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 ( UserFS, 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 )
36 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
42 import Maybes ( orElse )
48 -----------------------------------------------------------------------------
49 Conflicts: 36 shift/reduce (1.25)
51 10 for abiguity in 'if x then y else z + 1' [State 178]
52 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
53 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
55 1 for ambiguity in 'if x then y else z :: T' [State 178]
56 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
58 4 for ambiguity in 'if x then y else z -< e' [State 178]
59 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
60 There are four such operators: -<, >-, -<<, >>-
63 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
64 Which of these two is intended?
66 (x::T) -> T -- Rhs is T
69 (x::T -> T) -> .. -- Rhs is ...
71 10 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
74 As well as `b` we can have !, VARSYM, QCONSYM, and CONSYM, hence 5 cases
75 Same duplication between states 11 and 253 as the previous case
77 1 for ambiguity in 'let ?x ...' [State 329]
78 the parser can't tell whether the ?x is the lhs of a normal binding or
79 an implicit binding. Fortunately resolving as shift gives it the only
80 sensible meaning, namely the lhs of an implicit binding.
82 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
83 we don't know whether the '[' starts the activation or not: it
84 might be the start of the declaration with the activation being
87 6 for conflicts between `fdecl' and `fdeclDEPRECATED', [States 393,394]
88 which are resolved correctly, and moreover,
89 should go away when `fdeclDEPRECATED' is removed.
91 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
92 since 'forall' is a valid variable name, we don't know whether
93 to treat a forall on the input as the beginning of a quantifier
94 or the beginning of the rule itself. Resolving to shift means
95 it's always treated as a quantifier, hence the above is disallowed.
96 This saves explicitly defining a grammar for the rule lhs that
97 doesn't include 'forall'.
99 -- ---------------------------------------------------------------------------
100 -- Adding location info
102 This is done in a stylised way using the three macros below, L0, L1
103 and LL. Each of these macros can be thought of as having type
105 L0, L1, LL :: a -> Located a
107 They each add a SrcSpan to their argument.
109 L0 adds 'noSrcSpan', used for empty productions
111 L1 for a production with a single token on the lhs. Grabs the SrcSpan
114 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
115 the first and last tokens.
117 These suffice for the majority of cases. However, we must be
118 especially careful with empty productions: LL won't work if the first
119 or last token on the lhs can represent an empty span. In these cases,
120 we have to calculate the span using more of the tokens from the lhs, eg.
122 | 'newtype' tycl_hdr '=' newconstr deriving
124 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
126 We provide comb3 and comb4 functions which are useful in such cases.
128 Be careful: there's no checking that you actually got this right, the
129 only symptom will be that the SrcSpans of your syntax will be
133 * We must expand these macros *before* running Happy, which is why this file is
134 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
136 #define L0 L noSrcSpan
137 #define L1 sL (getLoc $1)
138 #define LL sL (comb2 $1 $>)
140 -- -----------------------------------------------------------------------------
145 '_' { L _ ITunderscore } -- Haskell keywords
147 'case' { L _ ITcase }
148 'class' { L _ ITclass }
149 'data' { L _ ITdata }
150 'default' { L _ ITdefault }
151 'deriving' { L _ ITderiving }
153 'else' { L _ ITelse }
154 'hiding' { L _ IThiding }
156 'import' { L _ ITimport }
158 'infix' { L _ ITinfix }
159 'infixl' { L _ ITinfixl }
160 'infixr' { L _ ITinfixr }
161 'instance' { L _ ITinstance }
163 'module' { L _ ITmodule }
164 'newtype' { L _ ITnewtype }
166 'qualified' { L _ ITqualified }
167 'then' { L _ ITthen }
168 'type' { L _ ITtype }
169 'where' { L _ ITwhere }
170 '_scc_' { L _ ITscc } -- ToDo: remove
172 'forall' { L _ ITforall } -- GHC extension keywords
173 'foreign' { L _ ITforeign }
174 'export' { L _ ITexport }
175 'label' { L _ ITlabel }
176 'dynamic' { L _ ITdynamic }
177 'safe' { L _ ITsafe }
178 'threadsafe' { L _ ITthreadsafe }
179 'unsafe' { L _ ITunsafe }
181 'stdcall' { L _ ITstdcallconv }
182 'ccall' { L _ ITccallconv }
183 'dotnet' { L _ ITdotnet }
184 'proc' { L _ ITproc } -- for arrow notation extension
185 'rec' { L _ ITrec } -- for arrow notation extension
187 '{-# SPECIALISE' { L _ ITspecialise_prag }
188 '{-# SOURCE' { L _ ITsource_prag }
189 '{-# INLINE' { L _ ITinline_prag }
190 '{-# NOINLINE' { L _ ITnoinline_prag }
191 '{-# RULES' { L _ ITrules_prag }
192 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
193 '{-# SCC' { L _ ITscc_prag }
194 '{-# DEPRECATED' { L _ ITdeprecated_prag }
195 '{-# UNPACK' { L _ ITunpack_prag }
196 '#-}' { L _ ITclose_prag }
198 '..' { L _ ITdotdot } -- reserved symbols
200 '::' { L _ ITdcolon }
204 '<-' { L _ ITlarrow }
205 '->' { L _ ITrarrow }
