diff --git a/CHANGES.md b/CHANGES.md
index 4a66843..0de2a3a 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,8 @@
+v2.4.0
+
+* enough performance improvements to justify a new version. 2-3x
+  speedup depending on mode of operation
+
 v2.3.1
 
 * fixes an issue where astral plane json escape sequences were
diff --git a/README.md b/README.md
index dd2bcd0..9f1e998 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# jsx (v2.3.1) #
+# jsx (v2.4) #
 
 an erlang application for consuming, producing and manipulating [json][json]. 
 inspired by [yajl][yajl]
@@ -387,10 +387,6 @@ additional options beyond these. see
     control codes and problematic codepoints and replacing them with the 
     appropriate escapes
 
-- `repeat_keys`
-
-    this flag circumvents checking for repeated keys in generated json
-
 - `stream`
 
     see [incomplete input](#incomplete-input)
diff --git a/config/maps b/config/maps
deleted file mode 100644
index 8aa3993..0000000
--- a/config/maps
+++ /dev/null
@@ -1 +0,0 @@
-maps:keys(#{0 => false, 1 => true}) == [0,1].
\ No newline at end of file
diff --git a/package.exs b/package.exs
deleted file mode 100644
index d5708a6..0000000
--- a/package.exs
+++ /dev/null
@@ -1,30 +0,0 @@
-defmodule JSX.Mixfile do
-use Mix.Project
-
-  def project do
-    [
-      app: :jsx,
-      version: "2.3.0",
-      description: "an erlang application for consuming, producing and manipulating json. inspired by yajl",
-      package: package
-    ]
-  end
-
-  defp package do
-    [
-      files: [
-        "CHANGES.md",
-        "LICENSE",
-        "package.exs",
-        "README.md",
-        "rebar.config",
-        "rebar.config.script",
-        "config",
-        "src"
-      ],
-      contributors: ["alisdair sullivan"],
-      links: %{"github" => "https://github.com/talentdeficit/jsx"},
-      licenses: ["MIT"]
-    ]
-  end
-end
\ No newline at end of file
diff --git a/rebar.config b/rebar.config
index c59e185..b2653a2 100644
--- a/rebar.config
+++ b/rebar.config
@@ -1,2 +1,4 @@
-% uncomment to disable encoding support for erlang maps
-% {jsx_nomaps, true}.
\ No newline at end of file
+{erl_opts, [
+  {platform_define, "R14|R15", 'no_binary_to_whatever'},
+  {platform_define, "^((?!R1[456]).)*$", 'maps_support'}
+]}.
\ No newline at end of file
diff --git a/rebar.config.script b/rebar.config.script
deleted file mode 100644
index c5d8d92..0000000
--- a/rebar.config.script
+++ /dev/null
@@ -1,9 +0,0 @@
-case os:getenv("JSX_NOMAPS") or proplists:get_value(jsx_nomaps, CONFIG, false) of
-  false ->
-    try file:script("config/maps") of
-      {ok, true} -> [{erl_opts, [{d, maps_support}]}] ++ CONFIG;
-      _ -> CONFIG
-    catch _:_ -> CONFIG
-    end;
-  _ -> CONFIG
-end.
\ No newline at end of file
diff --git a/src/jsx.app.src b/src/jsx.app.src
index a81e5c0..f0090de 100644
--- a/src/jsx.app.src
+++ b/src/jsx.app.src
@@ -1,7 +1,7 @@
 {application, jsx,
 [
     {description, "a streaming, evented json parsing toolkit"},
-    {vsn, "2.3.1"},
+    {vsn, "2.4.0"},
     {modules, [
         jsx,
         jsx_encoder,
diff --git a/src/jsx_config.erl b/src/jsx_config.erl
index f7b8d7a..b720033 100644
--- a/src/jsx_config.erl
+++ b/src/jsx_config.erl
@@ -63,12 +63,14 @@ parse_config([unescaped_jsonp|Rest], Config) ->
     parse_config(Rest, Config#config{unescaped_jsonp=true});
 parse_config([dirty_strings|Rest], Config) ->
     parse_config(Rest, Config#config{dirty_strings=true});
+%% retained for backwards compat, now does nothing however
 parse_config([repeat_keys|Rest], Config) ->
-    parse_config(Rest, Config#config{repeat_keys=true});
+    parse_config(Rest, Config);
 parse_config([uescape|Rest], Config) ->
     parse_config(Rest, Config#config{uescape=true});
 parse_config([strict|Rest], Config) ->
-    parse_config(Rest, Config#config{strict_comments=true,
+    parse_config(Rest, Config#config{
+        strict_comments=true,
         strict_commas=true,
         strict_utf8=true,
         strict_single_quotes=true,
@@ -190,7 +192,6 @@ config_test_() ->
                     escaped_strings = true,
                     unescaped_jsonp = true,
                     dirty_strings = true,
-                    repeat_keys = true,
                     strict_comments = true,
                     strict_commas = true,
                     strict_utf8 = true,
@@ -274,7 +275,6 @@ config_to_list_test_() ->
                 escaped_strings,
                 unescaped_jsonp,
                 dirty_strings,
-                repeat_keys,
                 stream,
                 uescape,
                 strict
@@ -284,7 +284,6 @@ config_to_list_test_() ->
                     escaped_strings = true,
                     unescaped_jsonp = true,
                     dirty_strings = true,
-                    repeat_keys = true,
                     strict_comments = true,
                     strict_utf8 = true,
                     strict_single_quotes = true,
diff --git a/src/jsx_config.hrl b/src/jsx_config.hrl
index e72247a..3b87da1 100644
--- a/src/jsx_config.hrl
+++ b/src/jsx_config.hrl
@@ -3,7 +3,6 @@
     escaped_strings = false             :: boolean(),
     unescaped_jsonp = false             :: boolean(),
     dirty_strings = false               :: boolean(),
-    repeat_keys = false                 :: boolean(),
     strict_comments = false             :: boolean(),
     strict_commas = false               :: boolean(),
     strict_utf8 = false                 :: boolean(),
diff --git a/src/jsx_decoder.erl b/src/jsx_decoder.erl
index a91c27c..4a049ed 100644
--- a/src/jsx_decoder.erl
+++ b/src/jsx_decoder.erl
@@ -58,10 +58,7 @@ resume(Rest, State, Handler, Acc, Stack, Config) ->
         colon -> colon(Rest, Handler, Stack, Config);
         key -> key(Rest, Handler, Stack, Config);
         string -> string(Rest, Handler, Acc, Stack, Config);
-        integer -> integer(Rest, Handler, Acc, Stack, Config);
-        decimal -> decimal(Rest, Handler, Acc, Stack, Config);
-        exp -> exp(Rest, Handler, Acc, Stack, Config);
-        zero -> zero(Rest, Handler, Acc, Stack, Config);
+        number -> number(Rest, Handler, Acc, Stack, Config);
         true -> true(Rest, Handler, Stack, Config);
         false -> false(Rest, Handler, Stack, Config);
         null -> null(Rest, Handler, Stack, Config);
@@ -119,10 +116,6 @@ resume(Rest, State, Handler, Acc, Stack, Config) ->
     Symbol >= $1 andalso Symbol =< $9
 ).
 
--define(is_whitespace(Symbol),
-    Symbol =:= ?space; Symbol =:= ?tab; Symbol =:= ?cr; Symbol =:= ?newline
-).
-
 
 %% error is a macro so the stack trace shows the error site when possible
 -ifndef(error).
@@ -177,26 +170,54 @@ start(Bin, Handler, Stack, Config) ->
 
 value(<<?doublequote, Rest/binary>>, Handler, Stack, Config) ->
     string(Rest, Handler, Stack, Config);
-value(<<?singlequote, Rest/binary>>, Handler, Stack, Config=#config{strict_single_quotes=false}) ->
-    string(Rest, Handler, [singlequote|Stack], Config);
+value(<<?space, Rest/binary>>, Handler, Stack, Config) ->
+    value(Rest, Handler, Stack, Config);
+value(<<?start_object, Rest/binary>>, Handler, Stack, Config) ->
+    object(Rest, handle_event(start_object, Handler, Config), [key|Stack], Config);
+value(<<?start_array, Rest/binary>>, Handler, Stack, Config) ->
+    array(Rest, handle_event(start_array, Handler, Config), [array|Stack], Config);
+value(<<$t, $r, $u, $e, Rest/binary>>, Handler, Stack, Config) ->
+    maybe_done(Rest, handle_event({literal, true}, Handler, Config), Stack, Config);
+value(<<$f, $a, $l, $s, $e, Rest/binary>>, Handler, Stack, Config) ->
+    maybe_done(Rest, handle_event({literal, false}, Handler, Config), Stack, Config);
+value(<<$n, $u, $l, $l, Rest/binary>>, Handler, Stack, Config) ->
+    maybe_done(Rest, handle_event({literal, null}, Handler, Config), Stack, Config);
+value(<<?zero, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [?zero], [zero|Stack], Config);
+value(<<$1, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$1], [integer|Stack], Config);
+value(<<$2, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$2], [integer|Stack], Config);
+value(<<$3, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$3], [integer|Stack], Config);
+value(<<$4, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$4], [integer|Stack], Config);
+value(<<$5, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$5], [integer|Stack], Config);
+value(<<$6, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$6], [integer|Stack], Config);
+value(<<$7, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$7], [integer|Stack], Config);
+value(<<$8, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$8], [integer|Stack], Config);
+value(<<$9, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$9], [integer|Stack], Config);
+value(<<?negative, Rest/binary>>, Handler, Stack, Config) ->
+    number(Rest, Handler, [$-], [negative|Stack], Config);
+value(<<?newline, Rest/binary>>, Handler, Stack, Config) ->
+    value(Rest, Handler, Stack, Config);
 value(<<$t, Rest/binary>>, Handler, Stack, Config) ->
     true(Rest, Handler, Stack, Config);
 value(<<$f, Rest/binary>>, Handler, Stack, Config) ->
     false(Rest, Handler, Stack, Config);
 value(<<$n, Rest/binary>>, Handler, Stack, Config) ->
     null(Rest, Handler, Stack, Config);
-value(<<?negative, Rest/binary>>, Handler, Stack, Config) ->
-    negative(Rest, Handler, [$-], Stack, Config);
-value(<<?zero, Rest/binary>>, Handler, Stack, Config) ->
-    zero(Rest, Handler, [$0], Stack, Config);
-value(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_nonzero(S) ->
-    integer(Rest, Handler, [S], Stack, Config);
-value(<<?start_object, Rest/binary>>, Handler, Stack, Config) ->
-    object(Rest, handle_event(start_object, Handler, Config), [key|Stack], Config);
-value(<<?start_array, Rest/binary>>, Handler, Stack, Config) ->
-    array(Rest, handle_event(start_array, Handler, Config), [array|Stack], Config);
-value(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_whitespace(S) ->
+value(<<?tab, Rest/binary>>, Handler, Stack, Config) ->
     value(Rest, Handler, Stack, Config);
+value(<<?cr, Rest/binary>>, Handler, Stack, Config) ->
+    value(Rest, Handler, Stack, Config);
+value(<<?singlequote, Rest/binary>>, Handler, Stack, Config=#config{strict_single_quotes=false}) ->
+    string(Rest, Handler, [singlequote|Stack], Config);
 value(<<?end_array, _/binary>> = Rest, Handler, Stack, Config=#config{strict_commas=false}) ->
     maybe_done(Rest, Handler, Stack, Config);
 value(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
@@ -215,12 +236,18 @@ value(Bin, Handler, Stack, Config) ->
 
