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 { unitOL (L1 (TyClD (unLoc $1))) }
448 | 'instance' inst_type where
449 { let (binds, sigs, ats) = cvBindsAndSigs (unLoc $3)
450 in unitOL (L (comb3 $1 $2 $3)
451 (InstD (InstDecl $2 binds sigs ats))) }
452 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
453 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
454 | '{-# DEPRECATED' deprecations '#-}' { $2 }
455 | '{-# RULES' rules '#-}' { $2 }
458 -- Template Haskell Extension
459 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
460 | TH_ID_SPLICE { unitOL (LL $ SpliceD (SpliceDecl $
461 L1 $ HsVar (mkUnqual varName (getTH_ID_SPLICE $1))
466 cl_decl :: { LTyClDecl RdrName }
467 : 'class' tycl_hdr fds where
468 {% do { let { (binds, sigs, ats) =
469 cvBindsAndSigs (unLoc $4)
470 ; (ctxt, tc, tvs, tparms) = unLoc $2}
471 ; checkTyVars tparms False -- only type vars allowed
473 ; return $ L (comb4 $1 $2 $3 $4)
474 (mkClassDecl (ctxt, tc, tvs)
475 (unLoc $3) sigs binds ats) } }
479 ty_decl :: { LTyClDecl RdrName }
480 -- type function signature and equations (w/ type synonyms as special
481 -- case); we need to handle all this in one rule to avoid a large
482 -- number of shift/reduce conflicts
483 : 'type' opt_iso type kind_or_ctype
485 -- Note the use of type for the head; this allows
486 -- infix type constructors to be declared and type
487 -- patterns for type function equations
489 -- We have that `typats :: Maybe [LHsType name]' is `Nothing'
490 -- (in the second case alternative) when all arguments are
491 -- variables (and we thus have a vanilla type synonym
492 -- declaration); otherwise, it contains all arguments as type
497 do { (tc, tvs, _) <- checkSynHdr $3 False
498 ; return (L (comb3 $1 $3 kind)
499 (TyFunction tc tvs $2 (unLoc kind)))
502 do { (tc, tvs, typats) <- checkSynHdr $3 True
503 ; return (L (comb2 $1 ty)
504 (TySynonym tc tvs typats ty)) }
505 Right ty | otherwise ->
506 parseError (comb2 $1 ty)
507 "iso tag is only allowed in kind signatures"
510 -- kind signature of indexed type
511 | data_or_newtype tycl_hdr '::' kind
512 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
513 ; checkTyVars tparms False -- no type pattern
516 (mkTyData (unLoc $1) (ctxt, tc, tvs, Nothing)
517 (Just (unLoc $4)) [] Nothing) } }
519 -- data type or newtype declaration
520 | data_or_newtype tycl_hdr constrs deriving
521 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
522 ; tpats <- checkTyVars tparms True -- can have type pats
524 L (comb4 $1 $2 $3 $4)
525 -- We need the location on tycl_hdr in case
526 -- constrs and deriving are both empty
527 (mkTyData (unLoc $1) (ctxt, tc, tvs, tpats)
528 Nothing (reverse (unLoc $3)) (unLoc $4)) } }
531 | data_or_newtype tycl_hdr opt_kind_sig
532 'where' gadt_constrlist
534 {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
535 ; tpats <- checkTyVars tparms True -- can have type pats
537 L (comb4 $1 $2 $4 $5)
538 (mkTyData (unLoc $1) (ctxt, tc, tvs, tpats) $3
539 (reverse (unLoc $5)) (unLoc $6)) } }
545 kind_or_ctype :: { Either (Located Kind) (LHsType RdrName) }
546 : '::' kind { Left (LL (unLoc $2)) }
547 | '=' ctype { Right (LL (unLoc $2)) }
548 -- Note ctype, not sigtype, on the right of '='
549 -- We allow an explicit for-all but we don't insert one
550 -- in type Foo a = (b,b)
551 -- Instead we just say b is out of scope
553 data_or_newtype :: { Located NewOrData }
554 : 'data' { L1 DataType }
555 | 'newtype' { L1 NewType }
557 opt_kind_sig :: { Maybe Kind }
559 | '::' kind { Just (unLoc $2) }
561 -- tycl_hdr parses the header of a class or data type decl,
562 -- which takes the form
565 -- (Eq a, Ord b) => T a b
566 -- T Int [a] -- for associated types
567 -- Rather a lot of inlining here, else we get reduce/reduce errors
568 tycl_hdr :: { Located (LHsContext RdrName,
570 [LHsTyVarBndr RdrName],
572 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
573 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
575 -----------------------------------------------------------------------------
576 -- Nested declarations
578 -- Type declaration or value declaration
580 tydecl :: { Located (OrdList (LHsDecl RdrName)) }
