{- ----------------------------------------------------------------------------- $Id: Parser.y,v 1.75 2001/10/22 09:37:24 simonpj Exp $ Haskell grammar. Author(s): Simon Marlow, Sven Panne 1997, 1998, 1999 ----------------------------------------------------------------------------- -} { module Parser ( parseModule, parseStmt, parseIdentifier ) where import HsSyn import HsTypes ( mkHsTupCon ) import RdrHsSyn import Lex import ParseUtil import RdrName import PrelNames ( mAIN_Name, unitTyCon_RDR, funTyCon_RDR, listTyCon_RDR, tupleTyCon_RDR, unitCon_RDR, nilCon_RDR, tupleCon_RDR ) import ForeignCall ( Safety(..), CExportSpec(..), CCallSpec(..), CCallConv(..), CCallTarget(..), defaultCCallConv, DNCallSpec(..) ) import OccName ( UserFS, varName, tcName, dataName, tcClsName, tvName ) import SrcLoc ( SrcLoc ) import Module import CmdLineOpts ( opt_SccProfilingOn ) import BasicTypes ( Boxity(..), Fixity(..), FixityDirection(..), NewOrData(..), StrictnessMark(..), Activation(..) ) import Panic import GlaExts import CStrings ( CLabelString ) import FastString import Maybes ( orElse ) import Outputable #include "HsVersions.h" } {- ----------------------------------------------------------------------------- Conflicts: 14 shift/reduce (note: it's currently 21 -- JRL, 31/1/2000) 8 for abiguity in 'if x then y else z + 1' (shift parses as 'if x then y else (z + 1)', as per longest-parse rule) 1 for ambiguity in 'if x then y else z :: T' (shift parses as 'if x then y else (z :: T)', as per longest-parse rule) 3 for ambiguity in 'case x of y :: a -> b' (don't know whether to reduce 'a' as a btype or shift the '->'. conclusion: bogus expression anyway, doesn't matter) 1 for ambiguity in '{-# RULES "name" forall = ... #-}' since 'forall' is a valid variable name, we don't know whether to treat a forall on the input as the beginning of a quantifier or the beginning of the rule itself. Resolving to shift means it's always treated as a quantifier, hence the above is disallowed. This saves explicitly defining a grammar for the rule lhs that doesn't include 'forall'. 1 for ambiguity in 'x @ Rec{..}'. Only sensible parse is 'x @ (Rec{..})', which is what resolving to shift gives us. ----------------------------------------------------------------------------- -} %token '_' { ITunderscore } -- Haskell keywords 'as' { ITas } 'case' { ITcase } 'class' { ITclass } 'data' { ITdata } 'default' { ITdefault } 'deriving' { ITderiving } 'do' { ITdo } 'else' { ITelse } 'hiding' { IThiding } 'if' { ITif } 'import' { ITimport } 'in' { ITin } 'infix' { ITinfix } 'infixl' { ITinfixl } 'infixr' { ITinfixr } 'instance' { ITinstance } 'let' { ITlet } 'module' { ITmodule } 'newtype' { ITnewtype } 'of' { ITof } 'qualified' { ITqualified } 'then' { ITthen } 'type' { ITtype } 'where' { ITwhere } '_scc_' { ITscc } -- ToDo: remove 'forall' { ITforall } -- GHC extension keywords 'foreign' { ITforeign } 'export' { ITexport } 'label' { ITlabel } 'dynamic' { ITdynamic } 'unsafe' { ITunsafe } 'with' { ITwith } 'stdcall' { ITstdcallconv } 'ccall' { ITccallconv } 'dotnet' { ITdotnet } '_ccall_' { ITccall (False, False, PlayRisky) } '_ccall_GC_' { ITccall (False, False, PlaySafe) } '_casm_' { ITccall (False, True, PlayRisky) } '_casm_GC_' { ITccall (False, True, PlaySafe) } '{-# SPECIALISE' { ITspecialise_prag } '{-# SOURCE' { ITsource_prag } '{-# INLINE' { ITinline_prag } '{-# NOINLINE' { ITnoinline_prag } '{-# RULES' { ITrules_prag } '{-# SCC' { ITscc_prag } '{-# DEPRECATED' { ITdeprecated_prag } '#-}' { ITclose_prag } {- '__interface' { ITinterface } -- interface keywords '__export' { IT__export } '__instimport' { ITinstimport } '__forall' { IT__forall } '__letrec' { ITletrec } '__coerce' { ITcoerce } '__depends' { ITdepends } '__inline' { ITinline } '__DEFAULT' { ITdefaultbranch } '__bot' { ITbottom } '__integer' { ITinteger_lit } '__float' { ITfloat_lit } '__rational' { ITrational_lit } '__addr' { ITaddr_lit } '__label' { ITlabel_lit } '__litlit' { ITlit_lit } '__string' { ITstring_lit } '__ccall' { ITccall $$ } '__scc' { IT__scc } '__sccC' { ITsccAllCafs } '__A' { ITarity } '__P' { ITspecialise } '__C' { ITnocaf } '__U' { ITunfold } '__S' { ITstrict $$ } '__M' { ITcprinfo $$ } -} '..' { ITdotdot } -- reserved symbols '::' { ITdcolon } '=' { ITequal } '\\' { ITlam } '|' { ITvbar } '<-' { ITlarrow } '->' { ITrarrow } '@' { ITat } '~' { ITtilde } '=>' { ITdarrow } '-' { ITminus } '!' { ITbang } '.' { ITdot } '{' { ITocurly } -- special symbols '}' { ITccurly } '{|' { ITocurlybar } '|}' { ITccurlybar } vccurly { ITvccurly } -- virtual close curly (from layout) '[' { ITobrack } ']' { ITcbrack } '(' { IToparen } ')' { ITcparen } '(#' { IToubxparen } '#)' { ITcubxparen } ';' { ITsemi } ',' { ITcomma } '`' { ITbackquote } VARID { ITvarid $$ } -- identifiers CONID { ITconid $$ } VARSYM { ITvarsym $$ } CONSYM { ITconsym $$ } QVARID { ITqvarid $$ } QCONID { ITqconid $$ } QVARSYM { ITqvarsym $$ } QCONSYM { ITqconsym $$ } IPVARID { ITipvarid $$ } -- GHC extension CHAR { ITchar $$ } STRING { ITstring $$ } INTEGER { ITinteger $$ } RATIONAL { ITrational $$ } PRIMCHAR { ITprimchar $$ } PRIMSTRING { ITprimstring $$ } PRIMINTEGER { ITprimint $$ } PRIMFLOAT { ITprimfloat $$ } PRIMDOUBLE { ITprimdouble $$ } CLITLIT { ITlitlit $$ } %monad { P } { thenP } { returnP } %lexer { lexer } { ITeof } %name parseModule module %name parseStmt maybe_stmt %name parseIdentifier identifier %tokentype { Token } %% ----------------------------------------------------------------------------- -- Module Header -- The place for module deprecation is really too restrictive, but if it -- was allowed at its natural place just before 'module', we get an ugly -- s/r conflict with the second alternative. Another solution would be the -- introduction of a new pragma DEPRECATED_MODULE, but this is not very nice, -- either, and DEPRECATED is only expected to be used by people who really -- know what they are doing. :-) module :: { RdrNameHsModule } : srcloc 'module' modid maybemoddeprec maybeexports 'where' body { HsModule $3 Nothing $5 (fst $7) (snd $7) $4 $1 } | srcloc body { HsModule mAIN_Name Nothing Nothing (fst $2) (snd $2) Nothing $1 } maybemoddeprec :: { Maybe DeprecTxt } : '{-# DEPRECATED' STRING '#-}' { Just $2 } | {- empty -} { Nothing } body :: { ([RdrNameImportDecl], [RdrNameHsDecl]) } : '{' top '}' { $2 } | layout_on top close { $2 } top :: { ([RdrNameImportDecl], [RdrNameHsDecl]) } : importdecls { (reverse $1,[]) } | importdecls ';' cvtopdecls { (reverse $1,$3) } | cvtopdecls { ([],$1) } cvtopdecls :: { [RdrNameHsDecl] } : topdecls { cvTopDecls (groupBindings $1)} ----------------------------------------------------------------------------- -- The Export List maybeexports :: { Maybe [RdrNameIE] } : '(' exportlist ')' { Just $2 } | {- empty -} { Nothing } exportlist :: { [RdrNameIE] } : exportlist ',' export { $3 : $1 } | exportlist ',' { $1 } | export { [$1] } | {- empty -} { [] } -- GHC extension: we allow things like [] and (,,,) to be exported export :: { RdrNameIE } : qvar { IEVar $1 } | gtycon { IEThingAbs $1 } | gtycon '(' '..' ')' { IEThingAll $1 } | gtycon '(' ')' { IEThingWith $1 [] } | gtycon '(' qcnames ')' { IEThingWith $1 (reverse $3) } | 'module' modid { IEModuleContents $2 } qcnames :: { [RdrName] } : qcnames ',' qcname { $3 : $1 } | qcname { [$1] } qcname :: { RdrName } : qvar { $1 } | gcon { $1 } ----------------------------------------------------------------------------- -- Import Declarations -- import decls can be *empty*, or even just a string of semicolons -- whereas topdecls must contain at least one topdecl. importdecls :: { [RdrNameImportDecl] } : importdecls ';' importdecl { $3 : $1 } | importdecls ';' { $1 } | importdecl { [ $1 ] } | {- empty -} { [] } importdecl :: { RdrNameImportDecl } : 'import' srcloc maybe_src optqualified modid maybeas maybeimpspec { ImportDecl $5 $3 $4 $6 $7 $2 } maybe_src :: { WhereFrom } : '{-# SOURCE' '#-}' { ImportByUserSource } | {- empty -} { ImportByUser } optqualified :: { Bool } : 'qualified' { True } | {- empty -} { False } maybeas :: { Maybe ModuleName } : 'as' modid { Just $2 } | {- empty -} { Nothing } maybeimpspec :: { Maybe (Bool, [RdrNameIE]) } : impspec { Just $1 } | {- empty -} { Nothing } impspec :: { (Bool, [RdrNameIE]) } : '(' exportlist ')' { (False, reverse $2) } | 'hiding' '(' exportlist ')' { (True, reverse $3) } ----------------------------------------------------------------------------- -- Fixity Declarations prec :: { Int } : {- empty -} { 9 } | INTEGER {% checkPrec $1 `thenP_` returnP (fromInteger $1) } infix :: { FixityDirection } : 'infix' { InfixN } | 'infixl' { InfixL } | 'infixr' { InfixR } ops :: { [RdrName] } : ops ',' op { $3 : $1 } | op { [$1] } ----------------------------------------------------------------------------- -- Top-Level Declarations topdecls :: { [RdrBinding] } : topdecls ';' topdecl { ($3 : $1) } | topdecls ';' { $1 } | topdecl { [$1] } topdecl :: { RdrBinding } : srcloc 'type' simpletype '=' ctype -- Note ctype, not sigtype. -- We allow an explicit for-all but we don't insert one -- in type Foo a = (b,b) -- Instead we just say b is out of scope { RdrHsDecl (TyClD (TySynonym (fst $3) (snd $3) $5 $1)) } | srcloc 'data' ctype constrs deriving {% checkDataHeader $3 `thenP` \(cs,c,ts) -> returnP (RdrHsDecl (TyClD (mkTyData DataType cs c ts (reverse $4) (length $4) $5 $1))) } | srcloc 'newtype' ctype '=' newconstr deriving {% checkDataHeader $3 `thenP` \(cs,c,ts) -> returnP (RdrHsDecl (TyClD (mkTyData NewType cs c ts [$5] 1 $6 $1))) } | srcloc 'class' ctype fds where {% checkDataHeader $3 `thenP` \(cs,c,ts) -> let (binds,sigs) = cvMonoBindsAndSigs cvClassOpSig (groupBindings $5) in returnP (RdrHsDecl (TyClD (mkClassDecl cs c ts $4 sigs (Just binds) $1))) } | srcloc 'instance' inst_type where { let (binds,sigs) = cvMonoBindsAndSigs cvInstDeclSig (groupBindings $4) in RdrHsDecl (InstD (InstDecl $3 binds sigs Nothing $1)) } | srcloc 'default' '(' types0 ')' { RdrHsDecl (DefD (DefaultDecl $4 $1)) } | 'foreign' fordecl { RdrHsDecl $2 } | '{-# DEPRECATED' deprecations '#-}' { $2 } | '{-# RULES' rules '#-}' { $2 } | decl { $1 } fordecl :: { RdrNameHsDecl } fordecl : srcloc 'label' ext_name varid '::' sigtype { ForD (ForeignImport $4 $6 (LblImport ($3 `orElse` mkExtName $4)) $1) } ----------- ccall/stdcall decls ------------ | srcloc 'import' ccallconv ext_name unsafe_flag varid_no_unsafe '::' sigtype { let call_spec = CCallSpec (StaticTarget ($4 `orElse` mkExtName $6)) $3 $5 in ForD (ForeignImport $6 $8 (CImport call_spec) $1) } | srcloc 'import' ccallconv 'dynamic' unsafe_flag varid_no_unsafe '::' sigtype { let call_spec = CCallSpec DynamicTarget $3 $5 in ForD (ForeignImport $6 $8 (CImport call_spec) $1) } | srcloc 'export' ccallconv ext_name varid '::' sigtype { ForD (ForeignExport $5 $7 (CExport (CExportStatic ($4 `orElse` mkExtName $5) $3)) $1) } | srcloc 'export' ccallconv 'dynamic' varid '::' sigtype { ForD (ForeignImport $5 $7 (CDynImport $3) $1) } ----------- .NET decls ------------ | srcloc 'import' 'dotnet' ext_name varid '::' sigtype { ForD (ForeignImport $5 $7 (DNImport (DNCallSpec ($4 `orElse` mkExtName $5))) $1) } | srcloc 'import' 'dotnet' 'type' ext_name tycon { TyClD (ForeignType $6 $5 DNType $1) } decls :: { [RdrBinding] } : decls ';' decl { $3 : $1 } | decls ';' { $1 } | decl { [$1] } | {- empty -} { [] } decl :: { RdrBinding } : fixdecl { $1 } | valdef { $1 } | '{-# INLINE' srcloc activation qvar '#-}' { RdrSig (InlineSig True $4 $3 $2) } | '{-# NOINLINE' srcloc inverse_activation qvar '#-}' { RdrSig (InlineSig False $4 $3 $2) } | '{-# SPECIALISE' srcloc qvar '::' sigtypes '#-}' { foldr1 RdrAndBindings (map (\t -> RdrSig (SpecSig $3 t $2)) $5) } | '{-# SPECIALISE' srcloc 'instance' inst_type '#-}' { RdrSig (SpecInstSig $4 $2) } wherebinds :: { RdrNameHsBinds } : where { cvBinds cvValSig (groupBindings $1) } where :: { [RdrBinding] } : 'where' decllist { $2 } | {- empty -} { [] } declbinds :: { RdrNameHsBinds } : decllist { cvBinds cvValSig (groupBindings $1) } decllist :: { [RdrBinding] } : '{' decls '}' { $2 } | layout_on decls close { $2 } fixdecl :: { RdrBinding } : srcloc infix prec ops { foldr1 RdrAndBindings [ RdrSig (FixSig (FixitySig n (Fixity $3 $2) $1)) | n <- $4 ] } ----------------------------------------------------------------------------- -- Transformation Rules rules :: { RdrBinding } : rules ';' rule { $1 `RdrAndBindings` $3 } | rules ';' { $1 } | rule { $1 } | {- empty -} { RdrNullBind } rule :: { RdrBinding } : STRING activation rule_forall infixexp '=' srcloc exp { RdrHsDecl (RuleD (HsRule $1 $2 [] $3 $4 $7 $6)) } activation :: { Activation } -- Omitted means AlwaysActive : {- empty -} { AlwaysActive } | '[' INTEGER ']' { ActiveAfter (fromInteger $2) } inverse_activation :: { Activation } -- Omitted means NeverActive : {- empty -} { NeverActive } | '[' INTEGER ']' { ActiveAfter (fromInteger $2) } rule_forall :: { [RdrNameRuleBndr] } : 'forall' rule_var_list '.' { $2 } | {- empty -} { [] } rule_var_list :: { [RdrNameRuleBndr] } : rule_var { [$1] } | rule_var rule_var_list { $1 : $2 } rule_var :: { RdrNameRuleBndr } : varid { RuleBndr $1 } | '(' varid '::' ctype ')' { RuleBndrSig $2 $4 } ----------------------------------------------------------------------------- -- Deprecations deprecations :: { RdrBinding } : deprecations ';' deprecation { $1 `RdrAndBindings` $3 } | deprecations ';' { $1 } | deprecation { $1 } | {- empty -} { RdrNullBind } -- SUP: TEMPORARY HACK, not checking for `module Foo' deprecation :: { RdrBinding } : srcloc depreclist STRING { foldr RdrAndBindings RdrNullBind [ RdrHsDecl (DeprecD (Deprecation n $3 $1)) | n <- $2 ] } ----------------------------------------------------------------------------- -- Foreign import/export ccallconv :: { CCallConv } : 'stdcall' { StdCallConv } | 'ccall' { CCallConv } | {- empty -} { defaultCCallConv } unsafe_flag :: { Safety } : 'unsafe' { PlayRisky } | {- empty -} { PlaySafe } ext_name :: { Maybe CLabelString } : STRING { Just $1 } | STRING STRING { Just $2 } -- Ignore "module name" for now | {- empty -} { Nothing } ----------------------------------------------------------------------------- -- Type signatures opt_sig :: { Maybe RdrNameHsType } : {- empty -} { Nothing } | '::' sigtype { Just $2 } opt_asig :: { Maybe RdrNameHsType } : {- empty -} { Nothing } | '::' atype { Just $2 } sigtypes :: { [RdrNameHsType] } : sigtype { [ $1 ] } | sigtypes ',' sigtype { $3 : $1 } sigtype :: { RdrNameHsType } : ctype { (mkHsForAllTy Nothing [] $1) } sig_vars :: { [RdrName] } : sig_vars ',' var { $3 : $1 } | var { [ $1 ] } ----------------------------------------------------------------------------- -- Types -- A ctype is a for-all type ctype :: { RdrNameHsType } : 'forall' tyvars '.' ctype { mkHsForAllTy (Just $2) [] $4 } | context type { mkHsForAllTy Nothing $1 $2 } -- A type of form (context => type) is an *implicit* HsForAllTy | type { $1 } type :: { RdrNameHsType } : gentype '->' type { HsFunTy $1 $3 } | ipvar '::' type { mkHsIParamTy $1 $3 } | gentype { $1 } gentype :: { RdrNameHsType } : btype { $1 } -- Generics | atype tyconop atype { HsOpTy $1 $2 $3 } btype :: { RdrNameHsType } : btype atype { (HsAppTy $1 $2) } | atype { $1 } atype :: { RdrNameHsType } : gtycon { HsTyVar $1 } | tyvar { HsTyVar $1 } | '(' type ',' types ')' { HsTupleTy (mkHsTupCon tcName Boxed ($2:$4)) ($2 : reverse $4) } | '(#' types '#)' { HsTupleTy (mkHsTupCon tcName