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, parseType ) 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(..), CLabelString,
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, srcLocFile,
33 import CmdLineOpts ( opt_SccProfilingOn )
34 import Type ( Kind, mkArrowKind, liftedTypeKind )
35 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
38 import Bag ( emptyBag )
42 import Maybes ( orElse )
48 -----------------------------------------------------------------------------
49 Conflicts: 33 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 4 for ambiguity in 'if x then y else z -< e'
62 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
64 8 for ambiguity in 'e :: a `b` c'. Does this mean [States 160,246]
68 1 for ambiguity in 'let ?x ...' [State 268]
69 the parser can't tell whether the ?x is the lhs of a normal binding or
70 an implicit binding. Fortunately resolving as shift gives it the only
71 sensible meaning, namely the lhs of an implicit binding.
73 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 332]
74 we don't know whether the '[' starts the activation or not: it
75 might be the start of the declaration with the activation being
78 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 394]
79 since 'forall' is a valid variable name, we don't know whether
80 to treat a forall on the input as the beginning of a quantifier
81 or the beginning of the rule itself. Resolving to shift means
82 it's always treated as a quantifier, hence the above is disallowed.
83 This saves explicitly defining a grammar for the rule lhs that
84 doesn't include 'forall'.
86 6 for conflicts between `fdecl' and `fdeclDEPRECATED', [States 384,385]
87 which are resolved correctly, and moreover,
88 should go away when `fdeclDEPRECATED' is removed.
90 -- ---------------------------------------------------------------------------
91 -- Adding location info
93 This is done in a stylised way using the three macros below, L0, L1
94 and LL. Each of these macros can be thought of as having type
96 L0, L1, LL :: a -> Located a
98 They each add a SrcSpan to their argument.
100 L0 adds 'noSrcSpan', used for empty productions
102 L1 for a production with a single token on the lhs. Grabs the SrcSpan
105 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
106 the first and last tokens.
108 These suffice for the majority of cases. However, we must be
109 especially careful with empty productions: LL won't work if the first
110 or last token on the lhs can represent an empty span. In these cases,
111 we have to calculate the span using more of the tokens from the lhs, eg.
113 | 'newtype' tycl_hdr '=' newconstr deriving
115 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
117 We provide comb3 and comb4 functions which are useful in such cases.
119 Be careful: there's no checking that you actually got this right, the
120 only symptom will be that the SrcSpans of your syntax will be
124 * We must expand these macros *before* running Happy, which is why this file is
125 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
127 #define L0 L noSrcSpan
128 #define L1 sL (getLoc $1)
129 #define LL sL (comb2 $1 $>)
131 -- -----------------------------------------------------------------------------
136 '_' { L _ ITunderscore } -- Haskell keywords
138 'case' { L _ ITcase }
139 'class' { L _ ITclass }
140 'data' { L _ ITdata }
141 'default' { L _ ITdefault }
142 'deriving' { L _ ITderiving }
144 'else' { L _ ITelse }
145 'hiding' { L _ IThiding }
147 'import' { L _ ITimport }
149 'infix' { L _ ITinfix }
150 'infixl' { L _ ITinfixl }
151 'infixr' { L _ ITinfixr }
152 'instance' { L _ ITinstance }
154 'module' { L _ ITmodule }
155 'newtype' { L _ ITnewtype }
157 'qualified' { L _ ITqualified }
158 'then' { L _ ITthen }
159 'type' { L _ ITtype }
160 'where' { L _ ITwhere }
161 '_scc_' { L _ ITscc } -- ToDo: remove
163 'forall' { L _ ITforall } -- GHC extension keywords
164 'foreign' { L _ ITforeign }
165 'export' { L _ ITexport }
166 'label' { L _ ITlabel }
167 'dynamic' { L _ ITdynamic }
168 'safe' { L _ ITsafe }
169 'threadsafe' { L _ ITthreadsafe }
170 'unsafe' { L _ ITunsafe }
172 'stdcall' { L _ ITstdcallconv }
173 'ccall' { L _ ITccallconv }
174 'dotnet' { L _ ITdotnet }
175 'proc' { L _ ITproc } -- for arrow notation extension
176 'rec' { L _ ITrec } -- for arrow notation extension
178 '{-# SPECIALISE' { L _ ITspecialise_prag }
179 '{-# SOURCE' { L _ ITsource_prag }
180 '{-# INLINE' { L _ ITinline_prag }
181 '{-# NOINLINE' { L _ ITnoinline_prag }
182 '{-# RULES' { L _ ITrules_prag }
183 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
184 '{-# SCC' { L _ ITscc_prag }
185 '{-# DEPRECATED' { L _ ITdeprecated_prag }
186 '{-# UNPACK' { L _ ITunpack_prag }
