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 [] (noLoc []) (PrefixCon [$2]) }
859 | conid '{' var '::' ctype '}'
860 { LL $ ConDecl $1 [] (noLoc []) (RecCon [($3, $5)]) }
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 gadt_constr :: { LConDecl RdrName }
873 { LL (GadtDecl $1 $3) }
875 constrs :: { Located [LConDecl RdrName] }
876 : {- empty; a GHC extension -} { noLoc [] }
877 | '=' constrs1 { LL (unLoc $2) }
879 constrs1 :: { Located [LConDecl RdrName] }
880 : constrs1 '|' constr { LL ($3 : unLoc $1) }
883 constr :: { LConDecl RdrName }
884 : forall context '=>' constr_stuff
885 { let (con,details) = unLoc $4 in
886 LL (ConDecl con (unLoc $1) $2 details) }
887 | forall constr_stuff
888 { let (con,details) = unLoc $2 in
889 LL (ConDecl con (unLoc $1) (noLoc []) details) }
891 forall :: { Located [LHsTyVarBndr RdrName] }
892 : 'forall' tv_bndrs '.' { LL $2 }
893 | {- empty -} { noLoc [] }
895 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
896 -- We parse the constructor declaration
898 -- as a btype (treating C as a type constructor) and then convert C to be
899 -- a data constructor. Reason: it might continue like this:
901 -- in which case C really would be a type constructor. We can't resolve this
902 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
903 : btype {% mkPrefixCon $1 [] >>= return.LL }
904 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
905 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
906 | btype conop btype { LL ($2, InfixCon $1 $3) }
908 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
909 : fielddecl ',' fielddecls { unLoc $1 : $3 }
910 | fielddecl { [unLoc $1] }
912 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
913 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
915 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
916 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
917 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
918 -- We don't allow a context, but that's sorted out by the type checker.
919 deriving :: { Located (Maybe [LHsType RdrName]) }
920 : {- empty -} { noLoc Nothing }
921 | 'deriving' qtycon {% do { let { L loc tv = $2 }
922 ; p <- checkInstType (L loc (HsTyVar tv))
923 ; return (LL (Just [p])) } }
924 | 'deriving' '(' ')' { LL (Just []) }
925 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
926 -- Glasgow extension: allow partial
927 -- applications in derivings
929 -----------------------------------------------------------------------------
932 {- There's an awkward overlap with a type signature. Consider
933 f :: Int -> Int = ...rhs...
934 Then we can't tell whether it's a type signature or a value
935 definition with a result signature until we see the '='.
936 So we have to inline enough to postpone reductions until we know.
940 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
941 instead of qvar, we get another shift/reduce-conflict. Consider the
944 { (^^) :: Int->Int ; } Type signature; only var allowed
946 { (^^) :: Int->Int = ... ; } Value defn with result signature;
947 qvar allowed (because of instance decls)
949 We can't tell whether to reduce var to qvar until after we've read the signatures.
952 decl :: { Located (OrdList (LHsDecl RdrName)) }
954 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
955 return (LL $ unitOL (LL $ ValD r)) } }
957 rhs :: { Located (GRHSs RdrName) }
958 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
959 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
961 gdrhs :: { Located [LGRHS RdrName] }
962 : gdrhs gdrh { LL ($2 : unLoc $1) }
965 gdrh :: { LGRHS RdrName }
966 : '|' quals '=' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
968 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
969 : infixexp '::' sigtype
970 {% do s <- checkValSig $1 $3;
971 return (LL $ unitOL (LL $ SigD s)) }
972 -- See the above notes for why we need infixexp here
973 | var ',' sig_vars '::' sigtype
974 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
975 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
977 | '{-# INLINE' activation qvar '#-}'
978 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
979 | '{-# NOINLINE' inverse_activation qvar '#-}'
980 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
981 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
982 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
984 | '{-# SPECIALISE' 'instance' inst_type '#-}'
985 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
987 -----------------------------------------------------------------------------
990 exp :: { LHsExpr RdrName }
991 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
992 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
993 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
994 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
995 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
998 infixexp :: { LHsExpr RdrName }
1000 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1002 exp10 :: { LHsExpr RdrName }
1003 : '\\' aexp aexps opt_asig '->' exp
1004 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1005 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1006 (GRHSs (unguardedRHS $6) emptyLocalBinds
1008 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1009 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1010 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1011 | '-' fexp { LL $ mkHsNegApp $2 }
1013 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1014 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1015 return (L loc (mkHsDo DoExpr stmts body)) }
1016 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1017 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1018 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1019 | scc_annot exp { LL $ if opt_SccProfilingOn
1020 then HsSCC (unLoc $1) $2
1023 | 'proc' aexp '->' exp
1024 {% checkPattern $2 >>= \ p ->
1025 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1026 placeHolderType undefined)) }
1027 -- TODO: is LL right here?