208 '=>' { L _ ITdarrow }
212 '-<' { L _ ITlarrowtail } -- for arrow notation
213 '>-' { L _ ITrarrowtail } -- for arrow notation
214 '-<<' { L _ ITLarrowtail } -- for arrow notation
215 '>>-' { L _ ITRarrowtail } -- for arrow notation
218 '{' { L _ ITocurly } -- special symbols
220 '{|' { L _ ITocurlybar }
221 '|}' { L _ ITccurlybar }
222 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
223 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
226 '[:' { L _ ITopabrack }
227 ':]' { L _ ITcpabrack }
230 '(#' { L _ IToubxparen }
231 '#)' { L _ ITcubxparen }
232 '(|' { L _ IToparenbar }
233 '|)' { L _ ITcparenbar }
236 '`' { L _ ITbackquote }
238 VARID { L _ (ITvarid _) } -- identifiers
239 CONID { L _ (ITconid _) }
240 VARSYM { L _ (ITvarsym _) }
241 CONSYM { L _ (ITconsym _) }
242 QVARID { L _ (ITqvarid _) }
243 QCONID { L _ (ITqconid _) }
244 QVARSYM { L _ (ITqvarsym _) }
245 QCONSYM { L _ (ITqconsym _) }
247 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
248 IPSPLITVARID { L _ (ITsplitipvarid _) } -- GHC extension
250 CHAR { L _ (ITchar _) }
251 STRING { L _ (ITstring _) }
252 INTEGER { L _ (ITinteger _) }
253 RATIONAL { L _ (ITrational _) }
255 PRIMCHAR { L _ (ITprimchar _) }
256 PRIMSTRING { L _ (ITprimstring _) }
257 PRIMINTEGER { L _ (ITprimint _) }
258 PRIMFLOAT { L _ (ITprimfloat _) }
259 PRIMDOUBLE { L _ (ITprimdouble _) }
262 '[|' { L _ ITopenExpQuote }
263 '[p|' { L _ ITopenPatQuote }
264 '[t|' { L _ ITopenTypQuote }
265 '[d|' { L _ ITopenDecQuote }
266 '|]' { L _ ITcloseQuote }
267 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
268 '$(' { L _ ITparenEscape } -- $( exp )
269 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
270 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
272 %monad { P } { >>= } { return }
273 %lexer { lexer } { L _ ITeof }
274 %name parseModule module
275 %name parseStmt maybe_stmt
276 %name parseIdentifier identifier
277 %name parseType ctype
278 %partial parseHeader header
279 %tokentype { Located Token }
282 -----------------------------------------------------------------------------
283 -- Identifiers; one of the entry points
284 identifier :: { Located RdrName }
290 -----------------------------------------------------------------------------
293 -- The place for module deprecation is really too restrictive, but if it
294 -- was allowed at its natural place just before 'module', we get an ugly
295 -- s/r conflict with the second alternative. Another solution would be the
296 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
297 -- either, and DEPRECATED is only expected to be used by people who really
298 -- know what they are doing. :-)
300 module :: { Located (HsModule RdrName) }
301 : 'module' modid maybemoddeprec maybeexports 'where' body
302 {% fileSrcSpan >>= \ loc ->
303 return (L loc (HsModule (Just $2) $4 (fst $6) (snd $6) $3)) }
304 | missing_module_keyword top close
305 {% fileSrcSpan >>= \ loc ->
306 return (L loc (HsModule Nothing Nothing
307 (fst $2) (snd $2) Nothing)) }
309 missing_module_keyword :: { () }
310 : {- empty -} {% pushCurrentContext }
312 maybemoddeprec :: { Maybe DeprecTxt }
313 : '{-# DEPRECATED' STRING '#-}' { Just (getSTRING $2) }
314 | {- empty -} { Nothing }
316 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
318 | vocurly top close { $2 }
320 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
321 : importdecls { (reverse $1,[]) }
322 | importdecls ';' cvtopdecls { (reverse $1,$3) }
323 | cvtopdecls { ([],$1) }
325 cvtopdecls :: { [LHsDecl RdrName] }
326 : topdecls { cvTopDecls $1 }
328 -----------------------------------------------------------------------------
329 -- Module declaration & imports only
331 header :: { Located (HsModule RdrName) }
332 : 'module' modid maybemoddeprec maybeexports 'where' header_body
333 {% fileSrcSpan >>= \ loc ->
334 return (L loc (HsModule (Just $2) $4 $6 [] $3)) }
335 | missing_module_keyword importdecls
336 {% fileSrcSpan >>= \ loc ->
337 return (L loc (HsModule Nothing Nothing $2 [] Nothing)) }
339 header_body :: { [LImportDecl RdrName] }
340 : '{' importdecls { $2 }
341 | vocurly importdecls { $2 }
343 -----------------------------------------------------------------------------
346 maybeexports :: { Maybe [LIE RdrName] }
347 : '(' exportlist ')' { Just $2 }
348 | {- empty -} { Nothing }
350 exportlist :: { [LIE RdrName] }
351 : exportlist ',' export { $3 : $1 }
352 | exportlist ',' { $1 }
356 -- No longer allow things like [] and (,,,) to be exported
357 -- They are built in syntax, always available
358 export :: { LIE RdrName }
359 : qvar { L1 (IEVar (unLoc $1)) }
360 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
361 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
362 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
363 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
364 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
366 qcnames :: { [RdrName] }
367 : qcnames ',' qcname { unLoc $3 : $1 }
368 | qcname { [unLoc $1] }
370 qcname :: { Located RdrName } -- Variable or data constructor
374 -----------------------------------------------------------------------------
375 -- Import Declarations
377 -- import decls can be *empty*, or even just a string of semicolons
378 -- whereas topdecls must contain at least one topdecl.
