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, parseIface ) where
13 #define INCLUDE #include
14 INCLUDE "HsVersions.h"
18 import HscTypes ( ModIface, IsBootInterface, DeprecTxt )
21 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
22 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
23 import Type ( funTyCon )
24 import ForeignCall ( Safety(..), CExportSpec(..),
25 CCallConv(..), CCallTarget(..), defaultCCallConv
27 import OccName ( UserFS, varName, dataName, tcClsName, tvName )
28 import DataCon ( DataCon, dataConName )
29 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
30 SrcSpan, combineLocs, mkGeneralSrcSpan, srcLocFile )
32 import CmdLineOpts ( opt_SccProfilingOn )
33 import Type ( Kind, mkArrowKind, liftedTypeKind )
34 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
37 import Bag ( emptyBag )
40 import CStrings ( CLabelString )
42 import Maybes ( orElse )
48 -----------------------------------------------------------------------------
49 Conflicts: 29 shift/reduce, [SDM 19/9/2002]
51 10 for abiguity in 'if x then y else z + 1' [State 136]
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 with ?x=3' [State 136]
56 (shift parses as 'if x then y else (z with ?x=3)'
58 1 for ambiguity in 'if x then y else z :: T' [State 136]
59 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
61 8 for ambiguity in 'e :: a `b` c'. Does this mean [States 160,246]
65 1 for ambiguity in 'let ?x ...' [State 268]
66 the parser can't tell whether the ?x is the lhs of a normal binding or
67 an implicit binding. Fortunately resolving as shift gives it the only
68 sensible meaning, namely the lhs of an implicit binding.
70 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 332]
71 we don't know whether the '[' starts the activation or not: it
72 might be the start of the declaration with the activation being
75 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 394]
76 since 'forall' is a valid variable name, we don't know whether
77 to treat a forall on the input as the beginning of a quantifier
78 or the beginning of the rule itself. Resolving to shift means
79 it's always treated as a quantifier, hence the above is disallowed.
80 This saves explicitly defining a grammar for the rule lhs that
81 doesn't include 'forall'.
83 6 for conflicts between `fdecl' and `fdeclDEPRECATED', [States 384,385]
84 which are resolved correctly, and moreover,
85 should go away when `fdeclDEPRECATED' is removed.
87 -- ---------------------------------------------------------------------------
88 -- Adding location info
90 This is done in a stylised way using the three macros below, L0, L1
91 and LL. Each of these macros can be thought of as having type
93 L0, L1, LL :: a -> Located a
95 They each add a SrcSpan to their argument.
97 L0 adds 'noSrcSpan', used for empty productions
99 L1 for a production with a single token on the lhs. Grabs the SrcSpan
102 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
103 the first and last tokens.
105 These suffice for the majority of cases. However, we must be
106 especially careful with empty productions: LL won't work if the first
107 or last token on the lhs can represent an empty span. In these cases,
108 we have to calculate the span using more of the tokens from the lhs, eg.
110 | 'newtype' tycl_hdr '=' newconstr deriving
112 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
114 We provide comb3 and comb4 functions which are useful in such cases.
116 Be careful: there's no checking that you actually got this right, the
117 only symptom will be that the SrcSpans of your syntax will be
121 * We must expand these macros *before* running Happy, which is why this file is
122 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
124 #define L0 L noSrcSpan
125 #define L1 sL (getLoc $1)
126 #define LL sL (comb2 $1 $>)
128 -- -----------------------------------------------------------------------------
133 '_' { L _ ITunderscore } -- Haskell keywords
135 'case' { L _ ITcase }
136 'class' { L _ ITclass }
137 'data' { L _ ITdata }
138 'default' { L _ ITdefault }
139 'deriving' { L _ ITderiving }
141 'else' { L _ ITelse }
142 'hiding' { L _ IThiding }
144 'import' { L _ ITimport }
146 'infix' { L _ ITinfix }
147 'infixl' { L _ ITinfixl }
148 'infixr' { L _ ITinfixr }
149 'instance' { L _ ITinstance }
151 'module' { L _ ITmodule }
152 'newtype' { L _ ITnewtype }
154 'qualified' { L _ ITqualified }
155 'then' { L _ ITthen }
156 'type' { L _ ITtype }
157 'where' { L _ ITwhere }
158 '_scc_' { L _ ITscc } -- ToDo: remove
160 'forall' { L _ ITforall } -- GHC extension keywords
161 'foreign' { L _ ITforeign }
162 'export' { L _ ITexport }
163 'label' { L _ ITlabel }
164 'dynamic' { L _ ITdynamic }
165 'safe' { L _ ITsafe }
166 'threadsafe' { L _ ITthreadsafe }
167 'unsafe' { L _ ITunsafe }
169 'stdcall' { L _ ITstdcallconv }
170 'ccall' { L _ ITccallconv }
171 'dotnet' { L _ ITdotnet }
172 'proc' { L _ ITproc } -- for arrow notation extension
173 'rec' { L _ ITrec } -- for arrow notation extension
175 '{-# SPECIALISE' { L _ ITspecialise_prag }
176 '{-# SOURCE' { L _ ITsource_prag }
177 '{-# INLINE' { L _ ITinline_prag }
178 '{-# NOINLINE' { L _ ITnoinline_prag }
179 '{-# RULES' { L _ ITrules_prag }
180 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
181 '{-# SCC' { L _ ITscc_prag }
182 '{-# DEPRECATED' { L _ ITdeprecated_prag }
183 '{-# UNPACK' { L _ ITunpack_prag }
184 '#-}' { L _ ITclose_prag }
186 '..' { L _ ITdotdot } -- reserved symbols
188 '::' { L _ ITdcolon }
192 '<-' { L _ ITlarrow }
193 '->' { L _ ITrarrow }
196 '=>' { L _ ITdarrow }
200 '-<' { L _ ITlarrowtail } -- for arrow notation
201 '>-' { L _ ITrarrowtail } -- for arrow notation
202 '-<<' { L _ ITLarrowtail } -- for arrow notation
203 '>>-' { L _ ITRarrowtail } -- for arrow notation
206 '{' { L _ ITocurly } -- special symbols
208 '{|' { L _ ITocurlybar }
209 '|}' { L _ ITccurlybar }
210 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
211 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
214 '[:' { L _ ITopabrack }
215 ':]' { L _ ITcpabrack }
218 '(#' { L _ IToubxparen }
219 '#)' { L _ ITcubxparen }
220 '(|' { L _ IToparenbar }
221 '|)' { L _ ITcparenbar }
224 '`' { L _ ITbackquote }
226 VARID { L _ (ITvarid _) } -- identifiers
227 CONID { L _ (ITconid _) }
228 VARSYM { L _ (ITvarsym _) }
229 CONSYM { L _ (ITconsym _) }
230 QVARID { L _ (ITqvarid _) }
231 QCONID { L _ (ITqconid _) }
232 QVARSYM { L _ (ITqvarsym _) }
233 QCONSYM { L _ (ITqconsym _) }
235 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
236 IPSPLITVARID { L _ (ITsplitipvarid _) } -- GHC extension
238 CHAR { L _ (ITchar _) }
239 STRING { L _ (ITstring _) }
240 INTEGER { L _ (ITinteger _) }
241 RATIONAL { L _ (ITrational _) }
243 PRIMCHAR { L _ (ITprimchar _) }
244 PRIMSTRING { L _ (ITprimstring _) }
245 PRIMINTEGER { L _ (ITprimint _) }
246 PRIMFLOAT { L _ (ITprimfloat _) }
247 PRIMDOUBLE { L _ (ITprimdouble _) }
250 '[|' { L _ ITopenExpQuote }
251 '[p|' { L _ ITopenPatQuote }
252 '[t|' { L _ ITopenTypQuote }
253 '[d|' { L _ ITopenDecQuote }
254 '|]' { L _ ITcloseQuote }
255 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
256 '$(' { L _ ITparenEscape } -- $( exp )
257 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
258 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
260 %monad { P } { >>= } { return }
261 %lexer { lexer } { L _ ITeof }
262 %name parseModule module
263 %name parseStmt maybe_stmt
264 %name parseIdentifier identifier
265 %name parseIface iface
266 %tokentype { Located Token }
269 -----------------------------------------------------------------------------
272 -- The place for module deprecation is really too restrictive, but if it
273 -- was allowed at its natural place just before 'module', we get an ugly
274 -- s/r conflict with the second alternative. Another solution would be the
275 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
276 -- either, and DEPRECATED is only expected to be used by people who really
277 -- know what they are doing. :-)
279 module :: { Located (HsModule RdrName) }
280 : 'module' modid maybemoddeprec maybeexports 'where' body
281 {% fileSrcSpan >>= \ loc ->
282 return (L loc (HsModule (Just (L (getLoc $2)
283 (mkHomeModule (unLoc $2))))
284 $4 (fst $6) (snd $6) $3)) }
285 | missing_module_keyword top close
286 {% fileSrcSpan >>= \ loc ->
287 return (L loc (HsModule Nothing Nothing
288 (fst $2) (snd $2) Nothing)) }
290 missing_module_keyword :: { () }
291 : {- empty -} {% pushCurrentContext }
293 maybemoddeprec :: { Maybe DeprecTxt }
294 : '{-# DEPRECATED' STRING '#-}' { Just (getSTRING $2) }
295 | {- empty -} { Nothing }
297 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
299 | vocurly top close { $2 }
301 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
302 : importdecls { (reverse $1,[]) }
303 | importdecls ';' cvtopdecls { (reverse $1,$3) }
304 | cvtopdecls { ([],$1) }
306 cvtopdecls :: { [LHsDecl RdrName] }
307 : topdecls { cvTopDecls $1 }
309 -----------------------------------------------------------------------------
310 -- Interfaces (.hi-boot files)
312 iface :: { ModIface }
313 : 'module' modid 'where' ifacebody { mkBootIface (unLoc $2) $4 }
315 ifacebody :: { [HsDecl RdrName] }
316 : '{' ifacedecls '}' { $2 }
317 | vocurly ifacedecls close { $2 }
319 ifacedecls :: { [HsDecl RdrName] }
320 : ifacedecl ';' ifacedecls { $1 : $3 }
321 | ';' ifacedecls { $2 }
325 ifacedecl :: { HsDecl RdrName }
328 | 'type' syn_hdr '=' ctype
329 { let (tc,tvs) = $2 in TyClD (TySynonym tc tvs $4) }
330 | 'data' tycl_hdr constrs -- No deriving in hi-boot
331 { TyClD (mkTyData DataType (unLoc $2) (reverse (unLoc $3)) Nothing) }
332 | 'newtype' tycl_hdr -- Constructor is optional
333 { TyClD (mkTyData NewType (unLoc $2) [] Nothing) }
334 | 'newtype' tycl_hdr '=' newconstr
335 { TyClD (mkTyData NewType (unLoc $2) [$4] Nothing) }
336 | 'class' tycl_hdr fds
337 { TyClD (mkClassDecl (unLoc $2) (unLoc $3) [] emptyBag) }
339 -----------------------------------------------------------------------------
342 maybeexports :: { Maybe [LIE RdrName] }
343 : '(' exportlist ')' { Just $2 }
344 | {- empty -} { Nothing }
346 exportlist :: { [LIE RdrName] }
347 : exportlist ',' export { $3 : $1 }
348 | exportlist ',' { $1 }
352 -- No longer allow things like [] and (,,,) to be exported
353 -- They are built in syntax, always available
354 export :: { LIE RdrName }
355 : qvar { L1 (IEVar (unLoc $1)) }
356 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
357 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
358 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
359 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
360 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
362 qcnames :: { [RdrName] }
363 : qcnames ',' qcname { unLoc $3 : $1 }
364 | qcname { [unLoc $1] }
366 qcname :: { Located RdrName } -- Variable or data constructor
370 -----------------------------------------------------------------------------
371 -- Import Declarations
373 -- import decls can be *empty*, or even just a string of semicolons
374 -- whereas topdecls must contain at least one topdecl.
