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,
14 #define INCLUDE #include
15 INCLUDE "HsVersions.h"
19 import HscTypes ( ModIface, IsBootInterface, DeprecTxt )
22 import TysWiredIn ( unitTyCon, unitDataCon, tupleTyCon, tupleCon, nilDataCon,
23 listTyCon_RDR, parrTyCon_RDR, consDataCon_RDR )
24 import Type ( funTyCon )
25 import ForeignCall ( Safety(..), CExportSpec(..), CLabelString,
26 CCallConv(..), CCallTarget(..), defaultCCallConv
28 import OccName ( UserFS, varName, dataName, tcClsName, tvName )
29 import DataCon ( DataCon, dataConName )
30 import SrcLoc ( Located(..), unLoc, getLoc, noLoc, combineSrcSpans,
31 SrcSpan, combineLocs, srcLocFile,
34 import CmdLineOpts ( opt_SccProfilingOn )
35 import Type ( Kind, mkArrowKind, liftedTypeKind )
36 import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), IPName(..),
39 import Bag ( emptyBag )
43 import Maybes ( orElse )
49 -----------------------------------------------------------------------------
50 Conflicts: 34 shift/reduce (1.15)
52 10 for abiguity in 'if x then y else z + 1' [State 178]
53 (shift parses as 'if x then y else (z + 1)', as per longest-parse rule)
54 10 because op might be: : - ! * . `x` VARSYM CONSYM QVARSYM QCONSYM
56 1 for ambiguity in 'if x then y else z :: T' [State 178]
57 (shift parses as 'if x then y else (z :: T)', as per longest-parse rule)
59 4 for ambiguity in 'if x then y else z -< e' [State 178]
60 (shift parses as 'if x then y else (z -< T)', as per longest-parse rule)
61 There are four such operators: -<, >-, -<<, >>-
64 2 for ambiguity in 'case v of { x :: T -> T ... } ' [States 11, 253]
65 Which of these two is intended?
67 (x::T) -> T -- Rhs is T
70 (x::T -> T) -> .. -- Rhs is ...
72 8 for ambiguity in 'e :: a `b` c'. Does this mean [States 11, 253]
75 As well as `b` we can have !, QCONSYM, and CONSYM, hence 3 cases
76 Same duplication between states 11 and 253 as the previous case
78 1 for ambiguity in 'let ?x ...' [State 329]
79 the parser can't tell whether the ?x is the lhs of a normal binding or
80 an implicit binding. Fortunately resolving as shift gives it the only
81 sensible meaning, namely the lhs of an implicit binding.
83 1 for ambiguity in '{-# RULES "name" [ ... #-} [State 382]
84 we don't know whether the '[' starts the activation or not: it
85 might be the start of the declaration with the activation being
88 6 for conflicts between `fdecl' and `fdeclDEPRECATED', [States 393,394]
89 which are resolved correctly, and moreover,
90 should go away when `fdeclDEPRECATED' is removed.
92 1 for ambiguity in '{-# RULES "name" forall = ... #-}' [State 474]
93 since 'forall' is a valid variable name, we don't know whether
94 to treat a forall on the input as the beginning of a quantifier
95 or the beginning of the rule itself. Resolving to shift means
96 it's always treated as a quantifier, hence the above is disallowed.
97 This saves explicitly defining a grammar for the rule lhs that
98 doesn't include 'forall'.
100 -- ---------------------------------------------------------------------------
101 -- Adding location info
103 This is done in a stylised way using the three macros below, L0, L1
104 and LL. Each of these macros can be thought of as having type
106 L0, L1, LL :: a -> Located a
108 They each add a SrcSpan to their argument.
110 L0 adds 'noSrcSpan', used for empty productions
112 L1 for a production with a single token on the lhs. Grabs the SrcSpan
115 LL for a production with >1 token on the lhs. Makes up a SrcSpan from
116 the first and last tokens.
118 These suffice for the majority of cases. However, we must be
119 especially careful with empty productions: LL won't work if the first
120 or last token on the lhs can represent an empty span. In these cases,
121 we have to calculate the span using more of the tokens from the lhs, eg.
123 | 'newtype' tycl_hdr '=' newconstr deriving
125 (mkTyData NewType (unLoc $2) [$4] (unLoc $5)) }
127 We provide comb3 and comb4 functions which are useful in such cases.
129 Be careful: there's no checking that you actually got this right, the
130 only symptom will be that the SrcSpans of your syntax will be
134 * We must expand these macros *before* running Happy, which is why this file is
135 * Parser.y.pp rather than just Parser.y - we run the C pre-processor first.
137 #define L0 L noSrcSpan
138 #define L1 sL (getLoc $1)
139 #define LL sL (comb2 $1 $>)
141 -- -----------------------------------------------------------------------------
146 '_' { L _ ITunderscore } -- Haskell keywords
148 'case' { L _ ITcase }
149 'class' { L _ ITclass }
150 'data' { L _ ITdata }
151 'default' { L _ ITdefault }
152 'deriving' { L _ ITderiving }
154 'else' { L _ ITelse }
155 'hiding' { L _ IThiding }
157 'import' { L _ ITimport }
159 'infix' { L _ ITinfix }
160 'infixl' { L _ ITinfixl }
161 'infixr' { L _ ITinfixr }
162 'instance' { L _ ITinstance }
164 'module' { L _ ITmodule }
165 'newtype' { L _ ITnewtype }
167 'qualified' { L _ ITqualified }
168 'then' { L _ ITthen }
169 'type' { L _ ITtype }
170 'where' { L _ ITwhere }
171 '_scc_' { L _ ITscc } -- ToDo: remove
173 'forall' { L _ ITforall } -- GHC extension keywords
174 'foreign' { L _ ITforeign }
175 'export' { L _ ITexport }
176 'label' { L _ ITlabel }
177 'dynamic' { L _ ITdynamic }
178 'safe' { L _ ITsafe }
179 'threadsafe' { L _ ITthreadsafe }
180 'unsafe' { L _ ITunsafe }
182 'stdcall' { L _ ITstdcallconv }
183 'ccall' { L _ ITccallconv }
184 'dotnet' { L _ ITdotnet }
185 'proc' { L _ ITproc } -- for arrow notation extension
186 'rec' { L _ ITrec } -- for arrow notation extension
188 '{-# SPECIALISE' { L _ ITspecialise_prag }
189 '{-# SOURCE' { L _ ITsource_prag }
190 '{-# INLINE' { L _ ITinline_prag }
191 '{-# NOINLINE' { L _ ITnoinline_prag }
192 '{-# RULES' { L _ ITrules_prag }
193 '{-# CORE' { L _ ITcore_prag } -- hdaume: annotated core
194 '{-# SCC' { L _ ITscc_prag }
195 '{-# DEPRECATED' { L _ ITdeprecated_prag }
196 '{-# UNPACK' { L _ ITunpack_prag }
197 '#-}' { L _ ITclose_prag }
199 '..' { L _ ITdotdot } -- reserved symbols
201 '::' { L _ ITdcolon }
205 '<-' { L _ ITlarrow }
206 '->' { L _ ITrarrow }
209 '=>' { L _ ITdarrow }
213 '-<' { L _ ITlarrowtail } -- for arrow notation
214 '>-' { L _ ITrarrowtail } -- for arrow notation
215 '-<<' { L _ ITLarrowtail } -- for arrow notation
216 '>>-' { L _ ITRarrowtail } -- for arrow notation
219 '{' { L _ ITocurly } -- special symbols
221 '{|' { L _ ITocurlybar }