380 importdecls :: { [LImportDecl RdrName] }
381 : importdecls ';' importdecl { $3 : $1 }
382 | importdecls ';' { $1 }
383 | importdecl { [ $1 ] }
386 importdecl :: { LImportDecl RdrName }
387 : 'import' maybe_src optqualified modid maybeas maybeimpspec
388 { L (comb4 $1 $4 $5 $6) (ImportDecl $4 $2 $3 (unLoc $5) (unLoc $6)) }
390 maybe_src :: { IsBootInterface }
391 : '{-# SOURCE' '#-}' { True }
392 | {- empty -} { False }
394 optqualified :: { Bool }
395 : 'qualified' { True }
396 | {- empty -} { False }
398 maybeas :: { Located (Maybe Module) }
399 : 'as' modid { LL (Just (unLoc $2)) }
400 | {- empty -} { noLoc Nothing }
402 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
403 : impspec { L1 (Just (unLoc $1)) }
404 | {- empty -} { noLoc Nothing }
406 impspec :: { Located (Bool, [LIE RdrName]) }
407 : '(' exportlist ')' { LL (False, reverse $2) }
408 | 'hiding' '(' exportlist ')' { LL (True, reverse $3) }
410 -----------------------------------------------------------------------------
411 -- Fixity Declarations
415 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
417 infix :: { Located FixityDirection }
418 : 'infix' { L1 InfixN }
419 | 'infixl' { L1 InfixL }
420 | 'infixr' { L1 InfixR }
422 ops :: { Located [Located RdrName] }
423 : ops ',' op { LL ($3 : unLoc $1) }
426 -----------------------------------------------------------------------------
427 -- Top-Level Declarations
429 topdecls :: { OrdList (LHsDecl RdrName) } -- Reversed
430 : topdecls ';' topdecl { $1 `appOL` $3 }
431 | topdecls ';' { $1 }
434 topdecl :: { OrdList (LHsDecl RdrName) }
435 : tycl_decl { unitOL (L1 (TyClD (unLoc $1))) }
436 | 'instance' inst_type where
437 { let (binds,sigs) = cvBindsAndSigs (unLoc $3)
438 in unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs))) }
439 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
440 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
441 | '{-# DEPRECATED' deprecations '#-}' { $2 }
442 | '{-# RULES' rules '#-}' { $2 }
443 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
446 tycl_decl :: { LTyClDecl RdrName }
447 : 'type' type '=' ctype
448 -- Note type on the left of the '='; this allows
449 -- infix type constructors to be declared
451 -- Note ctype, not sigtype, on the right
452 -- We allow an explicit for-all but we don't insert one
453 -- in type Foo a = (b,b)
454 -- Instead we just say b is out of scope
455 {% do { (tc,tvs) <- checkSynHdr $2
456 ; return (LL (TySynonym tc tvs $4)) } }
458 | 'data' tycl_hdr constrs deriving
459 { L (comb4 $1 $2 $3 $4) -- We need the location on tycl_hdr
460 -- in case constrs and deriving are both empty
461 (mkTyData DataType $2 Nothing (reverse (unLoc $3)) (unLoc $4)) }
463 | 'data' tycl_hdr opt_kind_sig
464 'where' gadt_constrlist
466 { L (comb4 $1 $2 $4 $5)
467 (mkTyData DataType $2 $3 (reverse (unLoc $5)) (unLoc $6)) }
469 | 'newtype' tycl_hdr '=' newconstr deriving
471 (mkTyData NewType $2 Nothing [$4] (unLoc $5)) }
473 | 'class' tycl_hdr fds where
475 (binds,sigs) = cvBindsAndSigs (unLoc $4)
477 L (comb4 $1 $2 $3 $4) (mkClassDecl (unLoc $2) (unLoc $3) sigs
480 opt_kind_sig :: { Maybe Kind }
482 | '::' kind { Just $2 }
484 -- tycl_hdr parses the header of a type or class decl,
485 -- which takes the form
488 -- (Eq a, Ord b) => T a b
489 -- Rather a lot of inlining here, else we get reduce/reduce errors
490 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
491 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
492 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
494 -----------------------------------------------------------------------------
495 -- Nested declarations
497 decls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
498 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
499 | decls ';' { LL (unLoc $1) }
501 | {- empty -} { noLoc nilOL }
504 decllist :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
505 : '{' decls '}' { LL (unLoc $2) }
506 | vocurly decls close { $2 }
508 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
509 -- No implicit parameters
510 : 'where' decllist { LL (unLoc $2) }
511 | {- empty -} { noLoc nilOL }
513 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
514 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
515 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
516 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
518 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
519 : 'where' binds { LL (unLoc $2) }
520 | {- empty -} { noLoc emptyLocalBinds }
523 -----------------------------------------------------------------------------
524 -- Transformation Rules
526 rules :: { OrdList (LHsDecl RdrName) } -- Reversed
527 : rules ';' rule { $1 `snocOL` $3 }
530 | {- empty -} { nilOL }
532 rule :: { LHsDecl RdrName }
533 : STRING activation rule_forall infixexp '=' exp
534 { LL $ RuleD (HsRule (getSTRING $1) $2 $3 $4 $6) }
536 activation :: { Activation } -- Omitted means AlwaysActive
537 : {- empty -} { AlwaysActive }
538 | explicit_activation { $1 }
540 inverse_activation :: { Activation } -- Omitted means NeverActive
541 : {- empty -} { NeverActive }
542 | explicit_activation { $1 }
544 explicit_activation :: { Activation } -- In brackets
545 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
546 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
548 rule_forall :: { [RuleBndr RdrName] }
549 : 'forall' rule_var_list '.' { $2 }
552 rule_var_list :: { [RuleBndr RdrName] }
554 | rule_var rule_var_list { $1 : $2 }
556 rule_var :: { RuleBndr RdrName }
557 : varid { RuleBndr $1 }
558 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
560 -----------------------------------------------------------------------------
561 -- Deprecations (c.f. rules)
563 deprecations :: { OrdList (LHsDecl RdrName) } -- Reversed
564 : deprecations ';' deprecation { $1 `appOL` $3 }
565 | deprecations ';' { $1 }
567 | {- empty -} { nilOL }
569 -- SUP: TEMPORARY HACK, not checking for `module Foo'
570 deprecation :: { OrdList (LHsDecl RdrName) }
572 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
576 -----------------------------------------------------------------------------
577 -- Foreign import and export declarations
579 -- for the time being, the following accepts foreign declarations conforming
580 -- to the FFI Addendum, Version 1.0 as well as pre-standard declarations
582 -- * a flag indicates whether pre-standard declarations have been used and
583 -- triggers a deprecation warning further down the road
585 -- NB: The first two rules could be combined into one by replacing `safety1'
586 -- with `safety'. However, the combined rule conflicts with the
589 fdecl :: { LHsDecl RdrName }
590 fdecl : 'import' callconv safety1 fspec
591 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
592 | 'import' callconv fspec
593 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
595 | 'export' callconv fspec
596 {% mkExport $2 (unLoc $3) >>= return.LL }
597 -- the following syntax is DEPRECATED
598 | fdecl1DEPRECATED { L1 (ForD (unLoc $1)) }
599 | fdecl2DEPRECATED { L1 (unLoc $1) }
601 fdecl1DEPRECATED :: { LForeignDecl RdrName }
603 ----------- DEPRECATED label decls ------------
604 : 'label' ext_name varid '::' sigtype
605 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
606 (CLabel ($2 `orElse` mkExtName (unLoc $3)))) True }
608 ----------- DEPRECATED ccall/stdcall decls ------------
610 -- NB: This business with the case expression below may seem overly
611 -- complicated, but it is necessary to avoid some conflicts.