376 importdecls :: { [LImportDecl RdrName] }
377 : importdecls ';' importdecl { $3 : $1 }
378 | importdecls ';' { $1 }
379 | importdecl { [ $1 ] }
382 importdecl :: { LImportDecl RdrName }
383 : 'import' maybe_src optqualified modid maybeas maybeimpspec
384 { L (comb4 $1 $4 $5 $6) (ImportDecl $4 $2 $3 (unLoc $5) (unLoc $6)) }
386 maybe_src :: { IsBootInterface }
387 : '{-# SOURCE' '#-}' { True }
388 | {- empty -} { False }
390 optqualified :: { Bool }
391 : 'qualified' { True }
392 | {- empty -} { False }
394 maybeas :: { Located (Maybe ModuleName) }
395 : 'as' modid { LL (Just (unLoc $2)) }
396 | {- empty -} { noLoc Nothing }
398 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
399 : impspec { L1 (Just (unLoc $1)) }
400 | {- empty -} { noLoc Nothing }
402 impspec :: { Located (Bool, [LIE RdrName]) }
403 : '(' exportlist ')' { LL (False, reverse $2) }
404 | 'hiding' '(' exportlist ')' { LL (True, reverse $3) }
406 -----------------------------------------------------------------------------
407 -- Fixity Declarations
411 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
413 infix :: { Located FixityDirection }
414 : 'infix' { L1 InfixN }
415 | 'infixl' { L1 InfixL }
416 | 'infixr' { L1 InfixR }
418 ops :: { Located [Located RdrName] }
419 : ops ',' op { LL ($3 : unLoc $1) }
422 -----------------------------------------------------------------------------
423 -- Top-Level Declarations
425 topdecls :: { OrdList (LHsDecl RdrName) } -- Reversed
426 : topdecls ';' topdecl { $1 `appOL` $3 }
427 | topdecls ';' { $1 }
430 topdecl :: { OrdList (LHsDecl RdrName) }
431 : tycl_decl { unitOL (L1 (TyClD (unLoc $1))) }
432 | 'instance' inst_type where
433 { let (binds,sigs) = cvBindsAndSigs (unLoc $3)
434 in unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs))) }
435 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
436 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
437 | '{-# DEPRECATED' deprecations '#-}' { $2 }
438 | '{-# RULES' rules '#-}' { $2 }
439 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
442 tycl_decl :: { LTyClDecl RdrName }
443 : 'type' syn_hdr '=' ctype
444 -- Note ctype, not sigtype.
445 -- We allow an explicit for-all but we don't insert one
446 -- in type Foo a = (b,b)
447 -- Instead we just say b is out of scope
448 { LL $ let (tc,tvs) = $2 in TySynonym tc tvs $4 }
450 | 'data' tycl_hdr constrs deriving
451 { L (comb4 $1 $2 $3 $4)
452 (mkTyData DataType (unLoc $2) (reverse (unLoc $3)) (unLoc $4)) }
454 | 'newtype' tycl_hdr '=' newconstr deriving
456 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
458 | 'class' tycl_hdr fds where
460 (binds,sigs) = cvBindsAndSigs (unLoc $4)
462 L (comb4 $1 $2 $3 $4) (mkClassDecl (unLoc $2) (unLoc $3) sigs
465 syn_hdr :: { (Located RdrName, [LHsTyVarBndr RdrName]) }
466 -- We don't retain the syntax of an infix
467 -- type synonym declaration. Oh well.
468 : tycon tv_bndrs { ($1, $2) }
469 | tv_bndr tyconop tv_bndr { ($2, [$1,$3]) }
471 -- tycl_hdr parses the header of a type or class decl,
472 -- which takes the form
475 -- (Eq a, Ord b) => T a b
476 -- Rather a lot of inlining here, else we get reduce/reduce errors
477 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
478 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
479 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
481 -----------------------------------------------------------------------------
482 -- Nested declarations
484 decls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
485 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
486 | decls ';' { LL (unLoc $1) }
488 | {- empty -} { noLoc nilOL }
491 decllist :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
492 : '{' decls '}' { LL (unLoc $2) }
493 | vocurly decls close { $2 }
495 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
496 -- No implicit parameters
497 : 'where' decllist { LL (unLoc $2) }
498 | {- empty -} { noLoc nilOL }
500 binds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
501 : decllist { L1 [cvBindGroup (unLoc $1)] }
502 | '{' dbinds '}' { LL [HsIPBinds (unLoc $2)] }
503 | vocurly dbinds close { L (getLoc $2) [HsIPBinds (unLoc $2)] }
505 wherebinds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
506 : 'where' binds { LL (unLoc $2) }
507 | {- empty -} { noLoc [] }
510 -----------------------------------------------------------------------------
511 -- Transformation Rules
513 rules :: { OrdList (LHsDecl RdrName) } -- Reversed
514 : rules ';' rule { $1 `snocOL` $3 }
517 | {- empty -} { nilOL }
519 rule :: { LHsDecl RdrName }
520 : STRING activation rule_forall infixexp '=' exp
521 { LL $ RuleD (HsRule (getSTRING $1) $2 $3 $4 $6) }
523 activation :: { Activation } -- Omitted means AlwaysActive
524 : {- empty -} { AlwaysActive }
525 | explicit_activation { $1 }
527 inverse_activation :: { Activation } -- Omitted means NeverActive
528 : {- empty -} { NeverActive }
529 | explicit_activation { $1 }
531 explicit_activation :: { Activation } -- In brackets
532 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
533 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
535 rule_forall :: { [RuleBndr RdrName] }
536 : 'forall' rule_var_list '.' { $2 }
539 rule_var_list :: { [RuleBndr RdrName] }
541 | rule_var rule_var_list { $1 : $2 }
543 rule_var :: { RuleBndr RdrName }
544 : varid { RuleBndr $1 }
545 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
547 -----------------------------------------------------------------------------
548 -- Deprecations (c.f. rules)
550 deprecations :: { OrdList (LHsDecl RdrName) } -- Reversed
551 : deprecations ';' deprecation { $1 `appOL` $3 }
552 | deprecations ';' { $1 }
554 | {- empty -} { nilOL }
556 -- SUP: TEMPORARY HACK, not checking for `module Foo'
557 deprecation :: { OrdList (LHsDecl RdrName) }
559 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
563 -----------------------------------------------------------------------------
564 -- Foreign import and export declarations
566 -- for the time being, the following accepts foreign declarations conforming
567 -- to the FFI Addendum, Version 1.0 as well as pre-standard declarations
569 -- * a flag indicates whether pre-standard declarations have been used and
570 -- triggers a deprecation warning further down the road
572 -- NB: The first two rules could be combined into one by replacing `safety1'
573 -- with `safety'. However, the combined rule conflicts with the
576 fdecl :: { LHsDecl RdrName }
577 fdecl : 'import' callconv safety1 fspec
578 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
579 | 'import' callconv fspec
580 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
582 | 'export' callconv fspec
583 {% mkExport $2 (unLoc $3) >>= return.LL }
584 -- the following syntax is DEPRECATED
585 | fdecl1DEPRECATED { L1 (ForD (unLoc $1)) }
586 | fdecl2DEPRECATED { L1 (unLoc $1) }
588 fdecl1DEPRECATED :: { LForeignDecl RdrName }
590 ----------- DEPRECATED label decls ------------
591 : 'label' ext_name varid '::' sigtype
592 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
593 (CLabel ($2 `orElse` mkExtName (unLoc $3)))) True }
595 ----------- DEPRECATED ccall/stdcall decls ------------
597 -- NB: This business with the case expression below may seem overly
598 -- complicated, but it is necessary to avoid some conflicts.
