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 'where' gadt_constrlist -- No deriving for GADTs
464 { L (comb4 $1 $2 $4 $5)
465 (mkTyData DataType $2 $3 (reverse (unLoc $5)) Nothing) }
467 | 'newtype' tycl_hdr '=' newconstr deriving
469 (mkTyData NewType $2 Nothing [$4] (unLoc $5)) }
471 | 'class' tycl_hdr fds where
473 (binds,sigs) = cvBindsAndSigs (unLoc $4)
475 L (comb4 $1 $2 $3 $4) (mkClassDecl (unLoc $2) (unLoc $3) sigs
478 opt_kind_sig :: { Maybe Kind }
480 | '::' kind { Just $2 }
482 -- tycl_hdr parses the header of a type or class decl,
483 -- which takes the form
486 -- (Eq a, Ord b) => T a b
487 -- Rather a lot of inlining here, else we get reduce/reduce errors
488 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
489 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
490 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
492 -----------------------------------------------------------------------------
493 -- Nested declarations
495 decls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
496 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
497 | decls ';' { LL (unLoc $1) }
499 | {- empty -} { noLoc nilOL }
502 decllist :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
503 : '{' decls '}' { LL (unLoc $2) }
504 | vocurly decls close { $2 }
506 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
507 -- No implicit parameters
508 : 'where' decllist { LL (unLoc $2) }
509 | {- empty -} { noLoc nilOL }
511 binds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
512 : decllist { L1 (HsValBinds (cvBindGroup (unLoc $1))) }
513 | '{' dbinds '}' { LL (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
514 | vocurly dbinds close { L (getLoc $2) (HsIPBinds (IPBinds (unLoc $2) emptyLHsBinds)) }
516 wherebinds :: { Located (HsLocalBinds RdrName) } -- May have implicit parameters
517 : 'where' binds { LL (unLoc $2) }
518 | {- empty -} { noLoc emptyLocalBinds }
521 -----------------------------------------------------------------------------
522 -- Transformation Rules
524 rules :: { OrdList (LHsDecl RdrName) } -- Reversed
525 : rules ';' rule { $1 `snocOL` $3 }
528 | {- empty -} { nilOL }
530 rule :: { LHsDecl RdrName }
531 : STRING activation rule_forall infixexp '=' exp
532 { LL $ RuleD (HsRule (getSTRING $1) $2 $3 $4 $6) }
534 activation :: { Activation } -- Omitted means AlwaysActive
535 : {- empty -} { AlwaysActive }
536 | explicit_activation { $1 }
538 inverse_activation :: { Activation } -- Omitted means NeverActive
539 : {- empty -} { NeverActive }
540 | explicit_activation { $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 [] (noLoc []) (PrefixCon [$2]) }
857 | conid '{' var '::' ctype '}'
858 { LL $ ConDecl $1 [] (noLoc []) (RecCon [($3, $5)]) }
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 gadt_constr :: { LConDecl RdrName }
871 { LL (GadtDecl $1 $3) }
873 constrs :: { Located [LConDecl RdrName] }
874 : {- empty; a GHC extension -} { noLoc [] }
875 | '=' constrs1 { LL (unLoc $2) }
877 constrs1 :: { Located [LConDecl RdrName] }
878 : constrs1 '|' constr { LL ($3 : unLoc $1) }
881 constr :: { LConDecl RdrName }
882 : forall context '=>' constr_stuff
883 { let (con,details) = unLoc $4 in
884 LL (ConDecl con (unLoc $1) $2 details) }
885 | forall constr_stuff
886 { let (con,details) = unLoc $2 in
887 LL (ConDecl con (unLoc $1) (noLoc []) details) }
889 forall :: { Located [LHsTyVarBndr RdrName] }
890 : 'forall' tv_bndrs '.' { LL $2 }
891 | {- empty -} { noLoc [] }
893 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
894 -- We parse the constructor declaration
896 -- as a btype (treating C as a type constructor) and then convert C to be
897 -- a data constructor. Reason: it might continue like this:
899 -- in which case C really would be a type constructor. We can't resolve this
900 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
901 : btype {% mkPrefixCon $1 [] >>= return.LL }
902 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
903 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
904 | btype conop btype { LL ($2, InfixCon $1 $3) }
906 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
907 : fielddecl ',' fielddecls { unLoc $1 : $3 }
908 | fielddecl { [unLoc $1] }
910 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
911 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
913 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
914 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
915 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
916 -- We don't allow a context, but that's sorted out by the type checker.
