2 -- ---------------------------------------------------------------------------
3 -- (c) The University of Glasgow 1997-2003
7 -- Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999
8 -- ---------------------------------------------------------------------------
11 module Parser ( parseModule, parseStmt, parseIdentifier, parseType,
14 #define INCLUDE #include
15 INCLUDE "HsVersions.h"
19 import HscTypes ( IsBootInterface, DeprecTxt )
22 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
23 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
24 import Type ( funTyCon )
25 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
26 CCallConv(..), CCallTarget(..), defaultCCallConv
28 import OccName ( varName, dataName, tcClsName, tvName )
29 import DataCon ( DataCon, dataConName )
30 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
31 SrcSpan, combineLocs, srcLocFile,
34 import StaticFlags ( opt_SccProfilingOn )
35 import Type ( Kind, mkArrowKind, liftedTypeKind, unliftedTypeKind )
36 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
37 Activation(..), defaultInlineSpec )
41 import Maybes ( orElse )
47 -----------------------------------------------------------------------------
50 Conflicts: 37 shift/reduce
53 The reduce/reduce conflict is weird. It's between tyconsym and consym, and I
54 would think the two should never occur in the same context.
58 -----------------------------------------------------------------------------
59 Conflicts: 36 shift/reduce (1.25)
61 10 for abiguity in 'if x then y else z + 1' [State 178]
62 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
63 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
65 1 for ambiguity in 'if x then y else z :: T' [State 178]
66 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
68 4 for ambiguity in 'if x then y else z -< e' [State 178]
69 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
70 There are four such operators: -<, >-, -<<, >>-
73 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
74 Which of these two is intended?
76 (x::T) -> T -- Rhs is T
79 (x::T -> T) -> .. -- Rhs is ...
81 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
84 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
85 Same duplication between states 11 and 253 as the previous case
87 1 for ambiguity in 'let ?x ...' [State 329]
88 the parser can't tell whether the ?x is the lhs of a normal binding or
89 an implicit binding. Fortunately resolving as shift gives it the only
90 sensible meaning, namely the lhs of an implicit binding.
92 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
93 we don't know whether the '[' starts the activation or not: it
94 might be the start of the declaration with the activation being
97 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
98 since 'forall' is a valid variable name, we don't know whether
99 to treat a forall on the input as the beginning of a quantifier
100 or the beginning of the rule itself. Resolving to shift means
101 it's always treated as a quantifier, hence the above is disallowed.
102 This saves explicitly defining a grammar for the rule lhs that
103 doesn't include 'forall'.
105 -- ---------------------------------------------------------------------------
106 -- Adding location info
108 This is done in a stylised way using the three macros below, L0, L1
109 and LL. Each of these macros can be thought of as having type
111 L0, L1, LL :: a -> Located a
113 They each add a SrcSpan to their argument.
115 L0 adds 'noSrcSpan', used for empty productions
116 -- This doesn't seem to work anymore -=chak
118 L1 for a production with a single token on the lhs. Grabs the SrcSpan
121 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
122 the first and last tokens.
124 These suffice for the majority of cases. However, we must be
125 especially careful with empty productions: LL won't work if the first
126 or last token on the lhs can represent an empty span. In these cases,
127 we have to calculate the span using more of the tokens from the lhs, eg.
129 | 'newtype' tycl_hdr '=' newconstr deriving
131 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
133 We provide comb3 and comb4 functions which are useful in such cases.
135 Be careful: there's no checking that you actually got this right, the
136 only symptom will be that the SrcSpans of your syntax will be
140 * We must expand these macros *before* running Happy, which is why this file is
141 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
143 #define L0 L noSrcSpan
144 #define L1 sL (getLoc $1)
145 #define LL sL (comb2 $1 $>)
147 -- -----------------------------------------------------------------------------
152 '_' { L _ ITunderscore } -- Haskell keywords
154 'case' { L _ ITcase }
155 'class' { L _ ITclass }
156 'data' { L _ ITdata }
157 'default' { L _ ITdefault }
158 'deriving' { L _ ITderiving }
160 'else' { L _ ITelse }
161 'hiding' { L _ IThiding }
163 'import' { L _ ITimport }
165 'infix' { L _ ITinfix }
166 'infixl' { L _ ITinfixl }
167 'infixr' { L _ ITinfixr }
168 'instance' { L _ ITinstance }
170 'module' { L _ ITmodule }
171 'newtype' { L _ ITnewtype }
173 'qualified' { L _ ITqualified }
174 'then' { L _ ITthen }
175 'type' { L _ ITtype }
176 'where' { L _ ITwhere }
177 '_scc_' { L _ ITscc } -- ToDo: remove
179 'forall' { L _ ITforall } -- GHC extension keywords
180 'foreign' { L _ ITforeign }
181 'export' { L _ ITexport }
182 'label' { L _ ITlabel }
183 'dynamic' { L _ ITdynamic }
184 'safe' { L _ ITsafe }
185 'threadsafe' { L _ ITthreadsafe }
186 'unsafe' { L _ ITunsafe }
189 'stdcall' { L _ ITstdcallconv }
190 'ccall' { L _ ITccallconv }
191 'dotnet' { L _ ITdotnet }
192 'proc' { L _ ITproc } -- for arrow notation extension
193 'rec' { L _ ITrec } -- for arrow notation extension
195 '{-# INLINE' { L _ (ITinline_prag _) }