 object(<<?doublequote, Rest/binary>>, Handler, Stack, Config) ->
     string(Rest, Handler, Stack, Config);
-object(<<?singlequote, Rest/binary>>, Handler, Stack, Config=#config{strict_single_quotes=false}) ->
-    string(Rest, Handler, [singlequote|Stack], Config);
+object(<<?space, Rest/binary>>, Handler, Stack, Config) ->
+    object(Rest, Handler, Stack, Config);
 object(<<?end_object, Rest/binary>>, Handler, [key|Stack], Config) ->
     maybe_done(Rest, handle_event(end_object, Handler, Config), Stack, Config);
-object(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_whitespace(S) ->
+object(<<?newline, Rest/binary>>, Handler, Stack, Config) ->
     object(Rest, Handler, Stack, Config);
+object(<<?tab, Rest/binary>>, Handler, Stack, Config) ->
+    object(Rest, Handler, Stack, Config);
+object(<<?cr, Rest/binary>>, Handler, Stack, Config) ->
+    object(Rest, Handler, Stack, Config);
+object(<<?singlequote, Rest/binary>>, Handler, Stack, Config=#config{strict_single_quotes=false}) ->
+    string(Rest, Handler, [singlequote|Stack], Config);
 object(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
     ?error(object, <<?solidus, Rest/binary>>, Handler, Stack, Config);
 object(<<?solidus, ?solidus, Rest/binary>>, Handler, Stack, Config) ->
@@ -237,7 +264,13 @@ object(Bin, Handler, Stack, Config) ->
 
 array(<<?end_array, Rest/binary>>, Handler, [array|Stack], Config) ->
     maybe_done(Rest, handle_event(end_array, Handler, Config), Stack, Config);
-array(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_whitespace(S) ->
+array(<<?space, Rest/binary>>, Handler, Stack, Config) ->
+    array(Rest, Handler, Stack, Config);
+array(<<?newline, Rest/binary>>, Handler, Stack, Config) ->
+    array(Rest, Handler, Stack, Config);
+array(<<?tab, Rest/binary>>, Handler, Stack, Config) ->
+    array(Rest, Handler, Stack, Config);
+array(<<?cr, Rest/binary>>, Handler, Stack, Config) ->
     array(Rest, Handler, Stack, Config);
 array(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
     value(<<?solidus, Rest/binary>>, Handler, Stack, Config);
@@ -255,7 +288,13 @@ array(Bin, Handler, Stack, Config) ->
 
 colon(<<?colon, Rest/binary>>, Handler, [key|Stack], Config) ->
     value(Rest, Handler, [object|Stack], Config);
-colon(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_whitespace(S) ->
+colon(<<?space, Rest/binary>>, Handler, Stack, Config) ->
+    colon(Rest, Handler, Stack, Config);
+colon(<<?newline, Rest/binary>>, Handler, Stack, Config) ->
+    colon(Rest, Handler, Stack, Config);
+colon(<<?tab, Rest/binary>>, Handler, Stack, Config) ->
+    colon(Rest, Handler, Stack, Config);
+colon(<<?cr, Rest/binary>>, Handler, Stack, Config) ->
     colon(Rest, Handler, Stack, Config);
 colon(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
     ?error(colon, <<?solidus, Rest/binary>>, Handler, Stack, Config);
@@ -273,12 +312,18 @@ colon(Bin, Handler, Stack, Config) ->
 
 key(<<?doublequote, Rest/binary>>, Handler, Stack, Config) ->
     string(Rest, Handler, Stack, Config);
-key(<<?singlequote, Rest/binary>>, Handler, Stack, Config=#config{strict_single_quotes=false}) ->
-    string(Rest, Handler, [singlequote|Stack], Config);
-key(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_whitespace(S) ->
+key(<<?space, Rest/binary>>, Handler, Stack, Config) ->
     key(Rest, Handler, Stack, Config);
 key(<<?end_object, Rest/binary>>, Handler, [key|Stack], Config=#config{strict_commas=false}) ->
     maybe_done(<<?end_object, Rest/binary>>, Handler, [object|Stack], Config);
+key(<<?newline, Rest/binary>>, Handler, Stack, Config) ->
+    key(Rest, Handler, Stack, Config);
+key(<<?tab, Rest/binary>>, Handler, Stack, Config) ->
+    key(Rest, Handler, Stack, Config);
+key(<<?cr, Rest/binary>>, Handler, Stack, Config) ->
+    key(Rest, Handler, Stack, Config);
+key(<<?singlequote, Rest/binary>>, Handler, Stack, Config=#config{strict_single_quotes=false}) ->
+    string(Rest, Handler, [singlequote|Stack], Config);
 key(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
     ?error(key, <<?solidus, Rest/binary>>, Handler, Stack, Config);
 key(<<?solidus, ?solidus, Rest/binary>>, Handler, Stack, Config) ->
@@ -310,10 +355,17 @@ string(<<?solidus, Rest/binary>>, Handler, Acc, Stack, Config) ->
     string(Rest, Handler, [Acc, maybe_replace(?solidus, Config)], Stack, Config);
 string(<<?rsolidus/utf8, Rest/binary>>, Handler, Acc, Stack, Config) ->
     unescape(Rest, Handler, Acc, Stack, Config);
-string(<<X/utf8, Rest/binary>>, Handler, Acc, Stack, Config=#config{uescape=true}) when X >= 16#80 ->
-    string(Rest, Handler, [Acc, maybe_replace(X, Config)], Stack, Config);
-string(<<X/utf8, Rest/binary>>, Handler, Acc, Stack, Config) when X == 16#2028; X == 16#2029 ->
-    string(Rest, Handler, [Acc, maybe_replace(X, Config)], Stack, Config);
+string(<<X/utf8, Rest/binary>>, Handler, Acc, Stack, Config=#config{uescape=true}) ->
+    case X of
+        X when X < 16#80 -> string(Rest, Handler, [Acc, X], Stack, Config);
+        X -> string(Rest, Handler, [Acc, json_escape_sequence(X)], Stack, Config)
+    end;
+%% u+2028
+string(<<226, 128, 168, Rest/binary>>, Handler, Acc, Stack, Config) ->
+    string(Rest, Handler, [Acc, maybe_replace(16#2028, Config)], Stack, Config);
+%% u+2029
+string(<<226, 128, 169, Rest/binary>>, Handler, Acc, Stack, Config) ->
+    string(Rest, Handler, [Acc, maybe_replace(16#2029, Config)], Stack, Config);
 string(<<_/utf8, _/binary>> = Bin, Handler, Acc, Stack, Config) ->
     Size = count(Bin, 0, Config),
     <<Clean:Size/binary, Rest/binary>> = Bin,
@@ -327,9 +379,9 @@ string(<<239, 191, 190, Rest/binary>>, Handler, Acc, Stack, Config) ->
     string(Rest, Handler, [Acc, <<16#fffe/utf8>>], Stack, Config);
 string(<<239, 191, 191, Rest/binary>>, Handler, Acc, Stack, Config) ->
     string(Rest, Handler, [Acc, <<16#ffff/utf8>>], Stack, Config);
-%% partial utf8 codepoints
 string(<<>>, Handler, Acc, Stack, Config) ->
     incomplete(string, <<>>, Handler, Acc, Stack, Config);
+%% partial utf8 codepoints
 string(<<X>>, Handler, Acc, Stack, Config) when X >= 2#11000000 ->
     incomplete(string, <<X>>, Handler, Acc, Stack, Config);
 string(<<X, Y>>, Handler, Acc, Stack, Config) when X >= 2#11100000, Y >= 2#10000000 ->
@@ -614,13 +666,16 @@ count(<<127, Rest/binary>>, N, Config) ->
 count(<<_, Rest/binary>>, N, Config=#config{dirty_strings=true}) ->
     count(Rest, N + 1, Config);
 count(<<_/utf8, _/binary>>, N, #config{uescape=true}) -> N;
-count(<<X/utf8, Rest/binary>>, N, Config) when X < 16#800 ->
-    count(Rest, N + 2, Config);
-count(<<X/utf8, _/binary>>, N, _) when X == 16#2028; X == 16#2029 -> N;
-count(<<X/utf8, Rest/binary>>, N, Config) when X < 16#10000 ->
-    count(Rest, N + 3, Config);
-count(<<_/utf8, Rest/binary>>, N, Config) ->
-    count(Rest, N + 4, Config);
+%% u+2028
+count(<<226, 128, 168, _/binary>>, N, _) -> N;
+%% u+2029
+count(<<226, 128, 169, _/binary>>, N, _) -> N;
+count(<<X/utf8, Rest/binary>>, N, Config) ->
+    case X of
+        X when X < 16#800 -> count(Rest, N + 2, Config);
+        X when X < 16#10000 -> count(Rest, N + 3, Config);
+        _ -> count(Rest, N + 4, Config)
+    end;
 count(_, N, _) -> N.
 
