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 CmdLineOpts ( opt_SccProfilingOn )
35 import Type ( Kind, mkArrowKind, liftedTypeKind )
36 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
42 import Maybes ( orElse )
48 -----------------------------------------------------------------------------
49 Conflicts: 34 shift/reduce (1.15)
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 8 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
74 As well as `b` we can have !, QCONSYM, and CONSYM, hence 3 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 -----------------------------------------------------------------------------
285 -- The place for module deprecation is really too restrictive, but if it
286 -- was allowed at its natural place just before 'module', we get an ugly
287 -- s/r conflict with the second alternative. Another solution would be the
288 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
289 -- either, and DEPRECATED is only expected to be used by people who really
290 -- know what they are doing. :-)
292 module :: { Located (HsModule RdrName) }
293 : 'module' modid maybemoddeprec maybeexports 'where' body
294 {% fileSrcSpan >>= \ loc ->
295 return (L loc (HsModule (Just $2) $4 (fst $6) (snd $6) $3)) }
296 | missing_module_keyword top close
297 {% fileSrcSpan >>= \ loc ->
298 return (L loc (HsModule Nothing Nothing
299 (fst $2) (snd $2) Nothing)) }
301 missing_module_keyword :: { () }
302 : {- empty -} {% pushCurrentContext }
304 maybemoddeprec :: { Maybe DeprecTxt }
305 : '{-# DEPRECATED' STRING '#-}' { Just (getSTRING $2) }
306 | {- empty -} { Nothing }
308 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
310 | vocurly top close { $2 }
312 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
313 : importdecls { (reverse $1,[]) }
314 | importdecls ';' cvtopdecls { (reverse $1,$3) }
315 | cvtopdecls { ([],$1) }
317 cvtopdecls :: { [LHsDecl RdrName] }
318 : topdecls { cvTopDecls $1 }
320 -----------------------------------------------------------------------------
321 -- Module declaration & imports only
323 header :: { Located (HsModule RdrName) }
324 : 'module' modid maybemoddeprec maybeexports 'where' header_body
325 {% fileSrcSpan >>= \ loc ->
326 return (L loc (HsModule (Just $2) $4 $6 [] $3)) }
327 | missing_module_keyword importdecls
328 {% fileSrcSpan >>= \ loc ->
329 return (L loc (HsModule Nothing Nothing $2 [] Nothing)) }
331 header_body :: { [LImportDecl RdrName] }
332 : '{' importdecls { $2 }
333 | vocurly importdecls { $2 }
335 -----------------------------------------------------------------------------
338 maybeexports :: { Maybe [LIE RdrName] }
339 : '(' exportlist ')' { Just $2 }
340 | {- empty -} { Nothing }
342 exportlist :: { [LIE RdrName] }
343 : exportlist ',' export { $3 : $1 }
344 | exportlist ',' { $1 }
348 -- No longer allow things like [] and (,,,) to be exported
349 -- They are built in syntax, always available
350 export :: { LIE RdrName }
351 : qvar { L1 (IEVar (unLoc $1)) }
352 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
353 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
354 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
355 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
356 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
358 qcnames :: { [RdrName] }
359 : qcnames ',' qcname { unLoc $3 : $1 }
360 | qcname { [unLoc $1] }
362 qcname :: { Located RdrName } -- Variable or data constructor
366 -----------------------------------------------------------------------------
367 -- Import Declarations
369 -- import decls can be *empty*, or even just a string of semicolons
370 -- whereas topdecls must contain at least one topdecl.
372 importdecls :: { [LImportDecl RdrName] }
373 : importdecls ';' importdecl { $3 : $1 }
374 | importdecls ';' { $1 }
375 | importdecl { [ $1 ] }
378 importdecl :: { LImportDecl RdrName }
379 : 'import' maybe_src optqualified modid maybeas maybeimpspec
380 { L (comb4 $1 $4 $5 $6) (ImportDecl $4 $2 $3 (unLoc $5) (unLoc $6)) }
382 maybe_src :: { IsBootInterface }
383 : '{-# SOURCE' '#-}' { True }
384 | {- empty -} { False }
386 optqualified :: { Bool }
387 : 'qualified' { True }
388 | {- empty -} { False }
390 maybeas :: { Located (Maybe Module) }
391 : 'as' modid { LL (Just (unLoc $2)) }
392 | {- empty -} { noLoc Nothing }
394 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
395 : impspec { L1 (Just (unLoc $1)) }
396 | {- empty -} { noLoc Nothing }
398 impspec :: { Located (Bool, [LIE RdrName]) }
399 : '(' exportlist ')' { LL (False, reverse $2) }
400 | 'hiding' '(' exportlist ')' { LL (True, reverse $3) }
402 -----------------------------------------------------------------------------
403 -- Fixity Declarations
407 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
409 infix :: { Located FixityDirection }
410 : 'infix' { L1 InfixN }
411 | 'infixl' { L1 InfixL }
412 | 'infixr' { L1 InfixR }
414 ops :: { Located [Located RdrName] }
415 : ops ',' op { LL ($3 : unLoc $1) }
418 -----------------------------------------------------------------------------
419 -- Top-Level Declarations
421 topdecls :: { OrdList (LHsDecl RdrName) } -- Reversed
422 : topdecls ';' topdecl { $1 `appOL` $3 }
423 | topdecls ';' { $1 }
426 topdecl :: { OrdList (LHsDecl RdrName) }
427 : tycl_decl { unitOL (L1 (TyClD (unLoc $1))) }
428 | 'instance' inst_type where
429 { let (binds,sigs) = cvBindsAndSigs (unLoc $3)
430 in unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs))) }
431 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
432 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