196 '{-# SPECIALISE' { L _ ITspec_prag }
197 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
198 '{-# SOURCE' { L _ ITsource_prag }
199 '{-# RULES' { L _ ITrules_prag }
200 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
201 '{-# SCC' { L _ ITscc_prag }
202 '{-# DEPRECATED' { L _ ITdeprecated_prag }
203 '{-# UNPACK' { L _ ITunpack_prag }
204 '#-}' { L _ ITclose_prag }
206 '..' { L _ ITdotdot } -- reserved symbols
208 '::' { L _ ITdcolon }
212 '<-' { L _ ITlarrow }
213 '->' { L _ ITrarrow }
216 '=>' { L _ ITdarrow }
220 '-<' { L _ ITlarrowtail } -- for arrow notation
221 '>-' { L _ ITrarrowtail } -- for arrow notation
222 '-<<' { L _ ITLarrowtail } -- for arrow notation
223 '>>-' { L _ ITRarrowtail } -- for arrow notation
226 '{' { L _ ITocurly } -- special symbols
228 '{|' { L _ ITocurlybar }
229 '|}' { L _ ITccurlybar }
230 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
231 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
234 '[:' { L _ ITopabrack }
235 ':]' { L _ ITcpabrack }
238 '(#' { L _ IToubxparen }
239 '#)' { L _ ITcubxparen }
240 '(|' { L _ IToparenbar }
241 '|)' { L _ ITcparenbar }
244 '`' { L _ ITbackquote }
246 VARID { L _ (ITvarid _) } -- identifiers
247 CONID { L _ (ITconid _) }
248 VARSYM { L _ (ITvarsym _) }
249 CONSYM { L _ (ITconsym _) }
250 QVARID { L _ (ITqvarid _) }
251 QCONID { L _ (ITqconid _) }
252 QVARSYM { L _ (ITqvarsym _) }
253 QCONSYM { L _ (ITqconsym _) }
255 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
256 IPSPLITVARID { L _ (ITsplitipvarid _) } -- GHC extension
258 CHAR { L _ (ITchar _) }
259 STRING { L _ (ITstring _) }
260 INTEGER { L _ (ITinteger _) }
261 RATIONAL { L _ (ITrational _) }
263 PRIMCHAR { L _ (ITprimchar _) }
264 PRIMSTRING { L _ (ITprimstring _) }
265 PRIMINTEGER { L _ (ITprimint _) }
266 PRIMFLOAT { L _ (ITprimfloat _) }
267 PRIMDOUBLE { L _ (ITprimdouble _) }
270 '[|' { L _ ITopenExpQuote }
271 '[p|' { L _ ITopenPatQuote }
272 '[t|' { L _ ITopenTypQuote }
273 '[d|' { L _ ITopenDecQuote }
274 '|]' { L _ ITcloseQuote }
275 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
276 '$(' { L _ ITparenEscape } -- $( exp )
277 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
278 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
280 %monad { P } { >>= } { return }
281 %lexer { lexer } { L _ ITeof }
282 %name parseModule module
283 %name parseStmt maybe_stmt
284 %name parseIdentifier identifier
285 %name parseType ctype
286 %partial parseHeader header
287 %tokentype { (Located Token) }
290 -----------------------------------------------------------------------------
291 -- Identifiers; one of the entry points
292 identifier :: { Located RdrName }
298 -----------------------------------------------------------------------------
301 -- The place for module deprecation is really too restrictive, but if it
302 -- was allowed at its natural place just before 'module', we get an ugly
303 -- s/r conflict with the second alternative. Another solution would be the
304 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
305 -- either, and DEPRECATED is only expected to be used by people who really
306 -- know what they are doing. :-)
308 module :: { Located (HsModule RdrName) }
309 : 'module' modid maybemoddeprec maybeexports 'where' body
310 {% fileSrcSpan >>= \ loc ->
311 return (L loc (HsModule (Just $2) $4 (fst $6) (snd $6) $3)) }
312 | missing_module_keyword top close
313 {% fileSrcSpan >>= \ loc ->
314 return (L loc (HsModule Nothing Nothing
315 (fst $2) (snd $2) Nothing)) }
317 missing_module_keyword :: { () }
318 : {- empty -} {% pushCurrentContext }
320 maybemoddeprec :: { Maybe DeprecTxt }
321 : '{-# DEPRECATED' STRING '#-}' { Just (getSTRING $2) }
322 | {- empty -} { Nothing }
324 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
326 | vocurly top close { $2 }
328 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
329 : importdecls { (reverse $1,[]) }
330 | importdecls ';' cvtopdecls { (reverse $1,$3) }
331 | cvtopdecls { ([],$1) }
333 cvtopdecls :: { [LHsDecl RdrName] }
334 : topdecls { cvTopDecls $1 }
336 -----------------------------------------------------------------------------
337 -- Module declaration & imports only
339 header :: { Located (HsModule RdrName) }
340 : 'module' modid maybemoddeprec maybeexports 'where' header_body
341 {% fileSrcSpan >>= \ loc ->
342 return (L loc (HsModule (Just $2) $4 $6 [] $3)) }
343 | missing_module_keyword importdecls
344 {% fileSrcSpan >>= \ loc ->
345 return (L loc (HsModule Nothing Nothing $2 [] Nothing)) }
347 header_body :: { [LImportDecl RdrName] }
348 : '{' importdecls { $2 }
349 | vocurly importdecls { $2 }
351 -----------------------------------------------------------------------------
354 maybeexports :: { Maybe [LIE RdrName] }
355 : '(' exportlist ')' { Just $2 }
356 | {- empty -} { Nothing }
358 exportlist :: { [LIE RdrName] }
362 exportlist1 :: { [LIE RdrName] }
364 | export ',' exportlist { $1 : $3 }
367 -- No longer allow things like [] and (,,,) to be exported
368 -- They are built in syntax, always available
369 export :: { LIE RdrName }
370 : qvar { L1 (IEVar (unLoc $1)) }
371 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
372 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
373 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
374 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
375 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
377 qcnames :: { [RdrName] }
378 : qcnames ',' qcname { unLoc $3 : $1 }
379 | qcname { [unLoc $1] }
381 qcname :: { Located RdrName } -- Variable or data constructor
385 -----------------------------------------------------------------------------
386 -- Import Declarations
388 -- import decls can be *empty*, or even just a string of semicolons
389 -- whereas topdecls must contain at least one topdecl.