 
@@ -666,9 +721,9 @@ strip_continuations(<<Rest/binary>>, Handler, Acc, Stack, Config, _) ->
 %% this all gets really gross and should probably eventually be folded into
 %%  but for now it fakes being part of string on incompletes and errors
 unescape(<<?rsolidus, Rest/binary>>, Handler, Acc, Stack, Config=#config{dirty_strings=true}) ->
-    string(<<?rsolidus, Rest/binary>>, Handler, [Acc, ?rsolidus], Stack, Config);
+    string(<<?rsolidus, Rest/binary>>, Handler, [Acc, <<?rsolidus>>], Stack, Config);
 unescape(<<C, Rest/binary>>, Handler, Acc, Stack, Config=#config{dirty_strings=true}) ->
-    string(Rest, Handler, [Acc, ?rsolidus, C], Stack, Config);
+    string(Rest, Handler, [Acc, <<?rsolidus, C>>], Stack, Config);
 unescape(<<$b, Rest/binary>>, Handler, Acc, Stack, Config) ->
     string(Rest, Handler, [Acc, maybe_replace($\b, Config)], Stack, Config);
 unescape(<<$f, Rest/binary>>, Handler, Acc, Stack, Config) ->
@@ -682,7 +737,7 @@ unescape(<<$t, Rest/binary>>, Handler, Acc, Stack, Config) ->
 unescape(<<?doublequote, Rest/binary>>, Handler, Acc, Stack, Config) ->
     string(Rest, Handler, [Acc, maybe_replace($\", Config)], Stack, Config);
 unescape(<<?singlequote, Rest/binary>>, Handler, Acc, Stack, Config=#config{strict_single_quotes=false}) ->
-    string(Rest, Handler, [Acc, ?singlequote], Stack, Config);
+    string(Rest, Handler, [Acc, <<?singlequote>>], Stack, Config);
 unescape(<<?rsolidus, Rest/binary>>, Handler, Acc, Stack, Config) ->
     string(Rest, Handler, [Acc, maybe_replace($\\, Config)], Stack, Config);
 unescape(<<?solidus, Rest/binary>>, Handler, Acc, Stack, Config) ->
@@ -733,7 +788,7 @@ unescape(Bin, Handler, Acc, Stack, Config) ->
         true -> incomplete(string, <<?rsolidus/utf8, Bin/binary>>, Handler, Acc, Stack, Config);
         false -> case Config#config.strict_escapes of
                 true -> ?error(string, <<?rsolidus, Bin/binary>>, Handler, Acc, Stack, Config);
-                false -> string(Bin, Handler, [Acc, ?rsolidus], Stack, Config)
+                false -> string(Bin, Handler, [Acc, <<?rsolidus>>], Stack, Config)
             end
     end.
 
@@ -746,19 +801,19 @@ is_partial_escape(<<>>) -> true;
 is_partial_escape(_) -> false.
 
 
-maybe_replace(C, #config{dirty_strings=true}) -> C;
-maybe_replace($\b, #config{escaped_strings=true}) -> [$\\, $b];
-maybe_replace($\t, #config{escaped_strings=true}) -> [$\\, $t];
-maybe_replace($\n, #config{escaped_strings=true}) -> [$\\, $n];
-maybe_replace($\f, #config{escaped_strings=true}) -> [$\\, $f];
-maybe_replace($\r, #config{escaped_strings=true}) -> [$\\, $r];
-maybe_replace($\", #config{escaped_strings=true}) -> [$\\, $\"];
+maybe_replace(C, #config{dirty_strings=true}) -> <<C>>;
+maybe_replace($\b, #config{escaped_strings=true}) -> <<$\\, $b>>;
+maybe_replace($\t, #config{escaped_strings=true}) -> <<$\\, $t>>;
+maybe_replace($\n, #config{escaped_strings=true}) -> <<$\\, $n>>;
+maybe_replace($\f, #config{escaped_strings=true}) -> <<$\\, $f>>;
+maybe_replace($\r, #config{escaped_strings=true}) -> <<$\\, $r>>;
+maybe_replace($\", #config{escaped_strings=true}) -> <<$\\, $\">>;
 maybe_replace($/, Config=#config{escaped_strings=true}) ->
     case Config#config.escaped_forward_slashes of
-        true -> [$\\, $/]
-        ; false -> $/
+        true -> <<$\\, $/>>
+        ; false -> <<$/>>
     end;
-maybe_replace($\\, #config{escaped_strings=true}) -> [$\\, $\\];
+maybe_replace($\\, #config{escaped_strings=true}) -> <<$\\, $\\>>;
 maybe_replace(X, Config=#config{escaped_strings=true})  when X == 16#2028; X == 16#2029 ->
     case Config#config.unescaped_jsonp of
         true -> <<X/utf8>>
@@ -766,20 +821,17 @@ maybe_replace(X, Config=#config{escaped_strings=true})  when X == 16#2028; X ==
     end;
 maybe_replace(X, #config{escaped_strings=true}) when X < 32 ->
     json_escape_sequence(X);
-%% escaped even if no other escaping requested!
-maybe_replace(X, #config{uescape=true}) when X >= 16#80 ->
-    json_escape_sequence(X);
 maybe_replace(X, _Config) -> <<X/utf8>>.
 
 
 %% convert a codepoint to it's \uXXXX equiv.
 json_escape_sequence(X) when X < 65536 ->
     <<A:4, B:4, C:4, D:4>> = <<X:16>>,
-    [$\\, $u, (to_hex(A)), (to_hex(B)), (to_hex(C)), (to_hex(D))];
+    <<$\\, $u, (to_hex(A)), (to_hex(B)), (to_hex(C)), (to_hex(D))>>;
 json_escape_sequence(X) ->
     Adjusted = X - 16#10000,
     <<A:10, B:10>> = <<Adjusted:20>>,
-    json_escape_sequence(A + 16#d800) ++ json_escape_sequence(B + 16#dc00).
+    [json_escape_sequence(A + 16#d800), json_escape_sequence(B + 16#dc00)].
 
 
 %% ascii "1" is [49], "2" is [50], etc...
@@ -792,93 +844,174 @@ to_hex(15) -> $f;
 to_hex(X) -> X + 48.
 
 
-%% like in strings, there's some pseudo states in here that will never
-%%  show up in errors or incompletes. some show up in value, some show
-%%  up in integer, decimal or exp
-negative(<<$0, Rest/binary>>, Handler, Acc, Stack, Config) ->
-    zero(Rest, Handler, acc_seq(Acc, $0), Stack, Config);
-negative(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when ?is_nonzero(S) ->
-    integer(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-negative(<<>>, Handler, [?negative], Stack, Config) ->
-    incomplete(value, <<?negative>>, Handler, Stack, Config);
-negative(Bin, Handler, Acc, Stack, Config) ->
-    ?error(value, <<?negative, Bin/binary>>, Handler, Acc, Stack, Config).
+number(<<$e, Rest/binary>>, Handler, Acc, [integer|Stack], Config) ->
+    number(Rest, Handler, [Acc, $., $0, $e], [e|Stack], Config);
+number(<<$E, Rest/binary>>, Handler, Acc, [integer|Stack], Config) ->
+    number(Rest, Handler, [Acc, $., $0, $e], [e|Stack], Config);
+number(<<$e, Rest/binary>>, Handler, Acc, [zero|Stack], Config) ->
+    number(Rest, Handler, [Acc, $., $0, $e], [e|Stack], Config);
+number(<<$E, Rest/binary>>, Handler, Acc, [zero|Stack], Config) ->
+    number(Rest, Handler, [Acc, $., $0, $e], [e|Stack], Config);
+number(<<>>, Handler, Acc, [State|Stack], Config=#config{stream=false}) ->
+    NumType = case State of
+        zero -> integer;
+        integer -> integer;
+        decimal -> float;
+        exp -> float
+    end,
+    finish_number(<<>>, Handler, {NumType, iolist_to_binary(Acc)}, Stack, Config);
+number(<<>>, Handler, Acc, Stack, Config) ->
+    incomplete(number, <<>>, Handler, Acc, Stack, Config);
+number(Bin, Handler, Acc, [State|Stack], Config) ->
+    Counted = case State of
+        zero -> zero(Bin, 0);
+        integer -> integer(Bin, 0);
+        negative -> negative(Bin, 0);
+        initialdecimal -> initialdecimal(Bin, 0);
+        decimal -> decimal(Bin, 0);
+        e -> e(Bin, 0);
+        ex -> ex(Bin, 0);
+        exp -> exp(Bin, 0)
+    end,
+    case Counted of
+        {finish_integer, Size} ->
+            <<Clean:Size/binary, Rest/binary>> = Bin,
+            finish_number(Rest, Handler, {integer, iolist_to_binary([Acc, Clean])}, Stack, Config);
+        {finish_float, Size} ->
+            <<Clean:Size/binary, Rest/binary>> = Bin,
+            finish_number(Rest, Handler, {float, iolist_to_binary([Acc, Clean])}, Stack, Config);
+        {error, Size} ->
+            <<Clean:Size/binary, Rest/binary>> = Bin,
+            ?error(number, Rest, Handler, [Acc, Clean], Stack, Config);
+        {NewState, Size} ->
+            <<Clean:Size/binary, Rest/binary>> = Bin,
+            number(Rest, Handler, [Acc, Clean], [NewState|Stack], Config)
+    end.
 
 
-zero(<<?decimalpoint, Rest/binary>>, Handler, Acc, Stack, Config) ->
-    decimal(Rest, Handler, acc_seq(Acc, ?decimalpoint), Stack, Config);
-zero(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= $e; S =:= $E ->
-    e(Rest, Handler, acc_seq(Acc, ".0e"), Stack, Config);
-zero(Bin, Handler, Acc, Stack, Config) ->
-    finish_number(Bin, Handler, {zero, Acc}, Stack, Config).
+zero(<<?decimalpoint, Rest/binary>>, N) -> initialdecimal(Rest, N + 1);
+zero(<<>>, N) -> {zero, N};
+zero(_, N) -> {finish_integer, N}.
 
