $ HsOpTy $1 $2 $3 }
1002 | btype tyvarop type docprev { LL $ HsDocTy (L (comb3 $1 $2 $3) (HsOpTy $1 $2 $3)) $4 }
1003 | btype '->' ctypedoc { LL $ HsFunTy $1 $3 }
1004 | btype docprev '->' ctypedoc { LL $ HsFunTy (L (comb2 $1 $2) (HsDocTy $1 $2)) $4 }
1005 | btype '~' btype { LL $ HsPredTy (HsEqualP $1 $3) }
1007 btype :: { LHsType RdrName }
1008 : btype atype { LL $ HsAppTy $1 $2 }
1011 atype :: { LHsType RdrName }
1012 : gtycon { L1 (HsTyVar (unLoc $1)) }
1013 | tyvar { L1 (HsTyVar (unLoc $1)) }
1014 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) } -- Constructor sigs only
1015 | '{' fielddecls '}' { LL $ HsRecTy $2 } -- Constructor sigs only
1016 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
1017 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
1018 | '[' ctype ']' { LL $ HsListTy $2 }
1019 | '<[' ctype ']>' '@' tyvar { LL $ HsModalBoxType (unLoc $5) $2 }
1020 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
1021 | '(' ctype ')' { LL $ HsParTy $2 }
1022 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
1023 | quasiquote { L1 (HsQuasiQuoteTy (unLoc $1)) }
1024 | '$(' exp ')' { LL $ mkHsSpliceTy $2 }
1025 | TH_ID_SPLICE { LL $ mkHsSpliceTy $ L1 $ HsVar $
1026 mkUnqual varName (getTH_ID_SPLICE $1) }
1028 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
1030 -- An inst_type is what occurs in the head of an instance decl
1031 -- e.g. (Foo a, Gaz b) => Wibble a b
1032 -- It's kept as a single type, with a MonoDictTy at the right
1033 -- hand corner, for convenience.
1034 inst_type :: { LHsType RdrName }
1035 : sigtype {% checkInstType $1 }
1037 inst_types1 :: { [LHsType RdrName] }
1038 : inst_type { [$1] }
1039 | inst_type ',' inst_types1 { $1 : $3 }
1041 comma_types0 :: { [LHsType RdrName] }
1042 : comma_types1 { $1 }
1043 | {- empty -} { [] }
1045 comma_types1 :: { [LHsType RdrName] }
1047 | ctype ',' comma_types1 { $1 : $3 }
1049 tv_bndrs :: { [LHsTyVarBndr RdrName] }
1050 : tv_bndr tv_bndrs { $1 : $2 }
1051 | {- empty -} { [] }
1053 tv_bndr :: { LHsTyVarBndr RdrName }
1054 : tyvar { L1 (UserTyVar (unLoc $1) placeHolderKind) }
1055 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
1058 fds :: { Located [Located (FunDep RdrName)] }
1059 : {- empty -} { noLoc [] }
1060 | '|' fds1 { LL (reverse (unLoc $2)) }
1062 fds1 :: { Located [Located (FunDep RdrName)] }
1063 : fds1 ',' fd { LL ($3 : unLoc $1) }
1066 fd :: { Located (FunDep RdrName) }
1067 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
1068 (reverse (unLoc $1), reverse (unLoc $3)) }
1070 varids0 :: { Located [RdrName] }
1071 : {- empty -} { noLoc [] }
1072 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
1074 -----------------------------------------------------------------------------
1077 kind :: { Located Kind }
1079 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
1081 akind :: { Located Kind }
1082 : '*' { L1 liftedTypeKind }
1083 | '!' { L1 unliftedTypeKind }
1084 | '(' kind ')' { LL (unLoc $2) }
1087 -----------------------------------------------------------------------------
1088 -- Datatype declarations
1090 gadt_constrlist :: { Located [LConDecl RdrName] } -- Returned in order
1091 : 'where' '{' gadt_constrs '}' { L (comb2 $1 $3) (unLoc $3) }
1092 | 'where' vocurly gadt_constrs close { L (comb2 $1 $3) (unLoc $3) }
1093 | {- empty -} { noLoc [] }
1095 gadt_constrs :: { Located [LConDecl RdrName] }
1096 : gadt_constr ';' gadt_constrs { L (comb2 (head $1) $3) ($1 ++ unLoc $3) }
1097 | gadt_constr { L (getLoc (head $1)) $1 }
1098 | {- empty -} { noLoc [] }
1100 -- We allow the following forms:
1101 -- C :: Eq a => a -> T a
1102 -- C :: forall a. Eq a => !a -> T a
1103 -- D { x,y :: a } :: T a
1104 -- forall a. Eq a => D { x,y :: a } :: T a
1106 gadt_constr :: { [LConDecl RdrName] } -- Returns a list because of: C,D :: ty
1107 : con_list '::' sigtype
1108 { map (sL (comb2 $1 $3)) (mkGadtDecl (unLoc $1) $3) }
1110 -- Deprecated syntax for GADT record declarations
1111 | oqtycon '{' fielddecls '}' '::' sigtype
1112 {% do { cd <- mkDeprecatedGadtRecordDecl (comb2 $1 $6) $1 $3 $6
1115 constrs :: { Located [LConDecl RdrName] }
1116 : maybe_docnext '=' constrs1 { L (comb2 $2 $3) (addConDocs (unLoc $3) $1) }
1118 constrs1 :: { Located [LConDecl RdrName] }
1119 : constrs1 maybe_docnext '|' maybe_docprev constr { LL (addConDoc $5 $2 : addConDocFirst (unLoc $1) $4) }
1120 | constr { L1 [$1] }
1122 constr :: { LConDecl RdrName }
1123 : maybe_docnext forall context '=>' constr_stuff maybe_docprev
1124 { let (con,details) = unLoc $5 in
1125 addConDoc (L (comb4 $2 $3 $4 $5) (mkSimpleConDecl con (unLoc $2) $3 details))
1127 | maybe_docnext forall constr_stuff maybe_docprev
1128 { let (con,details) = unLoc $3 in