222 '|}' { L _ ITccurlybar }
223 vocurly { L _ ITvocurly } -- virtual open curly (from layout)
224 vccurly { L _ ITvccurly } -- virtual close curly (from layout)
227 '[:' { L _ ITopabrack }
228 ':]' { L _ ITcpabrack }
231 '(#' { L _ IToubxparen }
232 '#)' { L _ ITcubxparen }
233 '(|' { L _ IToparenbar }
234 '|)' { L _ ITcparenbar }
237 '`' { L _ ITbackquote }
239 VARID { L _ (ITvarid _) } -- identifiers
240 CONID { L _ (ITconid _) }
241 VARSYM { L _ (ITvarsym _) }
242 CONSYM { L _ (ITconsym _) }
243 QVARID { L _ (ITqvarid _) }
244 QCONID { L _ (ITqconid _) }
245 QVARSYM { L _ (ITqvarsym _) }
246 QCONSYM { L _ (ITqconsym _) }
248 IPDUPVARID { L _ (ITdupipvarid _) } -- GHC extension
249 IPSPLITVARID { L _ (ITsplitipvarid _) } -- GHC extension
251 CHAR { L _ (ITchar _) }
252 STRING { L _ (ITstring _) }
253 INTEGER { L _ (ITinteger _) }
254 RATIONAL { L _ (ITrational _) }
256 PRIMCHAR { L _ (ITprimchar _) }
257 PRIMSTRING { L _ (ITprimstring _) }
258 PRIMINTEGER { L _ (ITprimint _) }
259 PRIMFLOAT { L _ (ITprimfloat _) }
260 PRIMDOUBLE { L _ (ITprimdouble _) }
263 '[|' { L _ ITopenExpQuote }
264 '[p|' { L _ ITopenPatQuote }
265 '[t|' { L _ ITopenTypQuote }
266 '[d|' { L _ ITopenDecQuote }
267 '|]' { L _ ITcloseQuote }
268 TH_ID_SPLICE { L _ (ITidEscape _) } -- $x
269 '$(' { L _ ITparenEscape } -- $( exp )
270 TH_VAR_QUOTE { L _ ITvarQuote } -- 'x
271 TH_TY_QUOTE { L _ ITtyQuote } -- ''T
273 %monad { P } { >>= } { return }
274 %lexer { lexer } { L _ ITeof }
275 %name parseModule module
276 %name parseStmt maybe_stmt
277 %name parseIdentifier identifier
278 %name parseIface iface
279 %name parseType ctype
280 %partial parseHeader header
281 %tokentype { Located Token }
284 -----------------------------------------------------------------------------
287 -- The place for module deprecation is really too restrictive, but if it
288 -- was allowed at its natural place just before 'module', we get an ugly
289 -- s/r conflict with the second alternative. Another solution would be the
290 -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice,
291 -- either, and DEPRECATED is only expected to be used by people who really
292 -- know what they are doing. :-)
294 module :: { Located (HsModule RdrName) }
295 : 'module' modid maybemoddeprec maybeexports 'where' body
296 {% fileSrcSpan >>= \ loc ->
297 return (L loc (HsModule (Just $2) $4 (fst $6) (snd $6) $3)) }
298 | missing_module_keyword top close
299 {% fileSrcSpan >>= \ loc ->
300 return (L loc (HsModule Nothing Nothing
301 (fst $2) (snd $2) Nothing)) }
303 missing_module_keyword :: { () }
304 : {- empty -} {% pushCurrentContext }
306 maybemoddeprec :: { Maybe DeprecTxt }
307 : '{-# DEPRECATED' STRING '#-}' { Just (getSTRING $2) }
308 | {- empty -} { Nothing }
310 body :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
312 | vocurly top close { $2 }
314 top :: { ([LImportDecl RdrName], [LHsDecl RdrName]) }
315 : importdecls { (reverse $1,[]) }
316 | importdecls ';' cvtopdecls { (reverse $1,$3) }
317 | cvtopdecls { ([],$1) }
319 cvtopdecls :: { [LHsDecl RdrName] }
320 : topdecls { cvTopDecls $1 }
322 -----------------------------------------------------------------------------
323 -- Module declaration & imports only
325 header :: { Located (HsModule RdrName) }
326 : 'module' modid maybemoddeprec maybeexports 'where' header_body
327 {% fileSrcSpan >>= \ loc ->
328 return (L loc (HsModule (Just $2) $4 $6 [] $3)) }
329 | missing_module_keyword importdecls
330 {% fileSrcSpan >>= \ loc ->
331 return (L loc (HsModule Nothing Nothing $2 [] Nothing)) }
333 header_body :: { [LImportDecl RdrName] }
334 : '{' importdecls { $2 }
335 | vocurly importdecls { $2 }
337 -----------------------------------------------------------------------------
338 -- Interfaces (.hi-boot files)
340 iface :: { ModIface }
341 : 'module' modid 'where' ifacebody { mkBootIface (unLoc $2) $4 }
343 ifacebody :: { ([(Module, IsBootInterface)], [HsDecl RdrName]) }
344 : '{' ifacetop '}' { $2 }
345 | vocurly ifacetop close { $2 }
347 ifacetop :: { ([(Module, IsBootInterface)], [HsDecl RdrName]) }
348 : ifaceimps { ($1,[]) }
349 | ifaceimps ';' ifacedecls { ($1,$3) }
350 | ifacedecls { ([],$1) }
352 ifaceimps :: { [(Module, IsBootInterface)] } -- Reversed, but that's ok
353 : ifaceimps ';' ifaceimp { $3 : $1 }
356 ifaceimp :: { (Module, IsBootInterface) }
357 : 'import' maybe_src modid { (unLoc $3, $2) }
359 -- The defn of iface decls allows a trailing ';', which the lexer geneates for
362 ifacedecls :: { [HsDecl RdrName] } -- Reversed, but doesn't matter
363 : ifacedecls ';' ifacedecl { $3 : $1 }
364 | ifacedecls ';' { $1 }
367 ifacedecl :: { HsDecl RdrName }
370 | 'type' syn_hdr '=' ctype
371 { let (tc,tvs) = $2 in TyClD (TySynonym tc tvs $4) }
372 | 'data' tycl_hdr constrs -- No deriving in hi-boot
373 { TyClD (mkTyData DataType $2 Nothing (reverse (unLoc $3)) Nothing) }
374 | 'data' tycl_hdr 'where' gadt_constrlist
375 { TyClD (mkTyData DataType $2 Nothing (reverse (unLoc $4)) Nothing) }
376 | 'newtype' tycl_hdr -- Constructor is optional
377 { TyClD (mkTyData NewType $2 Nothing [] Nothing) }
378 | 'newtype' tycl_hdr '=' newconstr
379 { TyClD (mkTyData NewType $2 Nothing [$4] Nothing) }
380 | 'class' tycl_hdr fds
381 { TyClD (mkClassDecl (unLoc $2) (unLoc $3) [] emptyBag) }
383 -----------------------------------------------------------------------------
386 maybeexports :: { Maybe [LIE RdrName] }
387 : '(' exportlist ')' { Just $2 }
388 | {- empty -} { Nothing }
390 exportlist :: { [LIE RdrName] }
391 : exportlist ',' export { $3 : $1 }
392 | exportlist ',' { $1 }
396 -- No longer allow things like [] and (,,,) to be exported
397 -- They are built in syntax, always available
398 export :: { LIE RdrName }
399 : qvar { L1 (IEVar (unLoc $1)) }
400 | oqtycon { L1 (IEThingAbs (unLoc $1)) }
401 | oqtycon '(' '..' ')' { LL (IEThingAll (unLoc $1)) }
402 | oqtycon '(' ')' { LL (IEThingWith (unLoc $1) []) }
403 | oqtycon '(' qcnames ')' { LL (IEThingWith (unLoc $1) (reverse $3)) }
404 | 'module' modid { LL (IEModuleContents (unLoc $2)) }
406 qcnames :: { [RdrName] }
407 : qcnames ',' qcname { unLoc $3 : $1 }
408 | qcname { [unLoc $1] }
410 qcname :: { Located RdrName } -- Variable or data constructor
414 -----------------------------------------------------------------------------
415 -- Import Declarations
417 -- import decls can be *empty*, or even just a string of semicolons
418 -- whereas topdecls must contain at least one topdecl.