613 -- DEPRECATED variant #1: lack of a calling convention specification
615 | 'import' {-no callconv-} ext_name safety varid_no_unsafe '::' sigtype
617 target = StaticTarget ($2 `orElse` mkExtName (unLoc $4))
619 LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
620 (CFunction target)) True }
622 -- DEPRECATED variant #2: external name consists of two separate strings
623 -- (module name and function name) (import)
624 | 'import' callconv STRING STRING safety varid_no_unsafe '::' sigtype
626 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
627 CCall cconv -> return $
629 imp = CFunction (StaticTarget (getSTRING $4))
631 LL $ ForeignImport $6 $8 (CImport cconv $5 nilFS nilFS imp) True }
633 -- DEPRECATED variant #3: `unsafe' after entity
634 | 'import' callconv STRING 'unsafe' varid_no_unsafe '::' sigtype
636 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
637 CCall cconv -> return $
639 imp = CFunction (StaticTarget (getSTRING $3))
641 LL $ ForeignImport $5 $7 (CImport cconv PlayRisky nilFS nilFS imp) True }
643 -- DEPRECATED variant #4: use of the special identifier `dynamic' without
644 -- an explicit calling convention (import)
645 | 'import' {-no callconv-} 'dynamic' safety varid_no_unsafe '::' sigtype
646 { LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
647 (CFunction DynamicTarget)) True }
649 -- DEPRECATED variant #5: use of the special identifier `dynamic' (import)
650 | 'import' callconv 'dynamic' safety varid_no_unsafe '::' sigtype
652 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
653 CCall cconv -> return $
654 LL $ ForeignImport $5 $7 (CImport cconv $4 nilFS nilFS
655 (CFunction DynamicTarget)) True }
657 -- DEPRECATED variant #6: lack of a calling convention specification
659 | 'export' {-no callconv-} ext_name varid '::' sigtype
660 { LL $ ForeignExport $3 $5 (CExport (CExportStatic ($2 `orElse` mkExtName (unLoc $3))
661 defaultCCallConv)) True }
663 -- DEPRECATED variant #7: external name consists of two separate strings
664 -- (module name and function name) (export)
665 | 'export' callconv STRING STRING varid '::' sigtype
667 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
668 CCall cconv -> return $
669 LL $ ForeignExport $5 $7
670 (CExport (CExportStatic (getSTRING $4) cconv)) True }
672 -- DEPRECATED variant #8: use of the special identifier `dynamic' without
673 -- an explicit calling convention (export)
674 | 'export' {-no callconv-} 'dynamic' varid '::' sigtype
675 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
678 -- DEPRECATED variant #9: use of the special identifier `dynamic' (export)
679 | 'export' callconv 'dynamic' varid '::' sigtype
681 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
682 CCall cconv -> return $
683 LL $ ForeignImport $4 $6
684 (CImport cconv (PlaySafe False) nilFS nilFS CWrapper) True }
686 ----------- DEPRECATED .NET decls ------------
687 -- NB: removed the .NET call declaration, as it is entirely subsumed
688 -- by the new standard FFI declarations
690 fdecl2DEPRECATED :: { LHsDecl RdrName }
692 : 'import' 'dotnet' 'type' ext_name tycon { LL $ TyClD (ForeignType $5 $4 DNType) }
693 -- left this one unchanged for the moment as type imports are not
694 -- covered currently by the FFI standard -=chak
697 callconv :: { CallConv }
698 : 'stdcall' { CCall StdCallConv }
699 | 'ccall' { CCall CCallConv }
700 | 'dotnet' { DNCall }
703 : 'unsafe' { PlayRisky }
704 | 'safe' { PlaySafe False }
705 | 'threadsafe' { PlaySafe True }
706 | {- empty -} { PlaySafe False }
708 safety1 :: { Safety }
709 : 'unsafe' { PlayRisky }
710 | 'safe' { PlaySafe False }
711 | 'threadsafe' { PlaySafe True }
712 -- only needed to avoid conflicts with the DEPRECATED rules
714 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
715 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
716 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
717 -- if the entity string is missing, it defaults to the empty string;
718 -- the meaning of an empty entity string depends on the calling
722 ext_name :: { Maybe CLabelString }
723 : STRING { Just (getSTRING $1) }
724 | STRING STRING { Just (getSTRING $2) } -- Ignore "module name" for now
725 | {- empty -} { Nothing }
728 -----------------------------------------------------------------------------
731 opt_sig :: { Maybe (LHsType RdrName) }
732 : {- empty -} { Nothing }
733 | '::' sigtype { Just $2 }
735 opt_asig :: { Maybe (LHsType RdrName) }
736 : {- empty -} { Nothing }
737 | '::' atype { Just $2 }
739 sigtypes1 :: { [LHsType RdrName] }
741 | sigtype ',' sigtypes1 { $1 : $3 }
743 sigtype :: { LHsType RdrName }
744 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
745 -- Wrap an Implicit forall if there isn't one there already
747 sig_vars :: { Located [Located RdrName] }
748 : sig_vars ',' var { LL ($3 : unLoc $1) }
751 -----------------------------------------------------------------------------
754 strict_mark :: { Located HsBang }
755 : '!' { L1 HsStrict }
756 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
758 -- A ctype is a for-all type
759 ctype :: { LHsType RdrName }
760 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
761 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
762 -- A type of form (context => type) is an *implicit* HsForAllTy
765 -- We parse a context as a btype so that we don't get reduce/reduce
766 -- errors in ctype. The basic problem is that
768 -- looks so much like a tuple type. We can't tell until we find the =>
769 context :: { LHsContext RdrName }
770 : btype {% checkContext $1 }
772 type :: { LHsType RdrName }
773 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
776 gentype :: { LHsType RdrName }
778 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
779 | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 }
780 | btype '->' gentype { LL $ HsFunTy $1 $3 }
782 btype :: { LHsType RdrName }
783 : btype atype { LL $ HsAppTy $1 $2 }
786 atype :: { LHsType RdrName }
787 : gtycon { L1 (HsTyVar (unLoc $1)) }
788 | tyvar { L1 (HsTyVar (unLoc $1)) }
789 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
790 | '(' type ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
791 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
792 | '[' type ']' { LL $ HsListTy $2 }
793 | '[:' type ':]' { LL $ HsPArrTy $2 }
794 | '(' ctype ')' { LL $ HsParTy $2 }
795 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
797 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
799 -- An inst_type is what occurs in the head of an instance decl
800 -- e.g. (Foo a, Gaz b) => Wibble a b
801 -- It's kept as a single type, with a MonoDictTy at the right
802 -- hand corner, for convenience.
