X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsDecls.lhs;h=2128ad399f4659c9eeb88d9c3a4cf59cf4c2c4ee;hp=f2bf9d3904e6388716397e2ba555b9bb597ff038;hb=9da4639011348fb6c318e3cba4b08622f811d9c4;hpb=72264dbcb05c7045dff28aa88b55634fa6c1ddf0 diff --git a/compiler/hsSyn/HsDecls.lhs b/compiler/hsSyn/HsDecls.lhs index f2bf9d3..2128ad3 100644 --- a/compiler/hsSyn/HsDecls.lhs +++ b/compiler/hsSyn/HsDecls.lhs @@ -18,7 +18,8 @@ module HsDecls ( DeprecDecl(..), LDeprecDecl, HsGroup(..), emptyRdrGroup, emptyRnGroup, appendGroups, tcdName, tyClDeclNames, tyClDeclTyVars, - isClassDecl, isTFunDecl, isSynDecl, isTEqnDecl, isDataDecl, + isClassDecl, isTFunDecl, isSynDecl, isDataDecl, isKindSigDecl, + isIdxTyDecl, countTyClDecls, conDetailsTys, instDeclATs, @@ -38,20 +39,19 @@ import HsPat ( HsConDetails(..), hsConArgs ) import HsImpExp ( pprHsVar ) import HsTypes import NameSet ( NameSet ) -import HscTypes ( DeprecTxt ) import CoreSyn ( RuleName ) -import Kind ( Kind, pprKind ) -import BasicTypes ( Activation(..) ) +import {- Kind parts of -} Type ( Kind, pprKind ) +import BasicTypes ( Activation(..), DeprecTxt ) import ForeignCall ( CCallTarget(..), DNCallSpec, CCallConv, Safety, CExportSpec(..), CLabelString ) -- others: -import FunDeps ( pprFundeps ) -import Class ( FunDep ) +import Class ( FunDep, pprFundeps ) import Outputable import Util ( count ) import SrcLoc ( Located(..), unLoc, noLoc ) import FastString +import Maybe ( isJust ) \end{code} @@ -329,6 +329,31 @@ Interface file code: -- for a module. That's why (despite the misnomer) IfaceSig and ForeignType -- are both in TyClDecl +-- Representation of indexed types +-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +-- Kind signatures of indexed types come in two flavours: +-- +-- * kind signatures for type functions: variant `TyFunction' and +-- +-- * kind signatures for indexed data types and newtypes : variant `TyData' +-- iff a kind is present in `tcdKindSig' and there are no constructors in +-- `tcdCons'. +-- +-- Indexed types are represented by 'TyData' and 'TySynonym' using the field +-- 'tcdTyPats::Maybe [LHsType name]', with the following meaning: +-- +-- * If it is 'Nothing', we have a *vanilla* data type declaration or type +-- synonym declaration and 'tcdVars' contains the type parameters of the +-- type constructor. +-- +-- * If it is 'Just pats', we have the definition of an indexed type Then, +-- 'pats' are type patterns for the type-indexes of the type constructor +-- and 'tcdVars' are the variables in those patterns. Hence, the arity of +-- the indexed type (ie, the number of indexes) is 'length tcdTyPats' and +-- *not* 'length tcdVars'. +-- +-- In both cases, 'tcdVars' collects all variables we need to quantify over. + type LTyClDecl name = Located (TyClDecl name) data TyClDecl name @@ -344,7 +369,9 @@ data TyClDecl name tcdTyVars :: [LHsTyVarBndr name], -- Type variables tcdTyPats :: Maybe [LHsType name], -- Type patterns tcdKindSig:: Maybe Kind, -- Optional kind sig; - -- (only for the 'where' form) + -- (only for the + -- 'where' form and + -- indexed type sigs) tcdCons :: [LConDecl name], -- Data constructors -- For data T a = T1 | T2 a the LConDecls all have ResTyH98 @@ -362,12 +389,14 @@ data TyClDecl name | TyFunction {tcdLName :: Located name, -- type constructor tcdTyVars :: [LHsTyVarBndr name], -- type variables tcdIso :: Bool, -- injective type? - tcdKindSig:: Maybe Kind -- result kind + tcdKind :: Kind -- result kind } | TySynonym { tcdLName :: Located name, -- type constructor tcdTyVars :: [LHsTyVarBndr name], -- type variables tcdTyPats :: Maybe [LHsType name], -- Type patterns + -- 'Nothing' => vanilla + -- type synonym tcdSynRhs :: LHsType name -- synonym expansion } @@ -378,7 +407,8 @@ data TyClDecl name tcdSigs :: [LSig