433 | '{-# DEPRECATED' deprecations '#-}' { $2 }
434 | '{-# RULES' rules '#-}' { $2 }
435 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
438 tycl_decl :: { LTyClDecl RdrName }
439 : 'type' type '=' ctype
440 -- Note type on the left of the '='; this allows
441 -- infix type constructors to be declared
443 -- Note ctype, not sigtype, on the right
444 -- We allow an explicit for-all but we don't insert one
445 -- in type Foo a = (b,b)
446 -- Instead we just say b is out of scope
447 {% do { (tc,tvs) <- checkSynHdr $2
448 ; return (LL (TySynonym tc tvs $4)) } }
450 | 'data' tycl_hdr constrs deriving
451 { L (comb4 $1 $2 $3 $4) -- We need the location on tycl_hdr
452 -- in case constrs and deriving are both empty
453 (mkTyData DataType $2 Nothing (reverse (unLoc $3)) (unLoc $4)) }
455 | 'data' tycl_hdr opt_kind_sig 'where' gadt_constrlist -- No deriving for GADTs
456 { L (comb4 $1 $2 $4 $5)
457 (mkTyData DataType $2 $3 (reverse (unLoc $5)) Nothing) }
459 | 'newtype' tycl_hdr '=' newconstr deriving
461 (mkTyData NewType $2 Nothing [$4] (unLoc $5)) }
463 | 'class' tycl_hdr fds where
465 (binds,sigs) = cvBindsAndSigs (unLoc $4)
467 L (comb4 $1 $2 $3 $4) (mkClassDecl (unLoc $2) (unLoc $3) sigs
470 opt_kind_sig :: { Maybe Kind }
472 | '::' kind { Just $2 }
474 -- tycl_hdr parses the header of a type or class decl,
475 -- which takes the form
478 -- (Eq a, Ord b) => T a b
479 -- Rather a lot of inlining here, else we get reduce/reduce errors
480 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
481 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
482 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
484 -----------------------------------------------------------------------------
485 -- Nested declarations
487 decls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
488 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
489 | decls ';' { LL (unLoc $1) }
491 | {- empty -} { noLoc nilOL }
494 decllist :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
495 : '{' decls '}' { LL (unLoc $2) }
496 | vocurly decls close { $2 }
498 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
499 -- No implicit parameters
500 : 'where' decllist { LL (unLoc $2) }
501 | {- empty -} { noLoc nilOL }
503 binds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
504 : decllist { L1 [cvBindGroup (unLoc $1)] }
505 | '{' dbinds '}' { LL [HsIPBinds (unLoc $2)] }
506 | vocurly dbinds close { L (getLoc $2) [HsIPBinds (unLoc $2)] }
508 wherebinds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
509 : 'where' binds { LL (unLoc $2) }
510 | {- empty -} { noLoc [] }
513 -----------------------------------------------------------------------------
514 -- Transformation Rules
516 rules :: { OrdList (LHsDecl RdrName) } -- Reversed
517 : rules ';' rule { $1 `snocOL` $3 }
520 | {- empty -} { nilOL }
522 rule :: { LHsDecl RdrName }
523 : STRING activation rule_forall infixexp '=' exp
524 { LL $ RuleD (HsRule (getSTRING $1) $2 $3 $4 $6) }
526 activation :: { Activation } -- Omitted means AlwaysActive
527 : {- empty -} { AlwaysActive }
528 | explicit_activation { $1 }
530 inverse_activation :: { Activation } -- Omitted means NeverActive
531 : {- empty -} { NeverActive }
532 | explicit_activation { $1 }
534 explicit_activation :: { Activation } -- In brackets
535 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
536 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
538 rule_forall :: { [RuleBndr RdrName] }
539 : 'forall' rule_var_list '.' { $2 }
542 rule_var_list :: { [RuleBndr RdrName] }
544 | rule_var rule_var_list { $1 : $2 }
546 rule_var :: { RuleBndr RdrName }
547 : varid { RuleBndr $1 }
548 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
550 -----------------------------------------------------------------------------
551 -- Deprecations (c.f. rules)
553 deprecations :: { OrdList (LHsDecl RdrName) } -- Reversed
554 : deprecations ';' deprecation { $1 `appOL` $3 }
555 | deprecations ';' { $1 }
557 | {- empty -} { nilOL }
559 -- SUP: TEMPORARY HACK, not checking for `module Foo'
560 deprecation :: { OrdList (LHsDecl RdrName) }
562 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
566 -----------------------------------------------------------------------------
567 -- Foreign import and export declarations
569 -- for the time being, the following accepts foreign declarations conforming
570 -- to the FFI Addendum, Version 1.0 as well as pre-standard declarations
572 -- * a flag indicates whether pre-standard declarations have been used and
573 -- triggers a deprecation warning further down the road
575 -- NB: The first two rules could be combined into one by replacing `safety1'
576 -- with `safety'. However, the combined rule conflicts with the
579 fdecl :: { LHsDecl RdrName }
580 fdecl : 'import' callconv safety1 fspec
581 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
582 | 'import' callconv fspec
583 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
585 | 'export' callconv fspec
586 {% mkExport $2 (unLoc $3) >>= return.LL }
587 -- the following syntax is DEPRECATED
588 | fdecl1DEPRECATED { L1 (ForD (unLoc $1)) }
589 | fdecl2DEPRECATED { L1 (unLoc $1) }
591 fdecl1DEPRECATED :: { LForeignDecl RdrName }
593 ----------- DEPRECATED label decls ------------
594 : 'label' ext_name varid '::' sigtype
595 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
596 (CLabel ($2 `orElse` mkExtName (unLoc $3)))) True }
598 ----------- DEPRECATED ccall/stdcall decls ------------
600 -- NB: This business with the case expression below may seem overly
601 -- complicated, but it is necessary to avoid some conflicts.