420 importdecls :: { [LImportDecl RdrName] }
421 : importdecls ';' importdecl { $3 : $1 }
422 | importdecls ';' { $1 }
423 | importdecl { [ $1 ] }
426 importdecl :: { LImportDecl RdrName }
427 : 'import' maybe_src optqualified modid maybeas maybeimpspec
428 { L (comb4 $1 $4 $5 $6) (ImportDecl $4 $2 $3 (unLoc $5) (unLoc $6)) }
430 maybe_src :: { IsBootInterface }
431 : '{-# SOURCE' '#-}' { True }
432 | {- empty -} { False }
434 optqualified :: { Bool }
435 : 'qualified' { True }
436 | {- empty -} { False }
438 maybeas :: { Located (Maybe Module) }
439 : 'as' modid { LL (Just (unLoc $2)) }
440 | {- empty -} { noLoc Nothing }
442 maybeimpspec :: { Located (Maybe (Bool, [LIE RdrName])) }
443 : impspec { L1 (Just (unLoc $1)) }
444 | {- empty -} { noLoc Nothing }
446 impspec :: { Located (Bool, [LIE RdrName]) }
447 : '(' exportlist ')' { LL (False, reverse $2) }
448 | 'hiding' '(' exportlist ')' { LL (True, reverse $3) }
450 -----------------------------------------------------------------------------
451 -- Fixity Declarations
455 | INTEGER {% checkPrecP (L1 (fromInteger (getINTEGER $1))) }
457 infix :: { Located FixityDirection }
458 : 'infix' { L1 InfixN }
459 | 'infixl' { L1 InfixL }
460 | 'infixr' { L1 InfixR }
462 ops :: { Located [Located RdrName] }
463 : ops ',' op { LL ($3 : unLoc $1) }
466 -----------------------------------------------------------------------------
467 -- Top-Level Declarations
469 topdecls :: { OrdList (LHsDecl RdrName) } -- Reversed
470 : topdecls ';' topdecl { $1 `appOL` $3 }
471 | topdecls ';' { $1 }
474 topdecl :: { OrdList (LHsDecl RdrName) }
475 : tycl_decl { unitOL (L1 (TyClD (unLoc $1))) }
476 | 'instance' inst_type where
477 { let (binds,sigs) = cvBindsAndSigs (unLoc $3)
478 in unitOL (L (comb3 $1 $2 $3) (InstD (InstDecl $2 binds sigs))) }
479 | 'default' '(' comma_types0 ')' { unitOL (LL $ DefD (DefaultDecl $3)) }
480 | 'foreign' fdecl { unitOL (LL (unLoc $2)) }
481 | '{-# DEPRECATED' deprecations '#-}' { $2 }
482 | '{-# RULES' rules '#-}' { $2 }
483 | '$(' exp ')' { unitOL (LL $ SpliceD (SpliceDecl $2)) }
486 tycl_decl :: { LTyClDecl RdrName }
487 : 'type' syn_hdr '=' ctype
488 -- Note ctype, not sigtype.
489 -- We allow an explicit for-all but we don't insert one
490 -- in type Foo a = (b,b)
491 -- Instead we just say b is out of scope
492 { LL $ let (tc,tvs) = $2 in TySynonym tc tvs $4 }
494 | 'data' tycl_hdr constrs deriving
495 { L (comb4 $1 $2 $3 $4)
496 (mkTyData DataType $2 Nothing (reverse (unLoc $3)) (unLoc $4)) }
498 | 'data' tycl_hdr opt_kind_sig 'where' gadt_constrlist -- No deriving for GADTs
499 { L (comb4 $1 $2 $4 $5)
500 (mkTyData DataType $2 $3 (reverse (unLoc $5)) Nothing) }
502 | 'newtype' tycl_hdr '=' newconstr deriving
504 (mkTyData NewType $2 Nothing [$4] (unLoc $5)) }
506 | 'class' tycl_hdr fds where
508 (binds,sigs) = cvBindsAndSigs (unLoc $4)
510 L (comb4 $1 $2 $3 $4) (mkClassDecl (unLoc $2) (unLoc $3) sigs
513 opt_kind_sig :: { Maybe Kind }
515 | '::' kind { Just $2 }
517 syn_hdr :: { (Located RdrName, [LHsTyVarBndr RdrName]) }
518 -- We don't retain the syntax of an infix
519 -- type synonym declaration. Oh well.
520 : tycon tv_bndrs { ($1, $2) }
521 | tv_bndr tyconop tv_bndr { ($2, [$1,$3]) }
523 -- tycl_hdr parses the header of a type or class decl,
524 -- which takes the form
527 -- (Eq a, Ord b) => T a b
528 -- Rather a lot of inlining here, else we get reduce/reduce errors
529 tycl_hdr :: { Located (LHsContext RdrName, Located RdrName, [LHsTyVarBndr RdrName]) }
530 : context '=>' type {% checkTyClHdr $1 $3 >>= return.LL }
531 | type {% checkTyClHdr (noLoc []) $1 >>= return.L1 }
533 -----------------------------------------------------------------------------
534 -- Nested declarations
536 decls :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
537 : decls ';' decl { LL (unLoc $1 `appOL` unLoc $3) }
538 | decls ';' { LL (unLoc $1) }
540 | {- empty -} { noLoc nilOL }
543 decllist :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
544 : '{' decls '}' { LL (unLoc $2) }
545 | vocurly decls close { $2 }
547 where :: { Located (OrdList (LHsDecl RdrName)) } -- Reversed
548 -- No implicit parameters
549 : 'where' decllist { LL (unLoc $2) }
550 | {- empty -} { noLoc nilOL }
552 binds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
553 : decllist { L1 [cvBindGroup (unLoc $1)] }
554 | '{' dbinds '}' { LL [HsIPBinds (unLoc $2)] }
555 | vocurly dbinds close { L (getLoc $2) [HsIPBinds (unLoc $2)] }
557 wherebinds :: { Located [HsBindGroup RdrName] } -- May have implicit parameters
558 : 'where' binds { LL (unLoc $2) }
559 | {- empty -} { noLoc [] }
562 -----------------------------------------------------------------------------
563 -- Transformation Rules
565 rules :: { OrdList (LHsDecl RdrName) } -- Reversed
566 : rules ';' rule { $1 `snocOL` $3 }
569 | {- empty -} { nilOL }
571 rule :: { LHsDecl RdrName }
572 : STRING activation rule_forall infixexp '=' exp
573 { LL $ RuleD (HsRule (getSTRING $1) $2 $3 $4 $6) }
575 activation :: { Activation } -- Omitted means AlwaysActive
576 : {- empty -} { AlwaysActive }
577 | explicit_activation { $1 }
579 inverse_activation :: { Activation } -- Omitted means NeverActive
580 : {- empty -} { NeverActive }
581 | explicit_activation { $1 }
583 explicit_activation :: { Activation } -- In brackets
584 : '[' INTEGER ']' { ActiveAfter (fromInteger (getINTEGER $2)) }
585 | '[' '~' INTEGER ']' { ActiveBefore (fromInteger (getINTEGER $3)) }
587 rule_forall :: { [RuleBndr RdrName] }
588 : 'forall' rule_var_list '.' { $2 }
591 rule_var_list :: { [RuleBndr RdrName] }
593 | rule_var rule_var_list { $1 : $2 }
595 rule_var :: { RuleBndr RdrName }
596 : varid { RuleBndr $1 }
597 | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 }
599 -----------------------------------------------------------------------------
600 -- Deprecations (c.f. rules)
602 deprecations :: { OrdList (LHsDecl RdrName) } -- Reversed
603 : deprecations ';' deprecation { $1 `appOL` $3 }
604 | deprecations ';' { $1 }
606 | {- empty -} { nilOL }
608 -- SUP: TEMPORARY HACK, not checking for `module Foo'
609 deprecation :: { OrdList (LHsDecl RdrName) }
611 { toOL [ LL $ DeprecD (Deprecation n (getSTRING $2))
615 -----------------------------------------------------------------------------
616 -- Foreign import and export declarations
618 -- for the time being, the following accepts foreign declarations conforming
619 -- to the FFI Addendum, Version 1.0 as well as pre-standard declarations
621 -- * a flag indicates whether pre-standard declarations have been used and
622 -- triggers a deprecation warning further down the road
624 -- NB: The first two rules could be combined into one by replacing `safety1'
625 -- with `safety'. However, the combined rule conflicts with the
628 fdecl :: { LHsDecl RdrName }
629 fdecl : 'import' callconv safety1 fspec
630 {% mkImport $2 $3 (unLoc $4) >>= return.LL }
631 | 'import' callconv fspec
632 {% do { d <- mkImport $2 (PlaySafe False) (unLoc $3);
634 | 'export' callconv fspec
635 {% mkExport $2 (unLoc $3) >>= return.LL }
636 -- the following syntax is DEPRECATED
637 | fdecl1DEPRECATED { L1 (ForD (unLoc $1)) }
638 | fdecl2DEPRECATED { L1 (unLoc $1) }
640 fdecl1DEPRECATED :: { LForeignDecl RdrName }
642 ----------- DEPRECATED label decls ------------
643 : 'label' ext_name varid '::' sigtype
644 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
645 (CLabel ($2 `orElse` mkExtName (unLoc $3)))) True }
647 ----------- DEPRECATED ccall/stdcall decls ------------
649 -- NB: This business with the case expression below may seem overly
650 -- complicated, but it is necessary to avoid some conflicts.