 
-integer(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= ?zero; ?is_nonzero(S) ->
-    integer(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-integer(<<?decimalpoint, Rest/binary>>, Handler, Acc, Stack, Config) ->
-    initialdecimal(Rest, Handler, acc_seq(Acc, ?decimalpoint), Stack, Config);
-integer(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= $e; S =:= $E ->
-    e(Rest, Handler, acc_seq(Acc, ".0e"), Stack, Config);
-integer(Bin, Handler, Acc, Stack, Config) ->
-    finish_number(Bin, Handler, {integer, Acc}, Stack, Config).
+integer(<<$0, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$1, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$2, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$3, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$4, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$5, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$6, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$7, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$8, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<$9, Rest/binary>>, N) -> integer(Rest, N + 1);
+integer(<<?decimalpoint, Rest/binary>>, N) -> initialdecimal(Rest, N + 1);
+integer(<<$e, _/binary>>, N) -> {integer, N};
+integer(<<$E, _/binary>>, N) -> {integer, N};
+integer(<<>>, N) -> {integer, N};
+integer(_, N) -> {finish_integer, N}.
 
 
-initialdecimal(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= ?zero; ?is_nonzero(S) ->
-    decimal(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-initialdecimal(<<>>, Handler, [?decimalpoint|Acc], Stack, Config) ->
-    incomplete(integer, <<?decimalpoint>>, Handler, Acc, Stack, Config);
-initialdecimal(Bin, Handler, Acc, Stack, Config) ->
-    ?error(decimal, Bin, Handler, Acc, Stack, Config).
+negative(<<$0, Rest/binary>>, N) -> zero(Rest, N + 1);
+negative(<<$1, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$2, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$3, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$4, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$5, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$6, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$7, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$8, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<$9, Rest/binary>>, N) -> integer(Rest, N + 1);
+negative(<<>>, N) -> {negative, N};
+negative(_, N) -> {error, N}.
 
 
-decimal(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= ?zero; ?is_nonzero(S) ->
-    decimal(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-decimal(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= $e; S =:= $E ->
-    e(Rest, Handler, acc_seq(Acc, $e), Stack, Config);
-decimal(Bin, Handler, Acc, Stack, Config) ->
-    finish_number(Bin, Handler, {decimal, Acc}, Stack, Config).
+initialdecimal(<<$0, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$1, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$2, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$3, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$4, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$5, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$6, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$7, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$8, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<$9, Rest/binary>>, N) -> decimal(Rest, N + 1);
+initialdecimal(<<>>, N) -> {initialdecimal, N};
+initialdecimal(_, N) -> {error, N}.
 
 
-e(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= ?zero; ?is_nonzero(S) ->
-    exp(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-e(<<Sign, Rest/binary>>, Handler, Acc, Stack, Config) when Sign =:= ?positive; Sign =:= ?negative ->
-    ex(Rest, Handler, acc_seq(Acc, Sign), Stack, Config);
-e(<<>>, Handler, [$e|Acc], Stack, Config) ->
-    incomplete(decimal, <<$e>>, Handler, Acc, Stack, Config);
-e(Bin, Handler, Acc, Stack, Config) ->
-    ?error(decimal, <<$e, Bin/binary>>, Handler, Acc, Stack, Config).
+decimal(<<$0, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$1, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$2, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$3, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$4, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$5, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$6, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$7, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$8, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$9, Rest/binary>>, N) -> decimal(Rest, N + 1);
+decimal(<<$e, Rest/binary>>, N) -> e(Rest, N + 1);
+decimal(<<$E, Rest/binary>>, N) -> e(Rest, N + 1);
+decimal(<<>>, N) -> {decimal, N};
+decimal(_, N) -> {finish_float, N}.
 
 
-ex(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= ?zero; ?is_nonzero(S) ->
-    exp(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-ex(<<>>, Handler, [S, $e|Acc], Stack, Config) ->
-    incomplete(decimal, <<$e, S/utf8>>, Handler, Acc, Stack, Config);
-ex(Bin, Handler, [S, $e|Acc], Stack, Config) ->
-    ?error(decimal, <<$e, S, Bin/binary>>, Handler, Acc, Stack, Config).
+e(<<$0, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$1, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$2, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$3, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$4, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$5, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$6, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$7, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$8, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<$9, Rest/binary>>, N) -> exp(Rest, N + 1);
+e(<<?positive, Rest/binary>>, N) -> ex(Rest, N + 1);
+e(<<?negative, Rest/binary>>, N) -> ex(Rest, N + 1);
+e(<<>>, N) -> {e, N};
+e(_, N) -> {error, N}.
 
 
-exp(<<S, Rest/binary>>, Handler, Acc, Stack, Config) when S =:= ?zero; ?is_nonzero(S) ->
-    exp(Rest, Handler, acc_seq(Acc, S), Stack, Config);
-exp(Bin, Handler, Acc, Stack, Config) ->
-    finish_number(Bin, Handler, {exp, Acc}, Stack, Config).
+ex(<<$0, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$1, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$2, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$3, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$4, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$5, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$6, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$7, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$8, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<$9, Rest/binary>>, N) -> exp(Rest, N + 1);
+ex(<<>>, N) -> {ex, N};
+ex(_, N) -> {error, N}.
 
 
-acc_seq(Seq, C) when is_list(C) -> lists:reverse(C) ++ Seq;
-acc_seq(Seq, C) -> [C] ++ Seq.
+exp(<<$0, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$1, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$2, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$3, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$4, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$5, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$6, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$7, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$8, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<$9, Rest/binary>>, N) -> exp(Rest, N + 1);
+exp(<<>>, N) -> {exp, N};
+exp(_, N) -> {finish_float, N}.
 
 
-finish_number(Rest, Handler, Acc, [], Config=#config{stream=false}) ->
-    maybe_done(Rest, handle_event(format_number(Acc), Handler, Config), [], Config);
-finish_number(<<>>, Handler, {NumType, Acc}, Stack, Config) ->
-    incomplete(NumType, <<>>, Handler, Acc, Stack, Config);
 finish_number(Rest, Handler, Acc, Stack, Config) ->
     maybe_done(Rest, handle_event(format_number(Acc), Handler, Config), Stack, Config).
 
 
-format_number({zero, Acc}) -> {integer, list_to_integer(lists:reverse(Acc))};
-format_number({integer, Acc}) -> {integer, list_to_integer(lists:reverse(Acc))};
-format_number({decimal, Acc}) -> {float, list_to_float(lists:reverse(Acc))};
-format_number({exp, Acc}) -> {float, list_to_float(lists:reverse(Acc))}.
+-ifndef(no_binary_to_whatever).
+format_number({integer, Acc}) -> {integer, binary_to_integer(Acc)};
+format_number({float, Acc}) -> {float, binary_to_float(Acc)}.
+-endif.
+
+-ifdef(no_binary_to_whatever).
+format_number({integer, Acc}) -> {integer, list_to_integer(unicode:characters_to_list(Acc))};
+format_number({float, Acc}) -> {float, list_to_float(unicode:characters_to_list(Acc))}.
+-endif.
 
 
 true(<<$r, $u, $e, Rest/binary>>, Handler, Stack, Config) ->
@@ -947,6 +1080,8 @@ comment(Bin, Handler, Resume, Stack, Config) ->
 
 maybe_done(<<Rest/binary>>, Handler, [], Config) ->
     done(Rest, handle_event(end_json, Handler, Config), [], Config);
+maybe_done(<<?space, Rest/binary>>, Handler, Stack, Config) ->
+    maybe_done(Rest, Handler, Stack, Config);
 maybe_done(<<?end_object, Rest/binary>>, Handler, [object|Stack], Config) ->
     maybe_done(Rest, handle_event(end_object, Handler, Config), Stack, Config);
 maybe_done(<<?end_array, Rest/binary>>, Handler, [array|Stack], Config) ->
@@ -955,7 +1090,11 @@ maybe_done(<<?comma, Rest/binary>>, Handler, [object|Stack], Config) ->
     key(Rest, Handler, [key|Stack], Config);
 maybe_done(<<?comma, Rest/binary>>, Handler, [array|_] = Stack, Config) ->
     value(Rest, Handler, Stack, Config);
-maybe_done(<<S, Rest/binary>>, Handler, Stack, Config) when ?is_whitespace(S) ->
+maybe_done(<<?newline, Rest/binary>>, Handler, Stack, Config) ->
+    maybe_done(Rest, Handler, Stack, Config);
+maybe_done(<<?tab, Rest/binary>>, Handler, Stack, Config) ->
+    maybe_done(Rest, Handler, Stack, Config);
+maybe_done(<<?cr, Rest/binary>>, Handler, Stack, Config) ->
     maybe_done(Rest, Handler, Stack, Config);
 maybe_done(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
     ?error(maybe_done, <<?solidus, Rest/binary>>, Handler, Stack, Config);
@@ -971,7 +1110,13 @@ maybe_done(Bin, Handler, Stack, Config) ->
     ?error(maybe_done, Bin, Handler, Stack, Config).
 
 
-done(<<S, Rest/binary>>, Handler, [], Config) when ?is_whitespace(S) ->
+done(<<?space, Rest/binary>>, Handler, [], Config) ->
+    done(Rest, Handler, [], Config);
+done(<<?newline, Rest/binary>>, Handler, [], Config) ->
+    done(Rest, Handler, [], Config);
+done(<<?tab, Rest/binary>>, Handler, [], Config) ->
+    done(Rest, Handler, [], Config);
+done(<<?cr, Rest/binary>>, Handler, [], Config) ->
     done(Rest, Handler, [], Config);
 done(<<?solidus, Rest/binary>>, Handler, Stack, Config=#config{strict_comments=true}) ->
     ?error(done, <<?solidus, Rest/binary>>, Handler, Stack, Config);
diff --git a/src/jsx_encoder.erl b/src/jsx_encoder.erl
index d39d49a..12b1c67 100644
--- a/src/jsx_encoder.erl
+++ b/src/jsx_encoder.erl
@@ -23,7 +23,7 @@
 
 -module(jsx_encoder).
 