603 -- DEPRECATED variant #1: lack of a calling convention specification
605 | 'import' {-no callconv-} ext_name safety varid_no_unsafe '::' sigtype
607 target = StaticTarget ($2 `orElse` mkExtName (unLoc $4))
609 LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
610 (CFunction target)) True }
612 -- DEPRECATED variant #2: external name consists of two separate strings
613 -- (module name and function name) (import)
614 | 'import' callconv STRING STRING safety varid_no_unsafe '::' sigtype
616 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
617 CCall cconv -> return $
619 imp = CFunction (StaticTarget (getSTRING $4))
621 LL $ ForeignImport $6 $8 (CImport cconv $5 nilFS nilFS imp) True }
623 -- DEPRECATED variant #3: `unsafe' after entity
624 | 'import' callconv STRING 'unsafe' varid_no_unsafe '::' sigtype
626 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
627 CCall cconv -> return $
629 imp = CFunction (StaticTarget (getSTRING $3))
631 LL $ ForeignImport $5 $7 (CImport cconv PlayRisky nilFS nilFS imp) True }
633 -- DEPRECATED variant #4: use of the special identifier `dynamic' without
634 -- an explicit calling convention (import)
635 | 'import' {-no callconv-} 'dynamic' safety varid_no_unsafe '::' sigtype
636 { LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
637 (CFunction DynamicTarget)) True }
639 -- DEPRECATED variant #5: use of the special identifier `dynamic' (import)
640 | 'import' callconv 'dynamic' safety varid_no_unsafe '::' sigtype
642 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
643 CCall cconv -> return $
644 LL $ ForeignImport $5 $7 (CImport cconv $4 nilFS nilFS
645 (CFunction DynamicTarget)) True }
647 -- DEPRECATED variant #6: lack of a calling convention specification
649 | 'export' {-no callconv-} ext_name varid '::' sigtype
650 { LL $ ForeignExport $3 $5 (CExport (CExportStatic ($2 `orElse` mkExtName (unLoc $3))
651 defaultCCallConv)) True }
653 -- DEPRECATED variant #7: external name consists of two separate strings
654 -- (module name and function name) (export)
655 | 'export' callconv STRING STRING varid '::' sigtype
657 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
658 CCall cconv -> return $
659 LL $ ForeignExport $5 $7
660 (CExport (CExportStatic (getSTRING $4) cconv)) True }
662 -- DEPRECATED variant #8: use of the special identifier `dynamic' without
663 -- an explicit calling convention (export)
664 | 'export' {-no callconv-} 'dynamic' varid '::' sigtype
665 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
668 -- DEPRECATED variant #9: use of the special identifier `dynamic' (export)
669 | 'export' callconv 'dynamic' varid '::' sigtype
671 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
672 CCall cconv -> return $
673 LL $ ForeignImport $4 $6
674 (CImport cconv (PlaySafe False) nilFS nilFS CWrapper) True }
676 ----------- DEPRECATED .NET decls ------------
677 -- NB: removed the .NET call declaration, as it is entirely subsumed
678 -- by the new standard FFI declarations
680 fdecl2DEPRECATED :: { LHsDecl RdrName }
682 : 'import' 'dotnet' 'type' ext_name tycon { LL $ TyClD (ForeignType $5 $4 DNType) }
683 -- left this one unchanged for the moment as type imports are not
684 -- covered currently by the FFI standard -=chak
687 callconv :: { CallConv }
688 : 'stdcall' { CCall StdCallConv }
689 | 'ccall' { CCall CCallConv }
690 | 'dotnet' { DNCall }
693 : 'unsafe' { PlayRisky }
694 | 'safe' { PlaySafe False }
695 | 'threadsafe' { PlaySafe True }
696 | {- empty -} { PlaySafe False }
698 safety1 :: { Safety }
699 : 'unsafe' { PlayRisky }
700 | 'safe' { PlaySafe False }
701 | 'threadsafe' { PlaySafe True }
702 -- only needed to avoid conflicts with the DEPRECATED rules
704 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
705 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
706 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
707 -- if the entity string is missing, it defaults to the empty string;
708 -- the meaning of an empty entity string depends on the calling
712 ext_name :: { Maybe CLabelString }
713 : STRING { Just (getSTRING $1) }
714 | STRING STRING { Just (getSTRING $2) } -- Ignore "module name" for now
715 | {- empty -} { Nothing }
718 -----------------------------------------------------------------------------
721 opt_sig :: { Maybe (LHsType RdrName) }
722 : {- empty -} { Nothing }
723 | '::' sigtype { Just $2 }
725 opt_asig :: { Maybe (LHsType RdrName) }
726 : {- empty -} { Nothing }
727 | '::' atype { Just $2 }
729 sigtypes1 :: { [LHsType RdrName] }
731 | sigtype ',' sigtypes1 { $1 : $3 }
733 sigtype :: { LHsType RdrName }
734 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
735 -- Wrap an Implicit forall if there isn't one there already
737 sig_vars :: { Located [Located RdrName] }
738 : sig_vars ',' var { LL ($3 : unLoc $1) }
741 -----------------------------------------------------------------------------
744 strict_mark :: { Located HsBang }
745 : '!' { L1 HsStrict }
746 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
748 -- A ctype is a for-all type
749 ctype :: { LHsType RdrName }
750 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