652 -- DEPRECATED variant #1: lack of a calling convention specification
654 | 'import' {-no callconv-} ext_name safety varid_no_unsafe '::' sigtype
656 target = StaticTarget ($2 `orElse` mkExtName (unLoc $4))
658 LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
659 (CFunction target)) True }
661 -- DEPRECATED variant #2: external name consists of two separate strings
662 -- (module name and function name) (import)
663 | 'import' callconv STRING STRING safety varid_no_unsafe '::' sigtype
665 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
666 CCall cconv -> return $
668 imp = CFunction (StaticTarget (getSTRING $4))
670 LL $ ForeignImport $6 $8 (CImport cconv $5 nilFS nilFS imp) True }
672 -- DEPRECATED variant #3: `unsafe' after entity
673 | 'import' callconv STRING 'unsafe' varid_no_unsafe '::' sigtype
675 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
676 CCall cconv -> return $
678 imp = CFunction (StaticTarget (getSTRING $3))
680 LL $ ForeignImport $5 $7 (CImport cconv PlayRisky nilFS nilFS imp) True }
682 -- DEPRECATED variant #4: use of the special identifier `dynamic' without
683 -- an explicit calling convention (import)
684 | 'import' {-no callconv-} 'dynamic' safety varid_no_unsafe '::' sigtype
685 { LL $ ForeignImport $4 $6 (CImport defaultCCallConv $3 nilFS nilFS
686 (CFunction DynamicTarget)) True }
688 -- DEPRECATED variant #5: use of the special identifier `dynamic' (import)
689 | 'import' callconv 'dynamic' safety varid_no_unsafe '::' sigtype
691 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
692 CCall cconv -> return $
693 LL $ ForeignImport $5 $7 (CImport cconv $4 nilFS nilFS
694 (CFunction DynamicTarget)) True }
696 -- DEPRECATED variant #6: lack of a calling convention specification
698 | 'export' {-no callconv-} ext_name varid '::' sigtype
699 { LL $ ForeignExport $3 $5 (CExport (CExportStatic ($2 `orElse` mkExtName (unLoc $3))
700 defaultCCallConv)) True }
702 -- DEPRECATED variant #7: external name consists of two separate strings
703 -- (module name and function name) (export)
704 | 'export' callconv STRING STRING varid '::' sigtype
706 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
707 CCall cconv -> return $
708 LL $ ForeignExport $5 $7
709 (CExport (CExportStatic (getSTRING $4) cconv)) True }
711 -- DEPRECATED variant #8: use of the special identifier `dynamic' without
712 -- an explicit calling convention (export)
713 | 'export' {-no callconv-} 'dynamic' varid '::' sigtype
714 { LL $ ForeignImport $3 $5 (CImport defaultCCallConv (PlaySafe False) nilFS nilFS
717 -- DEPRECATED variant #9: use of the special identifier `dynamic' (export)
718 | 'export' callconv 'dynamic' varid '::' sigtype
720 DNCall -> parseError (comb2 $1 $>) "Illegal format of .NET foreign import"
721 CCall cconv -> return $
722 LL $ ForeignImport $4 $6
723 (CImport cconv (PlaySafe False) nilFS nilFS CWrapper) True }
725 ----------- DEPRECATED .NET decls ------------
726 -- NB: removed the .NET call declaration, as it is entirely subsumed
727 -- by the new standard FFI declarations
729 fdecl2DEPRECATED :: { LHsDecl RdrName }
731 : 'import' 'dotnet' 'type' ext_name tycon { LL $ TyClD (ForeignType $5 $4 DNType) }
732 -- left this one unchanged for the moment as type imports are not
733 -- covered currently by the FFI standard -=chak
736 callconv :: { CallConv }
737 : 'stdcall' { CCall StdCallConv }
738 | 'ccall' { CCall CCallConv }
739 | 'dotnet' { DNCall }
742 : 'unsafe' { PlayRisky }
743 | 'safe' { PlaySafe False }
744 | 'threadsafe' { PlaySafe True }
745 | {- empty -} { PlaySafe False }
747 safety1 :: { Safety }
748 : 'unsafe' { PlayRisky }
749 | 'safe' { PlaySafe False }
750 | 'threadsafe' { PlaySafe True }
751 -- only needed to avoid conflicts with the DEPRECATED rules
753 fspec :: { Located (Located FastString, Located RdrName, LHsType RdrName) }
754 : STRING var '::' sigtype { LL (L (getLoc $1) (getSTRING $1), $2, $4) }
755 | var '::' sigtype { LL (noLoc nilFS, $1, $3) }
756 -- if the entity string is missing, it defaults to the empty string;
757 -- the meaning of an empty entity string depends on the calling
761 ext_name :: { Maybe CLabelString }
762 : STRING { Just (getSTRING $1) }
763 | STRING STRING { Just (getSTRING $2) } -- Ignore "module name" for now
764 | {- empty -} { Nothing }
767 -----------------------------------------------------------------------------
770 opt_sig :: { Maybe (LHsType RdrName) }
771 : {- empty -} { Nothing }
772 | '::' sigtype { Just $2 }
774 opt_asig :: { Maybe (LHsType RdrName) }
775 : {- empty -} { Nothing }
776 | '::' atype { Just $2 }
778 sigtypes1 :: { [LHsType RdrName] }
780 | sigtype ',' sigtypes1 { $1 : $3 }
782 sigtype :: { LHsType RdrName }
783 : ctype { L1 (mkImplicitHsForAllTy (noLoc []) $1) }
784 -- Wrap an Implicit forall if there isn't one there already
786 sig_vars :: { Located [Located RdrName] }
787 : sig_vars ',' var { LL ($3 : unLoc $1) }
790 -----------------------------------------------------------------------------
793 strict_mark :: { Located HsBang }
794 : '!' { L1 HsStrict }
795 | '{-# UNPACK' '#-}' '!' { LL HsUnbox }
797 -- A ctype is a for-all type
798 ctype :: { LHsType RdrName }
799 : 'forall' tv_bndrs '.' ctype { LL $ mkExplicitHsForAllTy $2 (noLoc []) $4 }
800 | context '=>' type { LL $ mkImplicitHsForAllTy $1 $3 }
801 -- A type of form (context => type) is an *implicit* HsForAllTy
804 -- We parse a context as a btype so that we don't get reduce/reduce
805 -- errors in ctype. The basic problem is that
807 -- looks so much like a tuple type. We can't tell until we find the =>
808 context :: { LHsContext RdrName }
809 : btype {% checkContext $1 }
811 type :: { LHsType RdrName }
812 : ipvar '::' gentype { LL (HsPredTy (HsIParam (unLoc $1) $3)) }
815 gentype :: { LHsType RdrName }
817 | btype qtyconop gentype { LL $ HsOpTy $1 $2 $3 }
818 | btype '`' tyvar '`' gentype { LL $ HsOpTy $1 $3 $5 }
819 | btype '->' gentype { LL $ HsFunTy $1 $3 }
821 btype :: { LHsType RdrName }
822 : btype atype { LL $ HsAppTy $1 $2 }
825 atype :: { LHsType RdrName }
826 : gtycon { L1 (HsTyVar (unLoc $1)) }
827 | tyvar { L1 (HsTyVar (unLoc $1)) }
828 | strict_mark atype { LL (HsBangTy (unLoc $1) $2) }
829 | '(' type ',' comma_types1 ')' { LL $ HsTupleTy Boxed ($2:$4) }
830 | '(#' comma_types1 '#)' { LL $ HsTupleTy Unboxed $2 }
831 | '[' type ']' { LL $ HsListTy $2 }
832 | '[:' type ':]' { LL $ HsPArrTy $2 }
833 | '(' ctype ')' { LL $ HsParTy $2 }
834 | '(' ctype '::' kind ')' { LL $ HsKindSig $2 $4 }
836 | INTEGER { L1 (HsNumTy (getINTEGER $1)) }
838 -- An inst_type is what occurs in the head of an instance decl
839 -- e.g. (Foo a, Gaz b) => Wibble a b
840 -- It's kept as a single type, with a MonoDictTy at the right
841 -- hand corner, for convenience.