187 '#-}' { L _ ITclose_prag }
189 '..' { L _ ITdotdot } -- reserved symbols
191 '::' { L _ ITdcolon }
195 '<-' { L _ ITlarrow }
196 '->' { L _ ITrarrow }
199 '=>' { L _ ITdarrow }
203 '-<' { L _ ITlarrowtail } -- for arrow notation
204 '>-' { L _ ITrarrowtail } -- for arrow notation
205 '-<<' { L _ ITLarrowtail } -- for arrow notation
206 '>>-' { L _ ITRarrowtail } -- for arrow notation
209 '{' { L _ ITocurly } -- special symbols
211 '{|' { L _ ITocurlybar }
212 '|}' { L _ ITccurlybar }
213 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
214 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
217 '[:' { L _ ITopabrack }
218 ':]' { L _ ITcpabrack }
221 '(#' { L _ IToubxparen }
222 '#)' { L _ ITcubxparen }
223 '(|' { L _ IToparenbar }
224 '|)' { L _ ITcparenbar }
227 '`' { L _ ITbackquote }
229 VARID { L _ (ITvarid _) } -- identifiers
230 CONID { L _ (ITconid _) }
231 VARSYM { L _ (ITvarsym _) }
232 CONSYM { L _ (ITconsym _) }
233 QVARID { L _ (ITqvarid _) }
234 QCONID { L _ (ITqconid _) }
235 QVARSYM { L _ (ITqvarsym _) }
236 QCONSYM { L _ (ITqconsym _) }
238 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
239 IPSPLITVARID { L _ (ITsplitipvarid _) } -- GHC extension
241 CHAR { L _ (ITchar _) }
242 STRING { L _ (ITstring _) }
243 INTEGER { L _ (ITinteger _) }
244 RATIONAL { L _ (ITrational _) }
246 PRIMCHAR { L _ (ITprimchar _) }
247 PRIMSTRING { L _ (ITprimstring _) }
248 PRIMINTEGER { L _ (ITprimint _) }
249 PRIMFLOAT { L _ (ITprimfloat _) }
250 PRIMDOUBLE { L _ (ITprimdouble _) }
253 '[|' { L _ ITopenExpQuote }
254 '[p|' { L _ ITopenPatQuote }
255 '[t|' { L _ ITopenTypQuote }
256 '[d|' { L _ ITopenDecQuote }
257 '|]' { L _ ITcloseQuote }
258 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
259 '$(' { L _ ITparenEscape } -- $( exp )
260 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
261 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
263 %monad { P } { >>= } { return }
264 %lexer { lexer } { L _ ITeof }
265 %name parseModule module
266 %name parseStmt maybe_stmt
267 %name parseIdentifier identifier
268 %name parseIface iface
269 %name parseType ctype
270 %tokentype { Located Token }
273 -----------------------------------------------------------------------------
276 -- The place for module deprecation is really too restrictive, but if it
277 -- was allowed at its natural place just before 'module', we get an ugly
278 -- s/r conflict with the second alternative. Another solution would be the
279 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
280 -- either, and DEPRECATED is only expected to be used by people who really
281 -- know what they are doing. :-)
283 module :: { Located (HsModule RdrName) }
284 : 'module' modid maybemoddeprec maybeexports 'where' body
285 {% fileSrcSpan >>= \ loc ->
286 return (L loc (HsModule (Just $2) $4 (fst $6) (snd $6) $3)) }
287 | missing_module_keyword top close
288 {% fileSrcSpan >>= \ loc ->
289 return (L loc (HsModule Nothing Nothing
290 (fst $2) (snd $2) Nothing)) }
292 missing_module_keyword :: { () }
293 : {- empty -} {% pushCurrentContext }
295 maybemoddeprec :: { Maybe DeprecTxt }
296 : '{-# DEPRECATED' STRING '#-}' { Just (getSTRING $2) }
297 | {- empty -} { Nothing }
299 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
301 | vocurly top close { $2 }
303 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
304 : importdecls { (reverse $1,[]) }
305 | importdecls ';' cvtopdecls { (reverse $1,$3) }
306 | cvtopdecls { ([],$1) }
308 cvtopdecls :: { [LHsDecl RdrName] }
309 : topdecls { cvTopDecls $1 }
311 -----------------------------------------------------------------------------
312 -- Interfaces (.hi-boot files)
314 iface :: { ModIface }
315 : 'module' modid 'where' ifacebody { mkBootIface (unLoc $2) $4 }
317 ifacebody :: { [HsDecl RdrName] }
318 : '{' ifacedecls '}' { $2 }
319 | vocurly ifacedecls close { $2 }
321 ifacedecls :: { [HsDecl RdrName] }
322 : ifacedecl ';' ifacedecls { $1 : $3 }
323 | ';' ifacedecls { $2 }
327 ifacedecl :: { HsDecl RdrName }
330 | 'type' syn_hdr '=' ctype
331 { let (tc,tvs) = $2 in TyClD (TySynonym tc tvs $4) }
332 | 'data' tycl_hdr constrs -- No deriving in hi-boot
333 { TyClD (mkTyData DataType $2 Nothing (reverse (unLoc $3)) Nothing) }
334 | 'data' tycl_hdr 'where' gadt_constrlist
335 { TyClD (mkTyData DataType $2 Nothing (reverse (unLoc $4)) Nothing) }
336 | 'newtype' tycl_hdr -- Constructor is optional
337 { TyClD (mkTyData NewType $2 Nothing [] Nothing) }
338 | 'newtype' tycl_hdr '=' newconstr
339 { TyClD (mkTyData NewType $2 Nothing [$4] Nothing) }
340 | 'class' tycl_hdr fds
341 { TyClD (mkClassDecl (unLoc $2) (unLoc $3) [] emptyBag) }
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' syn_hdr '=' ctype
448 -- Note ctype, not sigtype.