1029 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1030 -- hdaume: core annotation
1033 scc_annot :: { Located FastString }
1034 : '_scc_' STRING { LL $ getSTRING $2 }
1035 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1037 fexp :: { LHsExpr RdrName }
1038 : fexp aexp { LL $ HsApp $1 $2 }
1041 aexps :: { [LHsExpr RdrName] }
1042 : aexps aexp { $2 : $1 }
1043 | {- empty -} { [] }
1045 aexp :: { LHsExpr RdrName }
1046 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1047 | '~' aexp { LL $ ELazyPat $2 }
1050 aexp1 :: { LHsExpr RdrName }
1051 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1056 -- Here was the syntax for type applications that I was planning
1057 -- but there are difficulties (e.g. what order for type args)
1058 -- so it's not enabled yet.
1059 -- But this case *is* used for the left hand side of a generic definition,
1060 -- which is parsed as an expression before being munged into a pattern
1061 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1062 (sL (getLoc $3) (HsType $3)) }
1064 aexp2 :: { LHsExpr RdrName }
1065 : ipvar { L1 (HsIPVar $! unLoc $1) }
1066 | qcname { L1 (HsVar $! unLoc $1) }
1067 | literal { L1 (HsLit $! unLoc $1) }
1068 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1069 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1070 | '(' exp ')' { LL (HsPar $2) }
1071 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1072 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1073 | '[' list ']' { LL (unLoc $2) }
1074 | '[:' parr ':]' { LL (unLoc $2) }
1075 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1076 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1077 | '_' { L1 EWildPat }
1079 -- MetaHaskell Extension
1080 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1081 (L1 $ HsVar (mkUnqual varName
1082 (getTH_ID_SPLICE $1)))) } -- $x
1083 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1085 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1086 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1087 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1088 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1089 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1090 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1091 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1092 return (LL $ HsBracket (PatBr p)) }
1093 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1095 -- arrow notation extension
1096 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1098 cmdargs :: { [LHsCmdTop RdrName] }
1099 : cmdargs acmd { $2 : $1 }
1100 | {- empty -} { [] }
1102 acmd :: { LHsCmdTop RdrName }
1103 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1105 cvtopbody :: { [LHsDecl RdrName] }
1106 : '{' cvtopdecls0 '}' { $2 }
1107 | vocurly cvtopdecls0 close { $2 }
1109 cvtopdecls0 :: { [LHsDecl RdrName] }
1110 : {- empty -} { [] }
1113 texps :: { [LHsExpr RdrName] }
1114 : texps ',' exp { $3 : $1 }
1118 -----------------------------------------------------------------------------
1121 -- The rules below are little bit contorted to keep lexps left-recursive while
1122 -- avoiding another shift/reduce-conflict.
1124 list :: { LHsExpr RdrName }
1125 : exp { L1 $ ExplicitList placeHolderType [$1] }
1126 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1127 | exp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1128 | exp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1129 | exp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1130 | exp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1131 | exp pquals { sL (comb2 $1 $>) $ mkHsDo ListComp (reverse (unLoc $2)) $1 }
1133 lexps :: { Located [LHsExpr RdrName] }
1134 : lexps ',' exp { LL ($3 : unLoc $1) }
1135 | exp ',' exp { LL [$3,$1] }
1137 -----------------------------------------------------------------------------
1138 -- List Comprehensions
1140 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1141 -- or a reversed list of Stmts
1142 : pquals1 { case unLoc $1 of
1144 qss -> L1 [L1 (ParStmt stmtss)]
1146 stmtss = [ (reverse qs, undefined)
1150 pquals1 :: { Located [[LStmt RdrName]] }
1151 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1152 | '|' quals { L (getLoc $2) [unLoc $2] }
1154 quals :: { Located [LStmt RdrName] }
1155 : quals ',' qual { LL ($3 : unLoc $1) }
1158 -----------------------------------------------------------------------------
1159 -- Parallel array expressions
1161 -- The rules below are little bit contorted; see the list case for details.
1162 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1163 -- Moreover, we allow explicit arrays with no element (represented by the nil
1164 -- constructor in the list case).
1166 parr :: { LHsExpr RdrName }
1167 : { noLoc (ExplicitPArr placeHolderType []) }
1168 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1169 | lexps { L1 $ ExplicitPArr placeHolderType
1170 (reverse (unLoc $1)) }
1171 | exp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1172 | exp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1173 | exp pquals { sL (comb2 $1 $>) $ mkHsDo PArrComp (reverse (unLoc $2)) $1 }
1175 -- We are reusing `lexps' and `pquals' from the list case.
1177 -----------------------------------------------------------------------------
1178 -- Case alternatives
1180 altslist :: { Located [LMatch RdrName] }
1181 : '{' alts '}' { LL (reverse (unLoc $2)) }
1182 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1184 alts :: { Located [LMatch RdrName] }
1185 : alts1 { L1 (unLoc $1) }
1186 | ';' alts { LL (unLoc $2) }
1188 alts1 :: { Located [LMatch RdrName] }
1189 : alts1 ';' alt { LL ($3 : unLoc $1) }
1190 | alts1 ';' { LL (unLoc $1) }
1193 alt :: { LMatch RdrName }
1194 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1195 return (LL (Match [p] $2 (unLoc $3))) }
1197 alt_rhs :: { Located (GRHSs RdrName) }
1198 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1200 ralt :: { Located [LGRHS RdrName] }
1201 : '->' exp { LL (unguardedRHS $2) }
1202 | gdpats { L1 (reverse (unLoc $1)) }
1204 gdpats :: { Located [LGRHS RdrName] }
1205 : gdpats gdpat { LL ($2 : unLoc $1) }
1208 gdpat :: { LGRHS RdrName }
1209 : '|' quals '->' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
1211 -----------------------------------------------------------------------------
1212 -- Statement sequences
1214 stmtlist :: { Located [LStmt RdrName] }
1215 : '{' stmts '}' { LL (unLoc $2) }
1216 | vocurly stmts close { $2 }
1218 -- do { ;; s ; s ; ; s ;; }
1219 -- The last Stmt should be an expression, but that's hard to enforce
1220 -- here, because we need too much lookahead if we see do { e ; }
1221 -- So we use ExprStmts throughout, and switch the last one over
1222 -- in ParseUtils.checkDo instead
1223 stmts :: { Located [LStmt RdrName] }
1224 : stmt stmts_help { LL ($1 : unLoc $2) }
1225 | ';' stmts { LL (unLoc $2) }
1226 | {- empty -} { noLoc [] }
1228 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1229 : ';' stmts { LL (unLoc $2) }
1230 | {- empty -} { noLoc [] }
1232 -- For typing stmts at the GHCi prompt, where
1233 -- the input may consist of just comments.
1234 maybe_stmt :: { Maybe (LStmt RdrName) }
1236 | {- nothing -} { Nothing }
1238 stmt :: { LStmt RdrName }
1240 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1241 return (LL $ mkBindStmt p $1) }
1242 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1244 qual :: { LStmt RdrName }
1245 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1246 return (LL $ mkBindStmt p $3) }
1247 | exp { L1 $ mkExprStmt $1 }
1248 | 'let' binds { LL $ LetStmt (unLoc $2) }
1250 -----------------------------------------------------------------------------
1251 -- Record Field Update/Construction
1253 fbinds :: { HsRecordBinds RdrName }
1255 | {- empty -} { [] }
1257 fbinds1 :: { HsRecordBinds RdrName }
1258 : fbinds1 ',' fbind { $3 : $1 }
1261 fbind :: { (Located RdrName, LHsExpr RdrName) }
1262 : qvar '=' exp { ($1,$3) }
1264 -----------------------------------------------------------------------------
1265 -- Implicit Parameter Bindings
1267 dbinds :: { Located [LIPBind RdrName] }
1268 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1269 | dbinds ';' { LL (unLoc $1) }
1271 -- | {- empty -} { [] }
1273 dbind :: { LIPBind RdrName }
1274 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1276 ipvar :: { Located (IPName RdrName) }
1277 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1278 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1280 -----------------------------------------------------------------------------
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 -----------------------------------------
1292 -- Data constructors
1293 qcon :: { Located RdrName }
1295 | '(' qconsym ')' { LL (unLoc $2) }
1296 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1297 -- The case of '[:' ':]' is part of the production `parr'
1299 con :: { Located RdrName }
1301 | '(' consym ')' { LL (unLoc $2) }
1302 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1304 sysdcon :: { Located DataCon } -- Wired in data constructors
1305 : '(' ')' { LL unitDataCon }
1306 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1307 | '[' ']' { LL nilDataCon }
1309 conop :: { Located RdrName }
1311 | '`' conid '`' { LL (unLoc $2) }
1313 qconop :: { Located RdrName }
1315 | '`' qconid '`' { LL (unLoc $2) }
1317 -----------------------------------------------------------------------------
1318 -- Type constructors
1320 gtycon :: { Located RdrName } -- A "general" qualified tycon
1322 | '(' ')' { LL $ getRdrName unitTyCon }
1323 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1324 | '(' '->' ')' { LL $ getRdrName funTyCon }
1325 | '[' ']' { LL $ listTyCon_RDR }
1326 | '[:' ':]' { LL $ parrTyCon_RDR }
1328 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1330 | '(' qtyconsym ')' { LL (unLoc $2) }
1332 qtyconop :: { Located RdrName } -- Qualified or unqualified
1334 | '`' qtycon '`' { LL (unLoc $2) }
1336 qtycon :: { Located RdrName } -- Qualified or unqualified
1337 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1340 tycon :: { Located RdrName } -- Unqualified
1341 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1343 qtyconsym :: { Located RdrName }
1344 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1347 tyconsym :: { Located RdrName }
1348 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1350 -----------------------------------------------------------------------------
1353 op :: { Located RdrName } -- used in infix decls
1357 varop :: { Located RdrName }
1359 | '`' varid '`' { LL (unLoc $2) }
1361 qop :: { LHsExpr RdrName } -- used in sections
1362 : qvarop { L1 $ HsVar (unLoc $1) }
1363 | qconop { L1 $ HsVar (unLoc $1) }
1365 qopm :: { LHsExpr RdrName } -- used in sections
1366 : qvaropm { L1 $ HsVar (unLoc $1) }
1367 | qconop { L1 $ HsVar (unLoc $1) }
1369 qvarop :: { Located RdrName }
1371 | '`' qvarid '`' { LL (unLoc $2) }
1373 qvaropm :: { Located RdrName }
1374 : qvarsym_no_minus { $1 }
1375 | '`' qvarid '`' { LL (unLoc $2) }
1377 -----------------------------------------------------------------------------
1380 tyvar :: { Located RdrName }
1381 tyvar : tyvarid { $1 }
1382 | '(' tyvarsym ')' { LL (unLoc $2) }
1384 tyvarop :: { Located RdrName }
1385 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1388 tyvarid :: { Located RdrName }
1389 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1390 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1391 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1392 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1393 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1395 tyvarsym :: { Located RdrName }
1396 -- Does not include "!", because that is used for strictness marks
1397 -- or ".", because that separates the quantified type vars from the rest
1398 -- or "*", because that's used for kinds
1399 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1401 -----------------------------------------------------------------------------
1404 var :: { Located RdrName }
1406 | '(' varsym ')' { LL (unLoc $2) }
1408 qvar :: { Located RdrName }
1410 | '(' varsym ')' { LL (unLoc $2) }
1411 | '(' qvarsym1 ')' { LL (unLoc $2) }
1412 -- We've inlined qvarsym here so that the decision about
1413 -- whether it's a qvar or a var can be postponed until
1414 -- *after* we see the close paren.