1129 addConDoc (L (comb2 $2 $3) (mkSimpleConDecl con (unLoc $2) (noLoc []) details))
1132 forall :: { Located [LHsTyVarBndr RdrName] }
1133 : 'forall' tv_bndrs '.' { LL $2 }
1134 | {- empty -} { noLoc [] }
1136 constr_stuff :: { Located (Located RdrName, HsConDeclDetails RdrName) }
1137 -- We parse the constructor declaration
1139 -- as a btype (treating C as a type constructor) and then convert C to be
1140 -- a data constructor. Reason: it might continue like this:
1142 -- in which case C really would be a type constructor. We can't resolve this
1143 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
1144 : btype {% splitCon $1 >>= return.LL }
1145 | btype conop btype { LL ($2, InfixCon $1 $3) }
1147 fielddecls :: { [ConDeclField RdrName] }
1148 : {- empty -} { [] }
1149 | fielddecls1 { $1 }
1151 fielddecls1 :: { [ConDeclField RdrName] }
1152 : fielddecl maybe_docnext ',' maybe_docprev fielddecls1
1153 { [ addFieldDoc f $4 | f <- $1 ] ++ addFieldDocs $5 $2 }
1154 -- This adds the doc $4 to each field separately
1157 fielddecl :: { [ConDeclField RdrName] } -- A list because of f,g :: Int
1158 : maybe_docnext sig_vars '::' ctype maybe_docprev { [ ConDeclField fld $4 ($1 `mplus` $5)
1159 | fld <- reverse (unLoc $2) ] }
1161 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
1162 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
1163 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
1164 -- We don't allow a context, but that's sorted out by the type checker.
1165 deriving :: { Located (Maybe [LHsType RdrName]) }
1166 : {- empty -} { noLoc Nothing }
1167 | 'deriving' qtycon {% do { let { L loc tv = $2 }
1168 ; p <- checkInstType (L loc (HsTyVar tv))
1169 ; return (LL (Just [p])) } }
1170 | 'deriving' '(' ')' { LL (Just []) }
1171 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
1172 -- Glasgow extension: allow partial
1173 -- applications in derivings
1175 -----------------------------------------------------------------------------
1176 -- Value definitions
1178 {- Note [Declaration/signature overlap]
1179 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1180 There's an awkward overlap with a type signature. Consider
1181 f :: Int -> Int = ...rhs...
1182 Then we can't tell whether it's a type signature or a value
1183 definition with a result signature until we see the '='.
1184 So we have to inline enough to postpone reductions until we know.
1188 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
1189 instead of qvar, we get another shift/reduce-conflict. Consider the
1192 { (^^) :: Int->Int ; } Type signature; only var allowed
1194 { (^^) :: Int->Int = ... ; } Value defn with result signature;
1195 qvar allowed (because of instance decls)
1197 We can't tell whether to reduce var to qvar until after we've read the signatures.
1200 docdecl :: { LHsDecl RdrName }
1201 : docdecld { L1 (DocD (unLoc $1)) }
1203 docdecld :: { LDocDecl }
1204 : docnext { L1 (DocCommentNext (unLoc $1)) }
1205 | docprev { L1 (DocCommentPrev (unLoc $1)) }
1206 | docnamed { L1 (case (unLoc $1) of (n, doc) -> DocCommentNamed n doc) }
1207 | docsection { L1 (case (unLoc $1) of (n, doc) -> DocGroup n doc) }
1209 decl :: { Located (OrdList (LHsDecl RdrName)) }
1212 | '!' aexp rhs {% do { let { e = LL (SectionR (LL (HsVar bang_RDR)) $2) };
1213 pat <- checkPattern e;
1214 return $ LL $ unitOL $ LL $ ValD $
1215 PatBind pat (unLoc $3)
1216 placeHolderType placeHolderNames } }
1217 -- Turn it all into an expression so that
1218 -- checkPattern can check that bangs are enabled
1220 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
1221 let { l = comb2 $1 $> };
1222 return $! (sL l (unitOL $! (sL l $ ValD r))) } }
1224 | docdecl { LL $ unitOL $1 }
1226 rhs :: { Located (GRHSs RdrName) }
1227 : '=' exp wherebinds { sL (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
1228 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1230 gdrhs :: { Located [LGRHS RdrName] }
1231 : gdrhs gdrh { LL ($2 : unLoc $1) }
1234 gdrh :: { LGRHS RdrName }
1235 : '|' guardquals '=' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1237 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1238 : infixexp '::' sigtypedoc {% do s <- checkValSig $1 $3
1239 ; return (LL $ unitOL (LL $ SigD s)) }
1240 -- See Note [Declaration/signature overlap] for why we need infixexp here
1242 | var ',' sig_vars '::' sigtypedoc
1243 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
1244 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1246 | '{-# INLINE' activation qvar '#-}'
1247 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlinePragma (getINLINE $1) $2))) }
1248 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1249 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlinePragma)