581 tydecl : ty_decl { LL (unitOL (L1 (TyClD (unLoc $1)))) }
584 tydecls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
585 : tydecls ';' tydecl { LL (unLoc $1 `appOL` unLoc $3) }
586 | tydecls ';' { LL (unLoc $1) }
588 | {- empty -} { noLoc nilOL }
592 :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
593 : '{' tydecls '}' { LL (unLoc $2) }
594 | vocurly tydecls close { $2 }
596 -- Form of the body of class and instance declarations
598 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
599 -- No implicit parameters
600 -- May have type declarations
601 : 'where' tydecllist { LL (unLoc $2) }
602 | {- empty -} { noLoc nilOL }
604 decls :: { Located (OrdList (LHsDecl RdrName)) }
605 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
606 | decls ';' { LL (unLoc $1) }
608 | {- empty -} { noLoc nilOL }
611 decllist :: { Located (OrdList (LHsDecl RdrName)) }
612 : '{' decls '}' { LL (unLoc $2) }
613 | vocurly decls close { $2 }
615 -- Binding groups other than those of class and instance declarations
617 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
618 -- No type declarations
619 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
620 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
621 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
623 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
624 -- No type declarations
625 : 'where' binds { LL (unLoc $2) }
626 | {- empty -} { noLoc emptyLocalBinds }
629 -----------------------------------------------------------------------------
630 -- Transformation Rules
632 rules :: { OrdList (LHsDecl RdrName) }
633 : rules ';' rule { $1 `snocOL` $3 }
636 | {- empty -} { nilOL }
638 rule :: { LHsDecl RdrName }
639 : STRING activation rule_forall infixexp '=' exp
640 { LL $ RuleD (HsRule (getSTRING $1)
641 ($2 `orElse` AlwaysActive)
642 $3 $4 placeHolderNames $6 placeHolderNames) }
644 activation :: { Maybe Activation }
645 : {- empty -} { Nothing }
646 | explicit_activation { Just $1 }
648 explicit_activation :: { Activation } -- In brackets
649 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
650 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
652 rule_forall :: { [RuleBndr RdrName] }
653 : 'forall' rule_var_list '.' { $2 }
656 rule_var_list :: { [RuleBndr RdrName] }
658 | rule_var rule_var_list { $1 : $2 }
660 rule_var :: { RuleBndr RdrName }
661 : varid { RuleBndr $1 }
662 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
664 -----------------------------------------------------------------------------
665 -- Deprecations (c.f. rules)
667 deprecations :: { OrdList (LHsDecl RdrName) }
668 : deprecations ';' deprecation { $1 `appOL` $3 }
669 | deprecations ';' { $1 }
671 | {- empty -} { nilOL }
673 -- SUP: TEMPORARY HACK, not checking for `module Foo'
674 deprecation :: { OrdList (LHsDecl RdrName) }
676 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
680 -----------------------------------------------------------------------------
681 -- Foreign import and export declarations
683 fdecl :: { LHsDecl RdrName }
684 fdecl : 'import' callconv safety fspec
685 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
686 | 'import' callconv fspec
687 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
689 | 'export' callconv fspec
690 {% mkExport $2 (unLoc $3) >>= return.LL }
692 callconv :: { CallConv }
693 : 'stdcall' { CCall StdCallConv }
694 | 'ccall' { CCall CCallConv }
695 | 'dotnet' { DNCall }
698 : 'unsafe' { PlayRisky }
699 | 'safe' { PlaySafe False }
700 | 'threadsafe' { PlaySafe True }
702 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
703 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
704 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
705 -- if the entity string is missing, it defaults to the empty string;
706 -- the meaning of an empty entity string depends on the calling
709 -----------------------------------------------------------------------------
712 opt_sig :: { Maybe (LHsType RdrName) }
713 : {- empty -} { Nothing }
714 | '::' sigtype { Just $2 }
716 opt_asig :: { Maybe (LHsType RdrName) }
717 : {- empty -} { Nothing }
718 | '::' atype { Just $2 }
720 sigtypes1 :: { [LHsType RdrName] }
722 | sigtype ',' sigtypes1 { $1 : $3 }
