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(..),
37 Activation(..), InlineSpec(..), defaultInlineSpec )
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 '{-# INLINE' { L _ (ITinline_prag _) }
188 '{-# SPECIALISE' { L _ ITspec_prag }
189 '{-# SPECIALISE_INLINE' { L _ (ITspec_inline_prag _) }
190 '{-# SOURCE' { L _ ITsource_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 (unLoc $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 (unLoc $2) $3 (reverse (unLoc $5)) (unLoc $6)) }
469 | 'newtype' tycl_hdr '=' newconstr deriving
471 (mkTyData NewType (unLoc $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)
535 ($2 `orElse` AlwaysActive)
538 activation :: { Maybe Activation }
539 : {- empty -} { Nothing }
540 | explicit_activation { Just $1 }
542 explicit_activation :: { Activation } -- In brackets
543 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
544 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
546 rule_forall :: { [RuleBndr RdrName] }
547 : 'forall' rule_var_list '.' { $2 }
550 rule_var_list :: { [RuleBndr RdrName] }
552 | rule_var rule_var_list { $1 : $2 }
554 rule_var :: { RuleBndr RdrName }
555 : varid { RuleBndr $1 }
556 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
558 -----------------------------------------------------------------------------
559 -- Deprecations (c.f. rules)
561 deprecations :: { OrdList (LHsDecl RdrName) } -- Reversed
562 : deprecations ';' deprecation { $1 `appOL` $3 }
563 | deprecations ';' { $1 }
565 | {- empty -} { nilOL }
567 -- SUP: TEMPORARY HACK, not checking for `module Foo'
568 deprecation :: { OrdList (LHsDecl RdrName) }
570 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
574 -----------------------------------------------------------------------------
575 -- Foreign import and export declarations
577 -- for the time being, the following accepts foreign declarations conforming
578 -- to the FFI Addendum, Version 1.0 as well as pre-standard declarations
580 -- * a flag indicates whether pre-standard declarations have been used and
581 -- triggers a deprecation warning further down the road
583 -- NB: The first two rules could be combined into one by replacing `safety1'
584 -- with `safety'. However, the combined rule conflicts with the
587 fdecl :: { LHsDecl RdrName }
588 fdecl : 'import' callconv safety1 fspec
589 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
590 | 'import' callconv fspec
591 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
593 | 'export' callconv fspec
594 {% mkExport $2 (unLoc $3) >>= return.LL }
595 -- the following syntax is DEPRECATED
596 | fdecl1DEPRECATED { L1 (ForD (unLoc $1)) }
597 | fdecl2DEPRECATED { L1 (unLoc $1) }
599 fdecl1DEPRECATED :: { LForeignDecl RdrName }
601 ----------- DEPRECATED label decls ------------
602 : 'label' ext_name varid '::' sigtype
603 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
604 (CLabel ($2 `orElse` mkExtName (unLoc $3)))) True }
606 ----------- DEPRECATED ccall/stdcall decls ------------
608 -- NB: This business with the case expression below may seem overly
609 -- complicated, but it is necessary to avoid some conflicts.