803 inst_type :: { LHsType RdrName }
804 : sigtype {% checkInstType $1 }
806 inst_types1 :: { [LHsType RdrName] }
808 | inst_type ',' inst_types1 { $1 : $3 }
810 comma_types0 :: { [LHsType RdrName] }
811 : comma_types1 { $1 }
814 comma_types1 :: { [LHsType RdrName] }
816 | type ',' comma_types1 { $1 : $3 }
818 tv_bndrs :: { [LHsTyVarBndr RdrName] }
819 : tv_bndr tv_bndrs { $1 : $2 }
822 tv_bndr :: { LHsTyVarBndr RdrName }
823 : tyvar { L1 (UserTyVar (unLoc $1)) }
824 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
826 fds :: { Located [Located ([RdrName], [RdrName])] }
827 : {- empty -} { noLoc [] }
828 | '|' fds1 { LL (reverse (unLoc $2)) }
830 fds1 :: { Located [Located ([RdrName], [RdrName])] }
831 : fds1 ',' fd { LL ($3 : unLoc $1) }
834 fd :: { Located ([RdrName], [RdrName]) }
835 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
836 (reverse (unLoc $1), reverse (unLoc $3)) }
838 varids0 :: { Located [RdrName] }
839 : {- empty -} { noLoc [] }
840 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
842 -----------------------------------------------------------------------------
847 | akind '->' kind { mkArrowKind $1 $3 }
850 : '*' { liftedTypeKind }
851 | '(' kind ')' { $2 }
854 -----------------------------------------------------------------------------
855 -- Datatype declarations
857 newconstr :: { LConDecl RdrName }
858 : conid atype { LL $ ConDecl $1 Explicit [] (noLoc []) (PrefixCon [$2]) ResTyH98 }
859 | conid '{' var '::' ctype '}'
860 { LL $ ConDecl $1 Explicit [] (noLoc []) (RecCon [($3, $5)]) ResTyH98 }
862 gadt_constrlist :: { Located [LConDecl RdrName] }
863 : '{' gadt_constrs '}' { LL (unLoc $2) }
864 | vocurly gadt_constrs close { $2 }
866 gadt_constrs :: { Located [LConDecl RdrName] }
867 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
868 | gadt_constrs ';' { $1 }
869 | gadt_constr { L1 [$1] }
871 -- We allow the following forms:
872 -- C :: Eq a => a -> T a
873 -- C :: forall a. Eq a => !a -> T a
874 -- D { x,y :: a } :: T a
875 -- forall a. Eq a => D { x,y :: a } :: T a
877 gadt_constr :: { LConDecl RdrName }
879 { LL (mkGadtDecl $1 $3) }
880 -- Syntax: Maybe merge the record stuff with the single-case above?
881 -- (to kill the mostly harmless reduce/reduce error)
882 -- XXX revisit autrijus
883 | constr_stuff_record '::' sigtype
884 { let (con,details) = unLoc $1 in
885 LL (ConDecl con Implicit [] (noLoc []) details (ResTyGADT $3)) }
887 | forall context '=>' constr_stuff_record '::' sigtype
888 { let (con,details) = unLoc $4 in
889 LL (ConDecl con Implicit (unLoc $1) $2 details (ResTyGADT $6)) }
890 | forall constr_stuff_record '::' sigtype
891 { let (con,details) = unLoc $2 in
892 LL (ConDecl con Implicit (unLoc $1) (noLoc []) details (ResTyGADT $4)) }
896 constrs :: { Located [LConDecl RdrName] }
897 : {- empty; a GHC extension -} { noLoc [] }
898 | '=' constrs1 { LL (unLoc $2) }
900 constrs1 :: { Located [LConDecl RdrName] }
901 : constrs1 '|' constr { LL ($3 : unLoc $1) }
904 constr :: { LConDecl RdrName }
905 : forall context '=>' constr_stuff
906 { let (con,details) = unLoc $4 in
907 LL (ConDecl con Explicit (unLoc $1) $2 details ResTyH98) }
908 | forall constr_stuff
909 { let (con,details) = unLoc $2 in
910 LL (ConDecl con Explicit (unLoc $1) (noLoc []) details ResTyH98) }
912 forall :: { Located [LHsTyVarBndr RdrName] }
913 : 'forall' tv_bndrs '.' { LL $2 }
914 | {- empty -} { noLoc [] }
916 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
917 -- We parse the constructor declaration
919 -- as a btype (treating C as a type constructor) and then convert C to be
920 -- a data constructor. Reason: it might continue like this:
922 -- in which case C really would be a type constructor. We can't resolve this
923 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
924 : btype {% mkPrefixCon $1 [] >>= return.LL }
925 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
926 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
927 | btype conop btype { LL ($2, InfixCon $1 $3) }
929 constr_stuff_record :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
930 : oqtycon '{' '}' {% mkRecCon $1 [] >>= return.sL (comb2 $1 $>) }
931 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.sL (comb2 $1 $>) }
933 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
934 : fielddecl ',' fielddecls { unLoc $1 : $3 }
935 | fielddecl { [unLoc $1] }
937 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
938 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
940 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
941 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
942 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
943 -- We don't allow a context, but that's sorted out by the type checker.
944 deriving :: { Located (Maybe [LHsType RdrName]) }
945 : {- empty -} { noLoc Nothing }
946 | 'deriving' qtycon {% do { let { L loc tv = $2 }
947 ; p <- checkInstType (L loc (HsTyVar tv))
948 ; return (LL (Just [p])) } }
949 | 'deriving' '(' ')' { LL (Just []) }
950 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
951 -- Glasgow extension: allow partial
952 -- applications in derivings
954 -----------------------------------------------------------------------------
957 {- There's an awkward overlap with a type signature. Consider
958 f :: Int -> Int = ...rhs...