1251 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1252 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlinePragma (getSPEC_INLINE $1) $2))
1254 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1255 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1257 -----------------------------------------------------------------------------
1260 quasiquote :: { Located (HsQuasiQuote RdrName) }
1261 : TH_QUASIQUOTE { let { loc = getLoc $1
1262 ; ITquasiQuote (quoter, quote, quoteSpan) = unLoc $1
1263 ; quoterId = mkUnqual varName quoter }
1264 in L1 (mkHsQuasiQuote quoterId quoteSpan quote) }
1266 incdepth :: { Located () } : {% do { incrBracketDepth ; return $ noLoc () } }
1267 decdepth :: { Located () } : {% do { decrBracketDepth ; return $ noLoc () } }
1270 exp :: { LHsExpr RdrName }
1271 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1272 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1273 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1274 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1275 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1277 | '~~$' decdepth exp incdepth { sL (comb2 $3 $>) (HsHetMetEsc placeHolderType placeHolderType $3) }
1279 infixexp :: { LHsExpr RdrName }
1281 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1283 exp10 :: { LHsExpr RdrName }
1284 : '\\' apat apats opt_asig '->' exp
1285 { LL $ HsLam (mkMatchGroup [LL $ Match ($2:$3) $4
1288 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1289 | 'if' exp optSemi 'then' exp optSemi 'else' exp
1290 {% checkDoAndIfThenElse $2 $3 $5 $6 $8 >>
1291 return (LL $ mkHsIf $2 $5 $8) }
1292 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1293 | '-' fexp { LL $ NegApp $2 noSyntaxExpr }
1295 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1296 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1297 return (L loc (mkHsDo DoExpr stmts body)) }
1298 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1299 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1300 return (L loc (mkHsDo MDoExpr
1301 [L loc (mkRecStmt stmts)]
1303 | scc_annot exp { LL $ if opt_SccProfilingOn
1304 then HsSCC (unLoc $1) $2
1306 | hpc_annot exp { LL $ if opt_Hpc
1307 then HsTickPragma (unLoc $1) $2
1310 | 'proc' aexp '->' exp
1311 {% checkPattern $2 >>= \ p ->
1312 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1313 placeHolderType undefined)) }
1314 -- TODO: is LL right here?
1316 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1317 -- hdaume: core annotation
1322 | {- empty -} { False }
1324 scc_annot :: { Located FastString }
1325 : '_scc_' STRING {% (addWarning Opt_WarnWarningsDeprecations (getLoc $1) (text "_scc_ is deprecated; use an SCC pragma instead")) >>= \_ ->
1326 ( do scc <- getSCC $2; return $ LL scc ) }
1327 | '{-# SCC' STRING '#-}' {% do scc <- getSCC $2; return $ LL scc }
1329 hpc_annot :: { Located (FastString,(Int,Int),(Int,Int)) }
1330 : '{-# GENERATED' STRING INTEGER ':' INTEGER '-' INTEGER ':' INTEGER '#-}'
1331 { LL $ (getSTRING $2
1332 ,( fromInteger $ getINTEGER $3
1333 , fromInteger $ getINTEGER $5
1335 ,( fromInteger $ getINTEGER $7
1336 , fromInteger $ getINTEGER $9
1341 fexp :: { LHsExpr RdrName }
1342 : fexp aexp { LL $ HsApp $1 $2 }
1345 aexp :: { LHsExpr RdrName }
1346 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1347 | '~' aexp { LL $ ELazyPat $2 }
1350 aexp1 :: { LHsExpr RdrName }
1351 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4) $3
1355 -- Here was the syntax for type applications that I was planning
1356 -- but there are difficulties (e.g. what order for type args)
1357 -- so it's not enabled yet.
1358 -- But this case *is* used for the left hand side of a generic definition,
1359 -- which is parsed as an expression before being munged into a pattern
1360 | qcname '{|' type '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1361 (sL (getLoc $3) (HsType $3)) }
1363 aexp2 :: { LHsExpr RdrName }
1364 : ipvar { L1 (HsIPVar $! unLoc $1) }
1365 | qcname { L1 (HsVar $! unLoc $1) }
1366 | literal { L1 (HsLit $! unLoc $1) }
1367 -- This will enable overloaded strings permanently. Normally the renamer turns HsString
1368 -- into HsOverLit when -foverloaded-strings is on.
1369 -- | STRING { sL (getLoc $1) (HsOverLit $! mkHsIsString (getSTRING $1) placeHolderType) }
1370 | INTEGER { sL (getLoc $1) (HsOverLit $! mkHsIntegral (getINTEGER $1) placeHolderType) }
1371 | RATIONAL { sL (getLoc $1) (HsOverLit $! mkHsFractional (getRATIONAL $1) placeHolderType) }
1373 -- N.B.: sections get parsed by these next two productions.
1374 -- This allows you to write, e.g., '(+ 3, 4 -)', which isn't
1375 -- correct Haskell (you'd have to write '((+ 3), (4 -))')
1376 -- but the less cluttered version fell out of having texps.
