Commit c58414c7 authored by chak@cse.unsw.edu.au.'s avatar chak@cse.unsw.edu.au.
Browse files

Make data con wrappers for GADTs express the user type directly

Mon Sep 18 16:44:29 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
  * Make data con wrappers for GADTs express the user type directly
  Sun Aug  6 17:24:17 EDT 2006  Manuel M T Chakravarty <chak@cse.unsw.edu.au>
    * Make data con wrappers for GADTs express the user type directly
    Wed Jul 26 08:19:09 EDT 2006  simonpj@microsoft.com
parent bda859ad
......@@ -46,7 +46,8 @@ import TysPrim ( openAlphaTyVars, alphaTyVar, alphaTy,
)
import TysWiredIn ( charTy, mkListTy )
import PrelRules ( primOpRules )
import Type ( TyThing(..), mkForAllTy, tyVarsOfTypes, newTyConInstRhs, coreEqType )
import Type ( TyThing(..), mkForAllTy, tyVarsOfTypes, newTyConInstRhs, coreEqType,
mkTopTvSubst, substTyVar )
import Coercion ( mkSymCoercion, mkUnsafeCoercion,
splitNewTypeRepCo_maybe )
import TcType ( Type, ThetaType, mkDictTy, mkPredTys, mkPredTy,
......@@ -70,7 +71,7 @@ import PrimOp ( PrimOp, primOpSig, primOpOcc, primOpTag )
import ForeignCall ( ForeignCall )
import DataCon ( DataCon, DataConIds(..), dataConTyCon, dataConUnivTyVars,
dataConFieldLabels, dataConRepArity, dataConResTys,
dataConRepArgTys, dataConRepType,
dataConRepArgTys, dataConRepType, dataConFullSig,
dataConSig, dataConStrictMarks, dataConExStricts,
splitProductType, isVanillaDataCon, dataConFieldType,
dataConInstOrigArgTys, deepSplitProductType
......@@ -95,7 +96,7 @@ import PrelNames
import Util ( dropList, isSingleton )
import Outputable
import FastString
import ListSetOps ( assoc )
import ListSetOps ( assoc, minusList )
\end{code}
%************************************************************************
......@@ -193,24 +194,28 @@ mkDataConIds wrap_name wkr_name data_con
= NewDC nt_wrap_id
| any isMarkedStrict all_strict_marks -- Algebraic, needs wrapper
|| not (null eq_spec)
= AlgDC (Just alg_wrap_id) wrk_id
| otherwise -- Algebraic, no wrapper
= AlgDC Nothing wrk_id
where
(tvs, theta, orig_arg_tys) = dataConSig data_con
tycon = dataConTyCon data_con
(univ_tvs, ex_tvs, eq_spec, theta, orig_arg_tys) = dataConFullSig data_con
tycon = dataConTyCon data_con
dict_tys = mkPredTys theta
all_arg_tys = dict_tys ++ orig_arg_tys
tycon_args = dataConUnivTyVars data_con
result_ty_args = (mkTyVarTys tycon_args)
result_ty = mkTyConApp tycon result_ty_args
wrap_ty = mkForAllTys tvs (mkFunTys all_arg_tys result_ty)
----------- Wrapper --------------
-- We used to include the stupid theta in the wrapper's args
-- but now we don't. Instead the type checker just injects these
-- extra constraints where necessary.
wrap_tvs = (univ_tvs `minusList` map fst eq_spec) ++ ex_tvs
subst = mkTopTvSubst eq_spec
dict_tys = mkPredTys theta
result_ty_args = map (substTyVar subst) univ_tvs
result_ty = mkTyConApp tycon result_ty_args
wrap_ty = mkForAllTys wrap_tvs $ mkFunTys dict_tys $
mkFunTys orig_arg_tys $ result_ty
-- NB: watch out here if you allow user-written equality
-- constraints in data constructor signatures
----------- Worker (algebraic data types only) --------------
-- The *worker* for the data constructor is the function that
......@@ -260,7 +265,7 @@ mkDataConIds wrap_name wkr_name data_con
-- No existentials on a newtype, but it can have a context
-- e.g. newtype Eq a => T a = MkT (...)
mkCompulsoryUnfolding $
mkLams tvs $ Lam id_arg1 $
mkLams wrap_tvs $ Lam id_arg1 $
wrapNewTypeBody tycon result_ty_args
(Var id_arg1)
......@@ -290,14 +295,16 @@ mkDataConIds wrap_name wkr_name data_con
-- we want to see that w is strict in its two arguments
alg_unf = mkTopUnfolding $ Note InlineMe $
mkLams tvs $
mkLams wrap_tvs $
mkLams dict_args $ mkLams id_args $
foldr mk_case con_app
(zip (dict_args ++ id_args) all_strict_marks)
i3 []
con_app i rep_ids = mkApps (Var wrk_id)
(map varToCoreExpr (tvs ++ reverse rep_ids))
con_app i rep_ids = Var wrk_id `mkTyApps` result_ty_args
`mkVarApps` ex_tvs
`mkTyApps` map snd eq_spec
`mkVarApps` reverse rep_ids
(dict_args,i2) = mkLocals 1 dict_tys
(id_args,i3) = mkLocals i2 orig_arg_tys
......
Markdown is supported
0% or .
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment