-mkPReprType :: [[Type]] -> VM Type
-mkPReprType [] = return unitTy
-mkPReprType tys
- = do
- embed <- builtin embedTyCon
- cross <- builtin crossTyCon
- plus <- builtin plusTyCon
-
- let mk_embed ty = mkTyConApp embed [ty]
- mk_cross ty1 ty2 = mkTyConApp cross [ty1, ty2]
- mk_plus ty1 ty2 = mkTyConApp plus [ty1, ty2]
-
- mk_tup [] = unitTy
- mk_tup tys = foldr1 mk_cross tys
-
- mk_sum [] = unitTy
- mk_sum tys = foldr1 mk_plus tys
-
- return . mk_sum
- . map (mk_tup . map mk_embed)
- $ tys
-
-mkPReprAlts :: [[CoreExpr]] -> VM ([CoreExpr], Type)
-mkPReprAlts ess
- = do
- embed_tc <- builtin embedTyCon
- embed_dc <- builtin embedDataCon
- cross_tc <- builtin crossTyCon
- cross_dc <- builtin crossDataCon
- plus_tc <- builtin plusTyCon
- left_dc <- builtin leftDataCon
- right_dc <- builtin rightDataCon
-
- let mk_embed (expr, ty, pa)
- = (mkConApp embed_dc [Type ty, pa, expr],
- mkTyConApp embed_tc [ty])
-
- mk_cross (expr1, ty1) (expr2, ty2)
- = (mkConApp cross_dc [Type ty1, Type ty2, expr1, expr2],
- mkTyConApp cross_tc [ty1, ty2])
-
- mk_tup [] = (Var unitDataConId, unitTy)
- mk_tup es = foldr1 mk_cross es
-
- mk_sum [] = ([Var unitDataConId], unitTy)
- mk_sum [(expr, ty)] = ([expr], ty)
- mk_sum ((expr, lty) : es)
- = let (alts, rty) = mk_sum es
- in
- (mkConApp left_dc [Type lty, Type rty, expr]
- : [mkConApp right_dc [Type lty, Type rty, alt] | alt <- alts],
- mkTyConApp plus_tc [lty, rty])
-
- liftM (mk_sum . map (mk_tup . map mk_embed))
- (mapM (mapM init) ess)
- where
- init expr = let ty = exprType expr
- in do
- pa <- paDictOfType ty
- return (expr, ty, pa)
-