1377 | '(' texp ')' { LL (HsPar $2) }
1378 | '(' tup_exprs ')' { LL (ExplicitTuple $2 Boxed) }
1380 | '(#' texp '#)' { LL (ExplicitTuple [Present $2] Unboxed) }
1381 | '(#' tup_exprs '#)' { LL (ExplicitTuple $2 Unboxed) }
1383 | '[' list ']' { LL (unLoc $2) }
1384 | '[:' parr ':]' { LL (unLoc $2) }
1385 | '_' { L1 EWildPat }
1387 -- Template Haskell Extension
1388 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1389 (L1 $ HsVar (mkUnqual varName
1390 (getTH_ID_SPLICE $1)))) }
1391 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) }
1394 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1395 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1396 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1397 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1398 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1399 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1400 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1401 return (LL $ HsBracket (PatBr p)) }
1402 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBrL $2) }
1403 | quasiquote { L1 (HsQuasiQuoteE (unLoc $1)) }
1405 -- arrow notation extension
1406 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1408 -- code type notation extension
1409 | '<[' incdepth exp decdepth ']>' { sL (comb2 $3 $>) (HsHetMetBrak placeHolderType $3) }
1410 | '~~' decdepth aexp incdepth { sL (comb2 $3 $>) (HsHetMetEsc placeHolderType placeHolderType $3) }
1411 | '%%' decdepth aexp incdepth { sL (comb2 $3 $>) (HsHetMetCSP placeHolderType $3) }
1413 cmdargs :: { [LHsCmdTop RdrName] }
1414 : cmdargs acmd { $2 : $1 }
1415 | {- empty -} { [] }
1417 acmd :: { LHsCmdTop RdrName }
1418 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1420 cvtopbody :: { [LHsDecl RdrName] }
1421 : '{' cvtopdecls0 '}' { $2 }
1422 | vocurly cvtopdecls0 close { $2 }
1424 cvtopdecls0 :: { [LHsDecl RdrName] }
1425 : {- empty -} { [] }
1428 -----------------------------------------------------------------------------
1429 -- Tuple expressions
1431 -- "texp" is short for tuple expressions:
1432 -- things that can appear unparenthesized as long as they're
1433 -- inside parens or delimitted by commas
1434 texp :: { LHsExpr RdrName }
1437 -- Note [Parsing sections]
1438 -- ~~~~~~~~~~~~~~~~~~~~~~~
1439 -- We include left and right sections here, which isn't
1440 -- technically right according to the Haskell standard.
1441 -- For example (3 +, True) isn't legal.
1442 -- However, we want to parse bang patterns like
1444 -- and it's convenient to do so here as a section
1445 -- Then when converting expr to pattern we unravel it again
1446 -- Meanwhile, the renamer checks that real sections appear
1448 | infixexp qop { LL $ SectionL $1 $2 }
1449 | qopm infixexp { LL $ SectionR $1 $2 }
1451 -- View patterns get parenthesized above
1452 | exp '->' texp { LL $ EViewPat $1 $3 }
1454 -- Always at least one comma
1455 tup_exprs :: { [HsTupArg RdrName] }
1456 : texp commas_tup_tail { Present $1 : $2 }
1457 | commas tup_tail { replicate $1 missingTupArg ++ $2 }
1459 -- Always starts with commas; always follows an expr
1460 commas_tup_tail :: { [HsTupArg RdrName] }
1461 commas_tup_tail : commas tup_tail { replicate ($1-1) missingTupArg ++ $2 }
1463 -- Always follows a comma
1464 tup_tail :: { [HsTupArg RdrName] }
1465 : texp commas_tup_tail { Present $1 : $2 }
1466 | texp { [Present $1] }
1467 | {- empty -} { [missingTupArg] }
1469 -----------------------------------------------------------------------------
1472 -- The rules below are little bit contorted to keep lexps left-recursive while
1473 -- avoiding another shift/reduce-conflict.
1475 list :: { LHsExpr RdrName }
1476 : texp { L1 $ ExplicitList placeHolderType [$1] }
1477 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1478 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1479 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1480 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1481 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1482 | texp '|' flattenedpquals { sL (comb2 $1 $>) $ mkHsDo ListComp (unLoc $3) $1 }
1484 lexps :: { Located [LHsExpr RdrName] }
1485 : lexps ',' texp { LL (((:) $! $3) $! unLoc $1) }
1486 | texp ',' texp { LL [$3,$1] }
1488 -----------------------------------------------------------------------------
1489 -- List Comprehensions
1491 flattenedpquals :: { Located [LStmt RdrName] }
1492 : pquals { case (unLoc $1) of
1494 -- We just had one thing in our "parallel" list so
1495 -- we simply return that thing directly
1497 qss -> L1 [L1 $ ParStmt [(qs, undefined) | qs <- qss]]
1498 -- We actually found some actual parallel lists so
1499 -- we wrap them into as a ParStmt
1502 pquals :: { Located [[LStmt RdrName]] }
1503 : squals '|' pquals { L (getLoc $2) (reverse (unLoc $1) : unLoc $3) }
1504 | squals { L (getLoc $1) [reverse (unLoc $1)] }
1506 squals :: { Located [LStmt RdrName] } -- In reverse order, because the last
1507 -- one can "grab" the earlier ones
1508 : squals ',' transformqual { LL [L (getLoc $3) ((unLoc $3) (reverse (unLoc $1)))] }
1509 | squals ',' qual { LL ($3 : unLoc $1) }
1510 | transformqual { LL [L (getLoc $1) ((unLoc $1) [])] }
1512 -- | transformquals1 ',' '{|' pquals '|}' { LL ($4 : unLoc $1) }
1513 -- | '{|' pquals '|}' { L1 [$2] }
1516 -- It is possible to enable bracketing (associating) qualifier lists by uncommenting the lines with {| |}
1517 -- above. Due to a lack of consensus on the syntax, this feature is not being used until we get user
1518 -- demand. Note that the {| |} symbols are reused from -XGenerics and hence if you want to compile
1519 -- a program that makes use of this temporary syntax you must supply that flag to GHC
1521 transformqual :: { Located ([LStmt RdrName] -> Stmt RdrName) }
1522 -- Function is applied to a list of stmts *in order*
1523 : 'then' exp { LL $ \leftStmts -> (mkTransformStmt leftStmts $2) }
1525 | 'then' exp 'by' exp { LL $ \leftStmts -> (mkTransformByStmt leftStmts $2 $4) }
1526 | 'then' 'group' 'by' exp { LL $ \leftStmts -> (mkGroupByStmt leftStmts $4) }
1528 -- These two productions deliberately have a shift-reduce conflict. I have made 'group' into a special_id,
1529 -- which means you can enable TransformListComp while still using Data.List.group. However, this makes the two
1530 -- productions ambiguous. I've set things up so that Happy chooses to resolve the conflict in that case by
1531 -- choosing the "group by" variant, which is what we want.