842 inst_type :: { LHsType RdrName }
843 : sigtype {% checkInstType $1 }
845 inst_types1 :: { [LHsType RdrName] }
847 | inst_type ',' inst_types1 { $1 : $3 }
849 comma_types0 :: { [LHsType RdrName] }
850 : comma_types1 { $1 }
853 comma_types1 :: { [LHsType RdrName] }
855 | type ',' comma_types1 { $1 : $3 }
857 tv_bndrs :: { [LHsTyVarBndr RdrName] }
858 : tv_bndr tv_bndrs { $1 : $2 }
861 tv_bndr :: { LHsTyVarBndr RdrName }
862 : tyvar { L1 (UserTyVar (unLoc $1)) }
863 | '(' tyvar '::' kind ')' { LL (KindedTyVar (unLoc $2) $4) }
865 fds :: { Located [Located ([RdrName], [RdrName])] }
866 : {- empty -} { noLoc [] }
867 | '|' fds1 { LL (reverse (unLoc $2)) }
869 fds1 :: { Located [Located ([RdrName], [RdrName])] }
870 : fds1 ',' fd { LL ($3 : unLoc $1) }
873 fd :: { Located ([RdrName], [RdrName]) }
874 : varids0 '->' varids0 { L (comb3 $1 $2 $3)
875 (reverse (unLoc $1), reverse (unLoc $3)) }
877 varids0 :: { Located [RdrName] }
878 : {- empty -} { noLoc [] }
879 | varids0 tyvar { LL (unLoc $2 : unLoc $1) }
881 -----------------------------------------------------------------------------
886 | akind '->' kind { mkArrowKind $1 $3 }
889 : '*' { liftedTypeKind }
890 | '(' kind ')' { $2 }
893 -----------------------------------------------------------------------------
894 -- Datatype declarations
896 newconstr :: { LConDecl RdrName }
897 : conid atype { LL $ ConDecl $1 [] (noLoc []) (PrefixCon [$2]) }
898 | conid '{' var '::' ctype '}'
899 { LL $ ConDecl $1 [] (noLoc []) (RecCon [($3, $5)]) }
901 gadt_constrlist :: { Located [LConDecl RdrName] }
902 : '{' gadt_constrs '}' { LL (unLoc $2) }
903 | vocurly gadt_constrs close { $2 }
905 gadt_constrs :: { Located [LConDecl RdrName] }
906 : gadt_constrs ';' gadt_constr { LL ($3 : unLoc $1) }
907 | gadt_constrs ';' { $1 }
908 | gadt_constr { L1 [$1] }
910 gadt_constr :: { LConDecl RdrName }
912 { LL (GadtDecl $1 $3) }
914 constrs :: { Located [LConDecl RdrName] }
915 : {- empty; a GHC extension -} { noLoc [] }
916 | '=' constrs1 { LL (unLoc $2) }
918 constrs1 :: { Located [LConDecl RdrName] }
919 : constrs1 '|' constr { LL ($3 : unLoc $1) }
922 constr :: { LConDecl RdrName }
923 : forall context '=>' constr_stuff
924 { let (con,details) = unLoc $4 in
925 LL (ConDecl con (unLoc $1) $2 details) }
926 | forall constr_stuff
927 { let (con,details) = unLoc $2 in
928 LL (ConDecl con (unLoc $1) (noLoc []) details) }
930 forall :: { Located [LHsTyVarBndr RdrName] }
931 : 'forall' tv_bndrs '.' { LL $2 }
932 | {- empty -} { noLoc [] }
934 constr_stuff :: { Located (Located RdrName, HsConDetails RdrName (LBangType RdrName)) }
935 -- We parse the constructor declaration
937 -- as a btype (treating C as a type constructor) and then convert C to be
938 -- a data constructor. Reason: it might continue like this:
940 -- in which case C really would be a type constructor. We can't resolve this
941 -- ambiguity till we come across the constructor oprerator :% (or not, more usually)
942 : btype {% mkPrefixCon $1 [] >>= return.LL }
943 | oqtycon '{' '}' {% mkRecCon $1 [] >>= return.LL }
944 | oqtycon '{' fielddecls '}' {% mkRecCon $1 $3 >>= return.LL }
945 | btype conop btype { LL ($2, InfixCon $1 $3) }
947 fielddecls :: { [([Located RdrName], LBangType RdrName)] }
948 : fielddecl ',' fielddecls { unLoc $1 : $3 }
949 | fielddecl { [unLoc $1] }
951 fielddecl :: { Located ([Located RdrName], LBangType RdrName) }
952 : sig_vars '::' ctype { LL (reverse (unLoc $1), $3) }
954 -- We allow the odd-looking 'inst_type' in a deriving clause, so that
955 -- we can do deriving( forall a. C [a] ) in a newtype (GHC extension).
956 -- The 'C [a]' part is converted to an HsPredTy by checkInstType
957 -- We don't allow a context, but that's sorted out by the type checker.
958 deriving :: { Located (Maybe [LHsType RdrName]) }
959 : {- empty -} { noLoc Nothing }
960 | 'deriving' qtycon {% do { let { L loc tv = $2 }
961 ; p <- checkInstType (L loc (HsTyVar tv))
962 ; return (LL (Just [p])) } }
963 | 'deriving' '(' ')' { LL (Just []) }
964 | 'deriving' '(' inst_types1 ')' { LL (Just $3) }
965 -- Glasgow extension: allow partial
966 -- applications in derivings
968 -----------------------------------------------------------------------------
971 {- There's an awkward overlap with a type signature. Consider
972 f :: Int -> Int = ...rhs...
973 Then we can't tell whether it's a type signature or a value
974 definition with a result signature until we see the '='.
975 So we have to inline enough to postpone reductions until we know.
979 ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var
980 instead of qvar, we get another shift/reduce-conflict. Consider the
983 { (^^) :: Int->Int ; } Type signature; only var allowed
985 { (^^) :: Int->Int = ... ; } Value defn with result signature;
986 qvar allowed (because of instance decls)
988 We can't tell whether to reduce var to qvar until after we've read the signatures.
991 decl :: { Located (OrdList (LHsDecl RdrName)) }
993 | infixexp opt_sig rhs {% do { r <- checkValDef $1 $2 $3;
994 return (LL $ unitOL (LL $ ValD r)) } }
996 rhs :: { Located (GRHSs RdrName) }
997 : '=' exp wherebinds { L (comb3 $1 $2 $3) $ GRHSs (unguardedRHS $2) (unLoc $3) }
998 | gdrhs wherebinds { LL $ GRHSs (reverse (unLoc $1)) (unLoc $2) }
1000 gdrhs :: { Located [LGRHS RdrName] }
1001 : gdrhs gdrh { LL ($2 : unLoc $1) }
1004 gdrh :: { LGRHS RdrName }
1005 : '|' quals '=' exp { LL $ GRHS (reverse (L (getLoc $4) (ResultStmt $4) :
1008 sigdecl :: { Located (OrdList (LHsDecl RdrName)) }
1009 : infixexp '::' sigtype
1010 {% do s <- checkValSig $1 $3;
1011 return (LL $ unitOL (LL $ SigD s)) }
1012 -- See the above notes for why we need infixexp here
1013 | var ',' sig_vars '::' sigtype
1014 { LL $ toOL [ LL $ SigD (Sig n $5) | n <- $1 : unLoc $3 ] }
1015 | infix prec ops { LL $ toOL [ LL $ SigD (FixSig (FixitySig n (Fixity $2 (unLoc $1))))
1017 | '{-# INLINE' activation qvar '#-}'
1018 { LL $ unitOL (LL $ SigD (InlineSig True $3 $2)) }
1019 | '{-# NOINLINE' inverse_activation qvar '#-}'
1020 { LL $ unitOL (LL $ SigD (InlineSig False $3 $2)) }
1021 | '{-# SPECIALISE' qvar '::' sigtypes1 '#-}'
1022 { LL $ toOL [ LL $ SigD (SpecSig $2 t)
1024 | '{-# SPECIALISE' 'instance' inst_type '#-}'
1025 { LL $ unitOL (LL $ SigD (SpecInstSig $3)) }
1027 -----------------------------------------------------------------------------
1030 exp :: { LHsExpr RdrName }
1031 : infixexp '::' sigtype { LL $ ExprWithTySig $1 $3 }
1032 | infixexp '-<' exp { LL $ HsArrApp $1 $3 placeHolderType HsFirstOrderApp True }
1033 | infixexp '>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsFirstOrderApp False }
1034 | infixexp '-<<' exp { LL $ HsArrApp $1 $3 placeHolderType HsHigherOrderApp True }
1035 | infixexp '>>-' exp { LL $ HsArrApp $3 $1 placeHolderType HsHigherOrderApp False}
1038 infixexp :: { LHsExpr RdrName }
1040 | infixexp qop exp10 { LL (OpApp $1 $2 (panic "fixity") $3) }
1042 exp10 :: { LHsExpr RdrName }
1043 : '\\' aexp aexps opt_asig '->' exp
1044 {% checkPatterns ($2 : reverse $3) >>= \ ps ->
1045 return (LL $ HsLam (mkMatchGroup [LL $ Match ps $4
1046 (GRHSs (unguardedRHS $6) []
1048 | 'let' binds 'in' exp { LL $ HsLet (unLoc $2) $4 }
1049 | 'if' exp 'then' exp 'else' exp { LL $ HsIf $2 $4 $6 }
1050 | 'case' exp 'of' altslist { LL $ HsCase $2 (mkMatchGroup (unLoc $4)) }
1051 | '-' fexp { LL $ mkHsNegApp $2 }
1053 | 'do' stmtlist {% let loc = comb2 $1 $2 in
1054 checkDo loc (unLoc $2) >>= \ stmts ->
1055 return (L loc (mkHsDo DoExpr stmts)) }
1056 | 'mdo' stmtlist {% let loc = comb2 $1 $2 in
1057 checkMDo loc (unLoc $2) >>= \ stmts ->
1058 return (L loc (mkHsDo MDoExpr stmts)) }
1060 | scc_annot exp { LL $ if opt_SccProfilingOn
1061 then HsSCC (unLoc $1) $2
1064 | 'proc' aexp '->' exp
1065 {% checkPattern $2 >>= \ p ->
1066 return (LL $ HsProc p (LL $ HsCmdTop $4 []
1067 placeHolderType undefined)) }
1068 -- TODO: is LL right here?