611 -- DEPRECATED variant #1: lack of a calling convention specification
613 | 'import' {-no callconv-} ext_name safety varid_no_unsafe '::' sigtype
615 target = StaticTarget ($2 `orElse` mkExtName (unLoc $4))
617 LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
618 (CFunction target)) True }
620 -- DEPRECATED variant #2: external name consists of two separate strings
621 -- (module name and function name) (import)
622 | 'import' callconv STRING STRING safety varid_no_unsafe '::' sigtype
624 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
625 CCall cconv -> return $
627 imp = CFunction (StaticTarget (getSTRING $4))
629 LL $ ForeignImport $6 $8 (CImport cconv $5 nilFS nilFS imp) True }
631 -- DEPRECATED variant #3: `unsafe' after entity
632 | 'import' callconv STRING 'unsafe' varid_no_unsafe '::' sigtype
634 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
635 CCall cconv -> return $
637 imp = CFunction (StaticTarget (getSTRING $3))
639 LL $ ForeignImport $5 $7 (CImport cconv PlayRisky nilFS nilFS imp) True }
641 -- DEPRECATED variant #4: use of the special identifier `dynamic' without
642 -- an explicit calling convention (import)
643 | 'import' {-no callconv-} 'dynamic' safety varid_no_unsafe '::' sigtype
644 { LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
645 (CFunction DynamicTarget)) True }
647 -- DEPRECATED variant #5: use of the special identifier `dynamic' (import)
648 | 'import' callconv 'dynamic' safety varid_no_unsafe '::' sigtype
650 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
651 CCall cconv -> return $
652 LL $ ForeignImport $5 $7 (CImport cconv $4 nilFS nilFS
653 (CFunction DynamicTarget)) True }
655 -- DEPRECATED variant #6: lack of a calling convention specification
657 | 'export' {-no callconv-} ext_name varid '::' sigtype
658 { LL $ ForeignExport $3 $5 (CExport (CExportStatic ($2 `orElse` mkExtName (unLoc $3))
659 defaultCCallConv)) True }
661 -- DEPRECATED variant #7: external name consists of two separate strings
662 -- (module name and function name) (export)
663 | 'export' callconv STRING STRING varid '::' sigtype
665 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
666 CCall cconv -> return $
667 LL $ ForeignExport $5 $7
668 (CExport (CExportStatic (getSTRING $4) cconv)) True }
670 -- DEPRECATED variant #8: use of the special identifier `dynamic' without
671 -- an explicit calling convention (export)
672 | 'export' {-no callconv-} 'dynamic' varid '::' sigtype
673 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
676 -- DEPRECATED variant #9: use of the special identifier `dynamic' (export)
677 | 'export' callconv 'dynamic' varid '::' sigtype
679 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
680 CCall cconv -> return $
681 LL $ ForeignImport $4 $6
682 (CImport cconv (PlaySafe False) nilFS nilFS CWrapper) True }
684 ----------- DEPRECATED .NET decls ------------
685 -- NB: removed the .NET call declaration, as it is entirely subsumed
686 -- by the new standard FFI declarations
688 fdecl2DEPRECATED :: { LHsDecl RdrName }
690 : 'import' 'dotnet' 'type' ext_name tycon { LL $ TyClD (ForeignType $5 $4 DNType) }
691 -- left this one unchanged for the moment as type imports are not
692 -- covered currently by the FFI standard -=chak
695 callconv :: { CallConv }
696 : 'stdcall' { CCall StdCallConv }
697 | 'ccall' { CCall CCallConv }
698 | 'dotnet' { DNCall }
701 : 'unsafe' { PlayRisky }
702 | 'safe' { PlaySafe False }
703 | 'threadsafe' { PlaySafe True }
704 | {- empty -} { PlaySafe False }
706 safety1 :: { Safety }
707 : 'unsafe' { PlayRisky }
708 | 'safe' { PlaySafe False }
709 | 'threadsafe' { PlaySafe True }
710 -- only needed to avoid conflicts with the DEPRECATED rules
712 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
713 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
714 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
715 -- if the entity string is missing, it defaults to the empty string;
716 -- the meaning of an empty entity string depends on the calling
720 ext_name :: { Maybe CLabelString }
721 : STRING { Just (getSTRING $1) }
722 | STRING STRING { Just (getSTRING $2) } -- Ignore "module name" for now
723 | {- empty -} { Nothing }
726 -----------------------------------------------------------------------------
729 opt_sig :: { Maybe (LHsType RdrName) }
730 : {- empty -} { Nothing }
731 | '::' sigtype { Just $2 }
733 opt_asig :: { Maybe (LHsType RdrName) }