600 -- DEPRECATED variant #1: lack of a calling convention specification
602 | 'import' {-no callconv-} ext_name safety varid_no_unsafe '::' sigtype
604 target = StaticTarget ($2 `orElse` mkExtName (unLoc $4))
606 LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
607 (CFunction target)) True }
609 -- DEPRECATED variant #2: external name consists of two separate strings
610 -- (module name and function name) (import)
611 | 'import' callconv STRING STRING safety varid_no_unsafe '::' sigtype
613 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
614 CCall cconv -> return $
616 imp = CFunction (StaticTarget (getSTRING $4))
618 LL $ ForeignImport $6 $8 (CImport cconv $5 nilFS nilFS imp) True }
620 -- DEPRECATED variant #3: `unsafe' after entity
621 | 'import' callconv STRING 'unsafe' varid_no_unsafe '::' sigtype
623 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
624 CCall cconv -> return $
626 imp = CFunction (StaticTarget (getSTRING $3))
628 LL $ ForeignImport $5 $7 (CImport cconv PlayRisky nilFS nilFS imp) True }
630 -- DEPRECATED variant #4: use of the special identifier `dynamic' without
631 -- an explicit calling convention (import)
632 | 'import' {-no callconv-} 'dynamic' safety varid_no_unsafe '::' sigtype
633 { LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
634 (CFunction DynamicTarget)) True }
636 -- DEPRECATED variant #5: use of the special identifier `dynamic' (import)
637 | 'import' callconv 'dynamic' safety varid_no_unsafe '::' sigtype
639 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
640 CCall cconv -> return $
641 LL $ ForeignImport $5 $7 (CImport cconv $4 nilFS nilFS
642 (CFunction DynamicTarget)) True }
644 -- DEPRECATED variant #6: lack of a calling convention specification
646 | 'export' {-no callconv-} ext_name varid '::' sigtype
647 { LL $ ForeignExport $3 $5 (CExport (CExportStatic ($2 `orElse` mkExtName (unLoc $3))
648 defaultCCallConv)) True }
650 -- DEPRECATED variant #7: external name consists of two separate strings
651 -- (module name and function name) (export)
652 | 'export' callconv STRING STRING varid '::' sigtype
654 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
655 CCall cconv -> return $
656 LL $ ForeignExport $5 $7
657 (CExport (CExportStatic (getSTRING $4) cconv)) True }
659 -- DEPRECATED variant #8: use of the special identifier `dynamic' without
660 -- an explicit calling convention (export)
661 | 'export' {-no callconv-} 'dynamic' varid '::' sigtype
662 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
665 -- DEPRECATED variant #9: use of the special identifier `dynamic' (export)
666 | 'export' callconv 'dynamic' varid '::' sigtype
668 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
669 CCall cconv -> return $
670 LL $ ForeignImport $4 $6
671 (CImport cconv (PlaySafe False) nilFS nilFS CWrapper) True }
673 ----------- DEPRECATED .NET decls ------------
674 -- NB: removed the .NET call declaration, as it is entirely subsumed
675 -- by the new standard FFI declarations
677 fdecl2DEPRECATED :: { LHsDecl RdrName }
679 : 'import' 'dotnet' 'type' ext_name tycon { LL $ TyClD (ForeignType $5 $4 DNType) }
680 -- left this one unchanged for the moment as type imports are not
681 -- covered currently by the FFI standard -=chak
684 callconv :: { CallConv }
685 : 'stdcall' { CCall StdCallConv }
686 | 'ccall' { CCall CCallConv }
687 | 'dotnet' { DNCall }
690 : 'unsafe' { PlayRisky }
691 | 'safe' { PlaySafe False }
692 | 'threadsafe' { PlaySafe True }
693 | {- empty -} { PlaySafe False }
695 safety1 :: { Safety }
696 : 'unsafe' { PlayRisky }
697 | 'safe' { PlaySafe False }
698 | 'threadsafe' { PlaySafe True }
699 -- only needed to avoid conflicts with the DEPRECATED rules
701 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
702 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
703 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
704 -- if the entity string is missing, it defaults to the empty string;
705 -- the meaning of an empty entity string depends on the calling
709 ext_name :: { Maybe CLabelString }
710 : STRING { Just (getSTRING $1) }
711 | STRING STRING { Just (getSTRING $2) } -- Ignore "module name" for now
712 | {- empty -} { Nothing }
715 -----------------------------------------------------------------------------
718 opt_sig :: { Maybe (LHsType RdrName) }
719 : {- empty -} { Nothing }
720 | '::' sigtype { Just $2 }
722 opt_asig :: { Maybe (LHsType RdrName) }
723 : {- empty -} { Nothing }
724 | '::' atype { Just $2 }
726 sigtypes1 :: { [LHsType RdrName] }
728 | sigtype ',' sigtypes1 { $1 : $3 }
730 sigtype :: { LHsType RdrName }
731 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
732 -- Wrap an Implicit forall if there isn't one there already
734 sig_vars :: { Located [Located RdrName] }
735 : sig_vars ',' var { LL ($3 : unLoc $1) }
738 -----------------------------------------------------------------------------
741 -- A ctype is a for-all type
742 ctype :: { LHsType RdrName }
743 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
744 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
745 -- A type of form (context => type) is an *implicit* HsForAllTy
748 -- We parse a context as a btype so that we don't get reduce/reduce
749 -- errors in ctype. The basic problem is that
751 -- looks so much like a tuple type. We can't tell until we find the =>
752 context :: { LHsContext RdrName }
753 : btype {% checkContext $1 }
755 type :: { LHsType RdrName }
756 : ipvar '::' gentype { LL (HsPredTy (LL $ HsIParam (unLoc $1) $3)) }
759 gentype :: { LHsType RdrName }
761 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
762 | btype '`' tyvar '`' gentype { LL $ HsOpTy $1 $3 $5 }
763 | btype '->' gentype { LL $ HsFunTy $1 $3 }
765 btype :: { LHsType RdrName }
766 : btype atype { LL $ HsAppTy $1 $2 }
769 atype :: { LHsType RdrName }
770 : gtycon { L1 (HsTyVar (unLoc $1)) }
771 | tyvar { L1 (HsTyVar (unLoc $1)) }
772 | '(' type ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
773 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
774 | '[' type ']' { LL $ HsListTy $2 }
775 | '[:' type ':]' { LL $ HsPArrTy $2 }
776 | '(' ctype ')' { LL $ HsParTy $2 }
777 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
779 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
781 -- An inst_type is what occurs in the head of an instance decl
782 -- e.g. (Foo a, Gaz b) => Wibble a b
783 -- It's kept as a single type, with a MonoDictTy at the right
784 -- hand corner, for convenience.