449 -- We allow an explicit for-all but we don't insert one
450 -- in type Foo a = (b,b)
451 -- Instead we just say b is out of scope
452 { LL $ let (tc,tvs) = $2 in TySynonym tc tvs $4 }
454 | 'data' tycl_hdr constrs deriving
455 { L (comb4 $1 $2 $3 $4)
456 (mkTyData DataType $2 Nothing (reverse (unLoc $3)) (unLoc $4)) }
458 | 'data' tycl_hdr opt_kind_sig 'where' gadt_constrlist -- No deriving for GADTs
459 { L (comb4 $1 $2 $4 $5)
460 (mkTyData DataType $2 $3 (reverse (unLoc $5)) Nothing) }
462 | 'newtype' tycl_hdr '=' newconstr deriving
464 (mkTyData NewType $2 Nothing [$4] (unLoc $5)) }
466 | 'class' tycl_hdr fds where
468 (binds,sigs) = cvBindsAndSigs (unLoc $4)
470 L (comb4 $1 $2 $3 $4) (mkClassDecl (unLoc $2) (unLoc $3) sigs
473 opt_kind_sig :: { Maybe Kind }
475 | '::' kind { Just $2 }
477 syn_hdr :: { (Located RdrName, [LHsTyVarBndr RdrName]) }
478 -- We don't retain the syntax of an infix
479 -- type synonym declaration. Oh well.
480 : tycon tv_bndrs { ($1, $2) }
481 | tv_bndr tyconop tv_bndr { ($2, [$1,$3]) }
483 -- tycl_hdr parses the header of a type or class decl,
484 -- which takes the form
487 -- (Eq a, Ord b) => T a b
488 -- Rather a lot of inlining here, else we get reduce/reduce errors
489 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
490 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
491 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
493 -----------------------------------------------------------------------------
494 -- Nested declarations
496 decls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
497 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
498 | decls ';' { LL (unLoc $1) }
500 | {- empty -} { noLoc nilOL }
503 decllist :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
504 : '{' decls '}' { LL (unLoc $2) }
505 | vocurly decls close { $2 }
507 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
508 -- No implicit parameters
509 : 'where' decllist { LL (unLoc $2) }
510 | {- empty -} { noLoc nilOL }
512 binds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
513 : decllist { L1 [cvBindGroup (unLoc $1)] }
514 | '{' dbinds '}' { LL [HsIPBinds (unLoc $2)] }
515 | vocurly dbinds close { L (getLoc $2) [HsIPBinds (unLoc $2)] }
517 wherebinds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
518 : 'where' binds { LL (unLoc $2) }
519 | {- empty -} { noLoc [] }
522 -----------------------------------------------------------------------------
523 -- Transformation Rules
525 rules :: { OrdList (LHsDecl RdrName) } -- Reversed
526 : rules ';' rule { $1 `snocOL` $3 }
529 | {- empty -} { nilOL }
531 rule :: { LHsDecl RdrName }
532 : STRING activation rule_forall infixexp '=' exp
533 { LL $ RuleD (HsRule (getSTRING $1) $2 $3 $4 $6) }
535 activation :: { Activation } -- Omitted means AlwaysActive
536 : {- empty -} { AlwaysActive }
537 | explicit_activation { $1 }
539 inverse_activation :: { Activation } -- Omitted means NeverActive
540 : {- empty -} { NeverActive }
541 | explicit_activation { $1 }
543 explicit_activation :: { Activation } -- In brackets
544 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
545 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
547 rule_forall :: { [RuleBndr RdrName] }
548 : 'forall' rule_var_list '.' { $2 }
551 rule_var_list :: { [RuleBndr RdrName] }
553 | rule_var rule_var_list { $1 : $2 }
555 rule_var :: { RuleBndr RdrName }
556 : varid { RuleBndr $1 }
557 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
559 -----------------------------------------------------------------------------
560 -- Deprecations (c.f. rules)
562 deprecations :: { OrdList (LHsDecl RdrName) } -- Reversed
563 : deprecations ';' deprecation { $1 `appOL` $3 }
564 | deprecations ';' { $1 }
566 | {- empty -} { nilOL }
568 -- SUP: TEMPORARY HACK, not checking for `module Foo'
569 deprecation :: { OrdList (LHsDecl RdrName) }
571 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
575 -----------------------------------------------------------------------------
576 -- Foreign import and export declarations
578 -- for the time being, the following accepts foreign declarations conforming
579 -- to the FFI Addendum, Version 1.0 as well as pre-standard declarations
581 -- * a flag indicates whether pre-standard declarations have been used and
582 -- triggers a deprecation warning further down the road
584 -- NB: The first two rules could be combined into one by replacing `safety1'
585 -- with `safety'. However, the combined rule conflicts with the
588 fdecl :: { LHsDecl RdrName }
589 fdecl : 'import' callconv safety1 fspec
590 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
591 | 'import' callconv fspec
592 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
594 | 'export' callconv fspec
595 {% mkExport $2 (unLoc $3) >>= return.LL }
596 -- the following syntax is DEPRECATED
597 | fdecl1DEPRECATED { L1 (ForD (unLoc $1)) }
598 | fdecl2DEPRECATED { L1 (unLoc $1) }
600 fdecl1DEPRECATED :: { LForeignDecl RdrName }
602 ----------- DEPRECATED label decls ------------
603 : 'label' ext_name varid '::' sigtype
604 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
605 (CLabel ($2 `orElse` mkExtName (unLoc $3)))) True }
607 ----------- DEPRECATED ccall/stdcall decls ------------
609 -- NB: This business with the case expression below may seem overly
610 -- complicated, but it is necessary to avoid some conflicts.