751 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
752 -- A type of form (context => type) is an *implicit* HsForAllTy
755 -- We parse a context as a btype so that we don't get reduce/reduce
756 -- errors in ctype. The basic problem is that
758 -- looks so much like a tuple type. We can't tell until we find the =>
759 context :: { LHsContext RdrName }
760 : btype {% checkContext $1 }
762 type :: { LHsType RdrName }
763 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
766 gentype :: { LHsType RdrName }
768 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
769 | btype '`' tyvar '`' gentype { LL $ HsOpTy $1 $3 $5 }
770 | btype '->' gentype { LL $ HsFunTy $1 $3 }
772 btype :: { LHsType RdrName }
773 : btype atype { LL $ HsAppTy $1 $2 }
776 atype :: { LHsType RdrName }
777 : gtycon { L1 (HsTyVar (unLoc $1)) }
778 | tyvar { L1 (HsTyVar (unLoc $1)) }
779 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
780 | '(' type ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
781 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
782 | '[' type ']' { LL $ HsListTy $2 }
783 | '[:' type ':]' { LL $ HsPArrTy $2 }
784 | '(' ctype ')' { LL $ HsParTy $2 }
785 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
787 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
789 -- An inst_type is what occurs in the head of an instance decl
790 -- e.g. (Foo a, Gaz b) => Wibble a b
791 -- It's kept as a single type, with a MonoDictTy at the right
792 -- hand corner, for convenience.
793 inst_type :: { LHsType RdrName }
794 : sigtype {% checkInstType $1 }
796 inst_types1 :: { [LHsType RdrName] }
798 | inst_type ',' inst_types1 { $1 : $3 }
800 comma_types0 :: { [LHsType RdrName] }
801 : comma_types1 { $1 }
804 comma_types1 :: { [LHsType RdrName] }
806 | type ',' comma_types1 { $1 : $3 }
808 tv_bndrs :: { [LHsTyVarBndr RdrName] }
809 : tv_bndr tv_bndrs { $1 : $2 }
812 tv_bndr :: { LHsTyVarBndr RdrName }
813 : tyvar { L1 (UserTyVar (unLoc $1)) }
814 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
816 fds :: { Located [Located ([RdrName], [RdrName])] }
817 : {- empty -} { noLoc [] }
818 | '|' fds1 { LL (reverse (unLoc $2)) }
820 fds1 :: { Located [Located ([RdrName], [RdrName])] }
821 : fds1 ',' fd { LL ($3 : unLoc $1) }
824 fd :: { Located ([RdrName], [RdrName]) }
825 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
826 (reverse (unLoc $1), reverse (unLoc $3)) }
828 varids0 :: { Located [RdrName] }
829 : {- empty -} { noLoc [] }
830 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
832 -----------------------------------------------------------------------------
837 | akind '->' kind { mkArrowKind $1 $3 }
840 : '*' { liftedTypeKind }
841 | '(' kind ')' { $2 }
844 -----------------------------------------------------------------------------
845 -- Datatype declarations
847 newconstr :: { LConDecl RdrName }
848 : conid atype { LL $ ConDecl $1 [] (noLoc []) (PrefixCon [$2]) }
849 | conid '{' var '::' ctype '}'
850 { LL $ ConDecl $1 [] (noLoc []) (RecCon [($3, $5)]) }
852 gadt_constrlist :: { Located [LConDecl RdrName] }
853 : '{' gadt_constrs '}' { LL (unLoc $2) }
854 | vocurly gadt_constrs close { $2 }
856 gadt_constrs :: { Located [LConDecl RdrName] }
857 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
858 | gadt_constrs ';' { $1 }
859 | gadt_constr { L1 [$1] }
861 gadt_constr :: { LConDecl RdrName }
863 { LL (GadtDecl $1 $3) }
865 constrs :: { Located [LConDecl RdrName] }
866 : {- empty; a GHC extension -} { noLoc [] }
867 | '=' constrs1 { LL (unLoc $2) }
869 constrs1 :: { Located [LConDecl RdrName] }
870 : constrs1 '|' constr { LL ($3 : unLoc $1) }
873 constr :: { LConDecl RdrName }
874 : forall context '=>' constr_stuff
875 { let (con,details) = unLoc $4 in
876 LL (ConDecl con (unLoc $1) $2 details) }
877 | forall constr_stuff
878 { let (con,details) = unLoc $2 in
879 LL (ConDecl con (unLoc $1) (noLoc []) details) }
881 forall :: { Located [LHsTyVarBndr RdrName] }
882 : 'forall' tv_bndrs '.' { LL $2 }
883 | {- empty -} { noLoc [] }
885 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
886 -- We parse the constructor declaration
888 -- as a btype (treating C as a type constructor) and then convert C to be
889 -- a data constructor. Reason: it might continue like this:
891 -- in which case C really would be a type constructor. We can't resolve this
892 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
893 : btype {% mkPrefixCon $1 [] >>= return.LL }
894 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
895 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
896 | btype conop btype { LL ($2, InfixCon $1 $3) }
898 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
899 : fielddecl ',' fielddecls { unLoc $1 : $3 }
900 | fielddecl { [unLoc $1] }
902 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
903 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
905 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
906 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
907 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
908 -- We don't allow a context, but that's sorted out by the type checker.