1070 | '{-# CORE' STRING '#-}' exp { LL $ HsCoreAnn (getSTRING $2) $4 }
1071 -- hdaume: core annotation
1074 scc_annot :: { Located FastString }
1075 : '_scc_' STRING { LL $ getSTRING $2 }
1076 | '{-# SCC' STRING '#-}' { LL $ getSTRING $2 }
1078 fexp :: { LHsExpr RdrName }
1079 : fexp aexp { LL $ HsApp $1 $2 }
1082 aexps :: { [LHsExpr RdrName] }
1083 : aexps aexp { $2 : $1 }
1084 | {- empty -} { [] }
1086 aexp :: { LHsExpr RdrName }
1087 : qvar '@' aexp { LL $ EAsPat $1 $3 }
1088 | '~' aexp { LL $ ELazyPat $2 }
1091 aexp1 :: { LHsExpr RdrName }
1092 : aexp1 '{' fbinds '}' {% do { r <- mkRecConstrOrUpdate $1 (comb2 $2 $4)
1097 -- Here was the syntax for type applications that I was planning
1098 -- but there are difficulties (e.g. what order for type args)
1099 -- so it's not enabled yet.
1100 -- But this case *is* used for the left hand side of a generic definition,
1101 -- which is parsed as an expression before being munged into a pattern
1102 | qcname '{|' gentype '|}' { LL $ HsApp (sL (getLoc $1) (HsVar (unLoc $1)))
1103 (sL (getLoc $3) (HsType $3)) }
1105 aexp2 :: { LHsExpr RdrName }
1106 : ipvar { L1 (HsIPVar $! unLoc $1) }
1107 | qcname { L1 (HsVar $! unLoc $1) }
1108 | literal { L1 (HsLit $! unLoc $1) }
1109 | INTEGER { L1 (HsOverLit $! mkHsIntegral (getINTEGER $1)) }
1110 | RATIONAL { L1 (HsOverLit $! mkHsFractional (getRATIONAL $1)) }
1111 | '(' exp ')' { LL (HsPar $2) }
1112 | '(' exp ',' texps ')' { LL $ ExplicitTuple ($2 : reverse $4) Boxed }
1113 | '(#' texps '#)' { LL $ ExplicitTuple (reverse $2) Unboxed }
1114 | '[' list ']' { LL (unLoc $2) }
1115 | '[:' parr ':]' { LL (unLoc $2) }
1116 | '(' infixexp qop ')' { LL $ SectionL $2 $3 }
1117 | '(' qopm infixexp ')' { LL $ SectionR $2 $3 }
1118 | '_' { L1 EWildPat }
1120 -- MetaHaskell Extension
1121 | TH_ID_SPLICE { L1 $ HsSpliceE (mkHsSplice
1122 (L1 $ HsVar (mkUnqual varName
1123 (getTH_ID_SPLICE $1)))) } -- $x
1124 | '$(' exp ')' { LL $ HsSpliceE (mkHsSplice $2) } -- $( exp )
1126 | TH_VAR_QUOTE qvar { LL $ HsBracket (VarBr (unLoc $2)) }
1127 | TH_VAR_QUOTE gcon { LL $ HsBracket (VarBr (unLoc $2)) }
1128 | TH_TY_QUOTE tyvar { LL $ HsBracket (VarBr (unLoc $2)) }
1129 | TH_TY_QUOTE gtycon { LL $ HsBracket (VarBr (unLoc $2)) }
1130 | '[|' exp '|]' { LL $ HsBracket (ExpBr $2) }
1131 | '[t|' ctype '|]' { LL $ HsBracket (TypBr $2) }
1132 | '[p|' infixexp '|]' {% checkPattern $2 >>= \p ->
1133 return (LL $ HsBracket (PatBr p)) }
1134 | '[d|' cvtopbody '|]' { LL $ HsBracket (DecBr (mkGroup $2)) }
1136 -- arrow notation extension
1137 | '(|' aexp2 cmdargs '|)' { LL $ HsArrForm $2 Nothing (reverse $3) }
1139 cmdargs :: { [LHsCmdTop RdrName] }
1140 : cmdargs acmd { $2 : $1 }
1141 | {- empty -} { [] }
1143 acmd :: { LHsCmdTop RdrName }
1144 : aexp2 { L1 $ HsCmdTop $1 [] placeHolderType undefined }
1146 cvtopbody :: { [LHsDecl RdrName] }
1147 : '{' cvtopdecls0 '}' { $2 }
1148 | vocurly cvtopdecls0 close { $2 }
1150 cvtopdecls0 :: { [LHsDecl RdrName] }
1151 : {- empty -} { [] }
1154 texps :: { [LHsExpr RdrName] }
1155 : texps ',' exp { $3 : $1 }
1159 -----------------------------------------------------------------------------
1162 -- The rules below are little bit contorted to keep lexps left-recursive while
1163 -- avoiding another shift/reduce-conflict.
1165 list :: { LHsExpr RdrName }
1166 : exp { L1 $ ExplicitList placeHolderType [$1] }
1167 | lexps { L1 $ ExplicitList placeHolderType (reverse (unLoc $1)) }
1168 | exp '..' { LL $ ArithSeqIn (From $1) }
1169 | exp ',' exp '..' { LL $ ArithSeqIn (FromThen $1 $3) }
1170 | exp '..' exp { LL $ ArithSeqIn (FromTo $1 $3) }
1171 | exp ',' exp '..' exp { LL $ ArithSeqIn (FromThenTo $1 $3 $5) }
1172 | exp pquals { LL $ mkHsDo ListComp
1173 (reverse (L (getLoc $1) (ResultStmt $1) :
1176 lexps :: { Located [LHsExpr RdrName] }
1177 : lexps ',' exp { LL ($3 : unLoc $1) }
1178 | exp ',' exp { LL [$3,$1] }
1180 -----------------------------------------------------------------------------
1181 -- List Comprehensions
1183 pquals :: { Located [LStmt RdrName] } -- Either a singleton ParStmt,
1184 -- or a reversed list of Stmts
1185 : pquals1 { case unLoc $1 of
1187 qss -> L1 [L1 (ParStmt stmtss)]
1189 stmtss = [ (reverse qs, undefined)
1193 pquals1 :: { Located [[LStmt RdrName]] }
1194 : pquals1 '|' quals { LL (unLoc $3 : unLoc $1) }
1195 | '|' quals { L (getLoc $2) [unLoc $2] }
1197 quals :: { Located [LStmt RdrName] }
1198 : quals ',' qual { LL ($3 : unLoc $1) }
1201 -----------------------------------------------------------------------------
1202 -- Parallel array expressions
1204 -- The rules below are little bit contorted; see the list case for details.
1205 -- Note that, in contrast to lists, we only have finite arithmetic sequences.
1206 -- Moreover, we allow explicit arrays with no element (represented by the nil
1207 -- constructor in the list case).