785 inst_type :: { LHsType RdrName }
786 : ctype {% checkInstType $1 }
788 inst_types1 :: { [LHsType RdrName] }
790 | inst_type ',' inst_types1 { $1 : $3 }
792 comma_types0 :: { [LHsType RdrName] }
793 : comma_types1 { $1 }
796 comma_types1 :: { [LHsType RdrName] }
798 | type ',' comma_types1 { $1 : $3 }
800 tv_bndrs :: { [LHsTyVarBndr RdrName] }
801 : tv_bndr tv_bndrs { $1 : $2 }
804 tv_bndr :: { LHsTyVarBndr RdrName }
805 : tyvar { L1 (UserTyVar (unLoc $1)) }
806 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
808 fds :: { Located [Located ([RdrName], [RdrName])] }
809 : {- empty -} { noLoc [] }
810 | '|' fds1 { LL (reverse (unLoc $2)) }
812 fds1 :: { Located [Located ([RdrName], [RdrName])] }
813 : fds1 ',' fd { LL ($3 : unLoc $1) }
816 fd :: { Located ([RdrName], [RdrName]) }
817 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
818 (reverse (unLoc $1), reverse (unLoc $3)) }
820 varids0 :: { Located [RdrName] }
821 : {- empty -} { noLoc [] }
822 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
824 -----------------------------------------------------------------------------
829 | akind '->' kind { mkArrowKind $1 $3 }
832 : '*' { liftedTypeKind }
833 | '(' kind ')' { $2 }
836 -----------------------------------------------------------------------------
837 -- Datatype declarations
839 newconstr :: { LConDecl RdrName }
840 : conid atype { LL $ ConDecl $1 [] (noLoc [])
841 (PrefixCon [(unbangedType $2)]) }
842 | conid '{' var '::' ctype '}'
843 { LL $ ConDecl $1 [] (noLoc [])
844 (RecCon [($3, (unbangedType $5))]) }
846 constrs :: { Located [LConDecl RdrName] }
847 : {- empty; a GHC extension -} { noLoc [] }
848 | '=' constrs1 { LL (unLoc $2) }
850 constrs1 :: { Located [LConDecl RdrName] }
851 : constrs1 '|' constr { LL ($3 : unLoc $1) }
854 constr :: { LConDecl RdrName }
855 : forall context '=>' constr_stuff
856 { let (con,details) = unLoc $4 in
857 LL (ConDecl con (unLoc $1) $2 details) }
858 | forall constr_stuff
859 { let (con,details) = unLoc $2 in
860 LL (ConDecl con (unLoc $1) (noLoc []) details) }
862 forall :: { Located [LHsTyVarBndr RdrName] }
863 : 'forall' tv_bndrs '.' { LL $2 }
864 | {- empty -} { noLoc [] }
866 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
867 : btype {% mkPrefixCon $1 [] >>= return.LL }
868 | btype bang_atype satypes {% do { r <- mkPrefixCon $1 ($2 : unLoc $3);
869 return (L (comb3 $1 $2 $3) r) } }
870 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
871 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
872 | sbtype conop sbtype { LL ($2, InfixCon $1 $3) }
874 bang_atype :: { LBangType RdrName }
875 : strict_mark atype { LL (BangType (unLoc $1) $2) }
877 satypes :: { Located [LBangType RdrName] }
878 : atype satypes { LL (unbangedType $1 : unLoc $2) }
879 | bang_atype satypes { LL ($1 : unLoc $2) }
880 | {- empty -} { noLoc [] }
882 sbtype :: { LBangType RdrName }
883 : btype { unbangedType $1 }
884 | strict_mark atype { LL (BangType (unLoc $1) $2) }
886 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
887 : fielddecl ',' fielddecls { unLoc $1 : $3 }
888 | fielddecl { [unLoc $1] }
890 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
891 : sig_vars '::' stype { LL (reverse (unLoc $1), $3) }
893 stype :: { LBangType RdrName }
894 : ctype { unbangedType $1 }
895 | strict_mark atype { LL (BangType (unLoc $1) $2) }
897 strict_mark :: { Located HsBang }
898 : '!' { L1 HsStrict }
899 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
901 deriving :: { Located (Maybe [LHsType RdrName]) }
902 : {- empty -} { noLoc Nothing }
903 | 'deriving' '(' ')' { LL (Just []) }
904 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
905 -- Glasgow extension: allow partial
906 -- applications in derivings
908 -----------------------------------------------------------------------------
911 {- There's an awkward overlap with a type signature. Consider
912 f :: Int -> Int = ...rhs...
913 Then we can't tell whether it's a type signature or a value
914 definition with a result signature until we see the '='.
