compiler: Use map generators instead of maps:fold/3

5 files changed, 14 insertions, 23 deletions

diff --git a/lib/compiler/src/beam_ssa_codegen.erl b/lib/compiler/src/beam_ssa_codegen.erl
index 9e7a525c3f..08b0e5d856 100644
--- a/lib/compiler/src/beam_ssa_codegen.erl
+++ b/lib/compiler/src/beam_ssa_codegen.erl
@@ -157,13 +157,11 @@ assert_exception_block(Blocks) ->
 add_parameter_annos([{label, _}=Entry | Body], Anno) ->
     ParamTypes = maps:get(parameter_info, Anno, #{}),
 
-    Annos = maps:fold(
-        fun(K, V, Acc) when is_map_key(K, ParamTypes) ->
-                Info = map_get(K, ParamTypes),
-                [{'%', {var_info, V, Info}} | Acc];
-           (_K, _V, Acc) ->
-                Acc
-        end, [], maps:get(registers, Anno)),
+    Annos = [begin
+                 Info = map_get(K, ParamTypes),
+                 {'%', {var_info, V, Info}}
+             end || K := V <- map_get(registers, Anno),
+                    is_map_key(K, ParamTypes)],
 
     [Entry | sort(Annos)] ++ Body.
 
diff --git a/lib/compiler/src/beam_ssa_pre_codegen.erl b/lib/compiler/src/beam_ssa_pre_codegen.erl
index e1b5f59738..e3406f12de 100644
--- a/lib/compiler/src/beam_ssa_pre_codegen.erl
+++ b/lib/compiler/src/beam_ssa_pre_codegen.erl
@@ -2993,8 +2993,8 @@ init_free(Res) ->
     #{x:=Xs0} = Free1 = maps:from_list(Free0),
     Xs = init_xregs(Xs0),
     Free = Free1#{x:=Xs},
-    Next = maps:fold(fun(K, V, A) -> [{{next,K},length(V)}|A] end, [], Free),
-    maps:merge(Free, maps:from_list(Next)).
+    Next = #{{next,K} => length(V) || K := V <- Free},
+    maps:merge(Free, Next).
 
 init_free_1([{_,{prefer,{x,_}=Reg}}|Res]) ->
     [{x,Reg}|init_free_1(Res)];
diff --git a/lib/compiler/src/beam_ssa_type.erl b/lib/compiler/src/beam_ssa_type.erl
index 5419090ddc..725eb9ee29 100644
--- a/lib/compiler/src/beam_ssa_type.erl
+++ b/lib/compiler/src/beam_ssa_type.erl
@@ -378,11 +378,7 @@ init_sig_st(StMap, FuncDb) ->
              wl=wl_defer_list(Roots, wl_new()) }.
 
 init_sig_roots(FuncDb) ->
-    maps:fold(fun(Id, #func_info{exported=true}, Acc) ->
-                      [Id | Acc];
-                 (_, _, Acc) ->
-                      Acc
-              end, [], FuncDb).
+    [Id || Id := #func_info{exported=true} <- FuncDb].
 
 init_sig_args([Root | Roots], StMap, Acc) ->
     #opt_st{args=Args0} = map_get(Root, StMap),
diff --git a/lib/compiler/src/beam_types.erl b/lib/compiler/src/beam_types.erl
index 5f7350516d..cf81c34670 100644
--- a/lib/compiler/src/beam_types.erl
+++ b/lib/compiler/src/beam_types.erl
@@ -1368,12 +1368,11 @@ verified_normal_type(#t_tuple{size=Size,elements=Es}=T) ->
     %% union). 'any' is prohibited since it's implicit and should never be
     %% present in the map, and a 'none' element ought to have reduced the
     %% entire tuple to 'none'.
-    maps:fold(fun(Index, Element, _) when is_integer(Index),
-                                          1 =< Index, Index =< Size,
-                                          Index =< ?TUPLE_ELEMENT_LIMIT,
-                                          Element =/= any, Element =/= none ->
-                      verified_type(Element)
-              end, [], Es),
+    _ = [verified_type(Element) ||
+            Index := Element <- Es,
+            is_integer(Index), 1 =< Index, Index =< Size,
+            Index =< ?TUPLE_ELEMENT_LIMIT,
+            Element =/= any, Element =/= none],
     T.
 
 %%%
diff --git a/lib/compiler/src/v3_kernel.erl b/lib/compiler/src/v3_kernel.erl
index 3443f43959..809924c7f3 100644
--- a/lib/compiler/src/v3_kernel.erl
+++ b/lib/compiler/src/v3_kernel.erl
@@ -1565,9 +1565,7 @@ group_value(_, Us, Cs) ->
     Map = group_values(Cs, #{}),
     %% We must sort the grouped values to ensure consistent
     %% order from compilation to compilation.
-    sort(maps:fold(fun (_, Vcs, Css) ->
-                           [{Us,reverse(Vcs)}|Css]
-                   end, [], Map)).
+    sort([{Us,reverse(Vcs)} || _ := Vcs <- Map]).
 
 group_values([C|Cs], Acc) ->
     Val = clause_val(C),