{-
-----------------------------------------------------------------------------
-$Id: Parser.y,v 1.4 1999/06/02 16:05:56 simonmar Exp $
+$Id: Parser.y,v 1.28 2000/03/23 17:45:22 simonpj Exp $
Haskell grammar.
import ParseUtil
import RdrName
import PrelMods ( mAIN_Name )
-import OccName ( varName, dataName, tcClsName, tvName )
+import OccName ( varName, ipName, dataName, tcClsName, tvName )
import SrcLoc ( SrcLoc )
import Module
import CallConv
import Panic
import GlaExts
+import FastString ( tailFS )
#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)
'label' { ITlabel }
'dynamic' { ITdynamic }
'unsafe' { ITunsafe }
+ 'with' { ITwith }
+ 'stdcall' { ITstdcallconv }
+ 'ccall' { ITccallconv }
'_ccall_' { ITccall (False, False, False) }
'_ccall_GC_' { ITccall (False, False, True) }
'_casm_' { ITccall (False, True, False) }
'{-# INLINE' { ITinline_prag }
'{-# NOINLINE' { ITnoinline_prag }
'{-# RULES' { ITrules_prag }
+ '{-# DEPRECATED' { ITdeprecated_prag }
'#-}' { ITclose_prag }
{-
QVARSYM { ITqvarsym $$ }
QCONSYM { ITqconsym $$ }
+ IPVARID { ITipvarid $$ } -- GHC extension
+
PRAGMA { ITpragma $$ }
CHAR { ITchar $$ }
PRIMSTRING { ITprimstring $$ }
PRIMINTEGER { ITprimint $$ }
PRIMFLOAT { ITprimfloat $$ }
- PRIMDOUBLE { ITprimdouble $$ }
+ PRIMDOUBLE { ITprimdouble $$ }
CLITLIT { ITlitlit $$ }
UNKNOWN { ITunknown $$ }
-----------------------------------------------------------------------------
-- 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 maybeexports 'where' body
- { HsModule $3 Nothing $4 (fst $6) (snd $6) $1 }
- | srcloc body
- { HsModule mAIN_Name Nothing Nothing (fst $2) (snd $2) $1 }
+ : 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 }
(TyData NewType cs c ts [$5] $6
NoDataPragmas $1))) }
- | srcloc 'class' ctype where
+ | srcloc 'class' ctype fds where
{% checkDataHeader $3 `thenP` \(cs,c,ts) ->
let (binds,sigs)
= cvMonoBindsAndSigs cvClassOpSig
- (groupBindings $4)
+ (groupBindings $5)
in
returnP (RdrHsDecl (TyClD
- (mkClassDecl cs c ts sigs binds
+ (mkClassDecl cs c ts $4 sigs binds
NoClassPragmas $1))) }
| srcloc 'instance' inst_type where
| srcloc 'foreign' 'import' callconv ext_name
unsafe_flag varid_no_unsafe '::' sigtype
- { RdrHsDecl (ForD (ForeignDecl $7 (FoImport $6) $9 $5 $4 $1)) }
+ { RdrHsDecl (ForD (ForeignDecl $7 (FoImport $6) $9 (mkExtName $5 $7) $4 $1)) }
| srcloc 'foreign' 'export' callconv ext_name varid '::' sigtype
- { RdrHsDecl (ForD (ForeignDecl $6 FoExport $8 $5 $4 $1)) }
+ { RdrHsDecl (ForD (ForeignDecl $6 FoExport $8 (mkExtName $5 $6) $4 $1)) }
| srcloc 'foreign' 'label' ext_name varid '::' sigtype
- { RdrHsDecl (ForD (ForeignDecl $5 FoLabel $7 $4
+ { RdrHsDecl (ForD (ForeignDecl $5 FoLabel $7 (mkExtName $4 $5)
defaultCallConv $1)) }
| decl { $1 }
| {- empty -} { [] }
decl :: { RdrBinding }
- : signdecl { $1 }
- | fixdecl { $1 }
- | valdef { RdrValBinding $1 }
- | '{-# INLINE' srcloc qvar '#-}' { RdrSig (InlineSig $3 $2) }
- | '{-# NOINLINE' srcloc qvar '#-}' { RdrSig (NoInlineSig $3 $2) }