915 So we have to inline enough to postpone reductions until we know.
919 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
920 instead of qvar, we get another shift/reduce-conflict. Consider the
923 { (^^) :: Int->Int ; } Type signature; only var allowed
925 { (^^) :: Int->Int = ... ; } Value defn with result signature;
926 qvar allowed (because of instance decls)
928 We can't tell whether to reduce var to qvar until after we've read the signatures.
931 decl :: { Located (OrdList (LHsDecl RdrName)) }
933 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 (unLoc $3);
934 return (LL $ unitOL (LL $ ValD r)) } }
936 rhs :: { Located (GRHSs RdrName) }
937 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) placeHolderType }
938 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) placeHolderType }
940 gdrhs :: { Located [LGRHS RdrName] }
941 : gdrhs gdrh { LL ($2 : unLoc $1) }
944 gdrh :: { LGRHS RdrName }
945 : '|' quals '=' exp { LL $ GRHS (reverse (L (getLoc $4) (ResultStmt $4) :
948 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
949 : infixexp '::' sigtype
950 {% do s <- checkValSig $1 $3;
951 return (LL $ unitOL (LL $ SigD s)) }
952 -- See the above notes for why we need infixexp here
953 | var ',' sig_vars '::' sigtype
954 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
955 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
957 | '{-# INLINE' activation qvar '#-}'
958 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
959 | '{-# NOINLINE' inverse_activation qvar '#-}'
960 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
961 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
962 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
964 | '{-# SPECIALISE' 'instance' inst_type '#-}'
965 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
967 -----------------------------------------------------------------------------
970 exp :: { LHsExpr RdrName }
971 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
972 | fexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
973 | fexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
974 | fexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
975 | fexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
978 infixexp :: { LHsExpr RdrName }
980 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
982 exp10 :: { LHsExpr RdrName }
983 : '\\' aexp aexps opt_asig '->' exp
984 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
985 return (LL $ HsLam (LL $ Match ps $4
986 (GRHSs (unguardedRHS $6) []
988 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
989 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
990 | 'case' exp 'of' altslist { LL $ HsCase $2 (unLoc $4) }
991 | '-' fexp { LL $ mkHsNegApp $2 }
993 | 'do' stmtlist {% let loc = comb2 $1 $2 in
994 checkDo loc (unLoc $2) >>= \ stmts ->
995 return (L loc (mkHsDo DoExpr stmts)) }
996 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
997 checkMDo loc (unLoc $2) >>= \ stmts ->
998 return (L loc (mkHsDo MDoExpr stmts)) }
1000 | scc_annot exp { LL $ if opt_SccProfilingOn
1001 then HsSCC (unLoc $1) $2
1004 | 'proc' aexp '->' exp
1005 {% checkPattern $2 >>= \ p ->
1006 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1007 placeHolderType undefined)) }
1008 -- TODO: is LL right here?
1010 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1011 -- hdaume: core annotation
1014 scc_annot :: { Located FastString }
1015 : '_scc_' STRING { LL $ getSTRING $2 }
1016 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1018 fexp :: { LHsExpr RdrName }
1019 : fexp aexp { LL $ HsApp $1 $2 }
1022 aexps :: { [LHsExpr RdrName] }
1023 : aexps aexp { $2 : $1 }
1024 | {- empty -} { [] }
1026 aexp :: { LHsExpr RdrName }
1027 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1028 | '~' aexp { LL $ ELazyPat $2 }
1031 aexp1 :: { LHsExpr RdrName }
1032 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1037 -- Here was the syntax for type applications that I was planning
1038 -- but there are difficulties (e.g. what order for type args)
1039 -- so it's not enabled yet.
1040 -- But this case *is* used for the left hand side of a generic definition,
1041 -- which is parsed as an expression before being munged into a pattern
1042 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1043 (sL (getLoc $3) (HsType $3)) }
1045 aexp2 :: { LHsExpr RdrName }
1046 : ipvar { L1 (HsIPVar $! unLoc $1) }
1047 | qcname { L1 (HsVar $! unLoc $1) }
1048 | literal { L1 (HsLit $! unLoc $1) }
1049 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1050 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1051 | '(' exp ')' { LL (HsPar $2) }
1052 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1053 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1054 | '[' list ']' { LL (unLoc $2) }
1055 | '[:' parr ':]' { LL (unLoc $2) }
1056 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1057 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1058 | '_' { L1 EWildPat }
1060 -- MetaHaskell Extension
1061 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1062 (L1 $ HsVar (mkUnqual varName
1063 (getTH_ID_SPLICE $1)))) } -- $x
1064 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1066 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1067 | TH_VAR_QUOTE qcon { LL $ HsBracket (VarBr (unLoc $2)) }
1068 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1069 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1070 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1071 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1072 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1073 return (LL $ HsBracket (PatBr p)) }
1074 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1076 -- arrow notation extension
1077 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1079 cmdargs :: { [LHsCmdTop RdrName] }
1080 : cmdargs acmd { $2 : $1 }
1081 | {- empty -} { [] }
1083 acmd :: { LHsCmdTop RdrName }
1084 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1086 cvtopbody :: { [LHsDecl RdrName] }
1087 : '{' cvtopdecls0 '}' { $2 }
1088 | vocurly cvtopdecls0 close { $2 }
1090 cvtopdecls0 :: { [LHsDecl RdrName] }
1091 : {- empty -} { [] }
1094 texps :: { [LHsExpr RdrName] }
1095 : texps ',' exp { $3 : $1 }
1099 -----------------------------------------------------------------------------
1102 -- The rules below are little bit contorted to keep lexps left-recursive while
1103 -- avoiding another shift/reduce-conflict.
1105 list :: { LHsExpr RdrName }
1106 : exp { L1 $ ExplicitList placeHolderType [$1] }
1107 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1108 | exp '..' { LL $ ArithSeqIn (From $1) }
1109 | exp ',' exp '..' { LL $ ArithSeqIn (FromThen $1 $3) }
1110 | exp '..' exp { LL $ ArithSeqIn (FromTo $1 $3) }
1111 | exp ',' exp '..' exp { LL $ ArithSeqIn (FromThenTo $1 $3 $5) }
1112 | exp pquals { LL $ mkHsDo ListComp
1113 (reverse (L (getLoc $1) (ResultStmt $1) :
1116 lexps :: { Located [LHsExpr RdrName] }
1117 : lexps ',' exp { LL ($3 : unLoc $1) }
1118 | exp ',' exp { LL [$3,$1] }
1120 -----------------------------------------------------------------------------
1121 -- List Comprehensions
1123 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1124 -- or a reversed list of Stmts
1125 : pquals1 { case unLoc $1 of
1127 qss -> L1 [L1 (ParStmt stmtss)]
1129 stmtss = [ (reverse qs, undefined)
1133 pquals1 :: { Located [[LStmt RdrName]] }
1134 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1135 | '|' quals { L (getLoc $2) [unLoc $2] }
1137 quals :: { Located [LStmt RdrName] }
1138 : quals ',' qual { LL ($3 : unLoc $1) }
1141 -----------------------------------------------------------------------------
1142 -- Parallel array expressions
1144 -- The rules below are little bit contorted; see the list case for details.
