% % (c) The AQUA Project, Glasgow University, 1996-1998 % \section[RnHsSyn]{Specialisations of the @HsSyn@ syntax for the renamer} \begin{code}

    module RnHsSyn(
            -- Names
            charTyCon_name, listTyCon_name, parrTyCon_name, tupleTyCon_name,
            extractHsTyVars, extractHsTyNames, extractHsTyNames_s,
            extractFunDepNames, extractHsCtxtTyNames, extractHsPredTyNames,

            -- Free variables
            hsSigsFVs, hsSigFVs, conDeclFVs, bangTyFVs,

            maybeGenericMatch
      ) where

    #include "HsVersions.h"

    import HsSyn
    import Class            ( FunDep )
    import TysWiredIn       ( tupleTyCon, listTyCon, parrTyCon, charTyCon )
    import Name             ( Name, getName, isTyVarName )
    import NameSet
    import BasicTypes       ( Boxity )
    import SrcLoc           ( Located(..), unLoc )

\end{code} %************************************************************************ %* * \subsection{Free variables} %* * %************************************************************************ These free-variable finders returns tycons and classes too. \begin{code}

    charTyCon_name, listTyCon_name, parrTyCon_name :: Name
    charTyCon_name    = getName charTyCon
    listTyCon_name    = getName listTyCon
    parrTyCon_name    = getName parrTyCon

    tupleTyCon_name :: Boxity -> Int -> Name
    tupleTyCon_name boxity n = getName (tupleTyCon boxity n)

    extractHsTyVars :: LHsType Name -> NameSet
    extractHsTyVars x = filterNameSet isTyVarName (extractHsTyNames x)

    extractFunDepNames :: FunDep Name -> NameSet
    extractFunDepNames (ns1, ns2) = mkNameSet ns1 `unionNameSets` mkNameSet ns2

    extractHsTyNames   :: LHsType Name -> NameSet
    extractHsTyNames ty
      = getl ty
      where
        getl (L _ ty) = get ty

        get (HsAppTy ty1 ty2)      = getl ty1 `unionNameSets` getl ty2
        get (HsListTy ty)          = unitNameSet listTyCon_name `unionNameSets` getl ty
        get (HsPArrTy ty)          = unitNameSet parrTyCon_name `unionNameSets` getl ty
        get (HsTupleTy _ tys)      = extractHsTyNames_s tys
        get (HsFunTy ty1 ty2)      = getl ty1 `unionNameSets` getl ty2
        get (HsPredTy p)           = extractHsPredTyNames p
        get (HsOpTy ty1 op ty2)    = getl ty1 `unionNameSets` getl ty2 `unionNameSets` unitNameSet (unLoc op)
        get (HsParTy ty)           = getl ty
        get (HsBangTy _ ty)        = getl ty
        get (HsRecTy flds)         = extractHsTyNames_s (map cd_fld_type flds)
        get (HsNumTy _)            = emptyNameSet
        get (HsTyVar tv)           = unitNameSet tv
        get (HsSpliceTy _ fvs _)   = fvs
        get (HsQuasiQuoteTy {})    = emptyNameSet
        get (HsKindSig ty _)       = getl ty
        get (HsForAllTy _ tvs
                        ctxt ty)   = (extractHsCtxtTyNames ctxt
                                             `unionNameSets` getl ty)
                                                `minusNameSet`
                                      mkNameSet (hsLTyVarNames tvs)
        get (HsDocTy ty _)         = getl ty
        get (HsCoreTy {})          = emptyNameSet	-- This probably isn't quite right
        		  	       	 		-- but I don't think it matters

    extractHsTyNames_s  :: [LHsType Name] -> NameSet
    extractHsTyNames_s tys = foldr (unionNameSets . extractHsTyNames) emptyNameSet tys

    extractHsCtxtTyNames :: LHsContext Name -> NameSet
    extractHsCtxtTyNames (L _ ctxt)
      = foldr (unionNameSets . extractHsPredTyNames . unLoc) emptyNameSet ctxt

    -- You don't import or export implicit parameters,
    -- so don't mention the IP names
    extractHsPredTyNames :: HsPred Name -> NameSet
    extractHsPredTyNames (HsClassP cls tys)
      = unitNameSet cls `unionNameSets` extractHsTyNames_s tys
    extractHsPredTyNames (HsEqualP ty1 ty2)
      = extractHsTyNames ty1 `unionNameSets` extractHsTyNames ty2
    extractHsPredTyNames (HsIParam _ ty)
      = extractHsTyNames ty

\end{code} %************************************************************************ %* * \subsection{Free variables of declarations} %* * %************************************************************************ Return the Names that must be in scope if we are to use this declaration. In all cases this is set up for interface-file declarations: - for class decls we ignore the bindings - for instance decls likewise, plus the pragmas - for rule decls, we ignore HsRules - for data decls, we ignore derivings *** See "THE NAMING STORY" in HsDecls **** \begin{code}

    ----------------
    hsSigsFVs :: [LSig Name] -> FreeVars
    hsSigsFVs sigs = plusFVs (map (hsSigFVs.unLoc) sigs)

    hsSigFVs :: Sig Name -> FreeVars
    hsSigFVs (TypeSig _ ty)   = extractHsTyNames ty
    hsSigFVs (SpecInstSig ty) = extractHsTyNames ty
    hsSigFVs (SpecSig _ ty _) = extractHsTyNames ty
    hsSigFVs _                = emptyFVs

    ----------------
    conDeclFVs :: LConDecl Name -> FreeVars
    conDeclFVs (L _ (ConDecl { con_qvars = tyvars, con_cxt = context,
                               con_details = details, con_res = res_ty}))
      = delFVs (map hsLTyVarName tyvars) $
        extractHsCtxtTyNames context  `plusFV`
        conDetailsFVs details         `plusFV`
        conResTyFVs res_ty

    conResTyFVs :: ResType Name -> FreeVars
    conResTyFVs ResTyH98       = emptyFVs
    conResTyFVs (ResTyGADT ty) = extractHsTyNames ty

    conDetailsFVs :: HsConDeclDetails Name -> FreeVars
    conDetailsFVs details = plusFVs (map bangTyFVs (hsConDeclArgTys details))

    bangTyFVs :: LHsType Name -> FreeVars
    bangTyFVs bty = extractHsTyNames (getBangType bty)

\end{code} %************************************************************************ %* * \subsection{A few functions on generic defintions %* * %************************************************************************ These functions on generics are defined over Matches Name, which is why they are here and not in HsMatches. \begin{code}

    maybeGenericMatch :: LMatch Name -> Maybe (HsType Name, LMatch Name)
      -- Tells whether a Match is for a generic definition
      -- and extract the type from a generic match and put it at the front

    maybeGenericMatch (L loc (Match (L _ (TypePat (L _ ty)) : pats) sig_ty grhss))
      = Just (ty, L loc (Match pats sig_ty grhss))

    maybeGenericMatch _ = Nothing

\end{code}