734 : {- empty -} { Nothing }
735 | '::' atype { Just $2 }
737 sigtypes1 :: { [LHsType RdrName] }
739 | sigtype ',' sigtypes1 { $1 : $3 }
741 sigtype :: { LHsType RdrName }
742 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
743 -- Wrap an Implicit forall if there isn't one there already
745 sig_vars :: { Located [Located RdrName] }
746 : sig_vars ',' var { LL ($3 : unLoc $1) }
749 -----------------------------------------------------------------------------
752 strict_mark :: { Located HsBang }
753 : '!' { L1 HsStrict }
754 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
756 -- A ctype is a for-all type
757 ctype :: { LHsType RdrName }
758 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
759 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
760 -- A type of form (context => type) is an *implicit* HsForAllTy
763 -- We parse a context as a btype so that we don't get reduce/reduce
764 -- errors in ctype. The basic problem is that
766 -- looks so much like a tuple type. We can't tell until we find the =>
767 context :: { LHsContext RdrName }
768 : btype {% checkContext $1 }
770 type :: { LHsType RdrName }
771 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
774 gentype :: { LHsType RdrName }
776 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
777 | btype tyvarop gentype { LL $ HsOpTy $1 $2 $3 }
778 | btype '->' gentype { LL $ HsFunTy $1 $3 }
780 btype :: { LHsType RdrName }
781 : btype atype { LL $ HsAppTy $1 $2 }
784 atype :: { LHsType RdrName }
785 : gtycon { L1 (HsTyVar (unLoc $1)) }
786 | tyvar { L1 (HsTyVar (unLoc $1)) }
787 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
788 | '(' type ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
789 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
790 | '[' type ']' { LL $ HsListTy $2 }
791 | '[:' type ':]' { LL $ HsPArrTy $2 }
792 | '(' ctype ')' { LL $ HsParTy $2 }
793 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
795 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
797 -- An inst_type is what occurs in the head of an instance decl
798 -- e.g. (Foo a, Gaz b) => Wibble a b
799 -- It's kept as a single type, with a MonoDictTy at the right
800 -- hand corner, for convenience.
801 inst_type :: { LHsType RdrName }
802 : sigtype {% checkInstType $1 }
804 inst_types1 :: { [LHsType RdrName] }
806 | inst_type ',' inst_types1 { $1 : $3 }
808 comma_types0 :: { [LHsType RdrName] }
809 : comma_types1 { $1 }
812 comma_types1 :: { [LHsType RdrName] }
814 | type ',' comma_types1 { $1 : $3 }
816 tv_bndrs :: { [LHsTyVarBndr RdrName] }
817 : tv_bndr tv_bndrs { $1 : $2 }
820 tv_bndr :: { LHsTyVarBndr RdrName }
821 : tyvar { L1 (UserTyVar (unLoc $1)) }
822 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
824 fds :: { Located [Located ([RdrName], [RdrName])] }
825 : {- empty -} { noLoc [] }
826 | '|' fds1 { LL (reverse (unLoc $2)) }
828 fds1 :: { Located [Located ([RdrName], [RdrName])] }
829 : fds1 ',' fd { LL ($3 : unLoc $1) }
832 fd :: { Located ([RdrName], [RdrName]) }
833 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
834 (reverse (unLoc $1), reverse (unLoc $3)) }
836 varids0 :: { Located [RdrName] }
837 : {- empty -} { noLoc [] }
838 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
840 -----------------------------------------------------------------------------
845 | akind '->' kind { mkArrowKind $1 $3 }
848 : '*' { liftedTypeKind }
849 | '(' kind ')' { $2 }
852 -----------------------------------------------------------------------------
853 -- Datatype declarations
855 newconstr :: { LConDecl RdrName }
856 : conid atype { LL $ ConDecl $1 Explicit [] (noLoc []) (PrefixCon [$2]) ResTyH98 }
857 | conid '{' var '::' ctype '}'
858 { LL $ ConDecl $1 Explicit [] (noLoc []) (RecCon [($3, $5)]) ResTyH98 }
860 gadt_constrlist :: { Located [LConDecl RdrName] }
861 : '{' gadt_constrs '}' { LL (unLoc $2) }
862 | vocurly gadt_constrs close { $2 }
864 gadt_constrs :: { Located [LConDecl RdrName] }
865 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
866 | gadt_constrs ';' { $1 }
867 | gadt_constr { L1 [$1] }
869 -- We allow the following forms:
870 -- C :: Eq a => a -> T a
871 -- C :: forall a. Eq a => !a -> T a
872 -- D { x,y :: a } :: T a
873 -- forall a. Eq a => D { x,y :: a } :: T a
875 gadt_constr :: { LConDecl RdrName }
877 { LL (mkGadtDecl $1 $3) }
878 -- Syntax: Maybe merge the record stuff with the single-case above?