1533 -- This is rather dubious: the user might be confused as to how to parse this statement. However, it is a good
1534 -- practical choice. NB: Data.List.group :: [a] -> [[a]], so using the first production would not even type check
1535 -- if /that/ is the group function we conflict with.
1536 | 'then' 'group' 'using' exp { LL $ \leftStmts -> (mkGroupUsingStmt leftStmts $4) }
1537 | 'then' 'group' 'by' exp 'using' exp { LL $ \leftStmts -> (mkGroupByUsingStmt leftStmts $4 $6) }
1539 -----------------------------------------------------------------------------
1540 -- Parallel array expressions
1542 -- The rules below are little bit contorted; see the list case for details.
1543 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1544 -- Moreover, we allow explicit arrays with no element (represented by the nil
1545 -- constructor in the list case).
1547 parr :: { LHsExpr RdrName }
1548 : { noLoc (ExplicitPArr placeHolderType []) }
1549 | texp { L1 $ ExplicitPArr placeHolderType [$1] }
1550 | lexps { L1 $ ExplicitPArr placeHolderType
1551 (reverse (unLoc $1)) }
1552 | texp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1553 | texp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1554 | texp '|' flattenedpquals { LL $ mkHsDo PArrComp (unLoc $3) $1 }
1556 -- We are reusing `lexps' and `flattenedpquals' from the list case.
1558 -----------------------------------------------------------------------------
1561 guardquals :: { Located [LStmt RdrName] }
1562 : guardquals1 { L (getLoc $1) (reverse (unLoc $1)) }
1564 guardquals1 :: { Located [LStmt RdrName] }
1565 : guardquals1 ',' qual { LL ($3 : unLoc $1) }
1568 -----------------------------------------------------------------------------
1569 -- Case alternatives
1571 altslist :: { Located [LMatch RdrName] }
1572 : '{' alts '}' { LL (reverse (unLoc $2)) }
1573 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1575 alts :: { Located [LMatch RdrName] }
1576 : alts1 { L1 (unLoc $1) }
1577 | ';' alts { LL (unLoc $2) }
1579 alts1 :: { Located [LMatch RdrName] }
1580 : alts1 ';' alt { LL ($3 : unLoc $1) }
1581 | alts1 ';' { LL (unLoc $1) }
1584 alt :: { LMatch RdrName }
1585 : pat opt_sig alt_rhs { LL (Match [$1] $2 (unLoc $3)) }
1587 alt_rhs :: { Located (GRHSs RdrName) }
1588 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1590 ralt :: { Located [LGRHS RdrName] }
1591 : '->' exp { LL (unguardedRHS $2) }
1592 | gdpats { L1 (reverse (unLoc $1)) }
1594 gdpats :: { Located [LGRHS RdrName] }
1595 : gdpats gdpat { LL ($2 : unLoc $1) }
1598 gdpat :: { LGRHS RdrName }
1599 : '|' guardquals '->' exp { sL (comb2 $1 $>) $ GRHS (unLoc $2) $4 }
1601 -- 'pat' recognises a pattern, including one with a bang at the top
1602 -- e.g. "!x" or "!(x,y)" or "C a b" etc
1603 -- Bangs inside are parsed as infix operator applications, so that
1604 -- we parse them right when bang-patterns are off
1605 pat :: { LPat RdrName }
1606 pat : exp {% checkPattern $1 }
1607 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1609 apat :: { LPat RdrName }
1610 apat : aexp {% checkPattern $1 }
1611 | '!' aexp {% checkPattern (LL (SectionR (L1 (HsVar bang_RDR)) $2)) }
1613 apats :: { [LPat RdrName] }
1614 : apat apats { $1 : $2 }
1615 | {- empty -} { [] }
1617 -----------------------------------------------------------------------------
1618 -- Statement sequences
1620 stmtlist :: { Located [LStmt RdrName] }
1621 : '{' stmts '}' { LL (unLoc $2) }
1622 | vocurly stmts close { $2 }
1624 -- do { ;; s ; s ; ; s ;; }
1625 -- The last Stmt should be an expression, but that's hard to enforce
1626 -- here, because we need too much lookahead if we see do { e ; }
1627 -- So we use ExprStmts throughout, and switch the last one over
1628 -- in ParseUtils.checkDo instead
1629 stmts :: { Located [LStmt RdrName] }
1630 : stmt stmts_help { LL ($1 : unLoc $2) }
1631 | ';' stmts { LL (unLoc $2) }
1632 | {- empty -} { noLoc [] }
1634 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1635 : ';' stmts { LL (unLoc $2) }
1636 | {- empty -} { noLoc [] }
1638 -- For typing stmts at the GHCi prompt, where
1639 -- the input may consist of just comments.