+ : fixdecl { $1 }
+ | valdef { $1 }
+ | '{-# INLINE' srcloc opt_phase qvar '#-}' { RdrSig (InlineSig $4 $3 $2) }
+ | '{-# NOINLINE' srcloc opt_phase qvar '#-}' { RdrSig (NoInlineSig $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) }
| '{-# RULES' rules '#-}' { $2 }
+ | '{-# DEPRECATED' deprecations '#-}' { $2 }
+
+opt_phase :: { Maybe Int }
+ : INTEGER { Just (fromInteger $1) }
+ | {- empty -} { Nothing }
sigtypes :: { [RdrNameHsType] }
: sigtype { [ $1 ] }
(Fixity $3 $2) $1))
| n <- $4 ] }
-signdecl :: { RdrBinding }
- : vars srcloc '::' sigtype { foldr1 RdrAndBindings
- [ RdrSig (Sig n $4 $2) | n <- $1 ] }
-
sigtype :: { RdrNameHsType }
- : ctype { case $1 of
- HsForAllTy _ _ _ -> $1
- other -> HsForAllTy Nothing [] $1 }
+ : ctype { mkHsForAllTy Nothing [] $1 }
-{-
- 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:
-
- { (+) :: ... } only var
- { (+) x y = ... } could (incorrectly) be qvar
-
- We re-use expressions for patterns, so a qvar would be allowed in patterns
- instead of a var only (which would be correct). But deciding what the + is,
- would require more lookahead. So let's check for ourselves...
--}
-
-vars :: { [RdrName] }
- : vars ',' var { $3 : $1 }
- | qvar { [ $1 ] }
+sig_vars :: { [RdrName] }
+ : sig_vars ',' var { $3 : $1 }
+ | var { [ $1 ] }
-----------------------------------------------------------------------------
-- Transformation Rules
rule_var_list :: { [RdrNameRuleBndr] }
: rule_var { [$1] }
- | rule_var ',' rule_var_list { $1 : $3 }
+ | rule_var rule_var_list { $1 : $2 }
rule_var :: { RdrNameRuleBndr }
: varid { RuleBndr $1 }
- | varid '::' ctype { RuleBndrSig $1 $3 }
+ | '(' 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 exportlist STRING
+ { foldr1 RdrAndBindings [ RdrSig (DeprecSig (Deprecation n $3) $1) | n <- $2 ] }
-----------------------------------------------------------------------------
-- Foreign import/export
callconv :: { Int }
- : VARID {% checkCallConv $1 }
+ : 'stdcall' { stdCallConv }
+ | 'ccall' { cCallConv }
| {- empty -} { defaultCallConv }
unsafe_flag :: { Bool }
: 'unsafe' { True }
| {- empty -} { False }
-ext_name :: { ExtName }
- : 'dynamic' { Dynamic }
- | STRING { ExtName $1 Nothing }
- | STRING STRING { ExtName $2 (Just $1) }
+ext_name :: { Maybe ExtName }
+ : 'dynamic' { Just Dynamic }
+ | STRING { Just (ExtName $1 Nothing) }
+ | STRING STRING { Just (ExtName $2 (Just $1)) }
+ | {- empty -} { Nothing }
-----------------------------------------------------------------------------
-- Types
-{- ToDo: forall stuff -}
+-- 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 }
: btype '->' type { MonoFunTy $1 $3 }
+ | ipvar '::' type { MonoIParamTy $1 $3 }
| btype { $1 }
btype :: { RdrNameHsType }
inst_type :: { RdrNameHsType }
: ctype {% checkInstType $1 }
-ctype :: { RdrNameHsType }
- : 'forall' tyvars '.' btype '=>' type
- {% checkContext $4 `thenP` \c ->
- returnP (HsForAllTy (Just $2) c $6) }
- | 'forall' tyvars '.' type { HsForAllTy (Just $2) [] $4 }
