diff options
Diffstat (limited to 'lib/compiler')
| -rw-r--r-- | lib/compiler/src/sys_core_fold.erl | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/lib/compiler/src/sys_core_fold.erl b/lib/compiler/src/sys_core_fold.erl index b78507c47e..e134a37f22 100644 --- a/lib/compiler/src/sys_core_fold.erl +++ b/lib/compiler/src/sys_core_fold.erl @@ -277,7 +277,7 @@ expr(#c_fun{}=Fun, effect, _) -> add_warning(Fun, useless_building), void(); expr(#c_fun{vars=Vs0,body=B0}=Fun, Ctxt0, Sub0) -> - {Vs1,Sub1} = pattern_list(Vs0, Sub0), + {Vs1,Sub1} = var_list(Vs0, Sub0), Ctxt = case Ctxt0 of {letrec,Ctxt1} -> Ctxt1; value -> value @@ -420,13 +420,13 @@ expr(#c_try{anno=A,arg=E0,vars=Vs0,body=B0,evars=Evs0,handler=H0}=Try, _, Sub0) %% Here is the general try/catch construct outside of guards. %% We can remove try if the value is simple and replace it with a let. E1 = body(E0, value, Sub0), - {Vs1,Sub1} = pattern_list(Vs0, Sub0), + {Vs1,Sub1} = var_list(Vs0, Sub0), B1 = body(B0, value, Sub1), case is_safe_simple(E1, Sub0) of true -> expr(#c_let{anno=A,vars=Vs1,arg=E1,body=B1}, value, Sub0); false -> - {Evs1,Sub2} = pattern_list(Evs0, Sub0), + {Evs1,Sub2} = var_list(Evs0, Sub0), H1 = body(H0, value, Sub2), Try#c_try{arg=E1,vars=Vs1,body=B1,evars=Evs1,handler=H1} end. @@ -1124,7 +1124,7 @@ clause(#c_clause{pats=Ps0,guard=G0,body=B0}=Cl, Cexpr, Ctxt, Sub0) -> %% the unsubstituted variables and values. let_substs(Vs0, As0, Sub0) -> - {Vs1,Sub1} = pattern_list(Vs0, Sub0), + {Vs1,Sub1} = var_list(Vs0, Sub0), {Vs2,As1,Ss} = let_substs_1(Vs1, As0, Sub1), Sub2 = sub_add_scope([V || #c_var{name=V} <- Vs2], Sub1), {Vs2,As1, @@ -1224,6 +1224,16 @@ pattern_list(Ps, Sub) -> pattern_list(Ps, Sub, Sub). pattern_list(Ps0, Isub, Osub0) -> mapfoldl(fun (P, Osub) -> pattern(P, Isub, Osub) end, Osub0, Ps0). +%% var_list([Var], InSub) -> {Pattern,OutSub}. +%% Works like pattern_list/2 but only accept variables and is +%% guaranteed not to throw an exception. + +var_list(Vs, Sub0) -> + mapfoldl(fun (#c_var{}=V, Sub) -> + pattern(V, Sub, Sub) + end, Sub0, Vs). + + %% is_subst(Expr) -> true | false. %% Test whether an expression is a suitable substitution. @@ -2255,11 +2265,11 @@ move_let_into_expr(#c_let{vars=InnerVs0,body=InnerBody0}=Inner, %% Arg = body(Arg0, Sub0), ScopeSub0 = sub_subst_scope(Sub0#sub{t=#{}}), - {OuterVs,ScopeSub} = pattern_list(OuterVs0, ScopeSub0), + {OuterVs,ScopeSub} = var_list(OuterVs0, ScopeSub0), OuterBody = body(OuterBody0, ScopeSub), - {InnerVs,Sub} = pattern_list(InnerVs0, Sub0), + {InnerVs,Sub} = var_list(InnerVs0, Sub0), InnerBody = body(InnerBody0, Sub), Outer#c_let{vars=OuterVs,arg=Arg, body=Inner#c_let{vars=InnerVs,arg=OuterBody,body=InnerBody}}; @@ -2599,7 +2609,7 @@ move_case_into_arg(#c_case{arg=#c_let{vars=OuterVars0,arg=OuterArg, %% in case <InnerArg> of <InnerClauses> end %% ScopeSub0 = sub_subst_scope(Sub#sub{t=#{}}), - {OuterVars,ScopeSub} = pattern_list(OuterVars0, ScopeSub0), + {OuterVars,ScopeSub} = var_list(OuterVars0, ScopeSub0), InnerArg = body(InnerArg0, ScopeSub), Outer#c_let{vars=OuterVars,arg=OuterArg, body=Inner#c_case{arg=InnerArg,clauses=InnerClauses}}; |