1640 maybe_stmt :: { Maybe (LStmt RdrName) }
1642 | {- nothing -} { Nothing }
1644 stmt :: { LStmt RdrName }
1646 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1648 qual :: { LStmt RdrName }
1649 : pat '<-' exp { LL $ mkBindStmt $1 $3 }
1650 | exp { L1 $ mkExprStmt $1 }
1651 | 'let' binds { LL $ LetStmt (unLoc $2) }
1653 -----------------------------------------------------------------------------
1654 -- Record Field Update/Construction
1656 fbinds :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1658 | {- empty -} { ([], False) }
1660 fbinds1 :: { ([HsRecField RdrName (LHsExpr RdrName)], Bool) }
1661 : fbind ',' fbinds1 { case $3 of (flds, dd) -> ($1 : flds, dd) }
1662 | fbind { ([$1], False) }
1663 | '..' { ([], True) }
1665 fbind :: { HsRecField RdrName (LHsExpr RdrName) }
1666 : qvar '=' exp { HsRecField $1 $3 False }
1667 | qvar { HsRecField $1 placeHolderPunRhs True }
1668 -- In the punning case, use a place-holder
1669 -- The renamer fills in the final value
1671 -----------------------------------------------------------------------------
1672 -- Implicit Parameter Bindings
1674 dbinds :: { Located [LIPBind RdrName] }
1675 : dbinds ';' dbind { let { this = $3; rest = unLoc $1 }
1676 in rest `seq` this `seq` LL (this : rest) }
1677 | dbinds ';' { LL (unLoc $1) }
1678 | dbind { let this = $1 in this `seq` L1 [this] }
1679 -- | {- empty -} { [] }
1681 dbind :: { LIPBind RdrName }
1682 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1684 ipvar :: { Located (IPName RdrName) }
1685 : IPDUPVARID { L1 (IPName (mkUnqual varName (getIPDUPVARID $1))) }
1687 -----------------------------------------------------------------------------
1688 -- Warnings and deprecations
1690 namelist :: { Located [RdrName] }
1691 namelist : name_var { L1 [unLoc $1] }
1692 | name_var ',' namelist { LL (unLoc $1 : unLoc $3) }
1694 name_var :: { Located RdrName }
1695 name_var : var { $1 }
1698 -----------------------------------------
1699 -- Data constructors
1700 qcon :: { Located RdrName }
1702 | '(' qconsym ')' { LL (unLoc $2) }
1703 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1704 -- The case of '[:' ':]' is part of the production `parr'
1706 con :: { Located RdrName }
1708 | '(' consym ')' { LL (unLoc $2) }
1709 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1711 con_list :: { Located [Located RdrName] }
1712 con_list : con { L1 [$1] }
1713 | con ',' con_list { LL ($1 : unLoc $3) }
1715 sysdcon :: { Located DataCon } -- Wired in data constructors
1716 : '(' ')' { LL unitDataCon }
1717 | '(' commas ')' { LL $ tupleCon Boxed ($2 + 1) }
1718 | '(#' '#)' { LL $ unboxedSingletonDataCon }
1719 | '(#' commas '#)' { LL $ tupleCon Unboxed ($2 + 1) }
1720 | '[' ']' { LL nilDataCon }
1722 conop :: { Located RdrName }
1724 | '`' conid '`' { LL (unLoc $2) }
1726 qconop :: { Located RdrName }
1728 | '`' qconid '`' { LL (unLoc $2) }
1730 -----------------------------------------------------------------------------
1731 -- Type constructors
1733 gtycon :: { Located RdrName } -- A "general" qualified tycon
1735 | '(' ')' { LL $ getRdrName unitTyCon }
1736 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed ($2 + 1)) }
1737 | '(#' '#)' { LL $ getRdrName unboxedSingletonTyCon }
1738 | '(#' commas '#)' { LL $ getRdrName (tupleTyCon Unboxed ($2 + 1)) }
1739 | '(' '->' ')' { LL $ getRdrName funTyCon }
1740 | '[' ']' { LL $ listTyCon_RDR }
1741 | '[:' ':]' { LL $ parrTyCon_RDR }
1743 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1745 | '(' qtyconsym ')' { LL (unLoc $2) }
1747 qtyconop :: { Located RdrName } -- Qualified or unqualified
1749 | '`' qtycon '`' { LL (unLoc $2) }
1751 qtycon :: { Located RdrName } -- Qualified or unqualified
1752 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1753 | PREFIXQCONSYM { L1 $! mkQual tcClsName (getPREFIXQCONSYM $1) }
1756 tycon :: { Located RdrName } -- Unqualified
1757 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1759 qtyconsym :: { Located RdrName }
1760 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1763 tyconsym :: { Located RdrName }
1764 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1766 -----------------------------------------------------------------------------
1769 op :: { Located RdrName } -- used in infix decls
1773 varop :: { Located RdrName }
1775 | '`' varid '`' { LL (unLoc $2) }
1777 qop :: { LHsExpr RdrName } -- used in sections
1778 : qvarop { L1 $ HsVar (unLoc $1) }
1779 | qconop { L1 $ HsVar (unLoc $1) }
1781 qopm :: { LHsExpr RdrName } -- used in sections
1782 : qvaropm { L1 $ HsVar (unLoc $1) }
1783 | qconop { L1 $ HsVar (unLoc $1) }
1785 qvarop :: { Located RdrName }
1787 | '`' qvarid '`' { LL (unLoc $2) }
1789 qvaropm :: { Located RdrName }
1790 : qvarsym_no_minus { $1 }
1791 | '`' qvarid '`' { LL (unLoc $2) }
1793 -----------------------------------------------------------------------------
1796 tyvar :: { Located RdrName }
1797 tyvar : tyvarid { $1 }
1798 | '(' tyvarsym ')' { LL (unLoc $2) }
1800 tyvarop :: { Located RdrName }