917 deriving :: { Located (Maybe [LHsType RdrName]) }
918 : {- empty -} { noLoc Nothing }
919 | 'deriving' qtycon {% do { let { L loc tv = $2 }
920 ; p <- checkInstType (L loc (HsTyVar tv))
921 ; return (LL (Just [p])) } }
922 | 'deriving' '(' ')' { LL (Just []) }
923 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
924 -- Glasgow extension: allow partial
925 -- applications in derivings
927 -----------------------------------------------------------------------------
930 {- There's an awkward overlap with a type signature. Consider
931 f :: Int -> Int = ...rhs...
932 Then we can't tell whether it's a type signature or a value
933 definition with a result signature until we see the '='.
934 So we have to inline enough to postpone reductions until we know.
938 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
939 instead of qvar, we get another shift/reduce-conflict. Consider the
942 { (^^) :: Int->Int ; } Type signature; only var allowed
944 { (^^) :: Int->Int = ... ; } Value defn with result signature;
945 qvar allowed (because of instance decls)
947 We can't tell whether to reduce var to qvar until after we've read the signatures.
950 decl :: { Located (OrdList (LHsDecl RdrName)) }
952 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
953 return (LL $ unitOL (LL $ ValD r)) } }
955 rhs :: { Located (GRHSs RdrName) }
956 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
957 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
959 gdrhs :: { Located [LGRHS RdrName] }
960 : gdrhs gdrh { LL ($2 : unLoc $1) }
963 gdrh :: { LGRHS RdrName }
964 : '|' quals '=' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
966 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
967 : infixexp '::' sigtype
968 {% do s <- checkValSig $1 $3;
969 return (LL $ unitOL (LL $ SigD s)) }
970 -- See the above notes for why we need infixexp here
971 | var ',' sig_vars '::' sigtype
972 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
973 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
975 | '{-# INLINE' activation qvar '#-}'
976 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
977 | '{-# NOINLINE' inverse_activation qvar '#-}'
978 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
979 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
980 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
982 | '{-# SPECIALISE' 'instance' inst_type '#-}'
983 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
985 -----------------------------------------------------------------------------
988 exp :: { LHsExpr RdrName }
989 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
990 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
991 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
992 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
993 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
996 infixexp :: { LHsExpr RdrName }
998 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1000 exp10 :: { LHsExpr RdrName }
1001 : '\\' aexp aexps opt_asig '->' exp
1002 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1003 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1004 (GRHSs (unguardedRHS $6) emptyLocalBinds
1006 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1007 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1008 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1009 | '-' fexp { LL $ mkHsNegApp $2 }
1011 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1012 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1013 return (L loc (mkHsDo DoExpr stmts body)) }
1014 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1015 checkDo loc (unLoc $2) >>= \ (stmts,body) ->
1016 return (L loc (mkHsDo (MDoExpr noPostTcTable) stmts body)) }
1017 | scc_annot exp { LL $ if opt_SccProfilingOn
1018 then HsSCC (unLoc $1) $2
1021 | 'proc' aexp '->' exp
1022 {% checkPattern $2 >>= \ p ->
1023 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1024 placeHolderType undefined)) }
1025 -- TODO: is LL right here?
1027 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1028 -- hdaume: core annotation
1031 scc_annot :: { Located FastString }
1032 : '_scc_' STRING { LL $ getSTRING $2 }
1033 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1035 fexp :: { LHsExpr RdrName }
1036 : fexp aexp { LL $ HsApp $1 $2 }
1039 aexps :: { [LHsExpr RdrName] }
1040 : aexps aexp { $2 : $1 }
1041 | {- empty -} { [] }
1043 aexp :: { LHsExpr RdrName }
1044 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1045 | '~' aexp { LL $ ELazyPat $2 }
1048 aexp1 :: { LHsExpr RdrName }
1049 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1054 -- Here was the syntax for type applications that I was planning
1055 -- but there are difficulties (e.g. what order for type args)
1056 -- so it's not enabled yet.