612 -- DEPRECATED variant #1: lack of a calling convention specification
614 | 'import' {-no callconv-} ext_name safety varid_no_unsafe '::' sigtype
616 target = StaticTarget ($2 `orElse` mkExtName (unLoc $4))
618 LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
619 (CFunction target)) True }
621 -- DEPRECATED variant #2: external name consists of two separate strings
622 -- (module name and function name) (import)
623 | 'import' callconv STRING STRING safety varid_no_unsafe '::' sigtype
625 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
626 CCall cconv -> return $
628 imp = CFunction (StaticTarget (getSTRING $4))
630 LL $ ForeignImport $6 $8 (CImport cconv $5 nilFS nilFS imp) True }
632 -- DEPRECATED variant #3: `unsafe' after entity
633 | 'import' callconv STRING 'unsafe' varid_no_unsafe '::' sigtype
635 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
636 CCall cconv -> return $
638 imp = CFunction (StaticTarget (getSTRING $3))
640 LL $ ForeignImport $5 $7 (CImport cconv PlayRisky nilFS nilFS imp) True }
642 -- DEPRECATED variant #4: use of the special identifier `dynamic' without
643 -- an explicit calling convention (import)
644 | 'import' {-no callconv-} 'dynamic' safety varid_no_unsafe '::' sigtype
645 { LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
646 (CFunction DynamicTarget)) True }
648 -- DEPRECATED variant #5: use of the special identifier `dynamic' (import)
649 | 'import' callconv 'dynamic' safety varid_no_unsafe '::' sigtype
651 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
652 CCall cconv -> return $
653 LL $ ForeignImport $5 $7 (CImport cconv $4 nilFS nilFS
654 (CFunction DynamicTarget)) True }
656 -- DEPRECATED variant #6: lack of a calling convention specification
658 | 'export' {-no callconv-} ext_name varid '::' sigtype
659 { LL $ ForeignExport $3 $5 (CExport (CExportStatic ($2 `orElse` mkExtName (unLoc $3))
660 defaultCCallConv)) True }
662 -- DEPRECATED variant #7: external name consists of two separate strings
663 -- (module name and function name) (export)
664 | 'export' callconv STRING STRING varid '::' sigtype
666 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
667 CCall cconv -> return $
668 LL $ ForeignExport $5 $7
669 (CExport (CExportStatic (getSTRING $4) cconv)) True }
671 -- DEPRECATED variant #8: use of the special identifier `dynamic' without
672 -- an explicit calling convention (export)
673 | 'export' {-no callconv-} 'dynamic' varid '::' sigtype
674 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
677 -- DEPRECATED variant #9: use of the special identifier `dynamic' (export)
678 | 'export' callconv 'dynamic' varid '::' sigtype
680 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
681 CCall cconv -> return $
682 LL $ ForeignImport $4 $6
683 (CImport cconv (PlaySafe False) nilFS nilFS CWrapper) True }
685 ----------- DEPRECATED .NET decls ------------
686 -- NB: removed the .NET call declaration, as it is entirely subsumed
687 -- by the new standard FFI declarations
689 fdecl2DEPRECATED :: { LHsDecl RdrName }
691 : 'import' 'dotnet' 'type' ext_name tycon { LL $ TyClD (ForeignType $5 $4 DNType) }
692 -- left this one unchanged for the moment as type imports are not
693 -- covered currently by the FFI standard -=chak
696 callconv :: { CallConv }
697 : 'stdcall' { CCall StdCallConv }
698 | 'ccall' { CCall CCallConv }
699 | 'dotnet' { DNCall }
702 : 'unsafe' { PlayRisky }
703 | 'safe' { PlaySafe False }
704 | 'threadsafe' { PlaySafe True }
705 | {- empty -} { PlaySafe False }
707 safety1 :: { Safety }
708 : 'unsafe' { PlayRisky }
709 | 'safe' { PlaySafe False }
710 | 'threadsafe' { PlaySafe True }
711 -- only needed to avoid conflicts with the DEPRECATED rules
713 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
714 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
715 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
716 -- if the entity string is missing, it defaults to the empty string;
717 -- the meaning of an empty entity string depends on the calling
721 ext_name :: { Maybe CLabelString }
722 : STRING { Just (getSTRING $1) }
723 | STRING STRING { Just (getSTRING $2) } -- Ignore "module name" for now
724 | {- empty -} { Nothing }
727 -----------------------------------------------------------------------------
730 opt_sig :: { Maybe (LHsType RdrName) }
731 : {- empty -} { Nothing }
732 | '::' sigtype { Just $2 }
734 opt_asig :: { Maybe (LHsType RdrName) }
735 : {- empty -} { Nothing }
736 | '::' atype { Just $2 }
738 sigtypes1 :: { [LHsType RdrName] }
740 | sigtype ',' sigtypes1 { $1 : $3 }
742 sigtype :: { LHsType RdrName }
743 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
744 -- Wrap an Implicit forall if there isn't one there already
746 sig_vars :: { Located [Located RdrName] }
747 : sig_vars ',' var { LL ($3 : unLoc $1) }
750 -----------------------------------------------------------------------------
753 strict_mark :: { Located HsBang }
754 : '!' { L1 HsStrict }
755 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
757 -- A ctype is a for-all type
758 ctype :: { LHsType RdrName }
759 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
760 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
761 -- A type of form (context => type) is an *implicit* HsForAllTy
764 -- We parse a context as a btype so that we don't get reduce/reduce
765 -- errors in ctype. The basic problem is that
767 -- looks so much like a tuple type. We can't tell until we find the =>
768 context :: { LHsContext RdrName }
769 : btype {% checkContext $1 }
771 type :: { LHsType RdrName }
772 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
775 gentype :: { LHsType RdrName }
777 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
778 | btype '`' tyvar '`' gentype { LL $ HsOpTy $1 $3 $5 }
779 | btype '->' gentype { LL $ HsFunTy $1 $3 }
781 btype :: { LHsType RdrName }
782 : btype atype { LL $ HsAppTy $1 $2 }
785 atype :: { LHsType RdrName }
786 : gtycon { L1 (HsTyVar (unLoc $1)) }
787 | tyvar { L1 (HsTyVar (unLoc $1)) }
788 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
789 | '(' type ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
790 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
791 | '[' type ']' { LL $ HsListTy $2 }
792 | '[:' type ':]' { LL $ HsPArrTy $2 }
793 | '(' ctype ')' { LL $ HsParTy $2 }
794 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
796 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
798 -- An inst_type is what occurs in the head of an instance decl
799 -- e.g. (Foo a, Gaz b) => Wibble a b
800 -- It's kept as a single type, with a MonoDictTy at the right
801 -- hand corner, for convenience.