1801 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1803 | '.' {% parseErrorSDoc (getLoc $1)
1804 (vcat [ptext (sLit "Illegal symbol '.' in type"),
1805 ptext (sLit "Perhaps you intended -XRankNTypes or similar flag"),
1806 ptext (sLit "to enable explicit-forall syntax: forall <tvs>. <type>")])
1809 tyvarid :: { Located RdrName }
1810 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1811 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1812 | 'unsafe' { L1 $! mkUnqual tvName (fsLit "unsafe") }
1813 | 'safe' { L1 $! mkUnqual tvName (fsLit "safe") }
1814 | 'interruptible' { L1 $! mkUnqual tvName (fsLit "interruptible") }
1815 | 'threadsafe' { L1 $! mkUnqual tvName (fsLit "threadsafe") }
1817 tyvarsym :: { Located RdrName }
1818 -- Does not include "!", because that is used for strictness marks
1819 -- or ".", because that separates the quantified type vars from the rest
1820 -- or "*", because that's used for kinds
1821 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1823 -----------------------------------------------------------------------------
1826 var :: { Located RdrName }
1828 | '(' varsym ')' { LL (unLoc $2) }
1830 qvar :: { Located RdrName }
1832 | '(' varsym ')' { LL (unLoc $2) }
1833 | '(' qvarsym1 ')' { LL (unLoc $2) }
1834 -- We've inlined qvarsym here so that the decision about
1835 -- whether it's a qvar or a var can be postponed until
1836 -- *after* we see the close paren.
1838 qvarid :: { Located RdrName }
1840 | QVARID { L1 $! mkQual varName (getQVARID $1) }
1841 | PREFIXQVARSYM { L1 $! mkQual varName (getPREFIXQVARSYM $1) }
1843 varid :: { Located RdrName }
1844 : VARID {% do { depth <- getParserBrakDepth ; return (L1 $! mkUnqual (varNameDepth depth) (getVARID $1)) } }
1845 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1846 | 'unsafe' { L1 $! mkUnqual varName (fsLit "unsafe") }
1847 | 'safe' { L1 $! mkUnqual varName (fsLit "safe") }
1848 | 'interruptible' { L1 $! mkUnqual varName (fsLit "interruptible") }
1849 | 'threadsafe' { L1 $! mkUnqual varName (fsLit "threadsafe") }
1850 | 'forall' { L1 $! mkUnqual varName (fsLit "forall") }
1851 | 'family' { L1 $! mkUnqual varName (fsLit "family") }
1853 qvarsym :: { Located RdrName }
1857 qvarsym_no_minus :: { Located RdrName }
1858 : varsym_no_minus { $1 }
1861 qvarsym1 :: { Located RdrName }
1862 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1864 varsym :: { Located RdrName }
1865 : varsym_no_minus { $1 }
1866 | '-' { L1 $ mkUnqual varName (fsLit "-") }
1868 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1869 : VARSYM {% do { depth <- getParserBrakDepth
1870 ; return (L1 $! mkUnqual (varNameDepth depth) (getVARSYM $1)) } }
1871 | special_sym {% do { depth <- getParserBrakDepth
1872 ; return (L1 $! mkUnqual (varNameDepth depth) (unLoc $1)) } }
1874 -- These special_ids are treated as keywords in various places,
1875 -- but as ordinary ids elsewhere. 'special_id' collects all these
1876 -- except 'unsafe', 'interruptible', 'forall', and 'family' whose treatment differs
1877 -- depending on context
1878 special_id :: { Located FastString }
1880 : 'as' { L1 (fsLit "as") }
1881 | 'qualified' { L1 (fsLit "qualified") }
1882 | 'hiding' { L1 (fsLit "hiding") }
1883 | 'export' { L1 (fsLit "export") }
1884 | 'label' { L1 (fsLit "label") }
1885 | 'dynamic' { L1 (fsLit "dynamic") }
1886 | 'stdcall' { L1 (fsLit "stdcall") }
1887 | 'ccall' { L1 (fsLit "ccall") }
1888 | 'prim' { L1 (fsLit "prim") }
1889 | 'group' { L1 (fsLit "group") }
1891 special_sym :: { Located FastString }
1892 special_sym : '!' { L1 (fsLit "!") }
1893 | '.' { L1 (fsLit ".") }
1894 | '*' { L1 (fsLit "*") }
1896 -----------------------------------------------------------------------------
1897 -- Data constructors
1899 qconid :: { Located RdrName } -- Qualified or unqualified
1901 | QCONID { L1 $! mkQual dataName (getQCONID $1) }
1902 | PREFIXQCONSYM { L1 $! mkQual dataName (getPREFIXQCONSYM $1) }
1904 conid :: { Located RdrName }
1905 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1907 qconsym :: { Located RdrName } -- Qualified or unqualified
1909 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1911 consym :: { Located RdrName }
1912 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1914 -- ':' means only list cons
1915 | ':' { L1 $ consDataCon_RDR }
1918 -----------------------------------------------------------------------------
1921 literal :: { Located HsLit }
1922 : CHAR { L1 $ HsChar $ getCHAR $1 }
1923 | STRING { L1 $ HsString $ getSTRING $1 }
1924 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1925 | PRIMWORD { L1 $ HsWordPrim $ getPRIMWORD $1 }
1926 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1927 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1928 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1929 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1931 -----------------------------------------------------------------------------
1935 : vccurly { () } -- context popped in lexer.