1145 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1146 -- Moreover, we allow explicit arrays with no element (represented by the nil
1147 -- constructor in the list case).
1149 parr :: { LHsExpr RdrName }
1150 : { noLoc (ExplicitPArr placeHolderType []) }
1151 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1152 | lexps { L1 $ ExplicitPArr placeHolderType
1153 (reverse (unLoc $1)) }
1154 | exp '..' exp { LL $ PArrSeqIn (FromTo $1 $3) }
1155 | exp ',' exp '..' exp { LL $ PArrSeqIn (FromThenTo $1 $3 $5) }
1156 | exp pquals { LL $ mkHsDo PArrComp
1157 (reverse (L (getLoc $1) (ResultStmt $1) :
1161 -- We are reusing `lexps' and `pquals' from the list case.
1163 -----------------------------------------------------------------------------
1164 -- Case alternatives
1166 altslist :: { Located [LMatch RdrName] }
1167 : '{' alts '}' { LL (reverse (unLoc $2)) }
1168 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1170 alts :: { Located [LMatch RdrName] }
1171 : alts1 { L1 (unLoc $1) }
1172 | ';' alts { LL (unLoc $2) }
1174 alts1 :: { Located [LMatch RdrName] }
1175 : alts1 ';' alt { LL ($3 : unLoc $1) }
1176 | alts1 ';' { LL (unLoc $1) }
1179 alt :: { LMatch RdrName }
1180 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1181 return (LL (Match [p] $2 (unLoc $3))) }
1183 alt_rhs :: { Located (GRHSs RdrName) }
1184 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)
1187 ralt :: { Located [LGRHS RdrName] }
1188 : '->' exp { LL (unguardedRHS $2) }
1189 | gdpats { L1 (reverse (unLoc $1)) }
1191 gdpats :: { Located [LGRHS RdrName] }
1192 : gdpats gdpat { LL ($2 : unLoc $1) }
1195 gdpat :: { LGRHS RdrName }
1196 : '|' quals '->' exp { let r = L (getLoc $4) (ResultStmt $4)
1197 in LL $ GRHS (reverse (r : unLoc $2)) }
1199 -----------------------------------------------------------------------------
1200 -- Statement sequences
1202 stmtlist :: { Located [LStmt RdrName] }
1203 : '{' stmts '}' { LL (unLoc $2) }
1204 | vocurly stmts close { $2 }
1206 -- do { ;; s ; s ; ; s ;; }
1207 -- The last Stmt should be a ResultStmt, but that's hard to enforce
1208 -- here, because we need too much lookahead if we see do { e ; }
1209 -- So we use ExprStmts throughout, and switch the last one over
1210 -- in ParseUtils.checkDo instead
1211 stmts :: { Located [LStmt RdrName] }
1212 : stmt stmts_help { LL ($1 : unLoc $2) }
1213 | ';' stmts { LL (unLoc $2) }
1214 | {- empty -} { noLoc [] }
1216 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1217 : ';' stmts { LL (unLoc $2) }
1218 | {- empty -} { noLoc [] }
1220 -- For typing stmts at the GHCi prompt, where
1221 -- the input may consist of just comments.
1222 maybe_stmt :: { Maybe (LStmt RdrName) }
1224 | {- nothing -} { Nothing }
1226 stmt :: { LStmt RdrName }
1228 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1229 return (LL $ BindStmt p $1) }
1230 | 'rec' stmtlist { LL $ RecStmt (unLoc $2) undefined undefined undefined }
1232 qual :: { LStmt RdrName }
1233 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1234 return (LL $ BindStmt p $3) }
1235 | exp { L1 $ ExprStmt $1 placeHolderType }
1236 | 'let' binds { LL $ LetStmt (unLoc $2) }
1238 -----------------------------------------------------------------------------
1239 -- Record Field Update/Construction
1241 fbinds :: { HsRecordBinds RdrName }
1243 | {- empty -} { [] }
1245 fbinds1 :: { HsRecordBinds RdrName }
1246 : fbinds1 ',' fbind { $3 : $1 }
1249 fbind :: { (Located RdrName, LHsExpr RdrName) }
1250 : qvar '=' exp { ($1,$3) }
1252 -----------------------------------------------------------------------------
1253 -- Implicit Parameter Bindings
1255 dbinds :: { Located [LIPBind RdrName] }
1256 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1257 | dbinds ';' { LL (unLoc $1) }
1259 -- | {- empty -} { [] }
1261 dbind :: { LIPBind RdrName }
1262 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1264 -----------------------------------------------------------------------------
1265 -- Variables, Constructors and Operators.
1267 identifier :: { Located RdrName }
1273 depreclist :: { Located [RdrName] }
1274 depreclist : deprec_var { L1 [unLoc $1] }
1275 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1277 deprec_var :: { Located RdrName }
1278 deprec_var : var { $1 }
1281 gcon :: { Located RdrName } -- Data constructor namespace
1282 : sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1284 -- the case of '[:' ':]' is part of the production `parr'
1286 sysdcon :: { Located DataCon } -- Wired in data constructors
1287 : '(' ')' { LL unitDataCon }
1288 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1289 | '[' ']' { LL nilDataCon }
1291 var :: { Located RdrName }
1293 | '(' varsym ')' { LL (unLoc $2) }
1295 qvar :: { Located RdrName }
1297 | '(' varsym ')' { LL (unLoc $2) }
1298 | '(' qvarsym1 ')' { LL (unLoc $2) }
1299 -- We've inlined qvarsym here so that the decision about
1300 -- whether it's a qvar or a var can be postponed until
1301 -- *after* we see the close paren.