879 -- (to kill the mostly harmless reduce/reduce error)
880 -- XXX revisit autrijus
881 | constr_stuff_record '::' sigtype
882 { let (con,details) = unLoc $1 in
883 LL (ConDecl con Implicit [] (noLoc []) details (ResTyGADT $3)) }
885 | forall context '=>' constr_stuff_record '::' sigtype
886 { let (con,details) = unLoc $4 in
887 LL (ConDecl con Implicit (unLoc $1) $2 details (ResTyGADT $6)) }
888 | forall constr_stuff_record '::' sigtype
889 { let (con,details) = unLoc $2 in
890 LL (ConDecl con Implicit (unLoc $1) (noLoc []) details (ResTyGADT $4)) }
894 constrs :: { Located [LConDecl RdrName] }
895 : {- empty; a GHC extension -} { noLoc [] }
896 | '=' constrs1 { LL (unLoc $2) }
898 constrs1 :: { Located [LConDecl RdrName] }
899 : constrs1 '|' constr { LL ($3 : unLoc $1) }
902 constr :: { LConDecl RdrName }
903 : forall context '=>' constr_stuff
904 { let (con,details) = unLoc $4 in
905 LL (ConDecl con Explicit (unLoc $1) $2 details ResTyH98) }
906 | forall constr_stuff
907 { let (con,details) = unLoc $2 in
908 LL (ConDecl con Explicit (unLoc $1) (noLoc []) details ResTyH98) }
910 forall :: { Located [LHsTyVarBndr RdrName] }
911 : 'forall' tv_bndrs '.' { LL $2 }
912 | {- empty -} { noLoc [] }
914 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
915 -- We parse the constructor declaration
917 -- as a btype (treating C as a type constructor) and then convert C to be
918 -- a data constructor. Reason: it might continue like this:
920 -- in which case C really would be a type constructor. We can't resolve this
921 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
922 : btype {% mkPrefixCon $1 [] >>= return.LL }
923 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
924 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
925 | btype conop btype { LL ($2, InfixCon $1 $3) }
927 constr_stuff_record :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
928 : oqtycon '{' '}' {% mkRecCon $1 [] >>= return.sL (comb2 $1 $>) }
929 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.sL (comb2 $1 $>) }
931 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
932 : fielddecl ',' fielddecls { unLoc $1 : $3 }
933 | fielddecl { [unLoc $1] }
935 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
936 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
938 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
939 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
940 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
941 -- We don't allow a context, but that's sorted out by the type checker.
942 deriving :: { Located (Maybe [LHsType RdrName]) }
943 : {- empty -} { noLoc Nothing }
944 | 'deriving' qtycon {% do { let { L loc tv = $2 }
945 ; p <- checkInstType (L loc (HsTyVar tv))
946 ; return (LL (Just [p])) } }
947 | 'deriving' '(' ')' { LL (Just []) }
948 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
949 -- Glasgow extension: allow partial
950 -- applications in derivings
952 -----------------------------------------------------------------------------
955 {- There's an awkward overlap with a type signature. Consider
956 f :: Int -> Int = ...rhs...
957 Then we can't tell whether it's a type signature or a value
958 definition with a result signature until we see the '='.
959 So we have to inline enough to postpone reductions until we know.
963 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
964 instead of qvar, we get another shift/reduce-conflict. Consider the
967 { (^^) :: Int->Int ; } Type signature; only var allowed
969 { (^^) :: Int->Int = ... ; } Value defn with result signature;
970 qvar allowed (because of instance decls)