1209 parr :: { LHsExpr RdrName }
1210 : { noLoc (ExplicitPArr placeHolderType []) }
1211 | exp { L1 $ ExplicitPArr placeHolderType [$1] }
1212 | lexps { L1 $ ExplicitPArr placeHolderType
1213 (reverse (unLoc $1)) }
1214 | exp '..' exp { LL $ PArrSeqIn (FromTo $1 $3) }
1215 | exp ',' exp '..' exp { LL $ PArrSeqIn (FromThenTo $1 $3 $5) }
1216 | exp pquals { LL $ mkHsDo PArrComp
1217 (reverse (L (getLoc $1) (ResultStmt $1) :
1221 -- We are reusing `lexps' and `pquals' from the list case.
1223 -----------------------------------------------------------------------------
1224 -- Case alternatives
1226 altslist :: { Located [LMatch RdrName] }
1227 : '{' alts '}' { LL (reverse (unLoc $2)) }
1228 | vocurly alts close { L (getLoc $2) (reverse (unLoc $2)) }
1230 alts :: { Located [LMatch RdrName] }
1231 : alts1 { L1 (unLoc $1) }
1232 | ';' alts { LL (unLoc $2) }
1234 alts1 :: { Located [LMatch RdrName] }
1235 : alts1 ';' alt { LL ($3 : unLoc $1) }
1236 | alts1 ';' { LL (unLoc $1) }
1239 alt :: { LMatch RdrName }
1240 : infixexp opt_sig alt_rhs {% checkPattern $1 >>= \p ->
1241 return (LL (Match [p] $2 (unLoc $3))) }
1243 alt_rhs :: { Located (GRHSs RdrName) }
1244 : ralt wherebinds { LL (GRHSs (unLoc $1) (unLoc $2)) }
1246 ralt :: { Located [LGRHS RdrName] }
1247 : '->' exp { LL (unguardedRHS $2) }
1248 | gdpats { L1 (reverse (unLoc $1)) }
1250 gdpats :: { Located [LGRHS RdrName] }
1251 : gdpats gdpat { LL ($2 : unLoc $1) }
1254 gdpat :: { LGRHS RdrName }
1255 : '|' quals '->' exp { let r = L (getLoc $4) (ResultStmt $4)
1256 in LL $ GRHS (reverse (r : unLoc $2)) }
1258 -----------------------------------------------------------------------------
1259 -- Statement sequences
1261 stmtlist :: { Located [LStmt RdrName] }
1262 : '{' stmts '}' { LL (unLoc $2) }
1263 | vocurly stmts close { $2 }
1265 -- do { ;; s ; s ; ; s ;; }
1266 -- The last Stmt should be a ResultStmt, but that's hard to enforce
1267 -- here, because we need too much lookahead if we see do { e ; }
1268 -- So we use ExprStmts throughout, and switch the last one over
1269 -- in ParseUtils.checkDo instead
1270 stmts :: { Located [LStmt RdrName] }
1271 : stmt stmts_help { LL ($1 : unLoc $2) }
1272 | ';' stmts { LL (unLoc $2) }
1273 | {- empty -} { noLoc [] }
1275 stmts_help :: { Located [LStmt RdrName] } -- might be empty
1276 : ';' stmts { LL (unLoc $2) }
1277 | {- empty -} { noLoc [] }
1279 -- For typing stmts at the GHCi prompt, where
1280 -- the input may consist of just comments.
1281 maybe_stmt :: { Maybe (LStmt RdrName) }
1283 | {- nothing -} { Nothing }
1285 stmt :: { LStmt RdrName }
1287 | infixexp '->' exp {% checkPattern $3 >>= \p ->
1288 return (LL $ BindStmt p $1) }
1289 | 'rec' stmtlist { LL $ RecStmt (unLoc $2) undefined undefined undefined }
1291 qual :: { LStmt RdrName }
1292 : infixexp '<-' exp {% checkPattern $1 >>= \p ->
1293 return (LL $ BindStmt p $3) }
1294 | exp { L1 $ ExprStmt $1 placeHolderType }
1295 | 'let' binds { LL $ LetStmt (unLoc $2) }
1297 -----------------------------------------------------------------------------
1298 -- Record Field Update/Construction
1300 fbinds :: { HsRecordBinds RdrName }
1302 | {- empty -} { [] }
1304 fbinds1 :: { HsRecordBinds RdrName }
1305 : fbinds1 ',' fbind { $3 : $1 }
1308 fbind :: { (Located RdrName, LHsExpr RdrName) }
1309 : qvar '=' exp { ($1,$3) }
1311 -----------------------------------------------------------------------------
1312 -- Implicit Parameter Bindings
1314 dbinds :: { Located [LIPBind RdrName] }
1315 : dbinds ';' dbind { LL ($3 : unLoc $1) }
1316 | dbinds ';' { LL (unLoc $1) }
1318 -- | {- empty -} { [] }
1320 dbind :: { LIPBind RdrName }
1321 dbind : ipvar '=' exp { LL (IPBind (unLoc $1) $3) }
1323 -----------------------------------------------------------------------------
1324 -- Variables, Constructors and Operators.
1326 identifier :: { Located RdrName }
1332 depreclist :: { Located [RdrName] }
1333 depreclist : deprec_var { L1 [unLoc $1] }
1334 | deprec_var ',' depreclist { LL (unLoc $1 : unLoc $3) }
1336 deprec_var :: { Located RdrName }
1337 deprec_var : var { $1 }
1340 gcon :: { Located RdrName } -- Data constructor namespace
1341 : sysdcon { L1 $ nameRdrName (dataConName (unLoc $1)) }
1343 -- the case of '[:' ':]' is part of the production `parr'
1345 sysdcon :: { Located DataCon } -- Wired in data constructors
1346 : '(' ')' { LL unitDataCon }
1347 | '(' commas ')' { LL $ tupleCon Boxed $2 }
1348 | '[' ']' { LL nilDataCon }
1350 var :: { Located RdrName }
1352 | '(' varsym ')' { LL (unLoc $2) }
1354 qvar :: { Located RdrName }
1356 | '(' varsym ')' { LL (unLoc $2) }
1357 | '(' qvarsym1 ')' { LL (unLoc $2) }
1358 -- We've inlined qvarsym here so that the decision about
1359 -- whether it's a qvar or a var can be postponed until
1360 -- *after* we see the close paren.