724 sigtype :: { LHsType RdrName }
725 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
726 -- Wrap an Implicit forall if there isn't one there already
728 sig_vars :: { Located [Located RdrName] }
729 : sig_vars ',' var { LL ($3 : unLoc $1) }
732 -----------------------------------------------------------------------------
735 strict_mark :: { Located HsBang }
736 : '!' { L1 HsStrict }
737 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
739 -- A ctype is a for-all type
740 ctype :: { LHsType RdrName }
741 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
742 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
743 -- A type of form (context => type) is an *implicit* HsForAllTy
746 -- We parse a context as a btype so that we don't get reduce/reduce
747 -- errors in ctype. The basic problem is that
749 -- looks so much like a tuple type. We can't tell until we find the =>
750 context :: { LHsContext RdrName }
751 : btype {% checkContext $1 }
753 type :: { LHsType RdrName }
754 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
757 gentype :: { LHsType RdrName }
759 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
760 | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 }
761 | btype '->' ctype { LL $ HsFunTy $1 $3 }
763 btype :: { LHsType RdrName }
764 : btype atype { LL $ HsAppTy $1 $2 }
767 atype :: { LHsType RdrName }
768 : gtycon { L1 (HsTyVar (unLoc $1)) }
769 | tyvar { L1 (HsTyVar (unLoc $1)) }
770 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
771 | '(' ctype ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
772 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
773 | '[' ctype ']' { LL $ HsListTy $2 }
774 | '[:' ctype ':]' { LL $ HsPArrTy $2 }
775 | '(' ctype ')' { LL $ HsParTy $2 }
776 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 (unLoc $4) }
778 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
780 -- An inst_type is what occurs in the head of an instance decl
781 -- e.g. (Foo a, Gaz b) => Wibble a b
782 -- It's kept as a single type, with a MonoDictTy at the right
783 -- hand corner, for convenience.
784 inst_type :: { LHsType RdrName }
785 : sigtype {% checkInstType $1 }
787 inst_types1 :: { [LHsType RdrName] }
789 | inst_type ',' inst_types1 { $1 : $3 }
791 comma_types0 :: { [LHsType RdrName] }
792 : comma_types1 { $1 }
795 comma_types1 :: { [LHsType RdrName] }
797 | ctype ',' comma_types1 { $1 : $3 }
799 tv_bndrs :: { [LHsTyVarBndr RdrName] }
800 : tv_bndr tv_bndrs { $1 : $2 }
803 tv_bndr :: { LHsTyVarBndr RdrName }
804 : tyvar { L1 (UserTyVar (unLoc $1)) }
805 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2)
808 fds :: { Located [Located ([RdrName], [RdrName])] }
809 : {- empty -} { noLoc [] }
810 | '|' fds1 { LL (reverse (unLoc $2)) }
812 fds1 :: { Located [Located ([RdrName], [RdrName])] }
813 : fds1 ',' fd { LL ($3 : unLoc $1) }
816 fd :: { Located ([RdrName], [RdrName]) }
817 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
818 (reverse (unLoc $1), reverse (unLoc $3)) }
820 varids0 :: { Located [RdrName] }
821 : {- empty -} { noLoc [] }
822 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
824 -----------------------------------------------------------------------------
827 kind :: { Located Kind }
829 | akind '->' kind { LL (mkArrowKind (unLoc $1) (unLoc $3)) }
831 akind :: { Located Kind }
832 : '*' { L1 liftedTypeKind }
833 | '!' { L1 unliftedTypeKind }
834 | '(' kind ')' { LL (unLoc $2) }
837 -----------------------------------------------------------------------------
838 -- Datatype declarations
840 gadt_constrlist :: { Located [LConDecl RdrName] }
841 : '{' gadt_constrs '}' { LL (unLoc $2) }
842 | vocurly gadt_constrs close { $2 }
844 gadt_constrs :: { Located [LConDecl RdrName] }
845 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
846 | gadt_constrs ';' { $1 }
847 | gadt_constr { L1 [$1] }
849 -- We allow the following forms:
850 -- C :: Eq a => a -> T a
851 -- C :: forall a. Eq a => !a -> T a
852 -- D { x,y :: a } :: T a
853 -- forall a. Eq a => D { x,y :: a } :: T a
855 gadt_constr :: { LConDecl RdrName }
857 { LL (mkGadtDecl $1 $3) }
858 -- Syntax: Maybe merge the record stuff with the single-case above?
