import Name
import Var
import Id
-import PrelInfo
import DataCon
import TysWiredIn
import BasicTypes
-- if e then Left ((xs1)*ts) else Right ((xs2)*ts)) >>>
-- c1 ||| c2
-dsCmd ids local_vars env_ids stack res_ty (HsIf cond then_cmd else_cmd) = do
+dsCmd ids local_vars env_ids stack res_ty (HsIf mb_fun cond then_cmd else_cmd) = do
core_cond <- dsLExpr cond
(core_then, fvs_then, then_ids) <- dsfixCmd ids local_vars stack res_ty then_cmd
(core_else, fvs_else, else_ids) <- dsfixCmd ids local_vars stack res_ty else_cmd
either_con <- dsLookupTyCon eitherTyConName
left_con <- dsLookupDataCon leftDataConName
right_con <- dsLookupDataCon rightDataConName
- let
- left_expr ty1 ty2 e = mkConApp left_con [Type ty1, Type ty2, e]
- right_expr ty1 ty2 e = mkConApp right_con [Type ty1, Type ty2, e]
+
+ let mk_left_expr ty1 ty2 e = mkConApp left_con [Type ty1, Type ty2, e]
+ mk_right_expr ty1 ty2 e = mkConApp right_con [Type ty1, Type ty2, e]
in_ty = envStackType env_ids stack
then_ty = envStackType then_ids stack
else_ty = envStackType else_ids stack
sum_ty = mkTyConApp either_con [then_ty, else_ty]
fvs_cond = exprFreeVars core_cond `intersectVarSet` local_vars
-
- core_if <- matchEnvStack env_ids stack_ids
- (mkIfThenElse core_cond
- (left_expr then_ty else_ty (buildEnvStack then_ids stack_ids))
- (right_expr then_ty else_ty (buildEnvStack else_ids stack_ids)))
+
+ core_left = mk_left_expr then_ty else_ty (buildEnvStack then_ids stack_ids)
+ core_right = mk_right_expr then_ty else_ty (buildEnvStack else_ids stack_ids)
+
+ core_if <- case mb_fun of
+ Just fun -> do { core_fun <- dsExpr fun
+ ; matchEnvStack env_ids stack_ids $
+ mkCoreApps core_fun [core_cond, core_left, core_right] }
+ Nothing -> matchEnvStack env_ids stack_ids $
+ mkIfThenElse core_cond core_left core_right
+
return (do_map_arrow ids in_ty sum_ty res_ty
core_if
(do_choice ids then_ty else_ty res_ty core_then core_else),
core_body,
exprFreeVars core_binds `intersectVarSet` local_vars)
-dsCmd ids local_vars env_ids [] res_ty (HsDo _ctxt stmts body _)
- = dsCmdDo ids local_vars env_ids res_ty stmts body
+dsCmd ids local_vars env_ids [] res_ty (HsDo _ctxt stmts _)
+ = dsCmdDo ids local_vars env_ids res_ty stmts
-- A |- e :: forall e. a1 (e*ts1) t1 -> ... an (e*tsn) tn -> a (e*ts) t
-- A | xs |- ci :: [tsi] ti
-- so don't pull on it too early
-> Type -- return type of the statement
-> [LStmt Id] -- statements to desugar
- -> LHsExpr Id -- body
-> DsM (CoreExpr, -- desugared expression
IdSet) -- set of local vars that occur free
-- --------------------------
-- A | xs |- do { c } :: [] t
-dsCmdDo ids local_vars env_ids res_ty [] body
+dsCmdDo _ _ _ _ [] = panic "dsCmdDo"
+
+dsCmdDo ids local_vars env_ids res_ty [L _ (LastStmt body _)]
= dsLCmd ids local_vars env_ids [] res_ty body
-dsCmdDo ids local_vars env_ids res_ty (stmt:stmts) body = do
+dsCmdDo ids local_vars env_ids res_ty (stmt:stmts) = do
let
bound_vars = mkVarSet (collectLStmtBinders stmt)
local_vars' = local_vars `unionVarSet` bound_vars
(core_stmts, _, env_ids') <- fixDs (\ ~(_,_,env_ids') -> do
- (core_stmts, fv_stmts) <- dsCmdDo ids local_vars' env_ids' res_ty stmts body
+ (core_stmts, fv_stmts) <- dsCmdDo ids local_vars' env_ids' res_ty stmts
return (core_stmts, fv_stmts, varSetElems fv_stmts))
(core_stmt, fv_stmt) <- dsCmdLStmt ids local_vars env_ids env_ids' stmt
return (do_compose ids
-- ---> arr (\ (xs) -> ((xs1),(xs'))) >>> first c >>>
-- arr snd >>> ss
-dsCmdStmt ids local_vars env_ids out_ids (ExprStmt cmd _ c_ty) = do
+dsCmdStmt ids local_vars env_ids out_ids (ExprStmt cmd _ _ c_ty) = do
(core_cmd, fv_cmd, env_ids1) <- dsfixCmd ids local_vars [] c_ty cmd
core_mux <- matchEnvStack env_ids []
(mkCorePairExpr (mkBigCoreVarTup env_ids1) (mkBigCoreVarTup out_ids))
dsCmdStmt ids local_vars env_ids out_ids
(RecStmt { recS_stmts = stmts, recS_later_ids = later_ids, recS_rec_ids = rec_ids
- , recS_rec_rets = rhss, recS_dicts = _binds }) = do
- let -- ToDo: ****** binds not desugared; ROSS PLEASE FIX ********
+ , recS_rec_rets = rhss }) = do
+ let
env2_id_set = mkVarSet out_ids `minusVarSet` mkVarSet later_ids
env2_ids = varSetElems env2_id_set
env2_ty = mkBigCoreVarTupTy env2_ids
= go pat
where
go (VarPat var) = var : bndrs
- go (VarPatOut var bs) = var : collectEvBinders bs
- ++ bndrs
go (WildPat _) = bndrs
go (LazyPat pat) = collectl pat bndrs
go (BangPat pat) = collectl pat bndrs