--export([encoder/3, encode/1, encode/2, unzip/1]).
+-export([encoder/3, encode/1, encode/2]).
 
 -spec encoder(Handler::module(), State::any(), Config::list()) -> jsx:encoder().
 
@@ -44,11 +44,10 @@ encode(Term, EntryPoint) -> encode_(Term, EntryPoint).
 -endif.
 
 -ifdef(maps_support).
-encode(Map, _EntryPoint) when is_map(Map), map_size(Map) < 1 -> [start_object, end_object];
+encode(Map, _EntryPoint) when is_map(Map), map_size(Map) < 1 ->
+    [start_object, end_object];
 encode(Term, EntryPoint) when is_map(Term) ->
-    lists:flatten(
-        [start_object] ++ [ EntryPoint:encode(T, EntryPoint) || T <- unpack(Term) ] ++ [end_object]
-    );
+    [start_object] ++ unpack(Term, EntryPoint);
 encode(Term, EntryPoint) -> encode_(Term, EntryPoint).
 -endif.
 
@@ -56,28 +55,29 @@ encode_([], _EntryPoint) -> [start_array, end_array];
 encode_([{}], _EntryPoint) -> [start_object, end_object];
 
 encode_([{_, _}|_] = Term, EntryPoint) ->
-    lists:flatten(
-        [start_object] ++ [ EntryPoint:encode(T, EntryPoint) || T <- unzip(Term) ] ++ [end_object]
-    );
+    [start_object] ++ unzip(Term, EntryPoint);
 encode_(Term, EntryPoint) when is_list(Term) ->
-    lists:flatten(
-        [start_array] ++ [ EntryPoint:encode(T, EntryPoint) || T <- Term ] ++ [end_array]
-    );
+    [start_array] ++ unhitch(Term, EntryPoint);
 
 encode_(Else, _EntryPoint) -> [Else].
 
 
-unzip(List) -> unzip(List, []).
+unzip([{K, V}|Rest], EntryPoint) when is_integer(K); is_binary(K); is_atom(K) ->
+    [K] ++ EntryPoint:encode(V, EntryPoint) ++ unzip(Rest, EntryPoint);
+unzip([], _) -> [end_object].
+
+
+unhitch([V|Rest], EntryPoint) ->
+    EntryPoint:encode(V, EntryPoint) ++ unhitch(Rest, EntryPoint);
+unhitch([], _) -> [end_array].
 
-unzip([], Acc) -> lists:reverse(Acc);
-unzip([{K, V}|Rest], Acc) when is_binary(K); is_atom(K); is_integer(K) -> unzip(Rest, [V, K] ++ Acc).
 
 -ifdef(maps_support).
-unpack(Map) -> unpack(maps:keys(Map), Map, []).
+unpack(Map, EntryPoint) -> unpack(Map, maps:keys(Map), EntryPoint).
 
-unpack([], _, Acc) -> lists:reverse(Acc);
-unpack([K|Rest], Map, Acc) when is_binary(K); is_atom(K); is_integer(K) ->
-    unpack(Rest, Map, [maps:get(K, Map), K] ++ Acc).
+unpack(Map, [K|Rest], EntryPoint) when is_integer(K); is_binary(K); is_atom(K) ->
+    [K] ++ EntryPoint:encode(maps:get(K, Map), EntryPoint) ++ unpack(Map, Rest, EntryPoint);
+unpack(_, [], _) -> [end_object].
 -endif.
 
 
diff --git a/src/jsx_parser.erl b/src/jsx_parser.erl
index da128ff..7113c71 100644
--- a/src/jsx_parser.erl
+++ b/src/jsx_parser.erl
@@ -87,36 +87,26 @@ incomplete(State, Handler, Stack, Config=#config{incomplete_handler=F}) ->
 handle_event(Event, {Handler, State}, _Config) -> {Handler, Handler:handle_event(Event, State)}.
 
 
-value([start_object|Tokens], Handler, Stack, Config) ->
-    object(Tokens, handle_event(start_object, Handler, Config), [{object, sets:new()}|Stack], Config);
-value([start_array|Tokens], Handler, Stack, Config) ->
-    array(Tokens, handle_event(start_array, Handler, Config), [array|Stack], Config);
-value([{literal, Literal}|Tokens], Handler, Stack, Config) when Literal == true; Literal == false; Literal == null ->
-    maybe_done(Tokens, handle_event({literal, Literal}, Handler, Config), Stack, Config);
-value([Literal|Tokens], Handler, Stack, Config) when Literal == true; Literal == false; Literal == null ->
-    value([{literal, Literal}] ++ Tokens, Handler, Stack, Config);
-value([{integer, Number}|Tokens], Handler, Stack, Config) when is_integer(Number) ->
-    maybe_done(Tokens, handle_event({integer, Number}, Handler, Config), Stack, Config);
-value([{float, Number}|Tokens], Handler, Stack, Config) when is_float(Number) ->
-    maybe_done(Tokens, handle_event({float, Number}, Handler, Config), Stack, Config);
-value([{number, Number}|Tokens], Handler, Stack, Config) when is_integer(Number) ->
-    value([{integer, Number}] ++ Tokens, Handler, Stack, Config);
-value([{number, Number}|Tokens], Handler, Stack, Config) when is_float(Number) ->
-    value([{float, Number}] ++ Tokens, Handler, Stack, Config);
-value([Number|Tokens], Handler, Stack, Config) when is_integer(Number) ->
-    value([{integer, Number}] ++ Tokens, Handler, Stack, Config);
-value([Number|Tokens], Handler, Stack, Config) when is_float(Number) ->
-    value([{float, Number}] ++ Tokens, Handler, Stack, Config);
-value([{string, String}|Tokens], Handler, Stack, Config) when is_binary(String) ->
+value([String|Tokens], Handler, Stack, Config) when is_binary(String) ->
     try clean_string(String, Config) of Clean ->
         maybe_done(Tokens, handle_event({string, Clean}, Handler, Config), Stack, Config)
     catch error:badarg ->
         ?error(value, [{string, String}|Tokens], Handler, Stack, Config)
     end;
-value([String|Tokens], Handler, Stack, Config) when is_binary(String) ->
-    value([{string, String}] ++ Tokens, Handler, Stack, Config);
-value([String|Tokens], Handler, Stack, Config) when is_atom(String) ->
-    value([{string, atom_to_binary(String, utf8)}] ++ Tokens, Handler, Stack, Config);
+value([true|Tokens], Handler, Stack, Config) ->
+    maybe_done(Tokens, handle_event({literal, true}, Handler, Config), Stack, Config);
+value([false|Tokens], Handler, Stack, Config) ->
+    maybe_done(Tokens, handle_event({literal, false}, Handler, Config), Stack, Config);
+value([null|Tokens], Handler, Stack, Config) ->
+    maybe_done(Tokens, handle_event({literal, null}, Handler, Config), Stack, Config);
+value([start_object|Tokens], Handler, Stack, Config) ->
+    object(Tokens, handle_event(start_object, Handler, Config), [object|Stack], Config);
+value([start_array|Tokens], Handler, Stack, Config) ->
+    array(Tokens, handle_event(start_array, Handler, Config), [array|Stack], Config);
+value([Number|Tokens], Handler, Stack, Config) when is_integer(Number) ->
+    maybe_done(Tokens, handle_event({integer, Number}, Handler, Config), Stack, Config);
+value([Number|Tokens], Handler, Stack, Config) when is_float(Number) ->
+    maybe_done(Tokens, handle_event({float, Number}, Handler, Config), Stack, Config);
 value([{raw, Raw}|Tokens], Handler, Stack, Config) when is_binary(Raw) ->
     value((jsx:decoder(?MODULE, [], []))(Raw) ++ Tokens, Handler, Stack, Config);
 value([{{Year, Month, Day}, {Hour, Min, Sec}}|Tokens], Handler, Stack, Config)
@@ -129,6 +119,10 @@ when is_integer(Year), is_integer(Month), is_integer(Day), is_integer(Hour), is_
         Stack,
         Config
     );
+value([{_, Value}|Tokens], Handler, Stack, Config) ->
+    value([Value] ++ Tokens, Handler, Stack, Config);
+value([String|Tokens], Handler, Stack, Config) when is_atom(String) ->
+    value([{string, atom_to_binary(String, utf8)}] ++ Tokens, Handler, Stack, Config);
 value([], Handler, Stack, Config) ->
     incomplete(value, Handler, Stack, Config);
 value(BadTokens, Handler, Stack, Config) when is_list(BadTokens) ->
@@ -136,35 +130,19 @@ value(BadTokens, Handler, Stack, Config) when is_list(BadTokens) ->
 value(Token, Handler, Stack, Config) ->
     value([Token], Handler, Stack, Config).
 