909 deriving :: { Located (Maybe [LHsType RdrName]) }
910 : {- empty -} { noLoc Nothing }
911 | 'deriving' qtycon {% do { let { L loc tv = $2 }
912 ; p <- checkInstType (L loc (HsTyVar tv))
913 ; return (LL (Just [p])) } }
914 | 'deriving' '(' ')' { LL (Just []) }
915 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
916 -- Glasgow extension: allow partial
917 -- applications in derivings
919 -----------------------------------------------------------------------------
922 {- There's an awkward overlap with a type signature. Consider
923 f :: Int -> Int = ...rhs...
924 Then we can't tell whether it's a type signature or a value
925 definition with a result signature until we see the '='.
926 So we have to inline enough to postpone reductions until we know.
930 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
931 instead of qvar, we get another shift/reduce-conflict. Consider the
934 { (^^) :: Int->Int ; } Type signature; only var allowed
936 { (^^) :: Int->Int = ... ; } Value defn with result signature;
937 qvar allowed (because of instance decls)
939 We can't tell whether to reduce var to qvar until after we've read the signatures.
942 decl :: { Located (OrdList (LHsDecl RdrName)) }
944 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
945 return (LL $ unitOL (LL $ ValD r)) } }
947 rhs :: { Located (GRHSs RdrName) }
948 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
949 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
951 gdrhs :: { Located [LGRHS RdrName] }
952 : gdrhs gdrh { LL ($2 : unLoc $1) }
955 gdrh :: { LGRHS RdrName }
956 : '|' quals '=' exp { LL $ GRHS (reverse (L (getLoc $4) (ResultStmt $4) :
959 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
960 : infixexp '::' sigtype
961 {% do s <- checkValSig $1 $3;
962 return (LL $ unitOL (LL $ SigD s)) }
963 -- See the above notes for why we need infixexp here
964 | var ',' sig_vars '::' sigtype
965 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
966 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
968 | '{-# INLINE' activation qvar '#-}'
969 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
970 | '{-# NOINLINE' inverse_activation qvar '#-}'
971 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
972 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
973 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
975 | '{-# SPECIALISE' 'instance' inst_type '#-}'
976 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
978 -----------------------------------------------------------------------------
981 exp :: { LHsExpr RdrName }
982 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
983 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
984 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
985 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
986 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
989 infixexp :: { LHsExpr RdrName }
991 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
993 exp10 :: { LHsExpr RdrName }
994 : '\\' aexp aexps opt_asig '->' exp
995 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
996 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
997 (GRHSs (unguardedRHS $6) []
999 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1000 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1001 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1002 | '-' fexp { LL $ mkHsNegApp $2 }
1004 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1005 checkDo loc (unLoc $2) >>= \ stmts ->
1006 return (L loc (mkHsDo DoExpr stmts)) }
1007 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1008 checkMDo loc (unLoc $2) >>= \ stmts ->
1009 return (L loc (mkHsDo MDoExpr stmts)) }
1011 | scc_annot exp { LL $ if opt_SccProfilingOn
1012 then HsSCC (unLoc $1) $2
1015 | 'proc' aexp '->' exp
1016 {% checkPattern $2 >>= \ p ->
1017 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1018 placeHolderType undefined)) }
1019 -- TODO: is LL right here?
1021 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1022 -- hdaume: core annotation
1025 scc_annot :: { Located FastString }
1026 : '_scc_' STRING { LL $ getSTRING $2 }
1027 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1029 fexp :: { LHsExpr RdrName }
1030 : fexp aexp { LL $ HsApp $1 $2 }
1033 aexps :: { [LHsExpr RdrName] }
1034 : aexps aexp { $2 : $1 }
1035 | {- empty -} { [] }
1037 aexp :: { LHsExpr RdrName }
1038 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1039 | '~' aexp { LL $ ELazyPat $2 }
1042 aexp1 :: { LHsExpr RdrName }
1043 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1048 -- Here was the syntax for type applications that I was planning
1049 -- but there are difficulties (e.g. what order for type args)
1050 -- so it's not enabled yet.
