% % (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}