- | btype '=>' type {% checkContext $1 `thenP` \c ->
- returnP (HsForAllTy Nothing c $3) }
- | type { $1 }
-
types0 :: { [RdrNameHsType] }
: types { $1 }
| {- empty -} { [] }
: 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
: constrs '|' constr { $3 : $1 }
| constr { [$1] }
-{- ToDo: existential stuff -}
-
constr :: { RdrNameConDecl }
- : srcloc scontype
- { ConDecl (fst $2) [] [] (VanillaCon (snd $2)) $1 }
- | srcloc sbtype conop sbtype
- { ConDecl $3 [] [] (InfixCon $2 $4) $1 }
- | srcloc con '{' fielddecls '}'
- { ConDecl $2 [] [] (RecCon (reverse $4)) $1 }
+ : 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) }
+ : scontype { (fst $1, VanillaCon (snd $1)) }
+ | sbtype conop sbtype { ($2, InfixCon $1 $3) }
+ | con '{' fielddecls '}' { ($1, RecCon (reverse $3)) }
newconstr :: { RdrNameConDecl }
- : srcloc conid atype { ConDecl $2 [] [] (NewCon $3 Nothing) $1 }
+ : srcloc conid atype { mkConDecl $2 [] [] (NewCon $3 Nothing) $1 }
| srcloc conid '{' var '::' type '}'
- { ConDecl $2 [] [] (NewCon $6 (Just $4)) $1 }
+ { mkConDecl $2 [] [] (NewCon $6 (Just $4)) $1 }
scontype :: { (RdrName, [RdrNameBangType]) }
: btype {% splitForConApp $1 [] }
| fielddecl { [$1] }
fielddecl :: { ([RdrName],RdrNameBangType) }
- : vars '::' stype { (reverse $1, $3) }
+ : sig_vars '::' stype { (reverse $1, $3) }
stype :: { RdrNameBangType }
- : type { Unbanged $1 }
+ : ctype { Unbanged $1 }
| '!' atype { Banged $2 }
deriving :: { Maybe [RdrName] }
-----------------------------------------------------------------------------
-- Value definitions
-valdef :: { RdrNameMonoBinds }
- : infixexp {-ToDo: opt_sig-} srcloc rhs
- {% checkValDef $1 Nothing $3 $2 }
+{- 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)
| gdrh { [$1] }
gdrh :: { RdrNameGRHS }
- : '|' srcloc quals '=' exp { GRHS (reverse
- (ExprStmt $5 $2 : $3)) $2 }
+ : '|' srcloc quals '=' exp { GRHS (reverse (ExprStmt $5 $2 : $3)) $2 }
-----------------------------------------------------------------------------
-- Expressions
exp :: { RdrNameHsExpr }
: infixexp '::' sigtype { ExprWithTySig $1 $3 }
+ | infixexp 'with' dbinding { HsWith $1 $3 }
| infixexp { $1 }
infixexp :: { RdrNameHsExpr }
| '-' fexp { NegApp $2 (error "NegApp") }
| srcloc 'do' stmtlist { HsDo DoStmt $3 $1 }
- | '_ccall_' ccallid aexps0 { CCall $2 $3 False False cbot }
- | '_ccall_GC_' ccallid aexps0 { CCall $2 $3 True False cbot }
- | '_casm_' CLITLIT aexps0 { CCall $2 $3 False True cbot }
- | '_casm_GC_' CLITLIT aexps0 { CCall $2 $3 True True cbot }
+ | '_ccall_' ccallid aexps0 { HsCCall $2 $3 False False cbot }
+ | '_ccall_GC_' ccallid aexps0 { HsCCall $2 $3 True False cbot }
+ | '_casm_' CLITLIT aexps0 { HsCCall $2 $3 False True cbot }
+ | '_casm_GC_' CLITLIT aexps0 { HsCCall $2 $3 True True cbot }
| '_scc_' STRING exp { if opt_SccProfilingOn
then HsSCC $2 $3
- else $3 }
+ else HsPar $3 }
| fexp { $1 }
aexp1 :: { RdrNameHsExpr }
: qvar { HsVar $1 }
+ | ipvar { HsIPVar $1 }