1057 -- But this case *is* used for the left hand side of a generic definition,
1058 -- which is parsed as an expression before being munged into a pattern
1059 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1060 (sL (getLoc $3) (HsType $3)) }
1062 aexp2 :: { LHsExpr RdrName }
1063 : ipvar { L1 (HsIPVar $! unLoc $1) }
1064 | qcname { L1 (HsVar $! unLoc $1) }
1065 | literal { L1 (HsLit $! unLoc $1) }
1066 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1067 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1068 | '(' exp ')' { LL (HsPar $2) }
1069 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1070 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1071 | '[' list ']' { LL (unLoc $2) }
1072 | '[:' parr ':]' { LL (unLoc $2) }
1073 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1074 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1075 | '_' { L1 EWildPat }
1077 -- MetaHaskell Extension
1078 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1079 (L1 $ HsVar (mkUnqual varName
1080 (getTH_ID_SPLICE $1)))) } -- $x
1081 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1083 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1084 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1085 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1086 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1087 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1088 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1089 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1090 return (LL $ HsBracket (PatBr p)) }
1091 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1093 -- arrow notation extension
1094 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1096 cmdargs :: { [LHsCmdTop RdrName] }
1097 : cmdargs acmd { $2 : $1 }
1098 | {- empty -} { [] }
1100 acmd :: { LHsCmdTop RdrName }
1101 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1103 cvtopbody :: { [LHsDecl RdrName] }
1104 : '{' cvtopdecls0 '}' { $2 }
1105 | vocurly cvtopdecls0 close { $2 }
1107 cvtopdecls0 :: { [LHsDecl RdrName] }
1108 : {- empty -} { [] }
1111 texps :: { [LHsExpr RdrName] }
1112 : texps ',' exp { $3 : $1 }
1116 -----------------------------------------------------------------------------
1119 -- The rules below are little bit contorted to keep lexps left-recursive while
1120 -- avoiding another shift/reduce-conflict.
1122 list :: { LHsExpr RdrName }
1123 : exp { L1 $ ExplicitList placeHolderType [$1] }
1124 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1125 | exp '..' { LL $ ArithSeq noPostTcExpr (From $1) }
1126 | exp ',' exp '..' { LL $ ArithSeq noPostTcExpr (FromThen $1 $3) }
1127 | exp '..' exp { LL $ ArithSeq noPostTcExpr (FromTo $1 $3) }
1128 | exp ',' exp '..' exp { LL $ ArithSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1129 | exp pquals { sL (comb2 $1 $>) $ mkHsDo ListComp (reverse (unLoc $2)) $1 }
1131 lexps :: { Located [LHsExpr RdrName] }
1132 : lexps ',' exp { LL ($3 : unLoc $1) }
1133 | exp ',' exp { LL [$3,$1] }
1135 -----------------------------------------------------------------------------
1136 -- List Comprehensions
1138 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1139 -- or a reversed list of Stmts
1140 : pquals1 { case unLoc $1 of
1142 qss -> L1 [L1 (ParStmt stmtss)]
1144 stmtss = [ (reverse qs, undefined)
1148 pquals1 :: { Located [[LStmt RdrName]] }
1149 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1150 | '|' quals { L (getLoc $2) [unLoc $2] }
1152 quals :: { Located [LStmt RdrName] }
1153 : quals ',' qual { LL ($3 : unLoc $1) }
1156 -----------------------------------------------------------------------------
1157 -- Parallel array expressions
1159 -- The rules below are little bit contorted; see the list case for details.
1160 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1161 -- Moreover, we allow explicit arrays with no element (represented by the nil
1162 -- constructor in the list case).
1164 parr :: { LHsExpr RdrName }
1165 : { noLoc (ExplicitPArr placeHolderType []) }
1166 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1167 | lexps { L1 $ ExplicitPArr placeHolderType
1168 (reverse (unLoc $1)) }
1169 | exp '..' exp { LL $ PArrSeq noPostTcExpr (FromTo $1 $3) }
1170 | exp ',' exp '..' exp { LL $ PArrSeq noPostTcExpr (FromThenTo $1 $3 $5) }
1171 | exp pquals { sL (comb2 $1 $>) $ mkHsDo PArrComp (reverse (unLoc $2)) $1 }
1173 -- We are reusing `lexps' and `pquals' from the list case.