1051 -- But this case *is* used for the left hand side of a generic definition,
1052 -- which is parsed as an expression before being munged into a pattern
1053 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1054 (sL (getLoc $3) (HsType $3)) }
1056 aexp2 :: { LHsExpr RdrName }
1057 : ipvar { L1 (HsIPVar $! unLoc $1) }
1058 | qcname { L1 (HsVar $! unLoc $1) }
1059 | literal { L1 (HsLit $! unLoc $1) }
1060 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1061 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1062 | '(' exp ')' { LL (HsPar $2) }
1063 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1064 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1065 | '[' list ']' { LL (unLoc $2) }
1066 | '[:' parr ':]' { LL (unLoc $2) }
1067 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1068 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1069 | '_' { L1 EWildPat }
1071 -- MetaHaskell Extension
1072 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1073 (L1 $ HsVar (mkUnqual varName
1074 (getTH_ID_SPLICE $1)))) } -- $x
1075 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1077 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1078 | TH_VAR_QUOTE gcon { LL $ HsBracket (VarBr (unLoc $2)) }
1079 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1080 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1081 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1082 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1083 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1084 return (LL $ HsBracket (PatBr p)) }
1085 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1087 -- arrow notation extension
1088 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1090 cmdargs :: { [LHsCmdTop RdrName] }
1091 : cmdargs acmd { $2 : $1 }
1092 | {- empty -} { [] }
1094 acmd :: { LHsCmdTop RdrName }
1095 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1097 cvtopbody :: { [LHsDecl RdrName] }
1098 : '{' cvtopdecls0 '}' { $2 }
1099 | vocurly cvtopdecls0 close { $2 }
1101 cvtopdecls0 :: { [LHsDecl RdrName] }
1102 : {- empty -} { [] }
1105 texps :: { [LHsExpr RdrName] }
1106 : texps ',' exp { $3 : $1 }
1110 -----------------------------------------------------------------------------
1113 -- The rules below are little bit contorted to keep lexps left-recursive while
1114 -- avoiding another shift/reduce-conflict.
1116 list :: { LHsExpr RdrName }
1117 : exp { L1 $ ExplicitList placeHolderType [$1] }
1118 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1119 | exp '..' { LL $ ArithSeqIn (From $1) }
1120 | exp ',' exp '..' { LL $ ArithSeqIn (FromThen $1 $3) }
1121 | exp '..' exp { LL $ ArithSeqIn (FromTo $1 $3) }
1122 | exp ',' exp '..' exp { LL $ ArithSeqIn (FromThenTo $1 $3 $5) }
1123 | exp pquals { LL $ mkHsDo ListComp
1124 (reverse (L (getLoc $1) (ResultStmt $1) :
1127 lexps :: { Located [LHsExpr RdrName] }
1128 : lexps ',' exp { LL ($3 : unLoc $1) }
1129 | exp ',' exp { LL [$3,$1] }
1131 -----------------------------------------------------------------------------
1132 -- List Comprehensions
1134 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1135 -- or a reversed list of Stmts
1136 : pquals1 { case unLoc $1 of
1138 qss -> L1 [L1 (ParStmt stmtss)]
1140 stmtss = [ (reverse qs, undefined)
1144 pquals1 :: { Located [[LStmt RdrName]] }
1145 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1146 | '|' quals { L (getLoc $2) [unLoc $2] }
1148 quals :: { Located [LStmt RdrName] }
1149 : quals ',' qual { LL ($3 : unLoc $1) }
1152 -----------------------------------------------------------------------------
1153 -- Parallel array expressions
1155 -- The rules below are little bit contorted; see the list case for details.
1156 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1157 -- Moreover, we allow explicit arrays with no element (represented by the nil
1158 -- constructor in the list case).
1160 parr :: { LHsExpr RdrName }
1161 : { noLoc (ExplicitPArr placeHolderType []) }
1162 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1163 | lexps { L1 $ ExplicitPArr placeHolderType
1164 (reverse (unLoc $1)) }
1165 | exp '..' exp { LL $ PArrSeqIn (FromTo $1 $3) }
1166 | exp ',' exp '..' exp { LL $ PArrSeqIn (FromThenTo $1 $3 $5) }
1167 | exp pquals { LL $ mkHsDo PArrComp
1168 (reverse (L (getLoc $1) (ResultStmt $1) :
1172 -- We are reusing `lexps' and `pquals' from the list case.
1174 -----------------------------------------------------------------------------
1175 -- Case alternatives
1177 altslist :: { Located [LMatch RdrName] }
1178 : '{' alts '}' { LL (reverse (unLoc $2)) }
1179 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1181 alts :: { Located [LMatch RdrName] }
1182 : alts1 { L1 (unLoc $1) }
1183 | ';' alts { LL (unLoc $2) }
1185 alts1 :: { Located [LMatch RdrName] }
1186 : alts1 ';' alt { LL ($3 : unLoc $1) }
1187 | alts1 ';' { LL (unLoc $1) }
1190 alt :: { LMatch RdrName }
1191 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1192 return (LL (Match [p] $2 (unLoc $3))) }
1194 alt_rhs :: { Located (GRHSs RdrName) }
1195 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1197 ralt :: { Located [LGRHS RdrName] }
1198 : '->' exp { LL (unguardedRHS $2) }
1199 | gdpats { L1 (reverse (unLoc $1)) }
1201 gdpats :: { Located [LGRHS RdrName] }
1202 : gdpats gdpat { LL ($2 : unLoc $1) }
1205 gdpat :: { LGRHS RdrName }
1206 : '|' quals '->' exp { let r = L (getLoc $4) (ResultStmt $4)
1207 in LL $ GRHS (reverse (r : unLoc $2)) }
1209 -----------------------------------------------------------------------------
1210 -- Statement sequences
1212 stmtlist :: { Located [LStmt RdrName] }
1213 : '{' stmts '}' { LL (unLoc $2) }
1214 | vocurly stmts close { $2 }
1216 -- do { ;; s ; s ; ; s ;; }
1217 -- The last Stmt should be a ResultStmt, but that's hard to enforce
1218 -- here, because we need too much lookahead if we see do { e ; }
1219 -- So we use ExprStmts throughout, and switch the last one over
1220 -- in ParseUtils.checkDo instead
1221 stmts :: { Located [LStmt RdrName] }
1222 : stmt stmts_help { LL ($1 : unLoc $2) }
1223 | ';' stmts { LL (unLoc $2) }
1224 | {- empty -} { noLoc [] }
1226 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1227 : ';' stmts { LL (unLoc $2) }
1228 | {- empty -} { noLoc [] }
1230 -- For typing stmts at the GHCi prompt, where
1231 -- the input may consist of just comments.