Unboxed $2) (reverse $2) } | '[' type ']' { HsListTy $2 } | '(' ctype ')' { $2 } -- Generics | INTEGER { HsNumTy $1 } -- An inst_type is what occurs in the head of an instance decl -- e.g. (Foo a, Gaz b) => Wibble a b -- It's kept as a single type, with a MonoDictTy at the right -- hand corner, for convenience. inst_type :: { RdrNameHsType } : ctype {% checkInstType $1 } types0 :: { [RdrNameHsType] } : types { reverse $1 } | {- empty -} { [] } types :: { [RdrNameHsType] } : type { [$1] } | types ',' type { $3 : $1 } simpletype :: { (RdrName, [RdrNameHsTyVar]) } : tycon tyvars { ($1, reverse $2) } tyvars :: { [RdrNameHsTyVar] } : tyvars tyvar { UserTyVar $2 : $1 } | {- empty -} { [] } fds :: { [([RdrName], [RdrName])] } : {- empty -} { [] } | '|' fds1 { reverse $2 } fds1 :: { [([RdrName], [RdrName])] } : fds1 ',' fd { $3 : $1 } | fd { [$1] } fd :: { ([RdrName], [RdrName]) } : varids0 '->' varids0 { (reverse $1, reverse $3) } varids0 :: { [RdrName] } : {- empty -} { [] } | varids0 tyvar { $2 : $1 } ----------------------------------------------------------------------------- -- Datatype declarations newconstr :: { RdrNameConDecl } : srcloc conid atype { mkConDecl $2 [] [] (VanillaCon [unbangedType $3]) $1 } | srcloc conid '{' var '::' ctype '}' { mkConDecl $2 [] [] (RecCon [([$4], unbangedType $6)]) $1 } constrs :: { [RdrNameConDecl] } : {- empty; a GHC extension -} { [] } | '=' constrs1 { $2 } constrs1 :: { [RdrNameConDecl] } : constrs1 '|' constr { $3 : $1 } | constr { [$1] } constr :: { RdrNameConDecl } : srcloc forall context constr_stuff { mkConDecl (fst $4) $2 $3 (snd $4) $1 } | srcloc forall constr_stuff { mkConDecl (fst $3) $2 [] (snd $3) $1 } forall :: { [RdrNameHsTyVar] } : 'forall' tyvars '.' { $2 } | {- empty -} { [] } context :: { RdrNameContext } : btype '=>' {% checkContext $1 } constr_stuff :: { (RdrName, RdrNameConDetails) } : btype {% mkVanillaCon $1 [] } | btype '!' atype satypes {% mkVanillaCon $1 (BangType MarkedUserStrict $3 : $4) } | gtycon '{' fielddecls '}' {% mkRecCon $1 $3 } | sbtype conop sbtype { ($2, InfixCon $1 $3) } satypes :: { [RdrNameBangType] } : atype satypes { unbangedType $1 : $2 } | '!' atype satypes { BangType MarkedUserStrict $2 : $3 } | {- empty -} { [] } sbtype :: { RdrNameBangType } : btype { unbangedType $1 } | '!' atype { BangType MarkedUserStrict $2 } fielddecls :: { [([RdrName],RdrNameBangType)] } : fielddecl ',' fielddecls { $1 : $3 } | fielddecl { [$1] } fielddecl :: { ([RdrName],RdrNameBangType) } : sig_vars '::' stype { (reverse $1, $3) } stype :: { RdrNameBangType } : ctype { unbangedType $1 } | '!' atype { BangType MarkedUserStrict $2 } deriving :: { Maybe [RdrName] } : {- empty -} { Nothing } | 'deriving' qtycls { Just [$2] } | 'deriving' '(' ')' { Just [] } | 'deriving' '(' dclasses ')' { Just (reverse $3) } dclasses :: { [RdrName] } : dclasses ',' qtycls { $3 : $1 } | qtycls { [$1] } ----------------------------------------------------------------------------- -- Value definitions {- There's an awkward overlap with a type signature. Consider f :: Int -> Int = ...rhs... Then we can't tell whether it's a type signature or a value definition with a result signature until we see the '='. So we have to inline enough to postpone reductions until we know. -} {- ATTENTION: Dirty Hackery Ahead! If the second alternative of vars is var instead of qvar, we get another shift/reduce-conflict. Consider the following programs: { (^^) :: Int->Int ; } Type signature; only var allowed { (^^) :: Int->Int = ... ; } Value defn with result signature; qvar allowed (because of instance decls) We can't tell whether to reduce var to qvar until after we've read the signatures. -} valdef :: { RdrBinding } : infixexp srcloc opt_sig rhs {% (checkValDef $1 $3 $4 $2) } | infixexp srcloc '::' sigtype {% (checkValSig $1 $4 $2) } | var ',' sig_vars srcloc '::' sigtype { foldr1 RdrAndBindings [ RdrSig (Sig n $6 $4) | n <- $1:$3 ] } rhs :: { RdrNameGRHSs } : '=' srcloc exp wherebinds { (GRHSs (unguardedRHS $3 $2) $4 placeHolderType)} | gdrhs wherebinds { GRHSs (reverse $1) $2 placeHolderType } gdrhs :: { [RdrNameGRHS] } : gdrhs gdrh { $2 : $1 } | gdrh { [$1] } gdrh :: { RdrNameGRHS } : '|' srcloc quals '=' exp { GRHS (reverse (ResultStmt $5 $2 : $3)) $2 } ----------------------------------------------------------------------------- -- Expressions exp :: { RdrNameHsExpr } : infixexp '::' sigtype { (ExprWithTySig $1 $3) } | infixexp 'with' dbinding { HsWith $1 $3 } | infixexp { $1 } infixexp :: { RdrNameHsExpr } : exp10 { $1 } | infixexp qop exp10 { (OpApp $1 (HsVar $2) (panic "fixity") $3 )} exp10 :: { RdrNameHsExpr } : '\\' srcloc aexp aexps opt_asig '->' srcloc exp {% checkPatterns $2 ($3 : reverse $4) `thenP` \ ps -> returnP (HsLam (Match [] ps $5 (GRHSs (unguardedRHS $8 $7) EmptyBinds placeHolderType))) } | 'let' declbinds 'in' exp { HsLet $2 $4 } | 'if' srcloc exp 'then' exp 'else' exp { HsIf $3 $5 $7 $2 } | 'case' srcloc exp 'of' altslist { HsCase $3 $5 $2 } | '-' fexp { mkHsNegApp $2 } | srcloc 'do' stmtlist {% checkDo $3 `thenP` \ stmts -> returnP (HsDo DoExpr stmts $1) } | '_ccall_' ccallid aexps0 { HsCCall $2 $3 PlayRisky False placeHolderType } | '_ccall_GC_' ccallid aexps0 { HsCCall $2 $3 PlaySafe False placeHolderType } | '_casm_' CLITLIT aexps0 { HsCCall $2 $3 PlayRisky True placeHolderType } | '_casm_GC_' CLITLIT aexps0 { HsCCall $2 $3 PlaySafe True placeHolderType } | scc_annot exp { if opt_SccProfilingOn then HsSCC $1 $2 else HsPar $2 } | fexp { $1 } scc_annot :: { FAST_STRING } : '_scc_' STRING { $2 } | '{-# SCC' STRING '#-}' { $2 } ccallid :: { FAST_STRING } : VARID { $1 } | CONID { $1 } fexp :: { RdrNameHsExpr } : fexp aexp { (HsApp $1 $2) } | aexp { $1 } aexps0 :: { [RdrNameHsExpr] } : aexps { (reverse $1) } aexps :: { [RdrNameHsExpr] } : aexps aexp { $2 : $1 } | {- empty -} { [] } aexp :: { RdrNameHsExpr } : var_or_con '{|' gentype '|}' { (HsApp $1 (HsType $3)) } | aexp '{' fbinds '}' {% (mkRecConstrOrUpdate $1 (reverse $3)) } | aexp1 { $1 } var_or_con :: { RdrNameHsExpr } : qvar { HsVar $1 } | gcon { HsVar $1 } aexp1 :: { RdrNameHsExpr } : ipvar { HsIPVar $1 } | var_or_con { $1 } | literal { HsLit $1 } | INTEGER { HsOverLit (mkHsIntegral $1) } | RATIONAL { HsOverLit (mkHsFractional $1) } | '(' exp ')' { HsPar $2 } | '(' exp ',' texps ')' { ExplicitTuple ($2 : reverse $4) Boxed} | '(#' texps '#)' { ExplicitTuple (reverse $2) Unboxed } | '[' list ']' { $2 } | '(' infixexp qop ')' { (SectionL $2 (HsVar $3)) } | '(' qopm infixexp ')' { (SectionR $2 $3) } | qvar '@' aexp { EAsPat $1 $3 } | '_' { EWildPat } | '~' aexp1 { ELazyPat $2 } texps :: { [RdrNameHsExpr] } : texps ',' exp { $3 : $1 } | exp { [$1] } ----------------------------------------------------------------------------- -- List expressions -- The rules below are little bit contorted to keep lexps left-recursive while -- avoiding another shift/reduce-conflict. list :: { RdrNameHsExpr } : exp { ExplicitList placeHolderType [$1] } | lexps { ExplicitList placeHolderType (reverse $1) } | exp '..' { ArithSeqIn (From $1) } | exp ',' exp '..' { ArithSeqIn (FromThen $1 $3) } | exp '..' exp { ArithSeqIn (FromTo $1 $3) } | exp ',' exp '..' exp { ArithSeqIn (FromThenTo $1 $3 $5) } | exp srcloc pquals {% let { body [qs] = qs; body qss = [ParStmt (map reverse qss)] } in returnP ( HsDo ListComp (reverse (ResultStmt $1 $2 : body $3)) $2 ) } lexps :: { [RdrNameHsExpr] } : lexps ',' exp { $3 : $1 } | exp ',' exp { [$3,$1] } ----------------------------------------------------------------------------- -- List Comprehensions pquals :: { [[RdrNameStmt]] } : pquals '|' quals { $3 : $1 } | '|' quals { [$2] } quals :: { [RdrNameStmt] } : quals ',' stmt { $3 : $1 } | stmt { [$1] } ----------------------------------------------------------------------------- -- Case alternatives altslist :: { [RdrNameMatch] } : '{' alts '}' { reverse $2 } | layout_on alts close { reverse $2 } alts :: { [RdrNameMatch] } : alts1 { $1 } | ';' alts { $2 } alts1 :: { [RdrNameMatch] } : alts1 ';' alt { $3 : $1 } | alts1 ';' { $1 } | alt { [$1] } alt :: { RdrNameMatch } : srcloc infixexp opt_sig ralt wherebinds {% (checkPattern $1 $2 `thenP` \p -> returnP (Match [] [p] $3 (GRHSs $4 $5 placeHolderType)) )} ralt :: { [RdrNameGRHS] } : '->' srcloc exp { [GRHS [ResultStmt $3 $2] $2] } | gdpats { (reverse $1) } gdpats :: { [RdrNameGRHS] } : gdpats gdpat { $2 : $1 } | gdpat { [$1] } gdpat :: { RdrNameGRHS } : srcloc '|' quals '->' exp { GRHS (reverse (ResultStmt $5 $1:$3)) $1} ----------------------------------------------------------------------------- -- Statement sequences stmtlist :: { [RdrNameStmt] } : '{' stmts '}' { $2 } | layout_on_for_do stmts close { $2 } -- do { ;; s ; s ; ; s ;; } -- The last Stmt should be a ResultStmt, but that's hard to enforce -- here, because we need too much lookahead if we see do { e ; } -- So we use ExprStmts throughout, and switch the last one over -- in ParseUtils.checkDo instead stmts :: { [RdrNameStmt] } : stmt stmts_help { $1 : $2 } | ';' stmts { $2 } | {- empty -} { [] } stmts_help :: { [RdrNameStmt] } : ';' stmts { $2 } | {- empty -} { [] } -- For typing stmts at the GHCi prompt, where -- the input may consist of just comments. maybe_stmt :: { Maybe RdrNameStmt } : stmt { Just $1 } | {- nothing -} { Nothing } stmt :: { RdrNameStmt } : srcloc infixexp '<-' exp {% checkPattern $1 $2 `thenP` \p -> returnP (BindStmt p $4 $1) } | srcloc exp { ExprStmt $2 placeHolderType $1 } | srcloc 'let' declbinds { LetStmt $3 } ----------------------------------------------------------------------------- -- Record Field Update/Construction fbinds :: { RdrNameHsRecordBinds } : fbinds ',' fbind { $3 : $1 } | fbinds ',' { $1 } | fbind { [$1] } | {- empty -} { [] } fbind :: { (RdrName, RdrNameHsExpr, Bool) } : qvar '=' exp { ($1,$3,False) } ----------------------------------------------------------------------------- -- Implicit Parameter Bindings dbinding :: { [(RdrName, RdrNameHsExpr)] } : '{' dbinds '}' { $2 } | layout_on dbinds close { $2 } dbinds :: { [(RdrName, RdrNameHsExpr)] } : dbinds ';' dbind { $3 : $1 } | dbinds ';' { $1 } | dbind { [$1] } | {- empty -} { [] } dbind :: { (RdrName, RdrNameHsExpr) } dbind : ipvar '=' exp { ($1, $3) } ----------------------------------------------------------------------------- -- Variables, Constructors and Operators. identifier :: { RdrName } : qvar { $1 } | gcon { $1 } | qop { $1 } depreclist :: { [RdrName] } depreclist : deprec_var { [$1] } | deprec_var ',' depreclist { $1 : $3 } deprec_var :: { RdrName } deprec_var : var { $1 } | tycon { $1 } gtycon :: { RdrName } : qtycon { $1 } | '(' qtyconop ')' { $2 } | '(' ')' { unitTyCon_RDR } | '(' '->' ')' { funTyCon_RDR } | '[' ']' { listTyCon_RDR } | '(' commas ')' { tupleTyCon_RDR $2 } gcon :: { RdrName } : '(' ')' { unitCon_RDR } | '[' ']' { nilCon_RDR } | '(' commas ')' { tupleCon_RDR $2 } | qcon { $1 } var :: { RdrName } : varid { $1 } | '(' varsym ')' { $2 } qvar :: { RdrName } : qvarid { $1 } | '(' varsym ')' { $2 } | '(' qvarsym1 ')' { $2 } -- We've inlined qvarsym here so that the decision about -- whether it's a qvar or a var can be postponed until -- *after* we see the close paren. ipvar :: { RdrName } : IPVARID { (mkUnqual varName (tailFS $1)) } qcon :: { RdrName } : qconid { $1 } | '(' qconsym ')' { $2 } varop :: { RdrName } : varsym { $1 } | '`' varid '`' { $2 } qvarop :: { RdrName } : qvarsym { $1 } | '`' qvarid '`' { $2 } qvaropm :: { RdrName } : qvarsym_no_minus { $1 } | '`' qvarid '`' { $2 } conop :: { RdrName } : consym { $1 } | '`' conid '`' { $2 } qconop :: { RdrName } : qconsym { $1 } | '`' qconid '`' { $2 } ----------------------------------------------------------------------------- -- Any operator op :: { RdrName } -- used in infix decls : varop { $1 } | conop { $1 } qop :: { RdrName {-HsExpr-} } -- used in sections : qvarop { $1 } | qconop { $1 } qopm :: { RdrNameHsExpr } -- used in sections : qvaropm { HsVar $1 } | qconop { HsVar $1 } ----------------------------------------------------------------------------- -- VarIds qvarid :: { RdrName } : varid { $1 } | QVARID { mkQual varName $1 } varid :: { RdrName } : varid_no_unsafe { $1 } | 'unsafe' { mkUnqual varName SLIT("unsafe") } varid_no_unsafe :: { RdrName } : VARID { mkUnqual varName $1 } | special_id { mkUnqual varName $1 } | 'forall' { mkUnqual varName SLIT("forall") } tyvar :: { RdrName } : VARID { mkUnqual tvName $1 } | special_id { mkUnqual tvName $1 } | 'unsafe' { mkUnqual tvName SLIT("unsafe") } -- These special_ids are treated as keywords in various places, -- but as ordinary ids elsewhere. A special_id collects all thsee -- except 'unsafe' and 'forall' whose treatment differs depending on context special_id :: { UserFS } special_id : 'as' { SLIT("as") } | 'qualified' { SLIT("qualified") } | 'hiding' { SLIT("hiding") } | 'export' { SLIT("export") } | 'label' { SLIT("label") } | 'dynamic' { SLIT("dynamic") } | 'stdcall' { SLIT("stdcall") } | 'ccall' { SLIT("ccall") } ----------------------------------------------------------------------------- -- ConIds qconid :: { RdrName } : conid { $1 } | QCONID { mkQual dataName $1 } conid :: { RdrName } : CONID { mkUnqual dataName $1 } ----------------------------------------------------------------------------- -- ConSyms qconsym :: { RdrName } : consym { $1 } | QCONSYM { mkQual dataName $1 } consym :: { RdrName } : CONSYM { mkUnqual dataName $1 } ----------------------------------------------------------------------------- -- VarSyms qvarsym :: { RdrName } : varsym { $1 } | qvarsym1 { $1 } qvarsym_no_minus :: { RdrName } : varsym_no_minus { $1 } | qvarsym1 { $1 } qvarsym1 :: { RdrName } qvarsym1 : QVARSYM { mkQual varName $1 } varsym :: { RdrName } : varsym_no_minus { $1 } | '-' { mkUnqual varName SLIT("-") } varsym_no_minus :: { RdrName } -- varsym not including '-' : VARSYM { mkUnqual varName $1 } | special_sym { mkUnqual varName $1 } -- See comments with special_id special_sym :: { UserFS } special_sym : '!' { SLIT("!") } | '.' { SLIT(".") } ----------------------------------------------------------------------------- -- Literals literal :: { HsLit } : CHAR { HsChar $1 } | STRING { HsString $1 } | PRIMINTEGER { HsIntPrim $1 } | PRIMCHAR { HsCharPrim $1 } | PRIMSTRING { HsStringPrim $1 } | PRIMFLOAT { HsFloatPrim $1 } | PRIMDOUBLE { HsDoublePrim $1 } | CLITLIT { HsLitLit $1 placeHolderType } srcloc :: { SrcLoc } : {% getSrcLocP } ----------------------------------------------------------------------------- -- Layout close :: { () } : vccurly { () } -- context popped in lexer. | error {% popContext } layout_on :: { () } : {% layoutOn True{-strict-} } layout_on_for_do :: { () } : {% layoutOn False } ----------------------------------------------------------------------------- -- Miscellaneous (mostly renamings) modid :: { ModuleName } : CONID { mkModuleNameFS $1 } | QCONID { mkModuleNameFS (mkFastString (unpackFS (fst $1) ++ '.':unpackFS (snd $1))) } tycon :: { RdrName } : CONID { mkUnqual tcClsName $1 } tyconop :: { RdrName } : CONSYM { mkUnqual tcClsName $1 } qtycon :: { RdrName } : tycon { $1 } | QCONID { mkQual tcClsName $1 } qtyconop :: { RdrName } : tyconop { $1 } | QCONSYM { mkQual tcClsName $1 } qtycls :: { RdrName } : qtycon { $1 } commas :: { Int } : commas ',' { $1 + 1 } | ',' { 2 } ----------------------------------------------------------------------------- { happyError :: P a happyError buf PState{ loc = loc } = PFailed (srcParseErr buf loc) }