1175 -----------------------------------------------------------------------------
1176 -- Case alternatives
1178 altslist :: { Located [LMatch RdrName] }
1179 : '{' alts '}' { LL (reverse (unLoc $2)) }
1180 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1182 alts :: { Located [LMatch RdrName] }
1183 : alts1 { L1 (unLoc $1) }
1184 | ';' alts { LL (unLoc $2) }
1186 alts1 :: { Located [LMatch RdrName] }
1187 : alts1 ';' alt { LL ($3 : unLoc $1) }
1188 | alts1 ';' { LL (unLoc $1) }
1191 alt :: { LMatch RdrName }
1192 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1193 return (LL (Match [p] $2 (unLoc $3))) }
1195 alt_rhs :: { Located (GRHSs RdrName) }
1196 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1198 ralt :: { Located [LGRHS RdrName] }
1199 : '->' exp { LL (unguardedRHS $2) }
1200 | gdpats { L1 (reverse (unLoc $1)) }
1202 gdpats :: { Located [LGRHS RdrName] }
1203 : gdpats gdpat { LL ($2 : unLoc $1) }
1206 gdpat :: { LGRHS RdrName }
1207 : '|' quals '->' exp { sL (comb2 $1 $>) $ GRHS (reverse (unLoc $2)) $4 }
1209 -----------------------------------------------------------------------------
1210 -- Statement sequences
1212 stmtlist :: { Located [LStmt RdrName] }
1213 : '{' stmts '}' { LL (unLoc $2) }
1214 | vocurly stmts close { $2 }
1216 -- do { ;; s ; s ; ; s ;; }
1217 -- The last Stmt should be an expression, but that's hard to enforce
1218 -- here, because we need too much lookahead if we see do { e ; }
1219 -- So we use ExprStmts throughout, and switch the last one over
1220 -- in ParseUtils.checkDo instead
1221 stmts :: { Located [LStmt RdrName] }
1222 : stmt stmts_help { LL ($1 : unLoc $2) }
1223 | ';' stmts { LL (unLoc $2) }
1224 | {- empty -} { noLoc [] }
1226 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1227 : ';' stmts { LL (unLoc $2) }
1228 | {- empty -} { noLoc [] }
1230 -- For typing stmts at the GHCi prompt, where
1231 -- the input may consist of just comments.
1232 maybe_stmt :: { Maybe (LStmt RdrName) }
1234 | {- nothing -} { Nothing }
1236 stmt :: { LStmt RdrName }
1238 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1239 return (LL $ mkBindStmt p $1) }
1240 | 'rec' stmtlist { LL $ mkRecStmt (unLoc $2) }
1242 qual :: { LStmt RdrName }
1243 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1244 return (LL $ mkBindStmt p $3) }
1245 | exp { L1 $ mkExprStmt $1 }
1246 | 'let' binds { LL $ LetStmt (unLoc $2) }
1248 -----------------------------------------------------------------------------
1249 -- Record Field Update/Construction
1251 fbinds :: { HsRecordBinds RdrName }
1253 | {- empty -} { [] }
1255 fbinds1 :: { HsRecordBinds RdrName }
1256 : fbinds1 ',' fbind { $3 : $1 }
1259 fbind :: { (Located RdrName, LHsExpr RdrName) }
1260 : qvar '=' exp { ($1,$3) }
1262 -----------------------------------------------------------------------------
1263 -- Implicit Parameter Bindings
1265 dbinds :: { Located [LIPBind RdrName] }
1266 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1267 | dbinds ';' { LL (unLoc $1) }
1269 -- | {- empty -} { [] }
1271 dbind :: { LIPBind RdrName }
1272 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1274 ipvar :: { Located (IPName RdrName) }
1275 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1276 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1278 -----------------------------------------------------------------------------
1281 depreclist :: { Located [RdrName] }
1282 depreclist : deprec_var { L1 [unLoc $1] }
1283 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1285 deprec_var :: { Located RdrName }
1286 deprec_var : var { $1 }
1289 -----------------------------------------
1290 -- Data constructors