391 importdecls :: { [LImportDecl RdrName] }
392 : importdecls ';' importdecl { $3 : $1 }
393 | importdecls ';' { $1 }
394 | importdecl { [ $1 ] }
397 importdecl :: { LImportDecl RdrName }
398 : 'import' maybe_src optqualified modid maybeas maybeimpspec
399 { L (comb4 $1 $4 $5 $6) (ImportDecl $4 $2 $3 (unLoc $5) (unLoc $6)) }
401 maybe_src :: { IsBootInterface }
402 : '{-# SOURCE' '#-}' { True }
403 | {- empty -} { False }
405 optqualified :: { Bool }
406 : 'qualified' { True }
407 | {- empty -} { False }
409 maybeas :: { Located (Maybe ModuleName) }
410 : 'as' modid { LL (Just (unLoc $2)) }
411 | {- empty -} { noLoc Nothing }
413 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
414 : impspec { L1 (Just (unLoc $1)) }
415 | {- empty -} { noLoc Nothing }
417 impspec :: { Located (Bool, [LIE RdrName]) }
418 : '(' exportlist ')' { LL (False, $2) }
419 | 'hiding' '(' exportlist ')' { LL (True, $3) }
421 -----------------------------------------------------------------------------
422 -- Fixity Declarations
426 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
428 infix :: { Located FixityDirection }
429 : 'infix' { L1 InfixN }
430 | 'infixl' { L1 InfixL }
431 | 'infixr' { L1 InfixR }
433 ops :: { Located [Located RdrName] }
434 : ops ',' op { LL ($3 : unLoc $1) }
437 -----------------------------------------------------------------------------
438 -- Top-Level Declarations
440 topdecls :: { OrdList (LHsDecl RdrName) }
441 : topdecls ';' topdecl { $1 `appOL` $3 }
442 | topdecls ';' { $1 }
445 topdecl :: { OrdList (LHsDecl RdrName) }
446 : cl_decl { unitOL (L1 (TyClD (unLoc $1))) }
447 | ty_decl {% checkTopTypeD $1 >>=
449 | 'instance' inst_type where
450 { let (binds, sigs, ats) = cvBindsAndSigs (unLoc $3)
451 in unitOL (L (comb3 $1 $2 $3)
452 (InstD (InstDecl $2 binds sigs ats))) }
453 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
454 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
455 | '{-# DEPRECATED' deprecations '#-}' { $2 }
456 | '{-# RULES' rules '#-}' { $2 }
459 -- Template Haskell Extension
460 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
461 | TH_ID_SPLICE { unitOL (LL $ SpliceD (SpliceDecl $
462 L1 $ HsVar (mkUnqual varName (getTH_ID_SPLICE $1))
467 cl_decl :: { LTyClDecl RdrName }
468 : 'class' tycl_hdr fds where
469 {% do { let { (binds, sigs, ats) =
470 cvBindsAndSigs (unLoc $4)
471 ; (ctxt, tc, tvs, tparms) = unLoc $2}
472 ; checkTyVars tparms False -- only type vars allowed
474 ; return $ L (comb4 $1 $2 $3 $4)
475 (mkClassDecl (ctxt, tc, tvs)
476 (unLoc $3) sigs binds ats) } }
480 ty_decl :: { LTyClDecl RdrName }
481 -- type function signature and equations (w/ type synonyms as special
482 -- case); we need to handle all this in one rule to avoid a large
483 -- number of shift/reduce conflicts
484 : 'type' opt_iso type kind_or_ctype
486 -- Note the use of type for the head; this allows
487 -- infix type constructors to be declared and type
488 -- patterns for type function equations
490 -- We have that `typats :: Maybe [LHsType name]' is `Nothing'
491 -- (in the second case alternative) when all arguments are
492 -- variables (and we thus have a vanilla type synonym
493 -- declaration); otherwise, it contains all arguments as type
498 do { (tc, tvs, _) <- checkSynHdr $3 False
499 ; return (L (comb3 $1 $3 kind)
500 (TyFunction tc tvs $2 (unLoc kind)))
503 do { (tc, tvs, typats) <- checkSynHdr $3 True
504 ; return (L (comb2 $1 ty)
505 (TySynonym tc tvs typats ty)) }
506 Right ty | otherwise ->
507 parseError (comb2 $1 ty)
508 "iso tag is only allowed in kind signatures"
511 -- kind signature of indexed type
512 | data_or_newtype tycl_hdr '::' kind
513 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
514 ; checkTyVars tparms False -- no type pattern
517 (mkTyData (unLoc $1) (ctxt, tc, tvs, Nothing)
518 (Just (unLoc $4)) [] Nothing) } }
520 -- data type or newtype declaration
521 | data_or_newtype tycl_hdr constrs deriving
522 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
523 ; tpats <- checkTyVars tparms True -- can have type pats
525 L (comb4 $1 $2 $3 $4)
526 -- We need the location on tycl_hdr in case
527 -- constrs and deriving are both empty
528 (mkTyData (unLoc $1) (ctxt, tc, tvs, tpats)
529 Nothing (reverse (unLoc $3)) (unLoc $4)) } }
532 | data_or_newtype tycl_hdr opt_kind_sig
533 'where' gadt_constrlist
535 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
536 ; tpats <- checkTyVars tparms True -- can have type pats
538 L (comb4 $1 $2 $4 $5)
539 (mkTyData (unLoc $1) (ctxt, tc, tvs, tpats) $3
540 (reverse (unLoc $5)) (unLoc $6)) } }
546 kind_or_ctype :: { Either (Located Kind) (LHsType RdrName) }
547 : '::' kind { Left (LL (unLoc $2)) }
548 | '=' ctype { Right (LL (unLoc $2)) }
549 -- Note ctype, not sigtype, on the right of '='
550 -- We allow an explicit for-all but we don't insert one
551 -- in type Foo a = (b,b)
552 -- Instead we just say b is out of scope
554 data_or_newtype :: { Located NewOrData }
555 : 'data' { L1 DataType }
556 | 'newtype' { L1 NewType }
558 opt_kind_sig :: { Maybe Kind }
560 | '::' kind { Just (unLoc $2) }
562 -- tycl_hdr parses the header of a class or data type decl,
563 -- which takes the form
566 -- (Eq a, Ord b) => T a b
567 -- T Int [a] -- for associated types
568 -- Rather a lot of inlining here, else we get reduce/reduce errors
569 tycl_hdr :: { Located (LHsContext RdrName,
571 [LHsTyVarBndr RdrName],
573 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
574 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
576 -----------------------------------------------------------------------------
577 -- Nested declarations
579 -- Type declaration or value declaration
581 tydecl :: { Located (OrdList (LHsDecl RdrName)) }
582 tydecl : ty_decl { LL (unitOL (L1 (TyClD (unLoc $1)))) }
585 tydecls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
586 : tydecls ';' tydecl { LL (unLoc $1 `appOL` unLoc $3) }
587 | tydecls ';' { LL (unLoc $1) }
589 | {- empty -} { noLoc nilOL }
593 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