802 inst_type :: { LHsType RdrName }
803 : sigtype {% checkInstType $1 }
805 inst_types1 :: { [LHsType RdrName] }
807 | inst_type ',' inst_types1 { $1 : $3 }
809 comma_types0 :: { [LHsType RdrName] }
810 : comma_types1 { $1 }
813 comma_types1 :: { [LHsType RdrName] }
815 | type ',' comma_types1 { $1 : $3 }
817 tv_bndrs :: { [LHsTyVarBndr RdrName] }
818 : tv_bndr tv_bndrs { $1 : $2 }
821 tv_bndr :: { LHsTyVarBndr RdrName }
822 : tyvar { L1 (UserTyVar (unLoc $1)) }
823 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
825 fds :: { Located [Located ([RdrName], [RdrName])] }
826 : {- empty -} { noLoc [] }
827 | '|' fds1 { LL (reverse (unLoc $2)) }
829 fds1 :: { Located [Located ([RdrName], [RdrName])] }
830 : fds1 ',' fd { LL ($3 : unLoc $1) }
833 fd :: { Located ([RdrName], [RdrName]) }
834 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
835 (reverse (unLoc $1), reverse (unLoc $3)) }
837 varids0 :: { Located [RdrName] }
838 : {- empty -} { noLoc [] }
839 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
841 -----------------------------------------------------------------------------
846 | akind '->' kind { mkArrowKind $1 $3 }
849 : '*' { liftedTypeKind }
850 | '(' kind ')' { $2 }
853 -----------------------------------------------------------------------------
854 -- Datatype declarations
856 newconstr :: { LConDecl RdrName }
857 : conid atype { LL $ ConDecl $1 [] (noLoc []) (PrefixCon [$2]) }
858 | conid '{' var '::' ctype '}'
859 { LL $ ConDecl $1 [] (noLoc []) (RecCon [($3, $5)]) }
861 gadt_constrlist :: { Located [LConDecl RdrName] }
862 : '{' gadt_constrs '}' { LL (unLoc $2) }
863 | vocurly gadt_constrs close { $2 }
865 gadt_constrs :: { Located [LConDecl RdrName] }
866 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $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 { LL $ GRHS (reverse (L (getLoc $4) (ResultStmt $4) :
967 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
968 : infixexp '::' sigtype
969 {% do s <- checkValSig $1 $3;
970 return (LL $ unitOL (LL $ SigD s)) }
971 -- See the above notes for why we need infixexp here
972 | var ',' sig_vars '::' sigtype
973 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
974 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
976 | '{-# INLINE' activation qvar '#-}'
977 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
978 | '{-# NOINLINE' inverse_activation qvar '#-}'
979 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
980 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
981 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
983 | '{-# SPECIALISE' 'instance' inst_type '#-}'
984 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
986 -----------------------------------------------------------------------------
989 exp :: { LHsExpr RdrName }
990 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
991 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
992 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
993 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
994 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
997 infixexp :: { LHsExpr RdrName }
999 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1001 exp10 :: { LHsExpr RdrName }
1002 : '\\' aexp aexps opt_asig '->' exp
1003 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1004 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1005 (GRHSs (unguardedRHS $6) []
1007 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1008 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1009 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1010 | '-' fexp { LL $ mkHsNegApp $2 }
1012 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1013 checkDo loc (unLoc $2) >>= \ stmts ->
1014 return (L loc (mkHsDo DoExpr stmts)) }
1015 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1016 checkMDo loc (unLoc $2) >>= \ stmts ->
1017 return (L loc (mkHsDo MDoExpr stmts)) }
1019 | scc_annot exp { LL $ if opt_SccProfilingOn
1020 then HsSCC (unLoc $1) $2
1023 | 'proc' aexp '->' exp
1024 {% checkPattern $2 >>= \ p ->
1025 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1026 placeHolderType undefined)) }
1027 -- TODO: is LL right here?
1029 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1030 -- hdaume: core annotation
1033 scc_annot :: { Located FastString }
1034 : '_scc_' STRING { LL $ getSTRING $2 }
1035 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1037 fexp :: { LHsExpr RdrName }
1038 : fexp aexp { LL $ HsApp $1 $2 }
1041 aexps :: { [LHsExpr RdrName] }
1042 : aexps aexp { $2 : $1 }
1043 | {- empty -} { [] }
1045 aexp :: { LHsExpr RdrName }
1046 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1047 | '~' aexp { LL $ ELazyPat $2 }
1050 aexp1 :: { LHsExpr RdrName }
1051 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1056 -- Here was the syntax for type applications that I was planning
1057 -- but there are difficulties (e.g. what order for type args)
1058 -- so it's not enabled yet.