959 Then we can't tell whether it's a type signature or a value
960 definition with a result signature until we see the '='.
961 So we have to inline enough to postpone reductions until we know.
965 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
966 instead of qvar, we get another shift/reduce-conflict. Consider the
969 { (^^) :: Int->Int ; } Type signature; only var allowed
971 { (^^) :: Int->Int = ... ; } Value defn with result signature;
972 qvar allowed (because of instance decls)
974 We can't tell whether to reduce var to qvar until after we've read the signatures.
977 decl :: { Located (OrdList (LHsDecl RdrName)) }
979 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
980 return (LL $ unitOL (LL $ ValD r)) } }
982 rhs :: { Located (GRHSs RdrName) }
983 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
984 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
986 gdrhs :: { Located [LGRHS RdrName] }
987 : gdrhs gdrh { LL ($2 : unLoc $1) }
990 gdrh :: { LGRHS RdrName }
991 : '|' quals '=' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
993 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
994 : infixexp '::' sigtype
995 {% do s <- checkValSig $1 $3;
996 return (LL $ unitOL (LL $ SigD s)) }
997 -- See the above notes for why we need infixexp here
998 | var ',' sig_vars '::' sigtype
999 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
1000 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1002 | '{-# INLINE' activation qvar '#-}'
1003 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
1004 | '{-# NOINLINE' inverse_activation qvar '#-}'
1005 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
1006 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1007 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
1009 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1010 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1012 -----------------------------------------------------------------------------
1015 exp :: { LHsExpr RdrName }
1016 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1017 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1018 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1019 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1020 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1023 infixexp :: { LHsExpr RdrName }
1025 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1027 exp10 :: { LHsExpr RdrName }
1028 : '\\' aexp aexps opt_asig '->' exp
1029 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1030 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1031 (GRHSs (unguardedRHS $6) emptyLocalBinds
1033 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1034 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1035 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1036 | '-' fexp { LL $ mkHsNegApp $2 }
1038 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1039 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1040 return (L loc (mkHsDo DoExpr stmts body)) }
1041 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1042 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1043 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1044 | scc_annot exp { LL $ if opt_SccProfilingOn
1045 then HsSCC (unLoc $1) $2
1048 | 'proc' aexp '->' exp
1049 {% checkPattern $2 >>= \ p ->
1050 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1051 placeHolderType undefined)) }
1052 -- TODO: is LL right here?
1054 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1055 -- hdaume: core annotation
1058 scc_annot :: { Located FastString }
1059 : '_scc_' STRING { LL $ getSTRING $2 }
1060 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1062 fexp :: { LHsExpr RdrName }
1063 : fexp aexp { LL $ HsApp $1 $2 }
1066 aexps :: { [LHsExpr RdrName] }
1067 : aexps aexp { $2 : $1 }
1068 | {- empty -} { [] }
1070 aexp :: { LHsExpr RdrName }
1071 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1072 | '~' aexp { LL $ ELazyPat $2 }
1075 aexp1 :: { LHsExpr RdrName }
1076 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1081 -- Here was the syntax for type applications that I was planning
1082 -- but there are difficulties (e.g. what order for type args)
1083 -- so it's not enabled yet.
1084 -- But this case *is* used for the left hand side of a generic definition,
1085 -- which is parsed as an expression before being munged into a pattern
1086 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1087 (sL (getLoc $3) (HsType $3)) }
1089 aexp2 :: { LHsExpr RdrName }
1090 : ipvar { L1 (HsIPVar $! unLoc $1) }
1091 | qcname { L1 (HsVar $! unLoc $1) }
1092 | literal { L1 (HsLit $! unLoc $1) }
1093 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1094 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1095 | '(' exp ')' { LL (HsPar $2) }
1096 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1097 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1098 | '[' list ']' { LL (unLoc $2) }
1099 | '[:' parr ':]' { LL (unLoc $2) }
1100 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1101 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1102 | '_' { L1 EWildPat }
1104 -- MetaHaskell Extension
1105 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1106 (L1 $ HsVar (mkUnqual varName
1107 (getTH_ID_SPLICE $1)))) } -- $x
1108 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1110 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1111 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1112 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1113 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1114 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1115 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1116 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1117 return (LL $ HsBracket (PatBr p)) }
1118 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1120 -- arrow notation extension
1121 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1123 cmdargs :: { [LHsCmdTop RdrName] }
1124 : cmdargs acmd { $2 : $1 }
1125 | {- empty -} { [] }
1127 acmd :: { LHsCmdTop RdrName }
1128 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1130 cvtopbody :: { [LHsDecl RdrName] }
1131 : '{' cvtopdecls0 '}' { $2 }
1132 | vocurly cvtopdecls0 close { $2 }
1134 cvtopdecls0 :: { [LHsDecl RdrName] }
1135 : {- empty -} { [] }
1138 texps :: { [LHsExpr RdrName] }
1139 : texps ',' exp { $3 : $1 }
1143 -----------------------------------------------------------------------------
1146 -- The rules below are little bit contorted to keep lexps left-recursive while
1147 -- avoiding another shift/reduce-conflict.
1149 list :: { LHsExpr RdrName }
1150 : exp { L1 $ ExplicitList placeHolderType [$1] }
1151 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1152 | exp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1153 | exp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1154 | exp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1155 | exp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1156 | exp pquals { sL (comb2 $1 $>) $ mkHsDo ListComp (reverse (unLoc $2)) $1 }
1158 lexps :: { Located [LHsExpr RdrName] }
1159 : lexps ',' exp { LL ($3 : unLoc $1) }
1160 | exp ',' exp { LL [$3,$1] }
1162 -----------------------------------------------------------------------------
1163 -- List Comprehensions
1165 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1166 -- or a reversed list of Stmts
1167 : pquals1 { case unLoc $1 of
1169 qss -> L1 [L1 (ParStmt stmtss)]
1171 stmtss = [ (reverse qs, undefined)
1175 pquals1 :: { Located [[LStmt RdrName]] }
1176 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1177 | '|' quals { L (getLoc $2) [unLoc $2] }
1179 quals :: { Located [LStmt RdrName] }
1180 : quals ',' qual { LL ($3 : unLoc $1) }
1183 -----------------------------------------------------------------------------
1184 -- Parallel array expressions
1186 -- The rules below are little bit contorted; see the list case for details.