859 -- (to kill the mostly harmless reduce/reduce error)
860 -- XXX revisit audreyt
861 | constr_stuff_record '::' sigtype
862 { let (con,details) = unLoc $1 in
863 LL (ConDecl con Implicit [] (noLoc []) details (ResTyGADT $3)) }
865 | forall context '=>' constr_stuff_record '::' sigtype
866 { let (con,details) = unLoc $4 in
867 LL (ConDecl con Implicit (unLoc $1) $2 details (ResTyGADT $6)) }
868 | forall constr_stuff_record '::' sigtype
869 { let (con,details) = unLoc $2 in
870 LL (ConDecl con Implicit (unLoc $1) (noLoc []) details (ResTyGADT $4)) }
874 constrs :: { Located [LConDecl RdrName] }
875 : {- empty; a GHC extension -} { noLoc [] }
876 | '=' constrs1 { LL (unLoc $2) }
878 constrs1 :: { Located [LConDecl RdrName] }
879 : constrs1 '|' constr { LL ($3 : unLoc $1) }
882 constr :: { LConDecl RdrName }
883 : forall context '=>' constr_stuff
884 { let (con,details) = unLoc $4 in
885 LL (ConDecl con Explicit (unLoc $1) $2 details ResTyH98) }
886 | forall constr_stuff
887 { let (con,details) = unLoc $2 in
888 LL (ConDecl con Explicit (unLoc $1) (noLoc []) details ResTyH98) }
890 forall :: { Located [LHsTyVarBndr RdrName] }
891 : 'forall' tv_bndrs '.' { LL $2 }
892 | {- empty -} { noLoc [] }
894 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
895 -- We parse the constructor declaration
897 -- as a btype (treating C as a type constructor) and then convert C to be
898 -- a data constructor. Reason: it might continue like this:
900 -- in which case C really would be a type constructor. We can't resolve this
901 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
902 : btype {% mkPrefixCon $1 [] >>= return.LL }
903 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
904 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
905 | btype conop btype { LL ($2, InfixCon $1 $3) }
907 constr_stuff_record :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
908 : oqtycon '{' '}' {% mkRecCon $1 [] >>= return.sL (comb2 $1 $>) }
909 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.sL (comb2 $1 $>) }
911 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
912 : fielddecl ',' fielddecls { unLoc $1 : $3 }
913 | fielddecl { [unLoc $1] }
915 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
916 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
918 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
919 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
920 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
921 -- We don't allow a context, but that's sorted out by the type checker.
922 deriving :: { Located (Maybe [LHsType RdrName]) }
923 : {- empty -} { noLoc Nothing }
924 | 'deriving' qtycon {% do { let { L loc tv = $2 }
925 ; p <- checkInstType (L loc (HsTyVar tv))
926 ; return (LL (Just [p])) } }
927 | 'deriving' '(' ')' { LL (Just []) }
928 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
929 -- Glasgow extension: allow partial
930 -- applications in derivings
932 -----------------------------------------------------------------------------
935 {- There's an awkward overlap with a type signature. Consider
936 f :: Int -> Int = ...rhs...
937 Then we can't tell whether it's a type signature or a value
938 definition with a result signature until we see the '='.
939 So we have to inline enough to postpone reductions until we know.
943 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
944 instead of qvar, we get another shift/reduce-conflict. Consider the
947 { (^^) :: Int->Int ; } Type signature; only var allowed
949 { (^^) :: Int->Int = ... ; } Value defn with result signature;
950 qvar allowed (because of instance decls)
952 We can't tell whether to reduce var to qvar until after we've read the signatures.
955 decl :: { Located (OrdList (LHsDecl RdrName)) }
957 | '!' infixexp rhs {% do { pat <- checkPattern $2;
958 return (LL $ unitOL $ LL $ ValD $
959 PatBind (LL $ BangPat pat) (unLoc $3)
960 placeHolderType placeHolderNames) } }
961 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
962 return (LL $ unitOL (LL $ ValD r)) } }
964 rhs :: { Located (GRHSs RdrName) }
965 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
966 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
968 gdrhs :: { Located [LGRHS RdrName] }
969 : gdrhs gdrh { LL ($2 : unLoc $1) }
972 gdrh :: { LGRHS RdrName }
973 : '|' quals '=' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
975 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
976 : infixexp '::' sigtype
977 {% do s <- checkValSig $1 $3;
978 return (LL $ unitOL (LL $ SigD s)) }
979 -- See the above notes for why we need infixexp here
980 | var ',' sig_vars '::' sigtype
981 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
982 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
984 | '{-# INLINE' activation qvar '#-}'
985 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 (getINLINE $1)))) }
986 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
987 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlineSpec)
989 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
990 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlineSpec $2 (getSPEC_INLINE $1)))
992 | '{-# SPECIALISE' 'instance' inst_type '#-}'
993 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
995 -----------------------------------------------------------------------------
998 exp :: { LHsExpr RdrName }
999 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1000 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1001 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1002 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1003 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1006 infixexp :: { LHsExpr RdrName }
1008 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1010 exp10 :: { LHsExpr RdrName }
1011 : '\\' aexp aexps opt_asig '->' exp
1012 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1013 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1014 (GRHSs (unguardedRHS $6) emptyLocalBinds
1016 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1017 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1018 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1019 | '-' fexp { LL $ mkHsNegApp $2 }
1021 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1022 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1023 return (L loc (mkHsDo DoExpr stmts body)) }
1024 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1025 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1026 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1027 | scc_annot exp { LL $ if opt_SccProfilingOn
1028 then HsSCC (unLoc $1) $2
1031 | 'proc' aexp '->' exp
1032 {% checkPattern $2 >>= \ p ->
1033 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1034 placeHolderType undefined)) }
1035 -- TODO: is LL right here?