1362 ipvar :: { Located (IPName RdrName) }
1363 : IPDUPVARID { L1 (Dupable (mkUnqual varName (getIPDUPVARID $1))) }
1364 | IPSPLITVARID { L1 (Linear (mkUnqual varName (getIPSPLITVARID $1))) }
1366 qcon :: { Located RdrName }
1368 | '(' qconsym ')' { LL (unLoc $2) }
1370 varop :: { Located RdrName }
1372 | '`' varid '`' { LL (unLoc $2) }
1374 qvarop :: { Located RdrName }
1376 | '`' qvarid '`' { LL (unLoc $2) }
1378 qvaropm :: { Located RdrName }
1379 : qvarsym_no_minus { $1 }
1380 | '`' qvarid '`' { LL (unLoc $2) }
1382 conop :: { Located RdrName }
1384 | '`' conid '`' { LL (unLoc $2) }
1386 qconop :: { Located RdrName }
1388 | '`' qconid '`' { LL (unLoc $2) }
1390 -----------------------------------------------------------------------------
1391 -- Type constructors
1393 gtycon :: { Located RdrName } -- A "general" qualified tycon
1395 | '(' ')' { LL $ getRdrName unitTyCon }
1396 | '(' commas ')' { LL $ getRdrName (tupleTyCon Boxed $2) }
1397 | '(' '->' ')' { LL $ getRdrName funTyCon }
1398 | '[' ']' { LL $ listTyCon_RDR }
1399 | '[:' ':]' { LL $ parrTyCon_RDR }
1401 oqtycon :: { Located RdrName } -- An "ordinary" qualified tycon
1403 | '(' qtyconsym ')' { LL (unLoc $2) }
1405 qtyconop :: { Located RdrName } -- Qualified or unqualified
1407 | '`' qtycon '`' { LL (unLoc $2) }
1409 tyconop :: { Located RdrName } -- Unqualified
1411 | '`' tycon '`' { LL (unLoc $2) }
1413 qtycon :: { Located RdrName } -- Qualified or unqualified
1414 : QCONID { L1 $! mkQual tcClsName (getQCONID $1) }
1417 tycon :: { Located RdrName } -- Unqualified
1418 : CONID { L1 $! mkUnqual tcClsName (getCONID $1) }
1420 qtyconsym :: { Located RdrName }
1421 : QCONSYM { L1 $! mkQual tcClsName (getQCONSYM $1) }
1424 tyconsym :: { Located RdrName }
1425 : CONSYM { L1 $! mkUnqual tcClsName (getCONSYM $1) }
1427 -----------------------------------------------------------------------------
1430 op :: { Located RdrName } -- used in infix decls
1434 qop :: { LHsExpr RdrName } -- used in sections
1435 : qvarop { L1 $ HsVar (unLoc $1) }
1436 | qconop { L1 $ HsVar (unLoc $1) }
1438 qopm :: { LHsExpr RdrName } -- used in sections
1439 : qvaropm { L1 $ HsVar (unLoc $1) }
1440 | qconop { L1 $ HsVar (unLoc $1) }
1442 -----------------------------------------------------------------------------
1445 qvarid :: { Located RdrName }
1447 | QVARID { L1 $ mkQual varName (getQVARID $1) }
1449 varid :: { Located RdrName }
1450 : varid_no_unsafe { $1 }
1451 | 'unsafe' { L1 $! mkUnqual varName FSLIT("unsafe") }
1452 | 'safe' { L1 $! mkUnqual varName FSLIT("safe") }
1453 | 'threadsafe' { L1 $! mkUnqual varName FSLIT("threadsafe") }
1455 varid_no_unsafe :: { Located RdrName }
1456 : VARID { L1 $! mkUnqual varName (getVARID $1) }
1457 | special_id { L1 $! mkUnqual varName (unLoc $1) }
1458 | 'forall' { L1 $! mkUnqual varName FSLIT("forall") }
1460 tyvar :: { Located RdrName }
1461 : VARID { L1 $! mkUnqual tvName (getVARID $1) }
1462 | special_id { L1 $! mkUnqual tvName (unLoc $1) }
1463 | 'unsafe' { L1 $! mkUnqual tvName FSLIT("unsafe") }
1464 | 'safe' { L1 $! mkUnqual tvName FSLIT("safe") }
1465 | 'threadsafe' { L1 $! mkUnqual tvName FSLIT("threadsafe") }
1467 -- These special_ids are treated as keywords in various places,
1468 -- but as ordinary ids elsewhere. 'special_id' collects all these
1469 -- except 'unsafe' and 'forall' whose treatment differs depending on context
1470 special_id :: { Located UserFS }
1472 : 'as' { L1 FSLIT("as") }
1473 | 'qualified' { L1 FSLIT("qualified") }
1474 | 'hiding' { L1 FSLIT("hiding") }
1475 | 'export' { L1 FSLIT("export") }
1476 | 'label' { L1 FSLIT("label") }
1477 | 'dynamic' { L1 FSLIT("dynamic") }
1478 | 'stdcall' { L1 FSLIT("stdcall") }
1479 | 'ccall' { L1 FSLIT("ccall") }
1481 -----------------------------------------------------------------------------
1484 qvarsym :: { Located RdrName }
1488 qvarsym_no_minus :: { Located RdrName }
1489 : varsym_no_minus { $1 }
1492 qvarsym1 :: { Located RdrName }
1493 qvarsym1 : QVARSYM { L1 $ mkQual varName (getQVARSYM $1) }
1495 varsym :: { Located RdrName }
1496 : varsym_no_minus { $1 }
1497 | '-' { L1 $ mkUnqual varName FSLIT("-") }
1499 varsym_no_minus :: { Located RdrName } -- varsym not including '-'
1500 : VARSYM { L1 $ mkUnqual varName (getVARSYM $1) }
1501 | special_sym { L1 $ mkUnqual varName (unLoc $1) }
1504 -- See comments with special_id
1505 special_sym :: { Located UserFS }
1506 special_sym : '!' { L1 FSLIT("!") }
1507 | '.' { L1 FSLIT(".") }
1508 | '*' { L1 FSLIT("*") }
1510 -----------------------------------------------------------------------------
1511 -- Data constructors
1513 qconid :: { Located RdrName } -- Qualified or unqualified
1515 | QCONID { L1 $ mkQual dataName (getQCONID $1) }
1517 conid :: { Located RdrName }
1518 : CONID { L1 $ mkUnqual dataName (getCONID $1) }
1520 qconsym :: { Located RdrName } -- Qualified or unqualified
1522 | QCONSYM { L1 $ mkQual dataName (getQCONSYM $1) }
1524 consym :: { Located RdrName }
1525 : CONSYM { L1 $ mkUnqual dataName (getCONSYM $1) }
1527 -- ':' means only list cons
1528 | ':' { L1 $ consDataCon_RDR }
1531 -----------------------------------------------------------------------------
1534 literal :: { Located HsLit }
1535 : CHAR { L1 $ HsChar $ getCHAR $1 }
1536 | STRING { L1 $ HsString $ getSTRING $1 }
1537 | PRIMINTEGER { L1 $ HsIntPrim $ getPRIMINTEGER $1 }
1538 | PRIMCHAR { L1 $ HsCharPrim $ getPRIMCHAR $1 }
1539 | PRIMSTRING { L1 $ HsStringPrim $ getPRIMSTRING $1 }
1540 | PRIMFLOAT { L1 $ HsFloatPrim $ getPRIMFLOAT $1 }
1541 | PRIMDOUBLE { L1 $ HsDoublePrim $ getPRIMDOUBLE $1 }
1543 -----------------------------------------------------------------------------
1547 : vccurly { () } -- context popped in lexer.
1548 | error {% popContext }
1550 -----------------------------------------------------------------------------
1551 -- Miscellaneous (mostly renamings)
1553 modid :: { Located Module }
1554 : CONID { L1 $ mkModuleFS (getCONID $1) }
1555 | QCONID { L1 $ let (mod,c) = getQCONID $1 in
1558 (unpackFS mod ++ '.':unpackFS c))
1562 : commas ',' { $1 + 1 }
1565 -----------------------------------------------------------------------------
1569 happyError = srcParseFail
1571 getVARID (L _ (ITvarid x)) = x
1572 getCONID (L _ (ITconid x)) = x
1573 getVARSYM (L _ (ITvarsym x)) = x
1574 getCONSYM (L _ (ITconsym x)) = x
1575 getQVARID (L _ (ITqvarid x)) = x
1576 getQCONID (L _ (ITqconid x)) = x
1577 getQVARSYM (L _ (ITqvarsym x)) = x
1578 getQCONSYM (L _ (ITqconsym x)) = x
1579 getIPDUPVARID (L _ (ITdupipvarid x)) = x
1580 getIPSPLITVARID (L _ (ITsplitipvarid x)) = x
1581 getCHAR (L _ (ITchar x)) = x
1582 getSTRING (L _ (ITstring x)) = x
1583 getINTEGER (L _ (ITinteger x)) = x
1584 getRATIONAL (L _ (ITrational x)) = x
1585 getPRIMCHAR (L _ (ITprimchar x)) = x
1586 getPRIMSTRING (L _ (ITprimstring x)) = x
1587 getPRIMINTEGER (L _ (ITprimint x)) = x
1588 getPRIMFLOAT (L _ (ITprimfloat x)) = x
1589 getPRIMDOUBLE (L _ (ITprimdouble x)) = x
1590 getTH_ID_SPLICE (L _ (ITidEscape x)) = x
1592 -- Utilities for combining source spans
1593 comb2 :: Located a -> Located b -> SrcSpan
1596 comb3 :: Located a -> Located b -> Located c -> SrcSpan
1597 comb3 a b c = combineSrcSpans (getLoc a) (combineSrcSpans (getLoc b) (getLoc c))
1599 comb4 :: Located a -> Located b -> Located c -> Located d -> SrcSpan
1600 comb4 a b c d = combineSrcSpans (getLoc a) $ combineSrcSpans (getLoc b) $
1601 combineSrcSpans (getLoc c) (getLoc d)
1603 -- strict constructor version:
1605 sL :: SrcSpan -> a -> Located a
1606 sL span a = span `seq` L span a
1608 -- Make a source location for the file. We're a bit lazy here and just
1609 -- make a point SrcSpan at line 1, column 0. Strictly speaking we should
1610 -- try to find the span of the whole file (ToDo).
1611 fileSrcSpan :: P SrcSpan
1614 let loc = mkSrcLoc (srcLocFile l) 1 0;
1615 return (mkSrcSpan loc loc)