-object([end_object|Tokens], Handler, [{object, _}|Stack], Config) ->
+object([end_object|Tokens], Handler, [object|Stack], Config) ->
     maybe_done(Tokens, handle_event(end_object, Handler, Config), Stack, Config);
 object([{key, Key}|Tokens], Handler, Stack, Config)
 when is_atom(Key); is_binary(Key); is_integer(Key) ->
     object([Key|Tokens], Handler, Stack, Config);
-object([Key|Tokens], Handler, [{object, _Keys}|Stack], Config=#config{repeat_keys=true})
+object([Key|Tokens], Handler, [object|Stack], Config)
 when is_atom(Key); is_binary(Key); is_integer(Key) ->
     try clean_string(fix_key(Key), Config)
     of K ->
         value(
             Tokens,
             handle_event({key, K}, Handler, Config),
-            [{object, []}|Stack],
-            Config
-        )
-    catch error:badarg ->
-        ?error(object, [{string, Key}|Tokens], Handler, Stack, Config)
-    end;
-object([Key|Tokens], Handler, [{object, Keys}|Stack], Config)
-when is_atom(Key); is_binary(Key); is_integer(Key) ->
-    try
-        CleanKey = clean_string(fix_key(Key), Config),
-        case sets:is_element(CleanKey, Keys) of true -> erlang:error(badarg); _ -> ok end,
-        CleanKey
-    of K ->
-        value(
-            Tokens,
-            handle_event({key, K}, Handler, Config),
-            [{object, sets:add_element(K, Keys)}|Stack],
+            [object|Stack],
             Config
         )
     catch error:badarg ->
@@ -186,7 +164,7 @@ array(Token, Handler, Stack, Config) ->
 
 maybe_done([end_json], Handler, [], Config) ->
     done([end_json], Handler, [], Config);
-maybe_done(Tokens, Handler, [{object, _}|_] = Stack, Config) when is_list(Tokens) ->
+maybe_done(Tokens, Handler, [object|_] = Stack, Config) when is_list(Tokens) ->
     object(Tokens, Handler, Stack, Config);
 maybe_done(Tokens, Handler, [array|_] = Stack, Config) when is_list(Tokens) ->
     array(Tokens, Handler, Stack, Config);
@@ -219,35 +197,35 @@ clean_string(Bin, Config) -> clean(Bin, [], Config).
 
 clean(<<>>, Acc, _) -> iolist_to_binary(Acc);
 clean(<<X/utf8, Rest/binary>>, Acc, Config) when X < 16#20 ->
-    maybe_replace(X, Rest, Acc, Config);
+    clean(Rest, [Acc, maybe_replace(X, Config)], Config);
 clean(<<34, Rest/binary>>, Acc, Config) ->
-    maybe_replace(34, Rest, Acc, Config);
+    clean(Rest, [Acc, maybe_replace(34, Config)], Config);
 clean(<<47, Rest/binary>>, Acc, Config) ->
-    maybe_replace(47, Rest, Acc, Config);
+    clean(Rest, [Acc, maybe_replace(47, Config)], Config);
 clean(<<92, Rest/binary>>, Acc, Config) ->
-    maybe_replace(92, Rest, Acc, Config);
+    clean(Rest, [Acc, maybe_replace(92, Config)], Config);
 clean(<<X/utf8, Rest/binary>>, Acc, Config=#config{uescape=true}) when X >= 16#80 ->
-    maybe_replace(X, Rest, Acc, Config);
+    clean(Rest, [Acc, json_escape_sequence(X)], Config);
 clean(<<X/utf8, Rest/binary>>, Acc, Config) when X == 16#2028; X == 16#2029 ->
-    maybe_replace(X, Rest, Acc, Config);
+    clean(Rest, [Acc, maybe_replace(X, Config)], Config);
 clean(<<_/utf8, _/binary>> = Bin, Acc, Config) ->
     Size = count(Bin, 0, Config),
     <<Clean:Size/binary, Rest/binary>> = Bin,
     clean(Rest, [Acc, Clean], Config);
 %% surrogates
 clean(<<237, X, _, Rest/binary>>, Acc, Config) when X >= 160 ->
-    maybe_replace(surrogate, Rest, Acc, Config);
+    clean(Rest, [Acc, maybe_replace(surrogate, Config)], Config);
 %% overlong encodings and missing continuations of a 2 byte sequence
 clean(<<X, Rest/binary>>, Acc, Config) when X >= 192, X =< 223 ->
-    maybe_replace(badutf, strip_continuations(Rest, 1), Acc, Config);
+    clean(strip_continuations(Rest, 1), [Acc, maybe_replace(badutf, Config)], Config);
 %% overlong encodings and missing continuations of a 3 byte sequence
 clean(<<X, Rest/binary>>, Acc, Config) when X >= 224, X =< 239 ->
-    maybe_replace(badutf, strip_continuations(Rest, 2), Acc, Config);
+    clean(strip_continuations(Rest, 2), [Acc, maybe_replace(badutf, Config)], Config);
 %% overlong encodings and missing continuations of a 4 byte sequence
 clean(<<X, Rest/binary>>, Acc, Config) when X >= 240, X =< 247 ->
-    maybe_replace(badutf, strip_continuations(Rest, 3), Acc, Config);
+    clean(strip_continuations(Rest, 3), [Acc, maybe_replace(badutf, Config)], Config);
 clean(<<_, Rest/binary>>, Acc, Config) ->
-    maybe_replace(badutf, Rest, Acc, Config).
+    clean(Rest, [Acc, maybe_replace(badutf, Config)], Config).
 
 
 count(<<>>, N, _) -> N;
@@ -473,13 +451,16 @@ count(<<126, Rest/binary>>, N, Config) ->
 count(<<127, Rest/binary>>, N, Config) ->
     count(Rest, N + 1, Config);
 count(<<_/utf8, _/binary>>, N, #config{uescape=true}) -> N;
-count(<<X/utf8, _/binary>>, N, _) when X == 16#2028; X == 16#2029 -> N;
-count(<<X/utf8, Rest/binary>>, N, Config) when X < 16#800 ->
-    count(Rest, N + 2, Config);
-count(<<X/utf8, Rest/binary>>, N, Config) when X < 16#10000 ->
-    count(Rest, N + 3, Config);
-count(<<_/utf8, Rest/binary>>, N, Config) ->
-    count(Rest, N + 4, Config);
+%% u+2028
+count(<<226, 128, 168, _/binary>>, N, _) -> N;
+%% u+2029
+count(<<226, 128, 169, _/binary>>, N, _) -> N;
+count(<<X/utf8, Rest/binary>>, N, Config) ->
+    case X of
+        X when X < 16#800 -> count(Rest, N + 2, Config);
+        X when X < 16#10000 -> count(Rest, N + 3, Config);
+        _ -> count(Rest, N + 4, Config)
+    end;
 count(<<_, _/binary>>, N, _) -> N.
 
 
@@ -490,53 +471,43 @@ strip_continuations(<<X, Rest/binary>>, N) when X >= 128, X =< 191 ->
 strip_continuations(Bin, _) -> Bin.
 
 
-maybe_replace($\b, Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $b], Config);
-maybe_replace($\t, Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $t], Config);
-maybe_replace($\n, Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $n], Config);
-maybe_replace($\f, Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $f], Config);
-maybe_replace($\r, Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $r], Config);
-maybe_replace($\", Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $\"], Config);
-maybe_replace($/, Rest, Acc, Config=#config{escaped_strings=true}) ->
+maybe_replace($\b, #config{escaped_strings=true}) -> <<$\\, $b>>;
+maybe_replace($\t, #config{escaped_strings=true}) -> <<$\\, $t>>;
+maybe_replace($\n, #config{escaped_strings=true}) -> <<$\\, $n>>;
+maybe_replace($\f, #config{escaped_strings=true}) -> <<$\\, $f>>;
+maybe_replace($\r, #config{escaped_strings=true}) -> <<$\\, $r>>;
+maybe_replace($\", #config{escaped_strings=true}) -> <<$\\, $\">>;
+maybe_replace($/, Config=#config{escaped_strings=true}) ->
     case Config#config.escaped_forward_slashes of
-        true -> clean(Rest, [Acc, $\\, $/], Config);
-        false -> clean(Rest, [Acc, $/], Config)
+        true -> <<$\\, $/>>;
+        false -> <<$/>>
     end;
-maybe_replace($\\, Rest, Acc, Config=#config{escaped_strings=true}) ->
-    clean(Rest, [Acc, $\\, $\\], Config);
-maybe_replace(X, Rest, Acc, Config=#config{escaped_strings=true}) when X < 32 ->
-    clean(Rest, [Acc, json_escape_sequence(X)], Config);
-%% escaped even if no other escaping was requested!
-maybe_replace(X, Rest, Acc, Config=#config{uescape=true}) when X >= 16#80 ->
-    clean(Rest, [Acc, json_escape_sequence(X)], Config);
-maybe_replace(X, Rest, Acc, Config=#config{escaped_strings=true})  when X == 16#2028; X == 16#2029 ->
+maybe_replace($\\, #config{escaped_strings=true}) -> <<$\\, $\\>>;
+maybe_replace(X, #config{escaped_strings=true}) when X < 32 ->
+    json_escape_sequence(X);
+maybe_replace(X, Config=#config{escaped_strings=true})  when X == 16#2028; X == 16#2029 ->
     case Config#config.unescaped_jsonp of
-        true -> clean(Rest, [Acc, <<X/utf8>>], Config);
-        false -> clean(Rest, [Acc, json_escape_sequence(X)], Config)
+        true -> <<X/utf8>>;
+        false -> json_escape_sequence(X)
     end;
-maybe_replace(Atom, _, _, #config{strict_utf8=true}) when is_atom(Atom) ->
+maybe_replace(Atom, #config{strict_utf8=true}) when is_atom(Atom) ->
     erlang:error(badarg);
-maybe_replace(surrogate, Rest, Acc, Config) ->
-    clean(Rest, [Acc, <<16#fffd/utf8>>], Config);
-maybe_replace(badutf, Rest, Acc, Config) ->
-    clean(Rest, [Acc, <<16#fffd/utf8>>], Config);
-maybe_replace(X, Rest, Acc, Config) ->
-    clean(Rest, [Acc, <<X/utf8>>], Config).
+maybe_replace(surrogate, _Config) ->
+    <<16#fffd/utf8>>;
+maybe_replace(badutf, _Config) ->
+    <<16#fffd/utf8>>;
+maybe_replace(X, _Config) ->
+    <<X/utf8>>.
 