1037 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1038 -- hdaume: core annotation
1041 scc_annot :: { Located FastString }
1042 : '_scc_' STRING { LL $ getSTRING $2 }
1043 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1045 fexp :: { LHsExpr RdrName }
1046 : fexp aexp { LL $ HsApp $1 $2 }
1049 aexps :: { [LHsExpr RdrName] }
1050 : aexps aexp { $2 : $1 }
1051 | {- empty -} { [] }
1053 aexp :: { LHsExpr RdrName }
1054 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1055 | '~' aexp { LL $ ELazyPat $2 }
1056 -- | '!' aexp { LL $ EBangPat $2 }
1059 aexp1 :: { LHsExpr RdrName }
1060 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1065 -- Here was the syntax for type applications that I was planning
1066 -- but there are difficulties (e.g. what order for type args)
1067 -- so it's not enabled yet.
1068 -- But this case *is* used for the left hand side of a generic definition,
1069 -- which is parsed as an expression before being munged into a pattern
1070 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1071 (sL (getLoc $3) (HsType $3)) }
1073 aexp2 :: { LHsExpr RdrName }
1074 : ipvar { L1 (HsIPVar $! unLoc $1) }
1075 | qcname { L1 (HsVar $! unLoc $1) }
1076 | literal { L1 (HsLit $! unLoc $1) }
1077 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1078 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1079 | '(' exp ')' { LL (HsPar $2) }
1080 | '(' texp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1081 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1082 | '[' list ']' { LL (unLoc $2) }
1083 | '[:' parr ':]' { LL (unLoc $2) }
1084 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1085 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1086 | '_' { L1 EWildPat }
1088 -- Template Haskell Extension
1089 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1090 (L1 $ HsVar (mkUnqual varName
1091 (getTH_ID_SPLICE $1)))) } -- $x
1092 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1094 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1095 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1096 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1097 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1098 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1099 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1100 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1101 return (LL $ HsBracket (PatBr p)) }
1102 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1104 -- arrow notation extension
1105 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1107 cmdargs :: { [LHsCmdTop RdrName] }
1108 : cmdargs acmd { $2 : $1 }
1109 | {- empty -} { [] }
1111 acmd :: { LHsCmdTop RdrName }
1112 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1114 cvtopbody :: { [LHsDecl RdrName] }
1115 : '{' cvtopdecls0 '}' { $2 }
1116 | vocurly cvtopdecls0 close { $2 }
1118 cvtopdecls0 :: { [LHsDecl RdrName] }
1119 : {- empty -} { [] }
1122 texp :: { LHsExpr RdrName }
1124 | qopm infixexp { LL $ SectionR $1 $2 }
1125 -- The second production is really here only for bang patterns
1128 texps :: { [LHsExpr RdrName] }
1129 : texps ',' texp { $3 : $1 }
1133 -----------------------------------------------------------------------------
1136 -- The rules below are little bit contorted to keep lexps left-recursive while
1137 -- avoiding another shift/reduce-conflict.