1059 -- But this case *is* used for the left hand side of a generic definition,
1060 -- which is parsed as an expression before being munged into a pattern
1061 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1062 (sL (getLoc $3) (HsType $3)) }
1064 aexp2 :: { LHsExpr RdrName }
1065 : ipvar { L1 (HsIPVar $! unLoc $1) }
1066 | qcname { L1 (HsVar $! unLoc $1) }
1067 | literal { L1 (HsLit $! unLoc $1) }
1068 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1069 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1070 | '(' exp ')' { LL (HsPar $2) }
1071 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1072 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1073 | '[' list ']' { LL (unLoc $2) }
1074 | '[:' parr ':]' { LL (unLoc $2) }
1075 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1076 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1077 | '_' { L1 EWildPat }
1079 -- MetaHaskell Extension
1080 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1081 (L1 $ HsVar (mkUnqual varName
1082 (getTH_ID_SPLICE $1)))) } -- $x
1083 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1085 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1086 | TH_VAR_QUOTE gcon { LL $ HsBracket (VarBr (unLoc $2)) }
1087 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1088 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1089 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1090 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1091 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1092 return (LL $ HsBracket (PatBr p)) }
1093 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1095 -- arrow notation extension
1096 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1098 cmdargs :: { [LHsCmdTop RdrName] }
1099 : cmdargs acmd { $2 : $1 }
1100 | {- empty -} { [] }
1102 acmd :: { LHsCmdTop RdrName }
1103 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1105 cvtopbody :: { [LHsDecl RdrName] }
1106 : '{' cvtopdecls0 '}' { $2 }
1107 | vocurly cvtopdecls0 close { $2 }
1109 cvtopdecls0 :: { [LHsDecl RdrName] }
1110 : {- empty -} { [] }
1113 texps :: { [LHsExpr RdrName] }
1114 : texps ',' exp { $3 : $1 }
1118 -----------------------------------------------------------------------------
1121 -- The rules below are little bit contorted to keep lexps left-recursive while
1122 -- avoiding another shift/reduce-conflict.
1124 list :: { LHsExpr RdrName }
1125 : exp { L1 $ ExplicitList placeHolderType [$1] }
1126 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1127 | exp '..' { LL $ ArithSeqIn (From $1) }
1128 | exp ',' exp '..' { LL $ ArithSeqIn (FromThen $1 $3) }
1129 | exp '..' exp { LL $ ArithSeqIn (FromTo $1 $3) }
1130 | exp ',' exp '..' exp { LL $ ArithSeqIn (FromThenTo $1 $3 $5) }
1131 | exp pquals { LL $ mkHsDo ListComp
1132 (reverse (L (getLoc $1) (ResultStmt $1) :
1135 lexps :: { Located [LHsExpr RdrName] }
1136 : lexps ',' exp { LL ($3 : unLoc $1) }
1137 | exp ',' exp { LL [$3,$1] }
1139 -----------------------------------------------------------------------------
1140 -- List Comprehensions
1142 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1143 -- or a reversed list of Stmts
1144 : pquals1 { case unLoc $1 of
1146 qss -> L1 [L1 (ParStmt stmtss)]
1148 stmtss = [ (reverse qs, undefined)
1152 pquals1 :: { Located [[LStmt RdrName]] }
1153 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1154 | '|' quals { L (getLoc $2) [unLoc $2] }
1156 quals :: { Located [LStmt RdrName] }
1157 : quals ',' qual { LL ($3 : unLoc $1) }
1160 -----------------------------------------------------------------------------
1161 -- Parallel array expressions
1163 -- The rules below are little bit contorted; see the list case for details.
1164 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1165 -- Moreover, we allow explicit arrays with no element (represented by the nil
1166 -- constructor in the list case).
1168 parr :: { LHsExpr RdrName }
1169 : { noLoc (ExplicitPArr placeHolderType []) }
1170 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1171 | lexps { L1 $ ExplicitPArr placeHolderType
1172 (reverse (unLoc $1)) }
1173 | exp '..' exp { LL $ PArrSeqIn (FromTo $1 $3) }
1174 | exp ',' exp '..' exp { LL $ PArrSeqIn (FromThenTo $1 $3 $5) }
1175 | exp pquals { LL $ mkHsDo PArrComp
1176 (reverse (L (getLoc $1) (ResultStmt $1) :
1180 -- We are reusing `lexps' and `pquals' from the list case.