594 : '{' tydecls '}' { LL (unLoc $2) }
595 | vocurly tydecls close { $2 }
597 -- Form of the body of class and instance declarations
599 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
600 -- No implicit parameters
601 -- May have type declarations
602 : 'where' tydecllist { LL (unLoc $2) }
603 | {- empty -} { noLoc nilOL }
605 decls :: { Located (OrdList (LHsDecl RdrName)) }
606 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
607 | decls ';' { LL (unLoc $1) }
609 | {- empty -} { noLoc nilOL }
612 decllist :: { Located (OrdList (LHsDecl RdrName)) }
613 : '{' decls '}' { LL (unLoc $2) }
614 | vocurly decls close { $2 }
616 -- Binding groups other than those of class and instance declarations
618 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
619 -- No type declarations
620 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
621 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
622 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
624 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
625 -- No type declarations
626 : 'where' binds { LL (unLoc $2) }
627 | {- empty -} { noLoc emptyLocalBinds }
630 -----------------------------------------------------------------------------
631 -- Transformation Rules
633 rules :: { OrdList (LHsDecl RdrName) }
634 : rules ';' rule { $1 `snocOL` $3 }
637 | {- empty -} { nilOL }
639 rule :: { LHsDecl RdrName }
640 : STRING activation rule_forall infixexp '=' exp
641 { LL $ RuleD (HsRule (getSTRING $1)
642 ($2 `orElse` AlwaysActive)
643 $3 $4 placeHolderNames $6 placeHolderNames) }
645 activation :: { Maybe Activation }
646 : {- empty -} { Nothing }
647 | explicit_activation { Just $1 }
649 explicit_activation :: { Activation } -- In brackets
650 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
651 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
653 rule_forall :: { [RuleBndr RdrName] }
654 : 'forall' rule_var_list '.' { $2 }
657 rule_var_list :: { [RuleBndr RdrName] }
659 | rule_var rule_var_list { $1 : $2 }
661 rule_var :: { RuleBndr RdrName }
662 : varid { RuleBndr $1 }
663 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
665 -----------------------------------------------------------------------------
666 -- Deprecations (c.f. rules)
668 deprecations :: { OrdList (LHsDecl RdrName) }
669 : deprecations ';' deprecation { $1 `appOL` $3 }
670 | deprecations ';' { $1 }
672 | {- empty -} { nilOL }
674 -- SUP: TEMPORARY HACK, not checking for `module Foo'
675 deprecation :: { OrdList (LHsDecl RdrName) }
677 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
681 -----------------------------------------------------------------------------
682 -- Foreign import and export declarations
684 fdecl :: { LHsDecl RdrName }
685 fdecl : 'import' callconv safety fspec
686 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
687 | 'import' callconv fspec
688 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
690 | 'export' callconv fspec
691 {% mkExport $2 (unLoc $3) >>= return.LL }
693 callconv :: { CallConv }
694 : 'stdcall' { CCall StdCallConv }
695 | 'ccall' { CCall CCallConv }
696 | 'dotnet' { DNCall }
699 : 'unsafe' { PlayRisky }
700 | 'safe' { PlaySafe False }
701 | 'threadsafe' { PlaySafe True }
703 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
704 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
705 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
706 -- if the entity string is missing, it defaults to the empty string;
707 -- the meaning of an empty entity string depends on the calling
710 -----------------------------------------------------------------------------
713 opt_sig :: { Maybe (LHsType RdrName) }
714 : {- empty -} { Nothing }
715 | '::' sigtype { Just $2 }
717 opt_asig :: { Maybe (LHsType RdrName) }
718 : {- empty -} { Nothing }
719 | '::' atype { Just $2 }
721 sigtypes1 :: { [LHsType RdrName] }
723 | sigtype ',' sigtypes1 { $1 : $3 }
725 sigtype :: { LHsType RdrName }
726 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
727 -- Wrap an Implicit forall if there isn't one there already
729 sig_vars :: { Located [Located RdrName] }
730 : sig_vars ',' var { LL ($3 : unLoc $1) }
733 -----------------------------------------------------------------------------
736 strict_mark :: { Located HsBang }
737 : '!' { L1 HsStrict }
738 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
740 -- A ctype is a for-all type
741 ctype :: { LHsType RdrName }
742 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
743 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
744 -- A type of form (context => type) is an *implicit* HsForAllTy
747 -- We parse a context as a btype so that we don't get reduce/reduce
748 -- errors in ctype. The basic problem is that
750 -- looks so much like a tuple type. We can't tell until we find the =>
751 context :: { LHsContext RdrName }
752 : btype {% checkContext $1 }
754 type :: { LHsType RdrName }
755 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
758 gentype :: { LHsType RdrName }
760 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
761 | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 }
762 | btype '->' ctype { LL $ HsFunTy $1 $3 }
764 btype :: { LHsType RdrName }
765 : btype atype { LL $ HsAppTy $1 $2 }
768 atype :: { LHsType RdrName }
769 : gtycon { L1 (HsTyVar (unLoc $1)) }
770 | tyvar { L1 (HsTyVar (unLoc $1)) }
771 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
772 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
773 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
774 | '[' ctype ']' { LL $ HsListTy $2 }
775 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
776 | '(' ctype ')' { LL $ HsParTy $2 }
777 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
779 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
781 -- An inst_type is what occurs in the head of an instance decl
782 -- e.g. (Foo a, Gaz b) => Wibble a b
783 -- It's kept as a single type, with a MonoDictTy at the right
784 -- hand corner, for convenience.