1139 list :: { LHsExpr RdrName }
1140 : texp { L1 $ ExplicitList placeHolderType [$1] }
1141 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1142 | texp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1143 | texp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1144 | texp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1145 | texp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1146 | texp pquals { sL (comb2 $1 $>) $ mkHsDo ListComp (reverse (unLoc $2)) $1 }
1148 lexps :: { Located [LHsExpr RdrName] }
1149 : lexps ',' texp { LL ($3 : unLoc $1) }
1150 | texp ',' texp { LL [$3,$1] }
1152 -----------------------------------------------------------------------------
1153 -- List Comprehensions
1155 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1156 -- or a reversed list of Stmts
1157 : pquals1 { case unLoc $1 of
1159 qss -> L1 [L1 (ParStmt stmtss)]
1161 stmtss = [ (reverse qs, undefined)
1165 pquals1 :: { Located [[LStmt RdrName]] }
1166 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1167 | '|' quals { L (getLoc $2) [unLoc $2] }
1169 quals :: { Located [LStmt RdrName] }
1170 : quals ',' qual { LL ($3 : unLoc $1) }
1173 -----------------------------------------------------------------------------
1174 -- Parallel array expressions
1176 -- The rules below are little bit contorted; see the list case for details.
1177 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1178 -- Moreover, we allow explicit arrays with no element (represented by the nil
1179 -- constructor in the list case).
1181 parr :: { LHsExpr RdrName }
1182 : { noLoc (ExplicitPArr placeHolderType []) }
1183 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1184 | lexps { L1 $ ExplicitPArr placeHolderType
1185 (reverse (unLoc $1)) }
1186 | exp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1187 | exp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1188 | exp pquals { sL (comb2 $1 $>) $ mkHsDo PArrComp (reverse (unLoc $2)) $1 }
1190 -- We are reusing `lexps' and `pquals' from the list case.
1192 -----------------------------------------------------------------------------
1193 -- Case alternatives
1195 altslist :: { Located [LMatch RdrName] }
1196 : '{' alts '}' { LL (reverse (unLoc $2)) }
1197 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1199 alts :: { Located [LMatch RdrName] }
1200 : alts1 { L1 (unLoc $1) }
1201 | ';' alts { LL (unLoc $2) }
1203 alts1 :: { Located [LMatch RdrName] }
1204 : alts1 ';' alt { LL ($3 : unLoc $1) }
1205 | alts1 ';' { LL (unLoc $1) }
1208 alt :: { LMatch RdrName }
1209 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1210 return (LL (Match [p] $2 (unLoc $3))) }
1211 | '!' infixexp opt_sig alt_rhs {% checkPattern $2 >>= \p ->
1212 return (LL (Match [LL $ BangPat p] $3 (unLoc $4))) }
1214 alt_rhs :: { Located (GRHSs RdrName) }
1215 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1217 ralt :: { Located [LGRHS RdrName] }
1218 : '->' exp { LL (unguardedRHS $2) }
1219 | gdpats { L1 (reverse (unLoc $1)) }
1221 gdpats :: { Located [LGRHS RdrName] }
1222 : gdpats gdpat { LL ($2 : unLoc $1) }
1225 gdpat :: { LGRHS RdrName }
1226 : '|' quals '->' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
1228 -----------------------------------------------------------------------------
1229 -- Statement sequences
1231 stmtlist :: { Located [LStmt RdrName] }
1232 : '{' stmts '}' { LL (unLoc $2) }
1233 | vocurly stmts close { $2 }
1235 -- do { ;; s ; s ; ; s ;; }
1236 -- The last Stmt should be an expression, but that's hard to enforce
1237 -- here, because we need too much lookahead if we see do { e ; }
1238 -- So we use ExprStmts throughout, and switch the last one over
1239 -- in ParseUtils.checkDo instead
1240 stmts :: { Located [LStmt RdrName] }
1241 : stmt stmts_help { LL ($1 : unLoc $2) }
1242 | ';' stmts { LL (unLoc $2) }
1243 | {- empty -} { noLoc [] }
1245 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1246 : ';' stmts { LL (unLoc $2) }
1247 | {- empty -} { noLoc [] }
1249 -- For typing stmts at the GHCi prompt, where
1250 -- the input may consist of just comments.