name], -- Methods' signatures tcdMeths :: LHsBinds name, -- Default methods tcdATs :: [LTyClDecl name] -- Associated types; ie - -- only 'TyData' + -- only 'TyData', + -- 'TyFunction', -- and 'TySynonym' } @@ -391,7 +421,7 @@ data NewOrData Simple classifiers \begin{code} -isTFunDecl, isDataDecl, isSynDecl, isTEqnDecl, isClassDecl :: +isTFunDecl, isDataDecl, isSynDecl, isClassDecl, isKindSigDecl, isIdxTyDecl :: TyClDecl name -> Bool -- type function kind signature @@ -411,6 +441,18 @@ isDataDecl other = False isClassDecl (ClassDecl {}) = True isClassDecl other = False + +-- kind signature (for an indexed type) +isKindSigDecl (TyFunction {} ) = True +isKindSigDecl (TyData {tcdKindSig = Just _, + tcdCons = [] }) = True +isKindSigDecl other = False + +-- definition of an instance of an indexed type +isIdxTyDecl tydecl + | isTEqnDecl tydecl = True + | isDataDecl tydecl = isJust (tcdTyPats tydecl) + | otherwise = False \end{code} Dealing with names @@ -426,9 +468,7 @@ tyClDeclNames :: Eq name => TyClDecl name -> [Located name] -- We use the equality to filter out duplicate field names tyClDeclNames (TyFunction {tcdLName = name}) = [name] -tyClDeclNames (TySynonym {tcdLName = name, - tcdTyPats= Nothing}) = [name] -tyClDeclNames (TySynonym {} ) = [] -- type equation +tyClDeclNames (TySynonym {tcdLName = name}) = [name] tyClDeclNames (ForeignType {tcdLName = name}) = [name] tyClDeclNames (ClassDecl {tcdLName = cls_name, tcdSigs = sigs, tcdATs = ats}) @@ -472,27 +512,28 @@ instance OutputableBndr name = hsep [ptext SLIT("foreign import type dotnet"), ppr ltycon] ppr (TyFunction {tcdLName = ltycon, tcdTyVars = tyvars, tcdIso = iso, - tcdKindSig = mb_sig}) + tcdKind = kind}) = typeMaybeIso <+> pp_decl_head [] ltycon tyvars Nothing <+> - ppr_sig mb_sig + dcolon <+> pprKind kind where typeMaybeIso = if iso - then ptext SLIT("type iso") - else ptext SLIT("type") - - ppr_sig Nothing = empty - ppr_sig (Just kind) = dcolon <+> pprKind kind + then ptext SLIT("type family iso") + else ptext SLIT("type family") ppr (TySynonym {tcdLName = ltycon, tcdTyVars = tyvars, tcdTyPats = typats, tcdSynRhs = mono_ty}) - = hang (ptext SLIT("type") <+> pp_decl_head [] ltycon tyvars typats <+> + = hang (ptext SLIT("type") <+> + (if isJust typats then ptext SLIT("instance") else empty) <+> + pp_decl_head [] ltycon tyvars typats <+> equals) 4 (ppr mono_ty) ppr (TyData {tcdND = new_or_data, tcdCtxt = context, tcdLName = ltycon, tcdTyVars = tyvars, tcdTyPats = typats, tcdKindSig = mb_sig, tcdCons = condecls, tcdDerivs = derivings}) - = pp_tydecl (ppr new_or_data <+> + = pp_tydecl (null condecls && isJust mb_sig) + (ppr new_or_data <+> + (if isJust typats then ptext SLIT("instance") else empty) <+> pp_decl_head (unLoc context) ltycon tyvars typats <+> ppr_sig mb_sig) (pp_condecls condecls) @@ -536,12 +577,14 @@ pp_condecls cs@(L _ ConDecl{ con_res = ResTyGADT _ } : _) -- In GADT syntax pp_condecls cs -- In H98 syntax = equals <+> sep (punctuate (ptext SLIT(" |")) (map ppr cs)) -pp_tydecl pp_head pp_decl_rhs derivings +pp_tydecl True pp_head pp_decl_rhs derivings + = pp_head +pp_tydecl False pp_head pp_decl_rhs derivings = hang pp_head 4 (sep [ - pp_decl_rhs, - case derivings of - Nothing -> empty - Just ds -> hsep [ptext SLIT("deriving"), parens (interpp'SP ds)] + pp_decl_rhs, + case derivings of + Nothing -> empty + Just ds -> hsep [ptext SLIT("deriving"), parens (interpp'SP ds)] ]) instance Outputable NewOrData where @@ -653,7 +696,8 @@ data InstDecl name -- figures out the quantified type variables for us. (LHsBinds name) [LSig name] -- User-supplied pragmatic info - [LTyClDecl name]-- Associated types + [LTyClDecl name]-- Associated types (ie, 'TyData' and + -- 'TySynonym' only) instance (OutputableBndr name) => Outputable (InstDecl name) where