785 inst_type :: { LHsType RdrName }
786 : sigtype {% checkInstType $1 }
788 inst_types1 :: { [LHsType RdrName] }
790 | inst_type ',' inst_types1 { $1 : $3 }
792 comma_types0 :: { [LHsType RdrName] }
793 : comma_types1 { $1 }
796 comma_types1 :: { [LHsType RdrName] }
798 | ctype ',' comma_types1 { $1 : $3 }
800 tv_bndrs :: { [LHsTyVarBndr RdrName] }
801 : tv_bndr tv_bndrs { $1 : $2 }
804 tv_bndr :: { LHsTyVarBndr RdrName }
805 : tyvar { L1 (UserTyVar (unLoc $1)) }
806 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
809 fds :: { Located [Located ([RdrName], [RdrName])] }
810 : {- empty -} { noLoc [] }
811 | '|' fds1 { LL (reverse (unLoc $2)) }
813 fds1 :: { Located [Located ([RdrName], [RdrName])] }
814 : fds1 ',' fd { LL ($3 : unLoc $1) }
817 fd :: { Located ([RdrName], [RdrName]) }
818 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
819 (reverse (unLoc $1), reverse (unLoc $3)) }
821 varids0 :: { Located [RdrName] }
822 : {- empty -} { noLoc [] }
823 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
825 -----------------------------------------------------------------------------
828 kind :: { Located Kind }
830 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
832 akind :: { Located Kind }
833 : '*' { L1 liftedTypeKind }
834 | '!' { L1 unliftedTypeKind }
835 | '(' kind ')' { LL (unLoc $2) }
838 -----------------------------------------------------------------------------
839 -- Datatype declarations
841 gadt_constrlist :: { Located [LConDecl RdrName] }
842 : '{' gadt_constrs '}' { LL (unLoc $2) }
843 | vocurly gadt_constrs close { $2 }
845 gadt_constrs :: { Located [LConDecl RdrName] }
846 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
847 | gadt_constrs ';' { $1 }
848 | gadt_constr { L1 [$1] }
850 -- We allow the following forms:
851 -- C :: Eq a => a -> T a
852 -- C :: forall a. Eq a => !a -> T a
853 -- D { x,y :: a } :: T a
854 -- forall a. Eq a => D { x,y :: a } :: T a
856 gadt_constr :: { LConDecl RdrName }
858 { LL (mkGadtDecl $1 $3) }
859 -- Syntax: Maybe merge the record stuff with the single-case above?
860 -- (to kill the mostly harmless reduce/reduce error)
861 -- XXX revisit audreyt
862 | constr_stuff_record '::' sigtype
863 { let (con,details) = unLoc $1 in
864 LL (ConDecl con Implicit [] (noLoc []) details (ResTyGADT $3)) }
866 | forall context '=>' constr_stuff_record '::' sigtype
867 { let (con,details) = unLoc $4 in
868 LL (ConDecl con Implicit (unLoc $1) $2 details (ResTyGADT $6)) }
869 | forall constr_stuff_record '::' sigtype
870 { let (con,details) = unLoc $2 in
871 LL (ConDecl con Implicit (unLoc $1) (noLoc []) details (ResTyGADT $4)) }
875 constrs :: { Located [LConDecl RdrName] }
876 : {- empty; a GHC extension -} { noLoc [] }
877 | '=' constrs1 { LL (unLoc $2) }
879 constrs1 :: { Located [LConDecl RdrName] }
880 : constrs1 '|' constr { LL ($3 : unLoc $1) }
883 constr :: { LConDecl RdrName }
884 : forall context '=>' constr_stuff
885 { let (con,details) = unLoc $4 in
886 LL (ConDecl con Explicit (unLoc $1) $2 details ResTyH98) }
887 | forall constr_stuff
888 { let (con,details) = unLoc $2 in
889 LL (ConDecl con Explicit (unLoc $1) (noLoc []) details ResTyH98) }
891 forall :: { Located [LHsTyVarBndr RdrName] }
892 : 'forall' tv_bndrs '.' { LL $2 }
893 | {- empty -} { noLoc [] }
895 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
896 -- We parse the constructor declaration
898 -- as a btype (treating C as a type constructor) and then convert C to be
899 -- a data constructor. Reason: it might continue like this:
901 -- in which case C really would be a type constructor. We can't resolve this
902 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
903 : btype {% mkPrefixCon $1 [] >>= return.LL }
904 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
905 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
906 | btype conop btype { LL ($2, InfixCon $1 $3) }
908 constr_stuff_record :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
909 : oqtycon '{' '}' {% mkRecCon $1 [] >>= return.sL (comb2 $1 $>) }
910 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.sL (comb2 $1 $>) }
912 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
913 : fielddecl ',' fielddecls { unLoc $1 : $3 }
914 | fielddecl { [unLoc $1] }
916 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
917 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
919 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
920 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
921 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
922 -- We don't allow a context, but that's sorted out by the type checker.
923 deriving :: { Located (Maybe [LHsType RdrName]) }
924 : {- empty -} { noLoc Nothing }
925 | 'deriving' qtycon {% do { let { L loc tv = $2 }
926 ; p <- checkInstType (L loc (HsTyVar tv))
927 ; return (LL (Just [p])) } }
928 | 'deriving' '(' ')' { LL (Just []) }
929 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
930 -- Glasgow extension: allow partial
931 -- applications in derivings
933 -----------------------------------------------------------------------------
936 {- There's an awkward overlap with a type signature. Consider
937 f :: Int -> Int = ...rhs...
938 Then we can't tell whether it's a type signature or a value
939 definition with a result signature until we see the '='.
940 So we have to inline enough to postpone reductions until we know.
944 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
945 instead of qvar, we get another shift/reduce-conflict. Consider the
948 { (^^) :: Int->Int ; } Type signature; only var allowed
950 { (^^) :: Int->Int = ... ; } Value defn with result signature;
951 qvar allowed (because of instance decls)