1251 maybe_stmt :: { Maybe (LStmt RdrName) }
1253 | {- nothing -} { Nothing }
1255 stmt :: { LStmt RdrName }
1257 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1258 return (LL $ mkBindStmt p $1) }
1259 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1261 qual :: { LStmt RdrName }
1262 : exp '<-' exp {% checkPattern $1 >>= \p ->
1263 return (LL $ mkBindStmt p $3) }
1264 | exp { L1 $ mkExprStmt $1 }
1265 | 'let' binds { LL $ LetStmt (unLoc $2) }
1267 -----------------------------------------------------------------------------
1268 -- Record Field Update/Construction
1270 fbinds :: { HsRecordBinds RdrName }
1272 | {- empty -} { [] }
1274 fbinds1 :: { HsRecordBinds RdrName }
1275 : fbinds1 ',' fbind { $3 : $1 }
1278 fbind :: { (Located RdrName, LHsExpr RdrName) }
1279 : qvar '=' exp { ($1,$3) }
1281 -----------------------------------------------------------------------------
1282 -- Implicit Parameter Bindings
1284 dbinds :: { Located [LIPBind RdrName] }
1285 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1286 | dbinds ';' { LL (unLoc $1) }
1288 -- | {- empty -} { [] }
1290 dbind :: { LIPBind RdrName }
1291 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1293 ipvar :: { Located (IPName RdrName) }
1294 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1295 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1297 -----------------------------------------------------------------------------
1300 depreclist :: { Located [RdrName] }
1301 depreclist : deprec_var { L1 [unLoc $1] }
1302 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1304 deprec_var :: { Located RdrName }
1305 deprec_var : var { $1 }
1308 -----------------------------------------
1309 -- Data constructors
1310 qcon :: { Located RdrName }
1312 | '(' qconsym ')' { LL (unLoc $2) }
1313 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1314 -- The case of '[:' ':]' is part of the production `parr'
1316 con :: { Located RdrName }
1318 | '(' consym ')' { LL (unLoc $2) }
1319 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1321 sysdcon :: { Located DataCon } -- Wired in data constructors
1322 : '(' ')' { LL unitDataCon }
1323 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1324 | '[' ']' { LL nilDataCon }
1326 conop :: { Located RdrName }
1328 | '`' conid '`' { LL (unLoc $2) }
1330 qconop :: { Located RdrName }
1332 | '`' qconid '`' { LL (unLoc $2) }
1334 -----------------------------------------------------------------------------
1335 -- Type constructors
1337 gtycon :: { Located RdrName } -- A "general" qualified tycon
1339 | '(' ')' { LL $ getRdrName unitTyCon }
1340 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1341 | '(' '->' ')' { LL $ getRdrName funTyCon }
1342 | '[' ']' { LL $ listTyCon_RDR }
1343 | '[:' ':]' { LL $ parrTyCon_RDR }
1345 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1347 | '(' qtyconsym ')' { LL (unLoc $2) }
1349 qtyconop :: { Located RdrName } -- Qualified or unqualified
1351 | '`' qtycon '`' { LL (unLoc $2) }
1353 qtycon :: { Located RdrName } -- Qualified or unqualified
1354 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1357 tycon :: { Located RdrName } -- Unqualified
1358 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1360 qtyconsym :: { Located RdrName }
1361 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1364 tyconsym :: { Located RdrName }
1365 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1367 -----------------------------------------------------------------------------
1370 op :: { Located RdrName } -- used in infix decls
1374 varop :: { Located RdrName }
1376 | '`' varid '`' { LL (unLoc $2) }
1378 qop :: { LHsExpr RdrName } -- used in sections
1379 : qvarop { L1 $ HsVar (unLoc $1) }
1380 | qconop { L1 $ HsVar (unLoc $1) }
1382 qopm :: { LHsExpr RdrName } -- used in sections
1383 : qvaropm { L1 $ HsVar (unLoc $1) }
1384 | qconop { L1 $ HsVar (unLoc $1) }
1386 qvarop :: { Located RdrName }
1388 | '`' qvarid '`' { LL (unLoc $2) }
1390 qvaropm :: { Located RdrName }
1391 : qvarsym_no_minus { $1 }
1392 | '`' qvarid '`' { LL (unLoc $2) }
1394 -----------------------------------------------------------------------------
1397 tyvar :: { Located RdrName }
1398 tyvar : tyvarid { $1 }
1399 | '(' tyvarsym ')' { LL (unLoc $2) }
1401 tyvarop :: { Located RdrName }
1402 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1405 tyvarid :: { Located RdrName }
1406 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1407 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1408 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1409 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1410 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1412 tyvarsym :: { Located RdrName }
1413 -- Does not include "!", because that is used for strictness marks
1414 -- or ".", because that separates the quantified type vars from the rest
1415 -- or "*", because that's used for kinds
1416 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1418 -----------------------------------------------------------------------------
1421 var :: { Located RdrName }
1423 | '(' varsym ')' { LL (unLoc $2) }
1425 qvar :: { Located RdrName }
1427 | '(' varsym ')' { LL (unLoc $2) }
1428 | '(' qvarsym1 ')' { LL (unLoc $2) }
1429 -- We've inlined qvarsym here so that the decision about
1430 -- whether it's a qvar or a var can be postponed until
1431 -- *after* we see the close paren.