1416 qvarid :: { Located RdrName }
1418 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1420 varid :: { Located RdrName }
1421 : varid_no_unsafe { $1 }
1422 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1423 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1424 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1426 varid_no_unsafe :: { Located RdrName }
1427 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1428 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1429 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1431 qvarsym :: { Located RdrName }
1435 qvarsym_no_minus :: { Located RdrName }
1436 : varsym_no_minus { $1 }
1439 qvarsym1 :: { Located RdrName }
1440 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1442 varsym :: { Located RdrName }
1443 : varsym_no_minus { $1 }
1444 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1446 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1447 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1448 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1451 -- These special_ids are treated as keywords in various places,
1452 -- but as ordinary ids elsewhere. 'special_id' collects all these
1453 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1454 special_id :: { Located UserFS }
1456 : 'as' { L1 FSLIT("as") }
1457 | 'qualified' { L1 FSLIT("qualified") }
1458 | 'hiding' { L1 FSLIT("hiding") }
1459 | 'export' { L1 FSLIT("export") }
1460 | 'label' { L1 FSLIT("label") }
1461 | 'dynamic' { L1 FSLIT("dynamic") }
1462 | 'stdcall' { L1 FSLIT("stdcall") }
1463 | 'ccall' { L1 FSLIT("ccall") }
1465 special_sym :: { Located UserFS }
1466 special_sym : '!' { L1 FSLIT("!") }
1467 | '.' { L1 FSLIT(".") }
1468 | '*' { L1 FSLIT("*") }
1470 -----------------------------------------------------------------------------
1471 -- Data constructors
1473 qconid :: { Located RdrName } -- Qualified or unqualified
1475 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1477 conid :: { Located RdrName }
1478 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1480 qconsym :: { Located RdrName } -- Qualified or unqualified
1482 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1484 consym :: { Located RdrName }
1485 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1487 -- ':' means only list cons
1488 | ':' { L1 $ consDataCon_RDR }
1491 -----------------------------------------------------------------------------
1494 literal :: { Located HsLit }
1495 : CHAR { L1 $ HsChar $ getCHAR $1 }
1496 | STRING { L1 $ HsString $ getSTRING $1 }
1497 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1498 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1499 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1500 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1501 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1503 -----------------------------------------------------------------------------
1507 : vccurly { () } -- context popped in lexer.
1508 | error {% popContext }
1510 -----------------------------------------------------------------------------
1511 -- Miscellaneous (mostly renamings)
1513 modid :: { Located Module }
1514 : CONID { L1 $ mkModuleFS (getCONID $1) }
1515 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1518 (unpackFS mod ++ '.':unpackFS c))
1522 : commas ',' { $1 + 1 }
1525 -----------------------------------------------------------------------------
1529 happyError = srcParseFail
1531 getVARID (L _ (ITvarid x)) = x
1532 getCONID (L _ (ITconid x)) = x
1533 getVARSYM (L _ (ITvarsym x)) = x
1534 getCONSYM (L _ (ITconsym x)) = x
1535 getQVARID (L _ (ITqvarid x)) = x
1536 getQCONID (L _ (ITqconid x)) = x
1537 getQVARSYM (L _ (ITqvarsym x)) = x
1538 getQCONSYM (L _ (ITqconsym x)) = x
1539 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1540 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1541 getCHAR (L _ (ITchar x)) = x
1542 getSTRING (L _ (ITstring x)) = x
1543 getINTEGER (L _ (ITinteger x)) = x
1544 getRATIONAL (L _ (ITrational x)) = x
1545 getPRIMCHAR (L _ (ITprimchar x)) = x
1546 getPRIMSTRING (L _ (ITprimstring x)) = x
1547 getPRIMINTEGER (L _ (ITprimint x)) = x
1548 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1549 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1550 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1552 -- Utilities for combining source spans
1553 comb2 :: Located a -> Located b -> SrcSpan
1556 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1557 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1559 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1560 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1561 combineSrcSpans (getLoc c) (getLoc d)
1563 -- strict constructor version:
1565 sL :: SrcSpan -> a -> Located a
1566 sL span a = span `seq` L span a
1568 -- Make a source location for the file. We're a bit lazy here and just
1569 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1570 -- try to find the span of the whole file (ToDo).
1571 fileSrcSpan :: P SrcSpan
1574 let loc = mkSrcLoc (srcLocFile l) 1 0;
1575 return (mkSrcSpan loc loc)