1187 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1188 -- Moreover, we allow explicit arrays with no element (represented by the nil
1189 -- constructor in the list case).
1191 parr :: { LHsExpr RdrName }
1192 : { noLoc (ExplicitPArr placeHolderType []) }
1193 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1194 | lexps { L1 $ ExplicitPArr placeHolderType
1195 (reverse (unLoc $1)) }
1196 | exp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1197 | exp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1198 | exp pquals { sL (comb2 $1 $>) $ mkHsDo PArrComp (reverse (unLoc $2)) $1 }
1200 -- We are reusing `lexps' and `pquals' from the list case.
1202 -----------------------------------------------------------------------------
1203 -- Case alternatives
1205 altslist :: { Located [LMatch RdrName] }
1206 : '{' alts '}' { LL (reverse (unLoc $2)) }
1207 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1209 alts :: { Located [LMatch RdrName] }
1210 : alts1 { L1 (unLoc $1) }
1211 | ';' alts { LL (unLoc $2) }
1213 alts1 :: { Located [LMatch RdrName] }
1214 : alts1 ';' alt { LL ($3 : unLoc $1) }
1215 | alts1 ';' { LL (unLoc $1) }
1218 alt :: { LMatch RdrName }
1219 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1220 return (LL (Match [p] $2 (unLoc $3))) }
1222 alt_rhs :: { Located (GRHSs RdrName) }
1223 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1225 ralt :: { Located [LGRHS RdrName] }
1226 : '->' exp { LL (unguardedRHS $2) }
1227 | gdpats { L1 (reverse (unLoc $1)) }
1229 gdpats :: { Located [LGRHS RdrName] }
1230 : gdpats gdpat { LL ($2 : unLoc $1) }
1233 gdpat :: { LGRHS RdrName }
1234 : '|' quals '->' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
1236 -----------------------------------------------------------------------------
1237 -- Statement sequences
1239 stmtlist :: { Located [LStmt RdrName] }
1240 : '{' stmts '}' { LL (unLoc $2) }
1241 | vocurly stmts close { $2 }
1243 -- do { ;; s ; s ; ; s ;; }
1244 -- The last Stmt should be an expression, but that's hard to enforce
1245 -- here, because we need too much lookahead if we see do { e ; }
1246 -- So we use ExprStmts throughout, and switch the last one over
1247 -- in ParseUtils.checkDo instead
1248 stmts :: { Located [LStmt RdrName] }
1249 : stmt stmts_help { LL ($1 : unLoc $2) }
1250 | ';' stmts { LL (unLoc $2) }
1251 | {- empty -} { noLoc [] }
1253 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1254 : ';' stmts { LL (unLoc $2) }
1255 | {- empty -} { noLoc [] }
1257 -- For typing stmts at the GHCi prompt, where
1258 -- the input may consist of just comments.
1259 maybe_stmt :: { Maybe (LStmt RdrName) }
1261 | {- nothing -} { Nothing }
1263 stmt :: { LStmt RdrName }
1265 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1266 return (LL $ mkBindStmt p $1) }
1267 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1269 qual :: { LStmt RdrName }
1270 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1271 return (LL $ mkBindStmt p $3) }
1272 | exp { L1 $ mkExprStmt $1 }
1273 | 'let' binds { LL $ LetStmt (unLoc $2) }
1275 -----------------------------------------------------------------------------
1276 -- Record Field Update/Construction
1278 fbinds :: { HsRecordBinds RdrName }
1280 | {- empty -} { [] }
1282 fbinds1 :: { HsRecordBinds RdrName }
1283 : fbinds1 ',' fbind { $3 : $1 }
1286 fbind :: { (Located RdrName, LHsExpr RdrName) }
1287 : qvar '=' exp { ($1,$3) }
1289 -----------------------------------------------------------------------------
1290 -- Implicit Parameter Bindings
1292 dbinds :: { Located [LIPBind RdrName] }
1293 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1294 | dbinds ';' { LL (unLoc $1) }
1296 -- | {- empty -} { [] }
1298 dbind :: { LIPBind RdrName }
1299 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1301 ipvar :: { Located (IPName RdrName) }
1302 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1303 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1305 -----------------------------------------------------------------------------
1308 depreclist :: { Located [RdrName] }
1309 depreclist : deprec_var { L1 [unLoc $1] }
1310 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1312 deprec_var :: { Located RdrName }
1313 deprec_var : var { $1 }
1316 -----------------------------------------
1317 -- Data constructors
1318 qcon :: { Located RdrName }
1320 | '(' qconsym ')' { LL (unLoc $2) }
1321 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1322 -- The case of '[:' ':]' is part of the production `parr'
1324 con :: { Located RdrName }
1326 | '(' consym ')' { LL (unLoc $2) }
1327 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1329 sysdcon :: { Located DataCon } -- Wired in data constructors
1330 : '(' ')' { LL unitDataCon }
1331 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1332 | '[' ']' { LL nilDataCon }
1334 conop :: { Located RdrName }
1336 | '`' conid '`' { LL (unLoc $2) }
1338 qconop :: { Located RdrName }
1340 | '`' qconid '`' { LL (unLoc $2) }
1342 -----------------------------------------------------------------------------
1343 -- Type constructors
1345 gtycon :: { Located RdrName } -- A "general" qualified tycon
1347 | '(' ')' { LL $ getRdrName unitTyCon }
1348 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1349 | '(' '->' ')' { LL $ getRdrName funTyCon }
1350 | '[' ']' { LL $ listTyCon_RDR }
1351 | '[:' ':]' { LL $ parrTyCon_RDR }
1353 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1355 | '(' qtyconsym ')' { LL (unLoc $2) }
1357 qtyconop :: { Located RdrName } -- Qualified or unqualified
1359 | '`' qtycon '`' { LL (unLoc $2) }
1361 qtycon :: { Located RdrName } -- Qualified or unqualified
1362 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1365 tycon :: { Located RdrName } -- Unqualified
1366 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1368 qtyconsym :: { Located RdrName }
1369 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1372 tyconsym :: { Located RdrName }
1373 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1375 -----------------------------------------------------------------------------
1378 op :: { Located RdrName } -- used in infix decls
1382 varop :: { Located RdrName }
1384 | '`' varid '`' { LL (unLoc $2) }
1386 qop :: { LHsExpr RdrName } -- used in sections
1387 : qvarop { L1 $ HsVar (unLoc $1) }
1388 | qconop { L1 $ HsVar (unLoc $1) }
1390 qopm :: { LHsExpr RdrName } -- used in sections
1391 : qvaropm { L1 $ HsVar (unLoc $1) }
1392 | qconop { L1 $ HsVar (unLoc $1) }
1394 qvarop :: { Located RdrName }
1396 | '`' qvarid '`' { LL (unLoc $2) }
1398 qvaropm :: { Located RdrName }
1399 : qvarsym_no_minus { $1 }
1400 | '`' qvarid '`' { LL (unLoc $2) }
1402 -----------------------------------------------------------------------------
1405 tyvar :: { Located RdrName }
1406 tyvar : tyvarid { $1 }
1407 | '(' tyvarsym ')' { LL (unLoc $2) }
1409 tyvarop :: { Located RdrName }
1410 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1413 tyvarid :: { Located RdrName }
1414 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1415 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1416 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1417 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1418 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1420 tyvarsym :: { Located RdrName }
1421 -- Does not include "!", because that is used for strictness marks
1422 -- or ".", because that separates the quantified type vars from the rest
1423 -- or "*", because that's used for kinds
1424 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1426 -----------------------------------------------------------------------------
1429 var :: { Located RdrName }
1431 | '(' varsym ')' { LL (unLoc $2) }
1433 qvar :: { Located RdrName }
1435 | '(' varsym ')' { LL (unLoc $2) }
1436 | '(' qvarsym1 ')' { LL (unLoc $2) }
1437 -- We've inlined qvarsym here so that the decision about
1438 -- whether it's a qvar or a var can be postponed until
1439 -- *after* we see the close paren.