953 We can't tell whether to reduce var to qvar until after we've read the signatures.
956 decl :: { Located (OrdList (LHsDecl RdrName)) }
958 | '!' infixexp rhs {% do { pat <- checkPattern $2;
959 return (LL $ unitOL $ LL $ ValD $
960 PatBind (LL $ BangPat pat) (unLoc $3)
961 placeHolderType placeHolderNames) } }
962 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
963 return (LL $ unitOL (LL $ ValD r)) } }
965 rhs :: { Located (GRHSs RdrName) }
966 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
967 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
969 gdrhs :: { Located [LGRHS RdrName] }
970 : gdrhs gdrh { LL ($2 : unLoc $1) }
973 gdrh :: { LGRHS RdrName }
974 : '|' quals '=' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
976 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
977 : infixexp '::' sigtype
978 {% do s <- checkValSig $1 $3;
979 return (LL $ unitOL (LL $ SigD s)) }
980 -- See the above notes for why we need infixexp here
981 | var ',' sig_vars '::' sigtype
982 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
983 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
985 | '{-# INLINE' activation qvar '#-}'
986 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 (getINLINE $1)))) }
987 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
988 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlineSpec)
990 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
991 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlineSpec $2 (getSPEC_INLINE $1)))
993 | '{-# SPECIALISE' 'instance' inst_type '#-}'
994 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
996 -----------------------------------------------------------------------------
999 exp :: { LHsExpr RdrName }
1000 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1001 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1002 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1003 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1004 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1007 infixexp :: { LHsExpr RdrName }
1009 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1011 exp10 :: { LHsExpr RdrName }
1012 : '\\' aexp aexps opt_asig '->' exp
1013 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1014 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1015 (GRHSs (unguardedRHS $6) emptyLocalBinds
1017 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1018 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1019 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1020 | '-' fexp { LL $ mkHsNegApp $2 }
1022 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1023 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1024 return (L loc (mkHsDo DoExpr stmts body)) }
1025 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1026 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1027 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1028 | scc_annot exp { LL $ if opt_SccProfilingOn
1029 then HsSCC (unLoc $1) $2
1032 | 'proc' aexp '->' exp
1033 {% checkPattern $2 >>= \ p ->
1034 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1035 placeHolderType undefined)) }
1036 -- TODO: is LL right here?
1038 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1039 -- hdaume: core annotation
1042 scc_annot :: { Located FastString }
1043 : '_scc_' STRING { LL $ getSTRING $2 }
1044 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1046 fexp :: { LHsExpr RdrName }
1047 : fexp aexp { LL $ HsApp $1 $2 }
1050 aexps :: { [LHsExpr RdrName] }
1051 : aexps aexp { $2 : $1 }
1052 | {- empty -} { [] }
1054 aexp :: { LHsExpr RdrName }
1055 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1056 | '~' aexp { LL $ ELazyPat $2 }
1057 -- | '!' aexp { LL $ EBangPat $2 }
1060 aexp1 :: { LHsExpr RdrName }
1061 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1066 -- Here was the syntax for type applications that I was planning
1067 -- but there are difficulties (e.g. what order for type args)
1068 -- so it's not enabled yet.
1069 -- But this case *is* used for the left hand side of a generic definition,
1070 -- which is parsed as an expression before being munged into a pattern
1071 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1072 (sL (getLoc $3) (HsType $3)) }
1074 aexp2 :: { LHsExpr RdrName }
1075 : ipvar { L1 (HsIPVar $! unLoc $1) }
1076 | qcname { L1 (HsVar $! unLoc $1) }
1077 | literal { L1 (HsLit $! unLoc $1) }
1078 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1079 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1080 | '(' exp ')' { LL (HsPar $2) }
1081 | '(' texp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1082 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1083 | '[' list ']' { LL (unLoc $2) }
1084 | '[:' parr ':]' { LL (unLoc $2) }
1085 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1086 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1087 | '_' { L1 EWildPat }
1089 -- Template Haskell Extension
1090 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1091 (L1 $ HsVar (mkUnqual varName
1092 (getTH_ID_SPLICE $1)))) } -- $x
1093 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1095 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1096 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1097 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1098 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1099 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1100 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1101 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1102 return (LL $ HsBracket (PatBr p)) }
1103 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1105 -- arrow notation extension
1106 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1108 cmdargs :: { [LHsCmdTop RdrName] }
1109 : cmdargs acmd { $2 : $1 }
1110 | {- empty -} { [] }
1112 acmd :: { LHsCmdTop RdrName }
1113 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1115 cvtopbody :: { [LHsDecl RdrName] }
1116 : '{' cvtopdecls0 '}' { $2 }
1117 | vocurly cvtopdecls0 close { $2 }
1119 cvtopdecls0 :: { [LHsDecl RdrName] }
1120 : {- empty -} { [] }
1123 texp :: { LHsExpr RdrName }
1125 | qopm infixexp { LL $ SectionR $1 $2 }
1126 -- The second production is really here only for bang patterns
1129 texps :: { [LHsExpr RdrName] }
1130 : texps ',' texp { $3 : $1 }
1134 -----------------------------------------------------------------------------
1137 -- The rules below are little bit contorted to keep lexps left-recursive while
1138 -- avoiding another shift/reduce-conflict.
1140 list :: { LHsExpr RdrName }
1141 : texp { L1 $ ExplicitList placeHolderType [$1] }
1142 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1143 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1144 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1145 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1146 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1147 | texp pquals { sL (comb2 $1 $>) $ mkHsDo ListComp (reverse (unLoc $2)) $1 }
1149 lexps :: { Located [LHsExpr RdrName] }
1150 : lexps ',' texp { LL ($3 : unLoc $1) }
1151 | texp ',' texp { LL [$3,$1] }
1153 -----------------------------------------------------------------------------
1154 -- List Comprehensions
1156 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1157 -- or a reversed list of Stmts
1158 : pquals1 { case unLoc $1 of
1160 qss -> L1 [L1 (ParStmt stmtss)]
1162 stmtss = [ (reverse qs, undefined)
1166 pquals1 :: { Located [[LStmt RdrName]] }
1167 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1168 | '|' quals { L (getLoc $2) [unLoc $2] }
1170 quals :: { Located [LStmt RdrName] }
1171 : quals ',' qual { LL ($3 : unLoc $1) }
1174 -----------------------------------------------------------------------------
1175 -- Parallel array expressions
1177 -- The rules below are little bit contorted; see the list case for details.
1178 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1179 -- Moreover, we allow explicit arrays with no element (represented by the nil
1180 -- constructor in the list case).
1182 parr :: { LHsExpr RdrName }
1183 : { noLoc (ExplicitPArr placeHolderType []) }
1184 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1185 | lexps { L1 $ ExplicitPArr placeHolderType
1186 (reverse (unLoc $1)) }
1187 | exp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1188 | exp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1189 | exp pquals { sL (comb2 $1 $>) $ mkHsDo PArrComp (reverse (unLoc $2)) $1 }
1191 -- We are reusing `lexps' and `pquals' from the list case.