 
 %% convert a codepoint to it's \uXXXX equiv.
 json_escape_sequence(X) when X < 65536 ->
     <<A:4, B:4, C:4, D:4>> = <<X:16>>,
-    [$\\, $u, (to_hex(A)), (to_hex(B)), (to_hex(C)), (to_hex(D))];
+    <<$\\, $u, (to_hex(A)), (to_hex(B)), (to_hex(C)), (to_hex(D))>>;
 json_escape_sequence(X) ->
     Adjusted = X - 16#10000,
     <<A:10, B:10>> = <<Adjusted:20>>,
-    json_escape_sequence(A + 16#d800) ++ json_escape_sequence(B + 16#dc00).
+    [json_escape_sequence(A + 16#d800), json_escape_sequence(B + 16#dc00)].
 
 
 to_hex(10) -> $a;
@@ -1052,11 +1023,12 @@ bad_utf8_test_() ->
 
 json_escape_sequence_test_() ->
     [
-        {"json escape sequence test - 16#0000", ?_assertEqual(json_escape_sequence(16#0000), "\\u0000")},
-        {"json escape sequence test - 16#abc", ?_assertEqual(json_escape_sequence(16#abc), "\\u0abc")},
-        {"json escape sequence test - 16#def", ?_assertEqual(json_escape_sequence(16#def), "\\u0def")}
+        {"json escape sequence test - 16#0000", ?_assertEqual(<<"\\u0000"/utf8>>, json_escape_sequence(16#0000))},
+        {"json escape sequence test - 16#abc", ?_assertEqual(<<"\\u0abc"/utf8>>, json_escape_sequence(16#abc))},
+        {"json escape sequence test - 16#def", ?_assertEqual(<<"\\u0def"/utf8>>, json_escape_sequence(16#def))}
     ].
 
+
 uescape_test_() ->
     [
         {"\"\\u0080\"", ?_assertEqual(
@@ -1080,6 +1052,7 @@ uescape_test_() ->
         )}
     ].
 
+
 fix_key_test_() ->
     [
         {"binary key", ?_assertEqual(fix_key(<<"foo">>), <<"foo">>)},
@@ -1088,16 +1061,6 @@ fix_key_test_() ->
     ].
 
 
-repeated_key_test_() ->
-    Parse = fun(Events, Config) -> (parser(?MODULE, [], Config))(Events ++ [end_json]) end,
-    [
-        {"repeated key", ?_assertError(
-            badarg,
-            Parse([start_object, <<"key">>, true, <<"key">>, true, end_object], [])
-        )}
-    ].
-
-
 datetime_test_() ->
     [
         {"datetime", ?_assertEqual(
diff --git a/src/jsx_to_term.erl b/src/jsx_to_term.erl
index 25cb227..b23450c 100644
--- a/src/jsx_to_term.erl
+++ b/src/jsx_to_term.erl
@@ -23,10 +23,17 @@
 
 -module(jsx_to_term).
 
--export([to_term/2]).
+-export([to_term/2, flatify/1]).
 -export([init/1, handle_event/2]).
--export([start_term/0, start_term/1]).
--export([start_object/1, start_array/1, finish/1, insert/2, insert/3, get_key/1, get_value/1]).
+-export([
+    start_term/1,
+    start_object/1,
+    start_array/1,
+    finish/1,
+    insert/2,
+    get_key/1,
+    get_value/1
+]).
 
 
 -record(config, {
@@ -37,15 +44,27 @@
 -type config() :: list().
 -export_type([config/0]).
 
-
--type json_value() :: list({binary(), json_value()})
-    | list(json_value())
+-ifndef(maps_support).
+-type json_value() :: list(json_value())
+    | list({binary() | atom(), json_value()})
     | true
     | false
     | null
     | integer()
     | float()
     | binary().
+-endif.
+
+-ifdef(maps_support).
+-type json_value() :: list(json_value())
+    | map()
+    | true
+    | false
+    | null
+    | integer()
+    | float()
+    | binary().
+-endif.
 
 
 -spec to_term(Source::binary(), Config::config()) -> json_value().
@@ -79,10 +98,11 @@ parse_config([K|Rest] = Options, Config) ->
 parse_config([], Config) ->
     Config.
 
--type state() :: {[any()], #config{}}.
+
+-type state() :: {list(), #config{}}.
 -spec init(Config::proplists:proplist()) -> state().
 
-init(Config) -> {[], parse_config(Config)}.
+init(Config) -> start_term(Config).
 
 -spec handle_event(Event::any(), State::state()) -> state().
 
@@ -118,47 +138,46 @@ format_key(Key, Config) ->
 %% the stack is a list of in progress objects/arrays
 %%  `[Current, Parent, Grandparent,...OriginalAncestor]`
 %% an object has the representation on the stack of
-%%  `{object, [{NthKey, NthValue}, {NMinus1Key, NthMinus1Value},...{FirstKey, FirstValue}]}`
-%% of if there's a key with a yet to be matched value
-%%  `{object, Key, [{NthKey, NthValue},...]}`
+%%  `{object, [
+%%    {NthKey, NthValue},
+%%    {NMinus1Key, NthMinus1Value},
+%%    ...,
+%%    {FirstKey, FirstValue}
+%%  ]}`
+%% or if returning maps
+%%  `{object, #{
+%%    FirstKey => FirstValue,
+%%    SecondKey => SecondValue,
+%%    ...,
+%%    NthKey => NthValue
+%%  }}`
+%% or if there's a key with a yet to be matched value
+%%  `{object, Key, ...}`
 %% an array looks like
 %%  `{array, [NthValue, NthMinus1Value,...FirstValue]}`
 
-start_term() -> {[], #config{}}.
-
 start_term(Config) when is_list(Config) -> {[], parse_config(Config)}.
 
+
+-ifndef(maps_support).
 %% allocate a new object on top of the stack
 start_object({Stack, Config}) -> {[{object, []}] ++ Stack, Config}.
 
+
 %% allocate a new array on top of the stack
 start_array({Stack, Config}) -> {[{array, []}] ++ Stack, Config}.
 
--ifndef(maps_support).
-finish(Any) -> finish0(Any).
--endif.
-
--ifdef(maps_support).
-finish({[{object, []}], Config=#config{return_maps=true}}) ->
-    {#{}, Config};
-finish({[{object, []}|Rest], Config=#config{return_maps=true}}) ->
-    insert(#{}, {Rest, Config});
-finish({[{object, Pairs}], Config=#config{return_maps=true}}) ->
-    {maps:from_list(Pairs), Config};
-finish({[{object, Pairs}|Rest], Config=#config{return_maps=true}}) ->
-    insert(maps:from_list(Pairs), {Rest, Config});
-finish(Else) -> finish0(Else).
--endif.
 
 %% finish an object or array and insert it into the parent object if it exists or
-%%  return it if it is the root object
-finish0({[{object, []}], Config}) -> {[{}], Config};
-finish0({[{object, []}|Rest], Config}) -> insert([{}], {Rest, Config});
-finish0({[{object, Pairs}], Config}) -> {lists:reverse(Pairs), Config};
-finish0({[{object, Pairs}|Rest], Config}) -> insert(lists:reverse(Pairs), {Rest, Config});
-finish0({[{array, Values}], Config}) -> {lists:reverse(Values), Config};
-finish0({[{array, Values}|Rest], Config}) -> insert(lists:reverse(Values), {Rest, Config});
-finish0(_) -> erlang:error(badarg).
+%% return it if it is the root object
+finish({[{object, []}], Config}) -> {[{}], Config};
+finish({[{object, []}|Rest], Config}) -> insert([{}], {Rest, Config});
+finish({[{object, Pairs}], Config}) -> {lists:reverse(Pairs), Config};
+finish({[{object, Pairs}|Rest], Config}) -> insert(lists:reverse(Pairs), {Rest, Config});
+finish({[{array, Values}], Config}) -> {lists:reverse(Values), Config};
+finish({[{array, Values}|Rest], Config}) -> insert(lists:reverse(Values), {Rest, Config});
+finish(_) -> erlang:error(badarg).
+
 
 %% insert a value when there's no parent object or array
 insert(Value, {[], Config}) -> {Value, Config};
@@ -170,11 +189,49 @@ insert(Value, {[{object, Key, Pairs}|Rest], Config}) ->
 insert(Value, {[{array, Values}|Rest], Config}) ->
     {[{array, [Value] ++ Values}] ++ Rest, Config};
 insert(_, _) -> erlang:error(badarg).
+-endif.
 
-%% insert a key/value pair into an object
-insert(Key, Value, {[{object, Pairs}|Rest], Config}) ->
+
+-ifdef(maps_support).
+%% allocate a new object on top of the stack
+start_object({Stack, Config=#config{return_maps=true}}) ->
+    {[{object, #{}}] ++ Stack, Config};
+start_object({Stack, Config}) ->
+    {[{object, []}] ++ Stack, Config}.
+
+
+%% allocate a new array on top of the stack
+start_array({Stack, Config}) -> {[{array, []}] ++ Stack, Config}.
+
+
+%% finish an object or array and insert it into the parent object if it exists or
+%% return it if it is the root object
+finish({[{object, Map}], Config=#config{return_maps=true}}) -> {Map, Config};
+finish({[{object, Map}|Rest], Config=#config{return_maps=true}}) -> insert(Map, {Rest, Config});
+finish({[{object, []}], Config}) -> {[{}], Config};
+finish({[{object, []}|Rest], Config}) -> insert([{}], {Rest, Config});
+finish({[{object, Pairs}], Config}) -> {lists:reverse(Pairs), Config};
+finish({[{object, Pairs}|Rest], Config}) -> insert(lists:reverse(Pairs), {Rest, Config});
+finish({[{array, Values}], Config}) -> {lists:reverse(Values), Config};
+finish({[{array, Values}|Rest], Config}) -> insert(lists:reverse(Values), {Rest, Config});
+finish(_) -> erlang:error(badarg).
+
+
+%% insert a value when there's no parent object or array
+insert(Value, {[], Config}) -> {Value, Config};
+%% insert a key or value into an object or array, autodetects the 'right' thing
+insert(Key, {[{object, Map}|Rest], Config=#config{return_maps=true}}) ->
+    {[{object, Key, Map}] ++ Rest, Config};
+insert(Key, {[{object, Pairs}|Rest], Config}) ->
+    {[{object, Key, Pairs}] ++ Rest, Config};
+insert(Value, {[{object, Key, Map}|Rest], Config=#config{return_maps=true}}) ->
+    {[{object, maps:put(Key, Value, Map)}] ++ Rest, Config};
+insert(Value, {[{object, Key, Pairs}|Rest], Config}) ->
     {[{object, [{Key, Value}] ++ Pairs}] ++ Rest, Config};
-insert(_, _, _) -> erlang:error(badarg).
+insert(Value, {[{array, Values}|Rest], Config}) ->
+    {[{array, [Value] ++ Values}] ++ Rest, Config};
+insert(_, _) -> erlang:error(badarg).
+-endif.
 
 
 get_key({[{object, Key, _}|_], _}) -> Key;
@@ -185,6 +242,15 @@ get_value({Value, _Config}) -> Value;
 get_value(_) -> erlang:error(badarg).
 