1433 qvarid :: { Located RdrName }
1435 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1437 varid :: { Located RdrName }
1438 : varid_no_unsafe { $1 }
1439 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1440 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1441 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1443 varid_no_unsafe :: { Located RdrName }
1444 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1445 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1446 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1448 qvarsym :: { Located RdrName }
1452 qvarsym_no_minus :: { Located RdrName }
1453 : varsym_no_minus { $1 }
1456 qvarsym1 :: { Located RdrName }
1457 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1459 varsym :: { Located RdrName }
1460 : varsym_no_minus { $1 }
1461 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1463 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1464 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1465 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1468 -- These special_ids are treated as keywords in various places,
1469 -- but as ordinary ids elsewhere. 'special_id' collects all these
1470 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1471 special_id :: { Located FastString }
1473 : 'as' { L1 FSLIT("as") }
1474 | 'qualified' { L1 FSLIT("qualified") }
1475 | 'hiding' { L1 FSLIT("hiding") }
1476 | 'export' { L1 FSLIT("export") }
1477 | 'label' { L1 FSLIT("label") }
1478 | 'dynamic' { L1 FSLIT("dynamic") }
1479 | 'stdcall' { L1 FSLIT("stdcall") }
1480 | 'ccall' { L1 FSLIT("ccall") }
1481 | 'iso' { L1 FSLIT("iso") }
1483 special_sym :: { Located FastString }
1484 special_sym : '!' { L1 FSLIT("!") }
1485 | '.' { L1 FSLIT(".") }
1486 | '*' { L1 FSLIT("*") }
1488 -----------------------------------------------------------------------------
1489 -- Data constructors
1491 qconid :: { Located RdrName } -- Qualified or unqualified
1493 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1495 conid :: { Located RdrName }
1496 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1498 qconsym :: { Located RdrName } -- Qualified or unqualified
1500 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1502 consym :: { Located RdrName }
1503 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1505 -- ':' means only list cons
1506 | ':' { L1 $ consDataCon_RDR }
1509 -----------------------------------------------------------------------------
1512 literal :: { Located HsLit }
1513 : CHAR { L1 $ HsChar $ getCHAR $1 }
1514 | STRING { L1 $ HsString $ getSTRING $1 }
1515 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1516 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1517 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1518 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1519 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1521 -----------------------------------------------------------------------------
1525 : vccurly { () } -- context popped in lexer.
1526 | error {% popContext }
1528 -----------------------------------------------------------------------------
1529 -- Miscellaneous (mostly renamings)
1531 modid :: { Located ModuleName }
1532 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1533 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1536 (unpackFS mod ++ '.':unpackFS c))
1540 : commas ',' { $1 + 1 }
1543 -----------------------------------------------------------------------------
1547 happyError = srcParseFail
1549 getVARID (L _ (ITvarid x)) = x
1550 getCONID (L _ (ITconid x)) = x
1551 getVARSYM (L _ (ITvarsym x)) = x
1552 getCONSYM (L _ (ITconsym x)) = x
1553 getQVARID (L _ (ITqvarid x)) = x
1554 getQCONID (L _ (ITqconid x)) = x
1555 getQVARSYM (L _ (ITqvarsym x)) = x
1556 getQCONSYM (L _ (ITqconsym x)) = x
1557 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1558 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1559 getCHAR (L _ (ITchar x)) = x
1560 getSTRING (L _ (ITstring x)) = x
1561 getINTEGER (L _ (ITinteger x)) = x
1562 getRATIONAL (L _ (ITrational x)) = x
1563 getPRIMCHAR (L _ (ITprimchar x)) = x
1564 getPRIMSTRING (L _ (ITprimstring x)) = x
1565 getPRIMINTEGER (L _ (ITprimint x)) = x
1566 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1567 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1568 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1569 getINLINE (L _ (ITinline_prag b)) = b
1570 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
1572 -- Utilities for combining source spans
1573 comb2 :: Located a -> Located b -> SrcSpan
1576 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1577 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1579 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1580 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1581 combineSrcSpans (getLoc c) (getLoc d)
1583 -- strict constructor version:
1585 sL :: SrcSpan -> a -> Located a
1586 sL span a = span `seq` L span a
1588 -- Make a source location for the file. We're a bit lazy here and just
1589 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1590 -- try to find the span of the whole file (ToDo).
1591 fileSrcSpan :: P SrcSpan
1594 let loc = mkSrcLoc (srcLocFile l) 1 0;
1595 return (mkSrcSpan loc loc)