1182 -----------------------------------------------------------------------------
1183 -- Case alternatives
1185 altslist :: { Located [LMatch RdrName] }
1186 : '{' alts '}' { LL (reverse (unLoc $2)) }
1187 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1189 alts :: { Located [LMatch RdrName] }
1190 : alts1 { L1 (unLoc $1) }
1191 | ';' alts { LL (unLoc $2) }
1193 alts1 :: { Located [LMatch RdrName] }
1194 : alts1 ';' alt { LL ($3 : unLoc $1) }
1195 | alts1 ';' { LL (unLoc $1) }
1198 alt :: { LMatch RdrName }
1199 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1200 return (LL (Match [p] $2 (unLoc $3))) }
1202 alt_rhs :: { Located (GRHSs RdrName) }
1203 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1205 ralt :: { Located [LGRHS RdrName] }
1206 : '->' exp { LL (unguardedRHS $2) }
1207 | gdpats { L1 (reverse (unLoc $1)) }
1209 gdpats :: { Located [LGRHS RdrName] }
1210 : gdpats gdpat { LL ($2 : unLoc $1) }
1213 gdpat :: { LGRHS RdrName }
1214 : '|' quals '->' exp { let r = L (getLoc $4) (ResultStmt $4)
1215 in LL $ GRHS (reverse (r : unLoc $2)) }
1217 -----------------------------------------------------------------------------
1218 -- Statement sequences
1220 stmtlist :: { Located [LStmt RdrName] }
1221 : '{' stmts '}' { LL (unLoc $2) }
1222 | vocurly stmts close { $2 }
1224 -- do { ;; s ; s ; ; s ;; }
1225 -- The last Stmt should be a ResultStmt, but that's hard to enforce
1226 -- here, because we need too much lookahead if we see do { e ; }
1227 -- So we use ExprStmts throughout, and switch the last one over
1228 -- in ParseUtils.checkDo instead
1229 stmts :: { Located [LStmt RdrName] }
1230 : stmt stmts_help { LL ($1 : unLoc $2) }
1231 | ';' stmts { LL (unLoc $2) }
1232 | {- empty -} { noLoc [] }
1234 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1235 : ';' stmts { LL (unLoc $2) }
1236 | {- empty -} { noLoc [] }
1238 -- For typing stmts at the GHCi prompt, where
1239 -- the input may consist of just comments.
1240 maybe_stmt :: { Maybe (LStmt RdrName) }
1242 | {- nothing -} { Nothing }
1244 stmt :: { LStmt RdrName }
1246 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1247 return (LL $ BindStmt p $1) }
1248 | 'rec' stmtlist { LL $ RecStmt (unLoc $2) undefined undefined undefined }
1250 qual :: { LStmt RdrName }
1251 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1252 return (LL $ BindStmt p $3) }
1253 | exp { L1 $ ExprStmt $1 placeHolderType }
1254 | 'let' binds { LL $ LetStmt (unLoc $2) }
1256 -----------------------------------------------------------------------------
1257 -- Record Field Update/Construction
1259 fbinds :: { HsRecordBinds RdrName }
1261 | {- empty -} { [] }
1263 fbinds1 :: { HsRecordBinds RdrName }
1264 : fbinds1 ',' fbind { $3 : $1 }
1267 fbind :: { (Located RdrName, LHsExpr RdrName) }
1268 : qvar '=' exp { ($1,$3) }
1270 -----------------------------------------------------------------------------
1271 -- Implicit Parameter Bindings
1273 dbinds :: { Located [LIPBind RdrName] }
1274 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1275 | dbinds ';' { LL (unLoc $1) }
1277 -- | {- empty -} { [] }
1279 dbind :: { LIPBind RdrName }
1280 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1282 -----------------------------------------------------------------------------
1283 -- Variables, Constructors and Operators.
1285 identifier :: { Located RdrName }
1291 depreclist :: { Located [RdrName] }
1292 depreclist : deprec_var { L1 [unLoc $1] }
1293 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1295 deprec_var :: { Located RdrName }
1296 deprec_var : var { $1 }
1299 gcon :: { Located RdrName } -- Data constructor namespace
1300 : sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1302 -- the case of '[:' ':]' is part of the production `parr'
1304 sysdcon :: { Located DataCon } -- Wired in data constructors
1305 : '(' ')' { LL unitDataCon }
1306 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1307 | '[' ']' { LL nilDataCon }
1309 var :: { Located RdrName }
1311 | '(' varsym ')' { LL (unLoc $2) }
1313 qvar :: { Located RdrName }
1315 | '(' varsym ')' { LL (unLoc $2) }
1316 | '(' qvarsym1 ')' { LL (unLoc $2) }
1317 -- We've inlined qvarsym here so that the decision about
1318 -- whether it's a qvar or a var can be postponed until
1319 -- *after* we see the close paren.