972 We can't tell whether to reduce var to qvar until after we've read the signatures.
975 decl :: { Located (OrdList (LHsDecl RdrName)) }
977 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
978 return (LL $ unitOL (LL $ ValD r)) } }
980 rhs :: { Located (GRHSs RdrName) }
981 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
982 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
984 gdrhs :: { Located [LGRHS RdrName] }
985 : gdrhs gdrh { LL ($2 : unLoc $1) }
988 gdrh :: { LGRHS RdrName }
989 : '|' quals '=' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
991 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
992 : infixexp '::' sigtype
993 {% do s <- checkValSig $1 $3;
994 return (LL $ unitOL (LL $ SigD s)) }
995 -- See the above notes for why we need infixexp here
996 | var ',' sig_vars '::' sigtype
997 { LL $ toOL [ LL $ SigD (TypeSig n $5) | n <- $1 : unLoc $3 ] }
998 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1000 | '{-# INLINE' activation qvar '#-}'
1001 { LL $ unitOL (LL $ SigD (InlineSig $3 (mkInlineSpec $2 (getINLINE $1)))) }
1002 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1003 { LL $ toOL [ LL $ SigD (SpecSig $2 t defaultInlineSpec)
1005 | '{-# SPECIALISE_INLINE' activation qvar '::' sigtypes1 '#-}'
1006 { LL $ toOL [ LL $ SigD (SpecSig $3 t (mkInlineSpec $2 (getSPEC_INLINE $1)))
1008 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1009 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1011 -----------------------------------------------------------------------------
1014 exp :: { LHsExpr RdrName }
1015 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1016 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1017 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1018 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1019 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1022 infixexp :: { LHsExpr RdrName }
1024 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1026 exp10 :: { LHsExpr RdrName }
1027 : '\\' aexp aexps opt_asig '->' exp
1028 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1029 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1030 (GRHSs (unguardedRHS $6) emptyLocalBinds
1032 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1033 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1034 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1035 | '-' fexp { LL $ mkHsNegApp $2 }
1037 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1038 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1039 return (L loc (mkHsDo DoExpr stmts body)) }
1040 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1041 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1042 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1043 | scc_annot exp { LL $ if opt_SccProfilingOn
1044 then HsSCC (unLoc $1) $2
1047 | 'proc' aexp '->' exp
1048 {% checkPattern $2 >>= \ p ->
1049 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1050 placeHolderType undefined)) }
1051 -- TODO: is LL right here?
1053 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1054 -- hdaume: core annotation
1057 scc_annot :: { Located FastString }
1058 : '_scc_' STRING { LL $ getSTRING $2 }
1059 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1061 fexp :: { LHsExpr RdrName }
1062 : fexp aexp { LL $ HsApp $1 $2 }
1065 aexps :: { [LHsExpr RdrName] }
1066 : aexps aexp { $2 : $1 }
1067 | {- empty -} { [] }
1069 aexp :: { LHsExpr RdrName }
1070 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1071 | '~' aexp { LL $ ELazyPat $2 }
1074 aexp1 :: { LHsExpr RdrName }
1075 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1080 -- Here was the syntax for type applications that I was planning
1081 -- but there are difficulties (e.g. what order for type args)
1082 -- so it's not enabled yet.
1083 -- But this case *is* used for the left hand side of a generic definition,
1084 -- which is parsed as an expression before being munged into a pattern
1085 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1086 (sL (getLoc $3) (HsType $3)) }
1088 aexp2 :: { LHsExpr RdrName }
1089 : ipvar { L1 (HsIPVar $! unLoc $1) }
1090 | qcname { L1 (HsVar $! unLoc $1) }
1091 | literal { L1 (HsLit $! unLoc $1) }
1092 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1093 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1094 | '(' exp ')' { LL (HsPar $2) }
1095 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1096 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1097 | '[' list ']' { LL (unLoc $2) }
1098 | '[:' parr ':]' { LL (unLoc $2) }
1099 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1100 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1101 | '_' { L1 EWildPat }
1103 -- MetaHaskell Extension
1104 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1105 (L1 $ HsVar (mkUnqual varName
1106 (getTH_ID_SPLICE $1)))) } -- $x
1107 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1109 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1110 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1111 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1112 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1113 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1114 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1115 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1116 return (LL $ HsBracket (PatBr p)) }
1117 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1119 -- arrow notation extension
1120 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1122 cmdargs :: { [LHsCmdTop RdrName] }
1123 : cmdargs acmd { $2 : $1 }
1124 | {- empty -} { [] }
1126 acmd :: { LHsCmdTop RdrName }
1127 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1129 cvtopbody :: { [LHsDecl RdrName] }
1130 : '{' cvtopdecls0 '}' { $2 }
1131 | vocurly cvtopdecls0 close { $2 }
1133 cvtopdecls0 :: { [LHsDecl RdrName] }
1134 : {- empty -} { [] }
1137 texps :: { [LHsExpr RdrName] }
1138 : texps ',' exp { $3 : $1 }
1142 -----------------------------------------------------------------------------
1145 -- The rules below are little bit contorted to keep lexps left-recursive while
1146 -- avoiding another shift/reduce-conflict.