1291 qcon :: { Located RdrName }
1293 | '(' qconsym ')' { LL (unLoc $2) }
1294 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1295 -- The case of '[:' ':]' is part of the production `parr'
1297 con :: { Located RdrName }
1299 | '(' consym ')' { LL (unLoc $2) }
1300 | sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1302 sysdcon :: { Located DataCon } -- Wired in data constructors
1303 : '(' ')' { LL unitDataCon }
1304 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1305 | '[' ']' { LL nilDataCon }
1307 conop :: { Located RdrName }
1309 | '`' conid '`' { LL (unLoc $2) }
1311 qconop :: { Located RdrName }
1313 | '`' qconid '`' { LL (unLoc $2) }
1315 -----------------------------------------------------------------------------
1316 -- Type constructors
1318 gtycon :: { Located RdrName } -- A "general" qualified tycon
1320 | '(' ')' { LL $ getRdrName unitTyCon }
1321 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1322 | '(' '->' ')' { LL $ getRdrName funTyCon }
1323 | '[' ']' { LL $ listTyCon_RDR }
1324 | '[:' ':]' { LL $ parrTyCon_RDR }
1326 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1328 | '(' qtyconsym ')' { LL (unLoc $2) }
1330 qtyconop :: { Located RdrName } -- Qualified or unqualified
1332 | '`' qtycon '`' { LL (unLoc $2) }
1334 qtycon :: { Located RdrName } -- Qualified or unqualified
1335 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1338 tycon :: { Located RdrName } -- Unqualified
1339 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1341 qtyconsym :: { Located RdrName }
1342 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1345 tyconsym :: { Located RdrName }
1346 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1348 -----------------------------------------------------------------------------
1351 op :: { Located RdrName } -- used in infix decls
1355 varop :: { Located RdrName }
1357 | '`' varid '`' { LL (unLoc $2) }
1359 qop :: { LHsExpr RdrName } -- used in sections
1360 : qvarop { L1 $ HsVar (unLoc $1) }
1361 | qconop { L1 $ HsVar (unLoc $1) }
1363 qopm :: { LHsExpr RdrName } -- used in sections
1364 : qvaropm { L1 $ HsVar (unLoc $1) }
1365 | qconop { L1 $ HsVar (unLoc $1) }
1367 qvarop :: { Located RdrName }
1369 | '`' qvarid '`' { LL (unLoc $2) }
1371 qvaropm :: { Located RdrName }
1372 : qvarsym_no_minus { $1 }
1373 | '`' qvarid '`' { LL (unLoc $2) }
1375 -----------------------------------------------------------------------------
1378 tyvar :: { Located RdrName }
1379 tyvar : tyvarid { $1 }
1380 | '(' tyvarsym ')' { LL (unLoc $2) }
1382 tyvarop :: { Located RdrName }
1383 tyvarop : '`' tyvarid '`' { LL (unLoc $2) }
1386 tyvarid :: { Located RdrName }
1387 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1388 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1389 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1390 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1391 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1393 tyvarsym :: { Located RdrName }
1394 -- Does not include "!", because that is used for strictness marks
1395 -- or ".", because that separates the quantified type vars from the rest
1396 -- or "*", because that's used for kinds
1397 tyvarsym : VARSYM { L1 $! mkUnqual tvName (getVARSYM $1) }
1399 -----------------------------------------------------------------------------
1402 var :: { Located RdrName }
1404 | '(' varsym ')' { LL (unLoc $2) }
1406 qvar :: { Located RdrName }
1408 | '(' varsym ')' { LL (unLoc $2) }
1409 | '(' qvarsym1 ')' { LL (unLoc $2) }
1410 -- We've inlined qvarsym here so that the decision about
1411 -- whether it's a qvar or a var can be postponed until
1412 -- *after* we see the close paren.
