From 5843dbc56a6da9e6a186dc571b0d2bd1c11ec35c Mon Sep 17 00:00:00 2001
From: alisdair sullivan <alisdairsullivan@yahoo.ca>
Date: Tue, 9 Dec 2014 08:05:48 +0000
Subject: [PATCH] actually i can use flatten in `jsx_to_term`! sweet

---
 src/jsx_to_term.erl | 51 ++++++++++++++++++++++++++-------------------
 1 file changed, 30 insertions(+), 21 deletions(-)

diff --git a/src/jsx_to_term.erl b/src/jsx_to_term.erl
index 5a628ea..6dc0c85 100644
--- a/src/jsx_to_term.erl
+++ b/src/jsx_to_term.erl
@@ -23,7 +23,7 @@
 
 -module(jsx_to_term).
 
--export([to_term/2]).
+-export([to_term/2, flatify/1]).
 -export([init/1, handle_event/2]).
 -export([
     start_term/1,
@@ -172,10 +172,10 @@ start_array({Stack, Config}) -> {[{array, []}] ++ Stack, Config}.
 %%  return it if it is the root object
 finish({[{object, []}], Config}) -> {[{}], Config};
 finish({[{object, []}|Rest], Config}) -> insert([{}], {Rest, Config});
-finish({[{object, Pairs}], Config}) -> {Pairs, Config};
-finish({[{object, Pairs}|Rest], Config}) -> insert(Pairs, {Rest, Config});
-finish({[{array, Values}], Config}) -> {Values, Config};
-finish({[{array, Values}|Rest], Config}) -> insert(Values, {Rest, Config});
+finish({[{object, Pairs}], Config}) -> {flatify(Pairs), Config};
+finish({[{object, Pairs}|Rest], Config}) -> insert(flatify(Pairs), {Rest, Config});
+finish({[{array, Values}], Config}) -> {flatify(Values), Config};
+finish({[{array, Values}|Rest], Config}) -> insert(flatify(Values), {Rest, Config});
 finish(_) -> erlang:error(badarg).
 
 
@@ -185,9 +185,9 @@ insert(Value, {[], Config}) -> {Value, Config};
 insert(Key, {[{object, Pairs}|Rest], Config}) ->
     {[{object, Key, Pairs}] ++ Rest, Config};
 insert(Value, {[{object, Key, Pairs}|Rest], Config}) ->
-    {[{object, Pairs ++ [{Key, Value}]}] ++ Rest, Config};
+    {[{object, [Pairs, {Key, Value}]}] ++ Rest, Config};
 insert(Value, {[{array, Values}|Rest], Config}) ->
-    {[{array, Values ++ [Value]}] ++ Rest, Config};
+    {[{array, [Values, Value]}] ++ Rest, Config};
 insert(_, _) -> erlang:error(badarg).
 -endif.
 
@@ -212,10 +212,10 @@ 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}) -> {Pairs, Config};
-finish({[{object, Pairs}|Rest], Config}) -> insert(Pairs, {Rest, Config});
-finish({[{array, Values}], Config}) -> {Values, Config};
-finish({[{array, Values}|Rest], Config}) -> insert(Values, {Rest, Config});
+finish({[{object, Pairs}], Config}) -> {flatify(Pairs), Config};
+finish({[{object, Pairs}|Rest], Config}) -> insert(flatify(Pairs), {Rest, Config});
+finish({[{array, Values}], Config}) -> {flatify(Values), Config};
+finish({[{array, Values}|Rest], Config}) -> insert(flatify(Values), {Rest, Config});
 finish(_) -> erlang:error(badarg).
 
 
@@ -229,9 +229,9 @@ insert(Key, {[{object, 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, Pairs ++ [{Key, Value}]}] ++ Rest, Config};
+    {[{object, [Pairs, {Key, Value}]}] ++ Rest, Config};
 insert(Value, {[{array, Values}|Rest], Config}) ->
-    {[{array, Values ++ [Value]}] ++ Rest, Config};
+    {[{array, [Values, Value]}] ++ Rest, Config};
 insert(_, _) -> erlang:error(badarg).
 -endif.
 
@@ -244,6 +244,15 @@ 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).
@@ -331,32 +340,32 @@ rep_manipulation_test_() ->
             get_key({[{array, []}], #config{}})
         )},
         {"insert a value into an object", ?_assertEqual(
-            {[{object, [{key, value}]}, junk], #config{}},
+            {[{object, [[], {key, value}]}, junk], #config{}},
             insert(value, {[{object, key, []}, junk], #config{}})
         )},
         {"insert a value into an array", ?_assertEqual(
-            {[{array, [value]}, junk], #config{}},
+            {[{array, [[], value]}, junk], #config{}},
             insert(value, {[{array, []}, junk], #config{}})
         )},
         {"finish an object with no ancestor", ?_assertEqual(
             {[{x, y}, {a, b}], #config{}},
-            finish({[{object, [{x, y}, {a, b}]}], #config{}})
+            finish({[{object, [[[], {x, y}], {a, b}]}], #config{}})
         )},
         {"finish an empty object", ?_assertEqual(
             {[{}], #config{}},
             finish({[{object, []}], #config{}})
         )},
         {"finish an object with an ancestor", ?_assertEqual(
-            {[{object, [{foo, bar}, {key, [{x, y}, {a, b}]}]}], #config{}},
-            finish({[{object, [{x, y}, {a, b}]}, {object, key, [{foo, bar}]}], #config{}})
+            {[{object, [[[], {foo, bar}], {key, [{x, y}, {a, b}]}]}], #config{}},
+            finish({[{object, [[[], {x, y}], {a, b}]}, {object, key, [[], {foo, bar}]}], #config{}})
         )},
         {"finish an array with no ancestor", ?_assertEqual(
             {[a, b, c], #config{}},
-            finish({[{array, [a, b, c]}], #config{}})
+            finish({[{array, [[[[], a], b], c]}], #config{}})
         )},
         {"finish an array with an ancestor", ?_assertEqual(
-            {[{array, [d, e, f, [a, b, c]]}], #config{}},
-            finish({[{array, [a, b, c]}, {array, [d, e, f]}], #config{}})
+            {[{array,[[[[[],d],e],f],[a,b,c]]}], #config{}},
+            finish({[{array, [[[[], a], b], c]}, {array, [[[[], d], e], f]}], #config{}})
         )}
     ].