1321 ipvar :: { Located (IPName RdrName) }
1322 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1323 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1325 qcon :: { Located RdrName }
1327 | '(' qconsym ')' { LL (unLoc $2) }
1329 varop :: { Located RdrName }
1331 | '`' varid '`' { LL (unLoc $2) }
1333 qvarop :: { Located RdrName }
1335 | '`' qvarid '`' { LL (unLoc $2) }
1337 qvaropm :: { Located RdrName }
1338 : qvarsym_no_minus { $1 }
1339 | '`' qvarid '`' { LL (unLoc $2) }
1341 conop :: { Located RdrName }
1343 | '`' conid '`' { LL (unLoc $2) }
1345 qconop :: { Located RdrName }
1347 | '`' qconid '`' { LL (unLoc $2) }
1349 -----------------------------------------------------------------------------
1350 -- Type constructors
1352 gtycon :: { Located RdrName } -- A "general" qualified tycon
1354 | '(' ')' { LL $ getRdrName unitTyCon }
1355 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1356 | '(' '->' ')' { LL $ getRdrName funTyCon }
1357 | '[' ']' { LL $ listTyCon_RDR }
1358 | '[:' ':]' { LL $ parrTyCon_RDR }
1360 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1362 | '(' qtyconsym ')' { LL (unLoc $2) }
1364 qtyconop :: { Located RdrName } -- Qualified or unqualified
1366 | '`' qtycon '`' { LL (unLoc $2) }
1368 tyconop :: { Located RdrName } -- Unqualified
1370 | '`' tycon '`' { LL (unLoc $2) }
1372 qtycon :: { Located RdrName } -- Qualified or unqualified
1373 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1376 tycon :: { Located RdrName } -- Unqualified
1377 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1379 qtyconsym :: { Located RdrName }
1380 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1383 tyconsym :: { Located RdrName }
1384 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1386 -----------------------------------------------------------------------------
1389 op :: { Located RdrName } -- used in infix decls
1393 qop :: { LHsExpr RdrName } -- used in sections
1394 : qvarop { L1 $ HsVar (unLoc $1) }
1395 | qconop { L1 $ HsVar (unLoc $1) }
1397 qopm :: { LHsExpr RdrName } -- used in sections
1398 : qvaropm { L1 $ HsVar (unLoc $1) }
1399 | qconop { L1 $ HsVar (unLoc $1) }
1401 -----------------------------------------------------------------------------
1404 qvarid :: { Located RdrName }
1406 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1408 varid :: { Located RdrName }
1409 : varid_no_unsafe { $1 }
1410 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1411 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1412 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1414 varid_no_unsafe :: { Located RdrName }
1415 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1416 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1417 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1419 tyvar :: { Located RdrName }
1420 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1421 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1422 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1423 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1424 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1426 -- These special_ids are treated as keywords in various places,
1427 -- but as ordinary ids elsewhere. 'special_id' collects all these
1428 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1429 special_id :: { Located UserFS }
1431 : 'as' { L1 FSLIT("as") }
1432 | 'qualified' { L1 FSLIT("qualified") }
1433 | 'hiding' { L1 FSLIT("hiding") }
1434 | 'export' { L1 FSLIT("export") }
1435 | 'label' { L1 FSLIT("label") }
1436 | 'dynamic' { L1 FSLIT("dynamic") }
1437 | 'stdcall' { L1 FSLIT("stdcall") }
1438 | 'ccall' { L1 FSLIT("ccall") }
1440 -----------------------------------------------------------------------------
1443 qvarsym :: { Located RdrName }
1447 qvarsym_no_minus :: { Located RdrName }
1448 : varsym_no_minus { $1 }
1451 qvarsym1 :: { Located RdrName }
1452 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1454 varsym :: { Located RdrName }
1455 : varsym_no_minus { $1 }
1456 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1458 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1459 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1460 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1463 -- See comments with special_id
1464 special_sym :: { Located UserFS }
1465 special_sym : '!' { L1 FSLIT("!") }
1466 | '.' { L1 FSLIT(".") }
1467 | '*' { L1 FSLIT("*") }
1469 -----------------------------------------------------------------------------
1470 -- Data constructors
1472 qconid :: { Located RdrName } -- Qualified or unqualified
1474 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1476 conid :: { Located RdrName }
1477 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1479 qconsym :: { Located RdrName } -- Qualified or unqualified
1481 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1483 consym :: { Located RdrName }
1484 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1486 -- ':' means only list cons
1487 | ':' { L1 $ consDataCon_RDR }
1490 -----------------------------------------------------------------------------
1493 literal :: { Located HsLit }
1494 : CHAR { L1 $ HsChar $ getCHAR $1 }
1495 | STRING { L1 $ HsString $ getSTRING $1 }
1496 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1497 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1498 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1499 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1500 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1502 -----------------------------------------------------------------------------
1506 : vccurly { () } -- context popped in lexer.
1507 | error {% popContext }
1509 -----------------------------------------------------------------------------
1510 -- Miscellaneous (mostly renamings)
1512 modid :: { Located Module }
1513 : CONID { L1 $ mkModuleFS (getCONID $1) }
1514 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1517 (unpackFS mod ++ '.':unpackFS c))
1521 : commas ',' { $1 + 1 }
1524 -----------------------------------------------------------------------------
1528 happyError = srcParseFail
1530 getVARID (L _ (ITvarid x)) = x
1531 getCONID (L _ (ITconid x)) = x
1532 getVARSYM (L _ (ITvarsym x)) = x
1533 getCONSYM (L _ (ITconsym x)) = x
1534 getQVARID (L _ (ITqvarid x)) = x
1535 getQCONID (L _ (ITqconid x)) = x
1536 getQVARSYM (L _ (ITqvarsym x)) = x
1537 getQCONSYM (L _ (ITqconsym x)) = x
1538 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1539 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1540 getCHAR (L _ (ITchar x)) = x
1541 getSTRING (L _ (ITstring x)) = x
1542 getINTEGER (L _ (ITinteger x)) = x
1543 getRATIONAL (L _ (ITrational x)) = x
1544 getPRIMCHAR (L _ (ITprimchar x)) = x
1545 getPRIMSTRING (L _ (ITprimstring x)) = x
1546 getPRIMINTEGER (L _ (ITprimint x)) = x
1547 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1548 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1549 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1551 -- Utilities for combining source spans
1552 comb2 :: Located a -> Located b -> SrcSpan
1555 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1556 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1558 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1559 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1560 combineSrcSpans (getLoc c) (getLoc d)
1562 -- strict constructor version:
1564 sL :: SrcSpan -> a -> Located a
1565 sL span a = span `seq` L span a
1567 -- Make a source location for the file. We're a bit lazy here and just
1568 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1569 -- try to find the span of the whole file (ToDo).
1570 fileSrcSpan :: P SrcSpan
1573 let loc = mkSrcLoc (srcLocFile l) 1 0;
1574 return (mkSrcSpan loc loc)