1232 maybe_stmt :: { Maybe (LStmt RdrName) }
1234 | {- nothing -} { Nothing }
1236 stmt :: { LStmt RdrName }
1238 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1239 return (LL $ BindStmt p $1) }
1240 | 'rec' stmtlist { LL $ RecStmt (unLoc $2) undefined undefined undefined }
1242 qual :: { LStmt RdrName }
1243 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1244 return (LL $ BindStmt p $3) }
1245 | exp { L1 $ ExprStmt $1 placeHolderType }
1246 | 'let' binds { LL $ LetStmt (unLoc $2) }
1248 -----------------------------------------------------------------------------
1249 -- Record Field Update/Construction
1251 fbinds :: { HsRecordBinds RdrName }
1253 | {- empty -} { [] }
1255 fbinds1 :: { HsRecordBinds RdrName }
1256 : fbinds1 ',' fbind { $3 : $1 }
1259 fbind :: { (Located RdrName, LHsExpr RdrName) }
1260 : qvar '=' exp { ($1,$3) }
1262 -----------------------------------------------------------------------------
1263 -- Implicit Parameter Bindings
1265 dbinds :: { Located [LIPBind RdrName] }
1266 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1267 | dbinds ';' { LL (unLoc $1) }
1269 -- | {- empty -} { [] }
1271 dbind :: { LIPBind RdrName }
1272 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1274 -----------------------------------------------------------------------------
1275 -- Variables, Constructors and Operators.
1277 identifier :: { Located RdrName }
1283 depreclist :: { Located [RdrName] }
1284 depreclist : deprec_var { L1 [unLoc $1] }
1285 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1287 deprec_var :: { Located RdrName }
1288 deprec_var : var { $1 }
1291 gcon :: { Located RdrName } -- Data constructor namespace
1292 : sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1294 -- the case of '[:' ':]' is part of the production `parr'
1296 sysdcon :: { Located DataCon } -- Wired in data constructors
1297 : '(' ')' { LL unitDataCon }
1298 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1299 | '[' ']' { LL nilDataCon }
1301 var :: { Located RdrName }
1303 | '(' varsym ')' { LL (unLoc $2) }
1305 qvar :: { Located RdrName }
1307 | '(' varsym ')' { LL (unLoc $2) }
1308 | '(' qvarsym1 ')' { LL (unLoc $2) }
1309 -- We've inlined qvarsym here so that the decision about
1310 -- whether it's a qvar or a var can be postponed until
1311 -- *after* we see the close paren.
1313 ipvar :: { Located (IPName RdrName) }
1314 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1315 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1317 qcon :: { Located RdrName }
1319 | '(' qconsym ')' { LL (unLoc $2) }
1321 varop :: { Located RdrName }
1323 | '`' varid '`' { LL (unLoc $2) }
1325 qvarop :: { Located RdrName }
1327 | '`' qvarid '`' { LL (unLoc $2) }
1329 qvaropm :: { Located RdrName }
1330 : qvarsym_no_minus { $1 }
1331 | '`' qvarid '`' { LL (unLoc $2) }
1333 conop :: { Located RdrName }
1335 | '`' conid '`' { LL (unLoc $2) }
1337 qconop :: { Located RdrName }
1339 | '`' qconid '`' { LL (unLoc $2) }
1341 -----------------------------------------------------------------------------
1342 -- Type constructors
1344 gtycon :: { Located RdrName } -- A "general" qualified tycon
1346 | '(' ')' { LL $ getRdrName unitTyCon }
1347 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1348 | '(' '->' ')' { LL $ getRdrName funTyCon }
1349 | '[' ']' { LL $ listTyCon_RDR }
1350 | '[:' ':]' { LL $ parrTyCon_RDR }
1352 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1354 | '(' qtyconsym ')' { LL (unLoc $2) }
1356 qtyconop :: { Located RdrName } -- Qualified or unqualified
1358 | '`' qtycon '`' { LL (unLoc $2) }
1360 tyconop :: { Located RdrName } -- Unqualified
1362 | '`' tycon '`' { LL (unLoc $2) }
1364 qtycon :: { Located RdrName } -- Qualified or unqualified
1365 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1368 tycon :: { Located RdrName } -- Unqualified
1369 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1371 qtyconsym :: { Located RdrName }
1372 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1375 tyconsym :: { Located RdrName }
1376 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1378 -----------------------------------------------------------------------------
1381 op :: { Located RdrName } -- used in infix decls
1385 qop :: { LHsExpr RdrName } -- used in sections
1386 : qvarop { L1 $ HsVar (unLoc $1) }
1387 | qconop { L1 $ HsVar (unLoc $1) }
1389 qopm :: { LHsExpr RdrName } -- used in sections
1390 : qvaropm { L1 $ HsVar (unLoc $1) }
1391 | qconop { L1 $ HsVar (unLoc $1) }
1393 -----------------------------------------------------------------------------
1396 qvarid :: { Located RdrName }
1398 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1400 varid :: { Located RdrName }
1401 : varid_no_unsafe { $1 }
1402 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1403 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1404 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1406 varid_no_unsafe :: { Located RdrName }