1148 list :: { LHsExpr RdrName }
1149 : exp { L1 $ ExplicitList placeHolderType [$1] }
1150 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1151 | exp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1152 | exp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1153 | exp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1154 | exp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1155 | exp pquals { sL (comb2 $1 $>) $ mkHsDo ListComp (reverse (unLoc $2)) $1 }
1157 lexps :: { Located [LHsExpr RdrName] }
1158 : lexps ',' exp { LL ($3 : unLoc $1) }
1159 | exp ',' exp { LL [$3,$1] }
1161 -----------------------------------------------------------------------------
1162 -- List Comprehensions
1164 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1165 -- or a reversed list of Stmts
1166 : pquals1 { case unLoc $1 of
1168 qss -> L1 [L1 (ParStmt stmtss)]
1170 stmtss = [ (reverse qs, undefined)
1174 pquals1 :: { Located [[LStmt RdrName]] }
1175 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1176 | '|' quals { L (getLoc $2) [unLoc $2] }
1178 quals :: { Located [LStmt RdrName] }
1179 : quals ',' qual { LL ($3 : unLoc $1) }
1182 -----------------------------------------------------------------------------
1183 -- Parallel array expressions
1185 -- The rules below are little bit contorted; see the list case for details.
1186 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1187 -- Moreover, we allow explicit arrays with no element (represented by the nil
1188 -- constructor in the list case).
1190 parr :: { LHsExpr RdrName }
1191 : { noLoc (ExplicitPArr placeHolderType []) }
1192 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1193 | lexps { L1 $ ExplicitPArr placeHolderType
1194 (reverse (unLoc $1)) }
1195 | exp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1196 | exp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1197 | exp pquals { sL (comb2 $1 $>) $ mkHsDo PArrComp (reverse (unLoc $2)) $1 }
1199 -- We are reusing `lexps' and `pquals' from the list case.
1201 -----------------------------------------------------------------------------
1202 -- Case alternatives
1204 altslist :: { Located [LMatch RdrName] }
1205 : '{' alts '}' { LL (reverse (unLoc $2)) }
1206 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1208 alts :: { Located [LMatch RdrName] }
1209 : alts1 { L1 (unLoc $1) }
1210 | ';' alts { LL (unLoc $2) }
1212 alts1 :: { Located [LMatch RdrName] }
1213 : alts1 ';' alt { LL ($3 : unLoc $1) }
1214 | alts1 ';' { LL (unLoc $1) }
1217 alt :: { LMatch RdrName }
1218 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1219 return (LL (Match [p] $2 (unLoc $3))) }
1221 alt_rhs :: { Located (GRHSs RdrName) }
1222 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1224 ralt :: { Located [LGRHS RdrName] }
1225 : '->' exp { LL (unguardedRHS $2) }
1226 | gdpats { L1 (reverse (unLoc $1)) }
1228 gdpats :: { Located [LGRHS RdrName] }
1229 : gdpats gdpat { LL ($2 : unLoc $1) }
1232 gdpat :: { LGRHS RdrName }
1233 : '|' quals '->' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
1235 -----------------------------------------------------------------------------
1236 -- Statement sequences
1238 stmtlist :: { Located [LStmt RdrName] }
1239 : '{' stmts '}' { LL (unLoc $2) }
1240 | vocurly stmts close { $2 }
1242 -- do { ;; s ; s ; ; s ;; }
1243 -- The last Stmt should be an expression, but that's hard to enforce
1244 -- here, because we need too much lookahead if we see do { e ; }
1245 -- So we use ExprStmts throughout, and switch the last one over
1246 -- in ParseUtils.checkDo instead
1247 stmts :: { Located [LStmt RdrName] }
1248 : stmt stmts_help { LL ($1 : unLoc $2) }
1249 | ';' stmts { LL (unLoc $2) }
1250 | {- empty -} { noLoc [] }
1252 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1253 : ';' stmts { LL (unLoc $2) }
1254 | {- empty -} { noLoc [] }
1256 -- For typing stmts at the GHCi prompt, where
1257 -- the input may consist of just comments.