1441 qvarid :: { Located RdrName }
1443 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1445 varid :: { Located RdrName }
1446 : varid_no_unsafe { $1 }
1447 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1448 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1449 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1451 varid_no_unsafe :: { Located RdrName }
1452 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1453 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1454 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1456 qvarsym :: { Located RdrName }
1460 qvarsym_no_minus :: { Located RdrName }
1461 : varsym_no_minus { $1 }
1464 qvarsym1 :: { Located RdrName }
1465 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1467 varsym :: { Located RdrName }
1468 : varsym_no_minus { $1 }
1469 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1471 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1472 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1473 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1476 -- These special_ids are treated as keywords in various places,
1477 -- but as ordinary ids elsewhere. 'special_id' collects all these
1478 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1479 special_id :: { Located UserFS }
1481 : 'as' { L1 FSLIT("as") }
1482 | 'qualified' { L1 FSLIT("qualified") }
1483 | 'hiding' { L1 FSLIT("hiding") }
1484 | 'export' { L1 FSLIT("export") }
1485 | 'label' { L1 FSLIT("label") }
1486 | 'dynamic' { L1 FSLIT("dynamic") }
1487 | 'stdcall' { L1 FSLIT("stdcall") }
1488 | 'ccall' { L1 FSLIT("ccall") }
1490 special_sym :: { Located UserFS }
1491 special_sym : '!' { L1 FSLIT("!") }
1492 | '.' { L1 FSLIT(".") }
1493 | '*' { L1 FSLIT("*") }
1495 -----------------------------------------------------------------------------
1496 -- Data constructors
1498 qconid :: { Located RdrName } -- Qualified or unqualified
1500 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1502 conid :: { Located RdrName }
1503 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1505 qconsym :: { Located RdrName } -- Qualified or unqualified
1507 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1509 consym :: { Located RdrName }
1510 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1512 -- ':' means only list cons
1513 | ':' { L1 $ consDataCon_RDR }
1516 -----------------------------------------------------------------------------
1519 literal :: { Located HsLit }
1520 : CHAR { L1 $ HsChar $ getCHAR $1 }
1521 | STRING { L1 $ HsString $ getSTRING $1 }
1522 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1523 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1524 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1525 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1526 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1528 -----------------------------------------------------------------------------
1532 : vccurly { () } -- context popped in lexer.
1533 | error {% popContext }
1535 -----------------------------------------------------------------------------
1536 -- Miscellaneous (mostly renamings)
1538 modid :: { Located Module }
1539 : CONID { L1 $ mkModuleFS (getCONID $1) }
1540 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1543 (unpackFS mod ++ '.':unpackFS c))
1547 : commas ',' { $1 + 1 }
1550 -----------------------------------------------------------------------------
1554 happyError = srcParseFail
1556 getVARID (L _ (ITvarid x)) = x
1557 getCONID (L _ (ITconid x)) = x
1558 getVARSYM (L _ (ITvarsym x)) = x
1559 getCONSYM (L _ (ITconsym x)) = x
1560 getQVARID (L _ (ITqvarid x)) = x
1561 getQCONID (L _ (ITqconid x)) = x
1562 getQVARSYM (L _ (ITqvarsym x)) = x
1563 getQCONSYM (L _ (ITqconsym x)) = x
1564 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1565 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1566 getCHAR (L _ (ITchar x)) = x
1567 getSTRING (L _ (ITstring x)) = x
1568 getINTEGER (L _ (ITinteger x)) = x
1569 getRATIONAL (L _ (ITrational x)) = x
1570 getPRIMCHAR (L _ (ITprimchar x)) = x
1571 getPRIMSTRING (L _ (ITprimstring x)) = x
1572 getPRIMINTEGER (L _ (ITprimint x)) = x
1573 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1574 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1575 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1577 -- Utilities for combining source spans
1578 comb2 :: Located a -> Located b -> SrcSpan
1581 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1582 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1584 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1585 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1586 combineSrcSpans (getLoc c) (getLoc d)
1588 -- strict constructor version:
1590 sL :: SrcSpan -> a -> Located a
1591 sL span a = span `seq` L span a
1593 -- Make a source location for the file. We're a bit lazy here and just
1594 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1595 -- try to find the span of the whole file (ToDo).
1596 fileSrcSpan :: P SrcSpan
1599 let loc = mkSrcLoc (srcLocFile l) 1 0;
1600 return (mkSrcSpan loc loc)