1193 -----------------------------------------------------------------------------
1194 -- Case alternatives
1196 altslist :: { Located [LMatch RdrName] }
1197 : '{' alts '}' { LL (reverse (unLoc $2)) }
1198 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1200 alts :: { Located [LMatch RdrName] }
1201 : alts1 { L1 (unLoc $1) }
1202 | ';' alts { LL (unLoc $2) }
1204 alts1 :: { Located [LMatch RdrName] }
1205 : alts1 ';' alt { LL ($3 : unLoc $1) }
1206 | alts1 ';' { LL (unLoc $1) }
1209 alt :: { LMatch RdrName }
1210 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1211 return (LL (Match [p] $2 (unLoc $3))) }
1212 | '!' infixexp opt_sig alt_rhs {% checkPattern $2 >>= \p ->
1213 return (LL (Match [LL $ BangPat p] $3 (unLoc $4))) }
1215 alt_rhs :: { Located (GRHSs RdrName) }
1216 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1218 ralt :: { Located [LGRHS RdrName] }
1219 : '->' exp { LL (unguardedRHS $2) }
1220 | gdpats { L1 (reverse (unLoc $1)) }
1222 gdpats :: { Located [LGRHS RdrName] }
1223 : gdpats gdpat { LL ($2 : unLoc $1) }
1226 gdpat :: { LGRHS RdrName }
1227 : '|' quals '->' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
1229 -----------------------------------------------------------------------------
1230 -- Statement sequences
1232 stmtlist :: { Located [LStmt RdrName] }
1233 : '{' stmts '}' { LL (unLoc $2) }
1234 | vocurly stmts close { $2 }
1236 -- do { ;; s ; s ; ; s ;; }
1237 -- The last Stmt should be an expression, but that's hard to enforce
1238 -- here, because we need too much lookahead if we see do { e ; }
1239 -- So we use ExprStmts throughout, and switch the last one over
1240 -- in ParseUtils.checkDo instead
1241 stmts :: { Located [LStmt RdrName] }
1242 : stmt stmts_help { LL ($1 : unLoc $2) }
1243 | ';' stmts { LL (unLoc $2) }
1244 | {- empty -} { noLoc [] }
1246 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1247 : ';' stmts { LL (unLoc $2) }
1248 | {- empty -} { noLoc [] }
1250 -- For typing stmts at the GHCi prompt, where
1251 -- the input may consist of just comments.
1252 maybe_stmt :: { Maybe (LStmt RdrName) }
1254 | {- nothing -} { Nothing }
1256 stmt :: { LStmt RdrName }
1258 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1259 return (LL $ mkBindStmt p $1) }
1260 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1262 qual :: { LStmt RdrName }
1263 : exp '<-' exp {% checkPattern $1 >>= \p ->
1264 return (LL $ mkBindStmt p $3) }
1265 | exp { L1 $ mkExprStmt $1 }
1266 | 'let' binds { LL $ LetStmt (unLoc $2) }
1268 -----------------------------------------------------------------------------
1269 -- Record Field Update/Construction
1271 fbinds :: { HsRecordBinds RdrName }
1273 | {- empty -} { [] }
1275 fbinds1 :: { HsRecordBinds RdrName }
1276 : fbinds1 ',' fbind { $3 : $1 }
1279 fbind :: { (Located RdrName, LHsExpr RdrName) }
1280 : qvar '=' exp { ($1,$3) }
1282 -----------------------------------------------------------------------------
1283 -- Implicit Parameter Bindings
1285 dbinds :: { Located [LIPBind RdrName] }
1286 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1287 | dbinds ';' { LL (unLoc $1) }
1289 -- | {- empty -} { [] }
1291 dbind :: { LIPBind RdrName }
1292 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1294 ipvar :: { Located (IPName RdrName) }
1295 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1296 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1298 -----------------------------------------------------------------------------
1301 depreclist :: { Located [RdrName] }
1302 depreclist : deprec_var { L1 [unLoc $1] }
1303 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1305 deprec_var :: { Located RdrName }
1306 deprec_var : var { $1 }
1309 -----------------------------------------
1310 -- Data constructors
1311 qcon :: { Located RdrName }
1313 | '(' qconsym ')' { LL (unLoc $2) }
1314 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1315 -- The case of '[:' ':]' is part of the production `parr'
1317 con :: { Located RdrName }
1319 | '(' consym ')' { LL (unLoc $2) }
1320 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1322 sysdcon :: { Located DataCon } -- Wired in data constructors
1323 : '(' ')' { LL unitDataCon }
1324 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1325 | '[' ']' { LL nilDataCon }
1327 conop :: { Located RdrName }
1329 | '`' conid '`' { LL (unLoc $2) }
1331 qconop :: { Located RdrName }
1333 | '`' qconid '`' { LL (unLoc $2) }
1335 -----------------------------------------------------------------------------
1336 -- Type constructors
1338 gtycon :: { Located RdrName } -- A "general" qualified tycon
1340 | '(' ')' { LL $ getRdrName unitTyCon }
1341 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1342 | '(' '->' ')' { LL $ getRdrName funTyCon }
1343 | '[' ']' { LL $ listTyCon_RDR }
1344 | '[:' ':]' { LL $ parrTyCon_RDR }
1346 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1348 | '(' qtyconsym ')' { LL (unLoc $2) }
1350 qtyconop :: { Located RdrName } -- Qualified or unqualified
1352 | '`' qtycon '`' { LL (unLoc $2) }
1354 qtycon :: { Located RdrName } -- Qualified or unqualified
1355 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1358 tycon :: { Located RdrName } -- Unqualified
1359 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1361 qtyconsym :: { Located RdrName }
1362 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1365 tyconsym :: { Located RdrName }
1366 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1368 -----------------------------------------------------------------------------
1371 op :: { Located RdrName } -- used in infix decls
1375 varop :: { Located RdrName }
1377 | '`' varid '`' { LL (unLoc $2) }
1379 qop :: { LHsExpr RdrName } -- used in sections
1380 : qvarop { L1 $ HsVar (unLoc $1) }
1381 | qconop { L1 $ HsVar (unLoc $1) }
1383 qopm :: { LHsExpr RdrName } -- used in sections
1384 : qvaropm { L1 $ HsVar (unLoc $1) }
1385 | qconop { L1 $ HsVar (unLoc $1) }
1387 qvarop :: { Located RdrName }
1389 | '`' qvarid '`' { LL (unLoc $2) }
1391 qvaropm :: { Located RdrName }
1392 : qvarsym_no_minus { $1 }
1393 | '`' qvarid '`' { LL (unLoc $2) }
1395 -----------------------------------------------------------------------------
1398 tyvar :: { Located RdrName }
1399 tyvar : tyvarid { $1 }
1400 | '(' tyvarsym ')' { LL (unLoc $2) }
1402 tyvarop :: { Located RdrName }
1403 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1406 tyvarid :: { Located RdrName }
1407 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1408 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1409 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1410 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1411 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1413 tyvarsym :: { Located RdrName }
1414 -- Does not include "!", because that is used for strictness marks
1415 -- or ".", because that separates the quantified type vars from the rest
1416 -- or "*", because that's used for kinds
1417 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1419 -----------------------------------------------------------------------------
1422 var :: { Located RdrName }
1424 | '(' varsym ')' { LL (unLoc $2) }
1426 qvar :: { Located RdrName }
1428 | '(' varsym ')' { LL (unLoc $2) }
1429 | '(' qvarsym1 ')' { LL (unLoc $2) }
1430 -- We've inlined qvarsym here so that the decision about
1431 -- whether it's a qvar or a var can be postponed until
1432 -- *after* we see the close paren.