1258 maybe_stmt :: { Maybe (LStmt RdrName) }
1260 | {- nothing -} { Nothing }
1262 stmt :: { LStmt RdrName }
1264 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1265 return (LL $ mkBindStmt p $1) }
1266 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1268 qual :: { LStmt RdrName }
1269 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1270 return (LL $ mkBindStmt p $3) }
1271 | exp { L1 $ mkExprStmt $1 }
1272 | 'let' binds { LL $ LetStmt (unLoc $2) }
1274 -----------------------------------------------------------------------------
1275 -- Record Field Update/Construction
1277 fbinds :: { HsRecordBinds RdrName }
1279 | {- empty -} { [] }
1281 fbinds1 :: { HsRecordBinds RdrName }
1282 : fbinds1 ',' fbind { $3 : $1 }
1285 fbind :: { (Located RdrName, LHsExpr RdrName) }
1286 : qvar '=' exp { ($1,$3) }
1288 -----------------------------------------------------------------------------
1289 -- Implicit Parameter Bindings
1291 dbinds :: { Located [LIPBind RdrName] }
1292 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1293 | dbinds ';' { LL (unLoc $1) }
1295 -- | {- empty -} { [] }
1297 dbind :: { LIPBind RdrName }
1298 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1300 ipvar :: { Located (IPName RdrName) }
1301 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1302 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1304 -----------------------------------------------------------------------------
1307 depreclist :: { Located [RdrName] }
1308 depreclist : deprec_var { L1 [unLoc $1] }
1309 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1311 deprec_var :: { Located RdrName }
1312 deprec_var : var { $1 }
1315 -----------------------------------------
1316 -- Data constructors
1317 qcon :: { Located RdrName }
1319 | '(' qconsym ')' { LL (unLoc $2) }
1320 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1321 -- The case of '[:' ':]' is part of the production `parr'
1323 con :: { Located RdrName }
1325 | '(' consym ')' { LL (unLoc $2) }
1326 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1328 sysdcon :: { Located DataCon } -- Wired in data constructors
1329 : '(' ')' { LL unitDataCon }
1330 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1331 | '[' ']' { LL nilDataCon }
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 qtycon :: { Located RdrName } -- Qualified or unqualified
1361 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1364 tycon :: { Located RdrName } -- Unqualified
1365 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1367 qtyconsym :: { Located RdrName }
1368 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1371 tyconsym :: { Located RdrName }
1372 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1374 -----------------------------------------------------------------------------
1377 op :: { Located RdrName } -- used in infix decls
1381 varop :: { Located RdrName }
1383 | '`' varid '`' { LL (unLoc $2) }
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 qvarop :: { Located RdrName }
1395 | '`' qvarid '`' { LL (unLoc $2) }
1397 qvaropm :: { Located RdrName }
1398 : qvarsym_no_minus { $1 }
1399 | '`' qvarid '`' { LL (unLoc $2) }
1401 -----------------------------------------------------------------------------
1404 tyvar :: { Located RdrName }
1405 tyvar : tyvarid { $1 }
1406 | '(' tyvarsym ')' { LL (unLoc $2) }
1408 tyvarop :: { Located RdrName }
1409 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1412 tyvarid :: { Located RdrName }
1413 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1414 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1415 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1416 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1417 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1419 tyvarsym :: { Located RdrName }
1420 -- Does not include "!", because that is used for strictness marks
1421 -- or ".", because that separates the quantified type vars from the rest
1422 -- or "*", because that's used for kinds
1423 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1425 -----------------------------------------------------------------------------
1428 var :: { Located RdrName }
1430 | '(' varsym ')' { LL (unLoc $2) }
1432 qvar :: { Located RdrName }
1434 | '(' varsym ')' { LL (unLoc $2) }
1435 | '(' qvarsym1 ')' { LL (unLoc $2) }
1436 -- We've inlined qvarsym here so that the decision about
1437 -- whether it's a qvar or a var can be postponed until
1438 -- *after* we see the close paren.