1407 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1408 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1409 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1411 tyvar :: { Located RdrName }
1412 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1413 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1414 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1415 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1416 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1418 -- These special_ids are treated as keywords in various places,
1419 -- but as ordinary ids elsewhere. 'special_id' collects all these
1420 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1421 special_id :: { Located UserFS }
1423 : 'as' { L1 FSLIT("as") }
1424 | 'qualified' { L1 FSLIT("qualified") }
1425 | 'hiding' { L1 FSLIT("hiding") }
1426 | 'export' { L1 FSLIT("export") }
1427 | 'label' { L1 FSLIT("label") }
1428 | 'dynamic' { L1 FSLIT("dynamic") }
1429 | 'stdcall' { L1 FSLIT("stdcall") }
1430 | 'ccall' { L1 FSLIT("ccall") }
1432 -----------------------------------------------------------------------------
1435 qvarsym :: { Located RdrName }
1439 qvarsym_no_minus :: { Located RdrName }
1440 : varsym_no_minus { $1 }
1443 qvarsym1 :: { Located RdrName }
1444 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1446 varsym :: { Located RdrName }
1447 : varsym_no_minus { $1 }
1448 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1450 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1451 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1452 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1455 -- See comments with special_id
1456 special_sym :: { Located UserFS }
1457 special_sym : '!' { L1 FSLIT("!") }
1458 | '.' { L1 FSLIT(".") }
1459 | '*' { L1 FSLIT("*") }
1461 -----------------------------------------------------------------------------
1462 -- Data constructors
1464 qconid :: { Located RdrName } -- Qualified or unqualified
1466 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1468 conid :: { Located RdrName }
1469 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1471 qconsym :: { Located RdrName } -- Qualified or unqualified
1473 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1475 consym :: { Located RdrName }
1476 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1478 -- ':' means only list cons
1479 | ':' { L1 $ consDataCon_RDR }
1482 -----------------------------------------------------------------------------
1485 literal :: { Located HsLit }
1486 : CHAR { L1 $ HsChar $ getCHAR $1 }
1487 | STRING { L1 $ HsString $ getSTRING $1 }
1488 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1489 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1490 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1491 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1492 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1494 -----------------------------------------------------------------------------
1498 : vccurly { () } -- context popped in lexer.
1499 | error {% popContext }
1501 -----------------------------------------------------------------------------
1502 -- Miscellaneous (mostly renamings)
1504 modid :: { Located Module }
1505 : CONID { L1 $ mkModuleFS (getCONID $1) }
1506 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1509 (unpackFS mod ++ '.':unpackFS c))
1513 : commas ',' { $1 + 1 }
1516 -----------------------------------------------------------------------------
1520 happyError = srcParseFail
1522 getVARID (L _ (ITvarid x)) = x
1523 getCONID (L _ (ITconid x)) = x
1524 getVARSYM (L _ (ITvarsym x)) = x
1525 getCONSYM (L _ (ITconsym x)) = x
1526 getQVARID (L _ (ITqvarid x)) = x
1527 getQCONID (L _ (ITqconid x)) = x
1528 getQVARSYM (L _ (ITqvarsym x)) = x
1529 getQCONSYM (L _ (ITqconsym x)) = x
1530 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1531 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1532 getCHAR (L _ (ITchar x)) = x
1533 getSTRING (L _ (ITstring x)) = x
1534 getINTEGER (L _ (ITinteger x)) = x
1535 getRATIONAL (L _ (ITrational x)) = x
1536 getPRIMCHAR (L _ (ITprimchar x)) = x
1537 getPRIMSTRING (L _ (ITprimstring x)) = x
1538 getPRIMINTEGER (L _ (ITprimint x)) = x
1539 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1540 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1541 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1543 -- Utilities for combining source spans
1544 comb2 :: Located a -> Located b -> SrcSpan
1547 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1548 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1550 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1551 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1552 combineSrcSpans (getLoc c) (getLoc d)
1554 -- strict constructor version:
1556 sL :: SrcSpan -> a -> Located a
1557 sL span a = span `seq` L span a
1559 -- Make a source location for the file. We're a bit lazy here and just
1560 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1561 -- try to find the span of the whole file (ToDo).
1562 fileSrcSpan :: P SrcSpan
1565 let loc = mkSrcLoc (srcLocFile l) 1 0;
1566 return (mkSrcSpan loc loc)