 
+%% we know the structure of our accumulator so we can safely
+%%  flatten like this
+flatify(List) -> flatify(List, []).
+%% head of list should always be []
+flatify([], Tail) -> Tail;
+flatify([H, T], Tail) -> flatify(H, [T] ++ Tail).
+
+
+
 %% eunit tests
 
 -ifdef(TEST).
@@ -235,10 +301,6 @@ format_key_test_() ->
 
 rep_manipulation_test_() ->
     [
-        {"allocate a new context", ?_assertEqual(
-            {[], #config{}},
-            start_term()
-        )},
         {"allocate a new context with option", ?_assertEqual(
             {[], #config{labels=atom}},
             start_term([{labels, atom}])
@@ -283,10 +345,6 @@ rep_manipulation_test_() ->
             {[{array, [value]}, junk], #config{}},
             insert(value, {[{array, []}, junk], #config{}})
         )},
-        {"insert a key/value pair into an object", ?_assertEqual(
-            {[{object, [{key, value}, {x, y}]}, junk], #config{}},
-            insert(key, value, {[{object, [{x, y}]}, junk], #config{}})
-        )},
         {"finish an object with no ancestor", ?_assertEqual(
             {[{a, b}, {x, y}], #config{}},
             finish({[{object, [{x, y}, {a, b}]}], #config{}})
@@ -309,7 +367,54 @@ rep_manipulation_test_() ->
         )}
     ].
 
+
 -ifdef(maps_support).
+rep_manipulation_with_maps_test_() ->
+    [
+        {"allocate a new object on an empty stack", ?_assertEqual(
+            {[{object, #{}}], #config{return_maps=true}},
+            start_object({[], #config{return_maps=true}})
+        )},
+        {"allocate a new object on a stack", ?_assertEqual(
+            {[{object, #{}}, {object, #{}}], #config{return_maps=true}},
+            start_object({[{object, #{}}], #config{return_maps=true}})
+        )},
+        {"insert a key into an object", ?_assertEqual(
+            {[{object, key, #{}}, junk], #config{return_maps=true}},
+            insert(key, {[{object, #{}}, junk], #config{return_maps=true}})
+        )},
+        {"get current key", ?_assertEqual(
+            key,
+            get_key({[{object, key, #{}}], #config{return_maps=true}})
+        )},
+        {"try to get non-key from object", ?_assertError(
+            badarg,
+            get_key({[{object, #{}}], #config{return_maps=true}})
+        )},
+        {"insert a value into an object", ?_assertEqual(
+            {[{object, #{key => value}}, junk], #config{return_maps=true}},
+            insert(value, {[{object, key, #{}}, junk], #config{return_maps=true}})
+        )},
+        {"finish an object with no ancestor", ?_assertEqual(
+            {#{a => b, x => y}, #config{return_maps=true}},
+            finish({[{object, #{x => y, a => b}}], #config{return_maps=true}})
+        )},
+        {"finish an empty object", ?_assertEqual(
+            {#{}, #config{return_maps=true}},
+            finish({[{object, #{}}], #config{return_maps=true}})
+        )},
+        {"finish an object with an ancestor", ?_assertEqual(
+            {
+                [{object, #{key => #{a => b, x => y}, foo => bar}}],
+                #config{return_maps=true}
+            },
+            finish({
+                [{object, #{x => y, a => b}}, {object, key, #{foo => bar}}],
+                #config{return_maps=true}
+            })
+        )}
+    ].
+
 
 return_maps_test_() ->
     [
@@ -334,7 +439,6 @@ return_maps_test_() ->
             jsx:decode(<<"[{}]">>, [return_maps])
         )}
     ].
-
 -endif.
 
 
diff --git a/src/jsx_verify.erl b/src/jsx_verify.erl
index 09a668d..2073b99 100644
--- a/src/jsx_verify.erl
+++ b/src/jsx_verify.erl
@@ -27,15 +27,7 @@
 -export([init/1, handle_event/2]).
 
 
--record(config, {
-    repeated_keys = true
-}).
-
--type config() :: [].
--export_type([config/0]).
-
-
--spec is_json(Source::binary(), Config::config()) -> true | false | {incomplete, jsx:decoder()}.
+-spec is_json(Source::binary(), Config::jsx_config:config()) -> true | false | {incomplete, jsx:decoder()}.
 
 is_json(Source, Config) when is_list(Config) ->
     try (jsx:decoder(?MODULE, Config, jsx_config:extract_config(Config)))(Source)
@@ -43,7 +35,7 @@ is_json(Source, Config) when is_list(Config) ->
     end.
 
 
--spec is_term(Source::any(), Config::config()) -> true | false | {incomplete, jsx:encoder()}.
+-spec is_term(Source::any(), Config::jsx_config:config()) -> true | false | {incomplete, jsx:encoder()}.
 
 is_term(Source, Config) when is_list(Config) ->
     try (jsx:encoder(?MODULE, Config, jsx_config:extract_config(Config)))(Source)
@@ -51,15 +43,15 @@ is_term(Source, Config) when is_list(Config) ->
     end.
 
 
-parse_config(Config) -> parse_config(Config, #config{}).
+parse_config(Config) -> parse_config(Config, []).
 
+%% ignore deprecated flags
 parse_config([no_repeated_keys|Rest], Config) ->
-    parse_config(Rest, Config#config{repeated_keys=false});
-%% deprecated, use `no_repeated_keys`
+    parse_config(Rest, Config);
 parse_config([{repeated_keys, Val}|Rest], Config) when Val == true; Val == false ->
-    parse_config(Rest, Config#config{repeated_keys=Val});
+    parse_config(Rest, Config);
 parse_config([repeated_keys|Rest], Config) ->
-    parse_config(Rest, Config#config{repeated_keys=true});
+    parse_config(Rest, Config);
 parse_config([{K, _}|Rest] = Options, Config) ->
     case lists:member(K, jsx_config:valid_flags()) of
         true -> parse_config(Rest, Config);
@@ -73,27 +65,18 @@ parse_config([K|Rest] = Options, Config) ->
 parse_config([], Config) ->
     Config.
 
--type state() :: {#config{}, any()}.
+
+%% we don't actually need any state for this
+-type state() :: [].
 -spec init(Config::proplists:proplist()) -> state().
 
-init(Config) -> {parse_config(Config), []}.
+init(Config) -> parse_config(Config).
 
 
 -spec handle_event(Event::any(), State::state()) -> state().
 
 handle_event(end_json, _) -> true;
 
-handle_event(_, {Config, _} = State) when Config#config.repeated_keys == true -> State;
-
-handle_event(start_object, {Config, Keys}) -> {Config, [dict:new()] ++ Keys};
-handle_event(end_object, {Config, [_|Keys]}) -> {Config, Keys};
-
-handle_event({key, Key}, {Config, [CurrentKeys|Keys]}) ->
-    case dict:is_key(Key, CurrentKeys) of
-        true -> erlang:error(badarg);
-        false -> {Config, [dict:store(Key, blah, CurrentKeys)|Keys]}
-    end;
-
 handle_event(_, State) -> State.
 
 
@@ -105,15 +88,15 @@ handle_event(_, State) -> State.
 
 config_test_() ->
     [
-        {"empty config", ?_assertEqual(#config{}, parse_config([]))},
-        {"no repeat keys", ?_assertEqual(#config{repeated_keys=false}, parse_config([no_repeated_keys]))},
-        {"bare repeated keys", ?_assertEqual(#config{}, parse_config([repeated_keys]))},
+        {"empty config", ?_assertEqual([], parse_config([]))},
+        {"no repeat keys", ?_assertEqual([], parse_config([no_repeated_keys]))},
+        {"bare repeated keys", ?_assertEqual([], parse_config([repeated_keys]))},
         {"repeated keys true", ?_assertEqual(
-            #config{},
+            [],
             parse_config([{repeated_keys, true}])
         )},
         {"repeated keys false", ?_assertEqual(
-            #config{repeated_keys=false},
+            [],
             parse_config([{repeated_keys, false}])
         )},
         {"invalid opt flag", ?_assertError(badarg, parse_config([error]))},
@@ -121,50 +104,13 @@ config_test_() ->
     ].
 
 
-repeated_keys_test_() ->
-    RepeatedKey = [
-        start_object,
-            {key, <<"alpha">>},
-            {literal, true},
-            {key, <<"alpha">>},
-            {literal, false},
-        end_object,
-        end_json
-    ],
-    NestedKey = [
-        start_object,
-            {key, <<"alpha">>},
-            start_object,
-                {key, <<"alpha">>},
-                start_object,
-                    {key, <<"alpha">>},
-                    {literal, true},
-                end_object,
-            end_object,
-        end_object,
-        end_json
-    ],
-    [
-        {"repeated key", ?_assert(
-            lists:foldl(fun handle_event/2, {#config{}, []}, RepeatedKey)
-        )},
-        {"no repeated key", ?_assertError(
-            badarg,
-            lists:foldl(fun handle_event/2, {#config{repeated_keys=false}, []}, RepeatedKey)
-        )},
-        {"nested key", ?_assert(
-            lists:foldl(fun handle_event/2, {#config{repeated_keys=false}, []}, NestedKey)
-        )}
-    ].
-
-
 handle_event_test_() ->
     Data = jsx:test_cases() ++ jsx:special_test_cases(),
     [
         {
             Title, ?_assertEqual(
                 true,
-                lists:foldl(fun handle_event/2, {#config{}, []}, Events ++ [end_json])
+                lists:foldl(fun handle_event/2, [], Events ++ [end_json])
             )
         } || {Title, _, _, Events} <- Data
     ].