| gcon { HsVar $1 }
| literal { HsLit $1 }
| '(' exp ')' { HsPar $2 }
: '{' alts '}' { reverse $2 }
| layout_on alts close { reverse $2 }
+alts :: { [RdrNameMatch] }
+ : alts1 { $1 }
+ | ';' alts { $2 }
-alts :: { [RdrNameMatch] }
- : alts ';' alt { $3 : $1 }
- | alts ';' { $1 }
+alts1 :: { [RdrNameMatch] }
+ : alts1 ';' alt { $3 : $1 }
+ | alts1 ';' { $1 }
| alt { [$1] }
- | {- empty -} { [] }
alt :: { RdrNameMatch }
: infixexp opt_sig ralt wherebinds
opt_sig :: { Maybe RdrNameHsType }
: {- empty -} { Nothing }
- | '::' type { Just $2 }
+ | '::' sigtype { Just $2 }
opt_asig :: { Maybe RdrNameHsType }
: {- empty -} { Nothing }
-- Statement sequences
stmtlist :: { [RdrNameStmt] }
- : '{' stmts '}' { reverse $2 }
- | layout_on stmts close { reverse $2 }
+ : '{' stmts '}' { reverse $2 }
+ | layout_on_for_do stmts close { reverse $2 }
+
+-- Stmt list should really end in an expression, but it's not
+-- convenient to enforce this here, so we throw out erroneous
+-- statement sequences in the renamer instead.
stmts :: { [RdrNameStmt] }
- : stmts ';' stmt { $3 : $1 }
- | stmts ';' { $1 }
+ : ';' stmts1 { $2 }
+ | stmts1 { $1 }
+
+stmts1 :: { [RdrNameStmt] }
+ : stmts1 ';' stmt { $3 : $1 }
+ | stmts1 ';' { $1 }
| stmt { [$1] }
- | {- empty -} { [] }
stmt :: { RdrNameStmt }
: srcloc infixexp '<-' exp {% checkPattern $2 `thenP` \p ->
: 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.
gcon :: { RdrName }
qvar :: { RdrName }
: qvarid { $1 }
- | '(' qvarsym ')' { $2 }
+ | '(' 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 { (mkSrcUnqual ipName (tailFS $1)) }
con :: { RdrName }
: conid { $1 }
| 'label' { label_var_RDR }
| 'dynamic' { dynamic_var_RDR }
| 'unsafe' { unsafe_var_RDR }
+ | 'stdcall' { stdcall_var_RDR }
+ | 'ccall' { ccall_var_RDR }
varid_no_unsafe :: { RdrName }
: VARID { mkSrcUnqual varName $1 }
| 'export' { export_var_RDR }
| 'label' { label_var_RDR }
| 'dynamic' { dynamic_var_RDR }
+ | 'stdcall' { stdcall_var_RDR }
+ | 'ccall' { ccall_var_RDR }
-----------------------------------------------------------------------------
-- ConIds
: vccurly { () } -- context popped in lexer.
| error {% popContext }
-layout_on :: { () } : {% layoutOn }
+layout_on :: { () } : {% layoutOn True{-strict-} }
+layout_on_for_do :: { () } : {% layoutOn False }
-----------------------------------------------------------------------------
-- Miscellaneous (mostly renamings)
| 'as' { as_tyvar_RDR }
| 'qualified' { qualified_tyvar_RDR }
| 'hiding' { hiding_tyvar_RDR }
- | 'export' { export_var_RDR }
- | 'label' { label_var_RDR }
- | 'dynamic' { dynamic_var_RDR }
- | 'unsafe' { unsafe_var_RDR }
+ | 'export' { export_tyvar_RDR }
+ | 'label' { label_tyvar_RDR }
+ | 'dynamic' { dynamic_tyvar_RDR }
+ | 'unsafe' { unsafe_tyvar_RDR }
+ | 'stdcall' { stdcall_tyvar_RDR }
+ | 'ccall' { ccall_tyvar_RDR }
-- NOTE: no 'forall'
-----------------------------------------------------------------------------
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