1303 ipvar :: { Located (IPName RdrName) }
1304 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1305 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1307 qcon :: { Located RdrName }
1309 | '(' qconsym ')' { LL (unLoc $2) }
1311 varop :: { Located RdrName }
1313 | '`' varid '`' { LL (unLoc $2) }
1315 qvarop :: { Located RdrName }
1317 | '`' qvarid '`' { LL (unLoc $2) }
1319 qvaropm :: { Located RdrName }
1320 : qvarsym_no_minus { $1 }
1321 | '`' qvarid '`' { LL (unLoc $2) }
1323 conop :: { Located RdrName }
1325 | '`' conid '`' { LL (unLoc $2) }
1327 qconop :: { Located RdrName }
1329 | '`' qconid '`' { LL (unLoc $2) }
1331 -----------------------------------------------------------------------------
1332 -- Type constructors
1334 gtycon :: { Located RdrName } -- A "general" qualified tycon
1336 | '(' ')' { LL $ getRdrName unitTyCon }
1337 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1338 | '(' '->' ')' { LL $ getRdrName funTyCon }
1339 | '[' ']' { LL $ listTyCon_RDR }
1340 | '[:' ':]' { LL $ parrTyCon_RDR }
1342 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1344 | '(' qtyconsym ')' { LL (unLoc $2) }
1346 qtyconop :: { Located RdrName } -- Qualified or unqualified
1348 | '`' qtycon '`' { LL (unLoc $2) }
1350 tyconop :: { Located RdrName } -- Unqualified
1352 | '`' tycon '`' { LL (unLoc $2) }
1354 qtycon :: { Located RdrName } -- Qualified or unqualified
1355 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1358 tycon :: { Located RdrName } -- Unqualified
1359 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1361 qtyconsym :: { Located RdrName }
1362 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1365 tyconsym :: { Located RdrName }
1366 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1368 -----------------------------------------------------------------------------
1371 op :: { Located RdrName } -- used in infix decls
1375 qop :: { LHsExpr RdrName } -- used in sections
1376 : qvarop { L1 $ HsVar (unLoc $1) }
1377 | qconop { L1 $ HsVar (unLoc $1) }
1379 qopm :: { LHsExpr RdrName } -- used in sections
1380 : qvaropm { L1 $ HsVar (unLoc $1) }
1381 | qconop { L1 $ HsVar (unLoc $1) }
1383 -----------------------------------------------------------------------------
1386 qvarid :: { Located RdrName }
1388 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1390 varid :: { Located RdrName }
1391 : varid_no_unsafe { $1 }
1392 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1393 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1394 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1396 varid_no_unsafe :: { Located RdrName }
1397 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1398 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1399 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1401 tyvar :: { Located RdrName }
1402 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1403 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1404 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1405 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1406 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1408 -- These special_ids are treated as keywords in various places,
1409 -- but as ordinary ids elsewhere. 'special_id' collects all these
1410 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1411 special_id :: { Located UserFS }
1413 : 'as' { L1 FSLIT("as") }
1414 | 'qualified' { L1 FSLIT("qualified") }
1415 | 'hiding' { L1 FSLIT("hiding") }
1416 | 'export' { L1 FSLIT("export") }
1417 | 'label' { L1 FSLIT("label") }
1418 | 'dynamic' { L1 FSLIT("dynamic") }
1419 | 'stdcall' { L1 FSLIT("stdcall") }
1420 | 'ccall' { L1 FSLIT("ccall") }
1422 -----------------------------------------------------------------------------
1425 qvarsym :: { Located RdrName }
1429 qvarsym_no_minus :: { Located RdrName }
1430 : varsym_no_minus { $1 }
1433 qvarsym1 :: { Located RdrName }
1434 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1436 varsym :: { Located RdrName }
1437 : varsym_no_minus { $1 }
1438 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1440 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1441 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1442 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1445 -- See comments with special_id
1446 special_sym :: { Located UserFS }
1447 special_sym : '!' { L1 FSLIT("!") }
1448 | '.' { L1 FSLIT(".") }
1449 | '*' { L1 FSLIT("*") }
1451 -----------------------------------------------------------------------------
1452 -- Data constructors
1454 qconid :: { Located RdrName } -- Qualified or unqualifiedb
1456 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1458 conid :: { Located RdrName }
1459 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1461 qconsym :: { Located RdrName } -- Qualified or unqualified
1463 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1465 consym :: { Located RdrName }
1466 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1468 -- ':' means only list cons
1469 | ':' { L1 $ consDataCon_RDR }
1472 -----------------------------------------------------------------------------
1475 literal :: { Located HsLit }
1476 : CHAR { L1 $ HsChar $ getCHAR $1 }
1477 | STRING { L1 $ HsString $ getSTRING $1 }
1478 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1479 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1480 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1481 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1482 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1484 -----------------------------------------------------------------------------
1488 : vccurly { () } -- context popped in lexer.
1489 | error {% popContext }
1491 -----------------------------------------------------------------------------
1492 -- Miscellaneous (mostly renamings)
1494 modid :: { Located ModuleName }
1495 : CONID { L1 $ mkModuleNameFS (getCONID $1) }
1496 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1499 (unpackFS mod ++ '.':unpackFS c))
1503 : commas ',' { $1 + 1 }
1506 -----------------------------------------------------------------------------
1510 happyError = srcParseFail
1512 getVARID (L _ (ITvarid x)) = x
1513 getCONID (L _ (ITconid x)) = x
1514 getVARSYM (L _ (ITvarsym x)) = x
1515 getCONSYM (L _ (ITconsym x)) = x
1516 getQVARID (L _ (ITqvarid x)) = x
1517 getQCONID (L _ (ITqconid x)) = x
1518 getQVARSYM (L _ (ITqvarsym x)) = x
1519 getQCONSYM (L _ (ITqconsym x)) = x
1520 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1521 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1522 getCHAR (L _ (ITchar x)) = x
1523 getSTRING (L _ (ITstring x)) = x
1524 getINTEGER (L _ (ITinteger x)) = x
1525 getRATIONAL (L _ (ITrational x)) = x
1526 getPRIMCHAR (L _ (ITprimchar x)) = x
1527 getPRIMSTRING (L _ (ITprimstring x)) = x
1528 getPRIMINTEGER (L _ (ITprimint x)) = x
1529 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1530 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1531 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1533 -- Utilities for combining source spans
1534 comb2 :: Located a -> Located b -> SrcSpan
1537 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1538 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1540 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1541 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1542 combineSrcSpans (getLoc c) (getLoc d)
1544 -- strict constructor version:
1546 sL :: SrcSpan -> a -> Located a
1547 sL span a = span `seq` L span a
1549 -- Make a source location that is just the filename. This seems slightly
1550 -- neater than trying to construct the span of the text within the file.
1551 fileSrcSpan :: P SrcSpan
1552 fileSrcSpan = do l <- getSrcLoc; return (mkGeneralSrcSpan (srcLocFile l))