1440 qvarid :: { Located RdrName }
1442 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1444 varid :: { Located RdrName }
1445 : varid_no_unsafe { $1 }
1446 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1447 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1448 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1450 varid_no_unsafe :: { Located RdrName }
1451 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1452 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1453 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1455 qvarsym :: { Located RdrName }
1459 qvarsym_no_minus :: { Located RdrName }
1460 : varsym_no_minus { $1 }
1463 qvarsym1 :: { Located RdrName }
1464 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1466 varsym :: { Located RdrName }
1467 : varsym_no_minus { $1 }
1468 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1470 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1471 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1472 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1475 -- These special_ids are treated as keywords in various places,
1476 -- but as ordinary ids elsewhere. 'special_id' collects all these
1477 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1478 special_id :: { Located UserFS }
1480 : 'as' { L1 FSLIT("as") }
1481 | 'qualified' { L1 FSLIT("qualified") }
1482 | 'hiding' { L1 FSLIT("hiding") }
1483 | 'export' { L1 FSLIT("export") }
1484 | 'label' { L1 FSLIT("label") }
1485 | 'dynamic' { L1 FSLIT("dynamic") }
1486 | 'stdcall' { L1 FSLIT("stdcall") }
1487 | 'ccall' { L1 FSLIT("ccall") }
1489 special_sym :: { Located UserFS }
1490 special_sym : '!' { L1 FSLIT("!") }
1491 | '.' { L1 FSLIT(".") }
1492 | '*' { L1 FSLIT("*") }
1494 -----------------------------------------------------------------------------
1495 -- Data constructors
1497 qconid :: { Located RdrName } -- Qualified or unqualified
1499 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1501 conid :: { Located RdrName }
1502 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1504 qconsym :: { Located RdrName } -- Qualified or unqualified
1506 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1508 consym :: { Located RdrName }
1509 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1511 -- ':' means only list cons
1512 | ':' { L1 $ consDataCon_RDR }
1515 -----------------------------------------------------------------------------
1518 literal :: { Located HsLit }
1519 : CHAR { L1 $ HsChar $ getCHAR $1 }
1520 | STRING { L1 $ HsString $ getSTRING $1 }
1521 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1522 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1523 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1524 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1525 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1527 -----------------------------------------------------------------------------
1531 : vccurly { () } -- context popped in lexer.
1532 | error {% popContext }
1534 -----------------------------------------------------------------------------
1535 -- Miscellaneous (mostly renamings)
1537 modid :: { Located Module }
1538 : CONID { L1 $ mkModuleFS (getCONID $1) }
1539 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1542 (unpackFS mod ++ '.':unpackFS c))
1546 : commas ',' { $1 + 1 }
1549 -----------------------------------------------------------------------------
1553 happyError = srcParseFail
1555 getVARID (L _ (ITvarid x)) = x
1556 getCONID (L _ (ITconid x)) = x
1557 getVARSYM (L _ (ITvarsym x)) = x
1558 getCONSYM (L _ (ITconsym x)) = x
1559 getQVARID (L _ (ITqvarid x)) = x
1560 getQCONID (L _ (ITqconid x)) = x
1561 getQVARSYM (L _ (ITqvarsym x)) = x
1562 getQCONSYM (L _ (ITqconsym x)) = x
1563 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1564 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1565 getCHAR (L _ (ITchar x)) = x
1566 getSTRING (L _ (ITstring x)) = x
1567 getINTEGER (L _ (ITinteger x)) = x
1568 getRATIONAL (L _ (ITrational x)) = x
1569 getPRIMCHAR (L _ (ITprimchar x)) = x
1570 getPRIMSTRING (L _ (ITprimstring x)) = x
1571 getPRIMINTEGER (L _ (ITprimint x)) = x
1572 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1573 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1574 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1575 getINLINE (L _ (ITinline_prag b)) = b
1576 getSPEC_INLINE (L _ (ITspec_inline_prag b)) = b
1578 -- Utilities for combining source spans
1579 comb2 :: Located a -> Located b -> SrcSpan
1582 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1583 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1585 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1586 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1587 combineSrcSpans (getLoc c) (getLoc d)
1589 -- strict constructor version:
1591 sL :: SrcSpan -> a -> Located a
1592 sL span a = span `seq` L span a
1594 -- Make a source location for the file. We're a bit lazy here and just
1595 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1596 -- try to find the span of the whole file (ToDo).
1597 fileSrcSpan :: P SrcSpan
1600 let loc = mkSrcLoc (srcLocFile l) 1 0;
1601 return (mkSrcSpan loc loc)