1414 qvarid :: { Located RdrName }
1416 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1418 varid :: { Located RdrName }
1419 : varid_no_unsafe { $1 }
1420 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1421 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1422 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1424 varid_no_unsafe :: { Located RdrName }
1425 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1426 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1427 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1429 qvarsym :: { Located RdrName }
1433 qvarsym_no_minus :: { Located RdrName }
1434 : varsym_no_minus { $1 }
1437 qvarsym1 :: { Located RdrName }
1438 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1440 varsym :: { Located RdrName }
1441 : varsym_no_minus { $1 }
1442 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1444 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1445 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1446 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1449 -- These special_ids are treated as keywords in various places,
1450 -- but as ordinary ids elsewhere. 'special_id' collects all these
1451 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1452 special_id :: { Located UserFS }
1454 : 'as' { L1 FSLIT("as") }
1455 | 'qualified' { L1 FSLIT("qualified") }
1456 | 'hiding' { L1 FSLIT("hiding") }
1457 | 'export' { L1 FSLIT("export") }
1458 | 'label' { L1 FSLIT("label") }
1459 | 'dynamic' { L1 FSLIT("dynamic") }
1460 | 'stdcall' { L1 FSLIT("stdcall") }
1461 | 'ccall' { L1 FSLIT("ccall") }
1463 special_sym :: { Located UserFS }
1464 special_sym : '!' { L1 FSLIT("!") }
1465 | '.' { L1 FSLIT(".") }
1466 | '*' { L1 FSLIT("*") }
1468 -----------------------------------------------------------------------------
1469 -- Data constructors
1471 qconid :: { Located RdrName } -- Qualified or unqualified
1473 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1475 conid :: { Located RdrName }
1476 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1478 qconsym :: { Located RdrName } -- Qualified or unqualified
1480 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1482 consym :: { Located RdrName }
1483 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1485 -- ':' means only list cons
1486 | ':' { L1 $ consDataCon_RDR }
1489 -----------------------------------------------------------------------------
1492 literal :: { Located HsLit }
1493 : CHAR { L1 $ HsChar $ getCHAR $1 }
1494 | STRING { L1 $ HsString $ getSTRING $1 }
1495 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1496 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1497 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1498 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1499 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1501 -----------------------------------------------------------------------------
1505 : vccurly { () } -- context popped in lexer.
1506 | error {% popContext }
1508 -----------------------------------------------------------------------------
1509 -- Miscellaneous (mostly renamings)
1511 modid :: { Located Module }
1512 : CONID { L1 $ mkModuleFS (getCONID $1) }
1513 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1516 (unpackFS mod ++ '.':unpackFS c))
1520 : commas ',' { $1 + 1 }
1523 -----------------------------------------------------------------------------
1527 happyError = srcParseFail
1529 getVARID (L _ (ITvarid x)) = x
1530 getCONID (L _ (ITconid x)) = x
1531 getVARSYM (L _ (ITvarsym x)) = x
1532 getCONSYM (L _ (ITconsym x)) = x
1533 getQVARID (L _ (ITqvarid x)) = x
1534 getQCONID (L _ (ITqconid x)) = x
1535 getQVARSYM (L _ (ITqvarsym x)) = x
1536 getQCONSYM (L _ (ITqconsym x)) = x
1537 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1538 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1539 getCHAR (L _ (ITchar x)) = x
1540 getSTRING (L _ (ITstring x)) = x
1541 getINTEGER (L _ (ITinteger x)) = x
1542 getRATIONAL (L _ (ITrational x)) = x
1543 getPRIMCHAR (L _ (ITprimchar x)) = x
1544 getPRIMSTRING (L _ (ITprimstring x)) = x
1545 getPRIMINTEGER (L _ (ITprimint x)) = x
1546 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1547 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1548 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1550 -- Utilities for combining source spans
1551 comb2 :: Located a -> Located b -> SrcSpan
1554 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1555 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1557 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1558 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1559 combineSrcSpans (getLoc c) (getLoc d)
1561 -- strict constructor version:
1563 sL :: SrcSpan -> a -> Located a
1564 sL span a = span `seq` L span a
1566 -- Make a source location for the file. We're a bit lazy here and just
1567 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1568 -- try to find the span of the whole file (ToDo).
1569 fileSrcSpan :: P SrcSpan
1572 let loc = mkSrcLoc (srcLocFile l) 1 0;
1573 return (mkSrcSpan loc loc)