1936 | error {% popContext }
1938 -----------------------------------------------------------------------------
1939 -- Miscellaneous (mostly renamings)
1941 modid :: { Located ModuleName }
1942 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1943 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1946 (unpackFS mod ++ '.':unpackFS c))
1950 : commas ',' { $1 + 1 }
1953 -----------------------------------------------------------------------------
1954 -- Documentation comments
1956 docnext :: { LHsDocString }
1957 : DOCNEXT {% return (L1 (HsDocString (mkFastString (getDOCNEXT $1)))) }
1959 docprev :: { LHsDocString }
1960 : DOCPREV {% return (L1 (HsDocString (mkFastString (getDOCPREV $1)))) }
1962 docnamed :: { Located (String, HsDocString) }
1964 let string = getDOCNAMED $1
1965 (name, rest) = break isSpace string
1966 in return (L1 (name, HsDocString (mkFastString rest))) }
1968 docsection :: { Located (Int, HsDocString) }
1969 : DOCSECTION {% let (n, doc) = getDOCSECTION $1 in
1970 return (L1 (n, HsDocString (mkFastString doc))) }
1972 moduleheader :: { Maybe LHsDocString }
1973 : DOCNEXT {% let string = getDOCNEXT $1 in
1974 return (Just (L1 (HsDocString (mkFastString string)))) }
1976 maybe_docprev :: { Maybe LHsDocString }
1977 : docprev { Just $1 }
1978 | {- empty -} { Nothing }
1980 maybe_docnext :: { Maybe LHsDocString }
1981 : docnext { Just $1 }
1982 | {- empty -} { Nothing }
1986 happyError = srcParseFail
1988 getVARID (L _ (ITvarid x)) = x
1989 getCONID (L _ (ITconid x)) = x
1990 getVARSYM (L _ (ITvarsym x)) = x
1991 getCONSYM (L _ (ITconsym x)) = x
1992 getQVARID (L _ (ITqvarid x)) = x
1993 getQCONID (L _ (ITqconid x)) = x
1994 getQVARSYM (L _ (ITqvarsym x)) = x
1995 getQCONSYM (L _ (ITqconsym x)) = x
1996 getPREFIXQVARSYM (L _ (ITprefixqvarsym x)) = x
1997 getPREFIXQCONSYM (L _ (ITprefixqconsym x)) = x
1998 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1999 getCHAR (L _ (ITchar x)) = x
2000 getSTRING (L _ (ITstring x)) = x
2001 getINTEGER (L _ (ITinteger x)) = x
2002 getRATIONAL (L _ (ITrational x)) = x
2003 getPRIMCHAR (L _ (ITprimchar x)) = x
2004 getPRIMSTRING (L _ (ITprimstring x)) = x
2005 getPRIMINTEGER (L _ (ITprimint x)) = x
2006 getPRIMWORD (L _ (ITprimword x)) = x
2007 getPRIMFLOAT (L _ (ITprimfloat x)) = x
2008 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
2009 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
2010 getINLINE (L _ (ITinline_prag inl conl)) = (inl,conl)
2011 getSPEC_INLINE (L _ (ITspec_inline_prag True)) = (Inline, FunLike)
2012 getSPEC_INLINE (L _ (ITspec_inline_prag False)) = (NoInline,FunLike)
2014 getDOCNEXT (L _ (ITdocCommentNext x)) = x
2015 getDOCPREV (L _ (ITdocCommentPrev x)) = x
2016 getDOCNAMED (L _ (ITdocCommentNamed x)) = x
2017 getDOCSECTION (L _ (ITdocSection n x)) = (n, x)
2019 getSCC :: Located Token -> P FastString
2020 getSCC lt = do let s = getSTRING lt
2021 err = "Spaces are not allowed in SCCs"
2022 -- We probably actually want to be more restrictive than this
2023 if ' ' `elem` unpackFS s
2024 then failSpanMsgP (getLoc lt) (text err)
2027 -- Utilities for combining source spans
2028 comb2 :: Located a -> Located b -> SrcSpan
2029 comb2 a b = a `seq` b `seq` combineLocs a b
2031 comb3 :: Located a -> Located b -> Located c -> SrcSpan
2032 comb3 a b c = a `seq` b `seq` c `seq`
2033 combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
2035 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
2036 comb4 a b c d = a `seq` b `seq` c `seq` d `seq`
2037 (combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
2038 combineSrcSpans (getLoc c) (getLoc d))
2040 -- strict constructor version:
2042 sL :: SrcSpan -> a -> Located a
2043 sL span a = span `seq` a `seq` L span a
2045 -- Make a source location for the file. We're a bit lazy here and just
2046 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
2047 -- try to find the span of the whole file (ToDo).
2048 fileSrcSpan :: P SrcSpan
2051 let loc = mkSrcLoc (srcLocFile l) 1 1;
2052 return (mkSrcSpan loc loc)