1434 qvarid :: { Located RdrName }
1436 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1438 varid :: { Located RdrName }
1439 : varid_no_unsafe { $1 }
1440 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1441 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1442 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1444 varid_no_unsafe :: { Located RdrName }
1445 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1446 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1447 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1449 qvarsym :: { Located RdrName }
1453 qvarsym_no_minus :: { Located RdrName }
1454 : varsym_no_minus { $1 }
1457 qvarsym1 :: { Located RdrName }
1458 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1460 varsym :: { Located RdrName }
1461 : varsym_no_minus { $1 }
1462 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1464 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1465 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1466 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1469 -- These special_ids are treated as keywords in various places,
1470 -- but as ordinary ids elsewhere. 'special_id' collects all these
1471 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1472 special_id :: { Located FastString }
1474 : 'as' { L1 FSLIT("as") }
1475 | 'qualified' { L1 FSLIT("qualified") }
1476 | 'hiding' { L1 FSLIT("hiding") }
1477 | 'export' { L1 FSLIT("export") }
1478 | 'label' { L1 FSLIT("label") }
1479 | 'dynamic' { L1 FSLIT("dynamic") }
1480 | 'stdcall' { L1 FSLIT("stdcall") }
1481 | 'ccall' { L1 FSLIT("ccall") }
1482 | 'iso' { L1 FSLIT("iso") }
1484 special_sym :: { Located FastString }
1485 special_sym : '!' { L1 FSLIT("!") }
1486 | '.' { L1 FSLIT(".") }
1487 | '*' { L1 FSLIT("*") }
1489 -----------------------------------------------------------------------------
1490 -- Data constructors
1492 qconid :: { Located RdrName } -- Qualified or unqualified
1494 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1496 conid :: { Located RdrName }
1497 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1499 qconsym :: { Located RdrName } -- Qualified or unqualified
1501 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1503 consym :: { Located RdrName }
1504 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1506 -- ':' means only list cons
1507 | ':' { L1 $ consDataCon_RDR }
1510 -----------------------------------------------------------------------------
1513 literal :: { Located HsLit }
1514 : CHAR { L1 $ HsChar $ getCHAR $1 }
1515 | STRING { L1 $ HsString $ getSTRING $1 }
1516 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1517 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1518 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1519 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1520 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1522 -----------------------------------------------------------------------------
1526 : vccurly { () } -- context popped in lexer.
1527 | error {% popContext }
1529 -----------------------------------------------------------------------------
1530 -- Miscellaneous (mostly renamings)
1532 modid :: { Located ModuleName }
1533 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1534 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1537 (unpackFS mod ++ '.':unpackFS c))
1541 : commas ',' { $1 + 1 }
1544 -----------------------------------------------------------------------------
1548 happyError = srcParseFail
1550 getVARID (L _ (ITvarid x)) = x
1551 getCONID (L _ (ITconid x)) = x
1552 getVARSYM (L _ (ITvarsym x)) = x
1553 getCONSYM (L _ (ITconsym x)) = x
1554 getQVARID (L _ (ITqvarid x)) = x
1555 getQCONID (L _ (ITqconid x)) = x
1556 getQVARSYM (L _ (ITqvarsym x)) = x
1557 getQCONSYM (L _ (ITqconsym x)) = x
1558 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1559 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1560 getCHAR (L _ (ITchar x)) = x
1561 getSTRING (L _ (ITstring x)) = x
1562 getINTEGER (L _ (ITinteger x)) = x
1563 getRATIONAL (L _ (ITrational x)) = x
1564 getPRIMCHAR (L _ (ITprimchar x)) = x
1565 getPRIMSTRING (L _ (ITprimstring x)) = x
1566 getPRIMINTEGER (L _ (ITprimint x)) = x
1567 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1568 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1569 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1570 getINLINE (L _ (ITinline_prag b)) = b
1571 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
1573 -- Utilities for combining source spans
1574 comb2 :: Located a -> Located b -> SrcSpan
1577 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1578 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1580 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1581 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1582 combineSrcSpans (getLoc c) (getLoc d)
1584 -- strict constructor version:
1586 sL :: SrcSpan -> a -> Located a
1587 sL span a = span `seq` L span a
1589 -- Make a source location for the file. We're a bit lazy here and just
1590 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1591 -- try to find the span of the whole file (ToDo).
1592 fileSrcSpan :: P SrcSpan
1595 let loc = mkSrcLoc (srcLocFile l) 1 0;
1596 return (mkSrcSpan loc loc)