# HG changeset patch
# User jbe
# Date 1406418705 -7200
# Node ID e3e5bf890aad5ff7389e6915a5f70fb438dbd524
# Parent  ece4e6f683c9ded59d0eb2f33dfe6133dac0075d
Set json.metatable in JSON library for any JSON object/array

diff -r ece4e6f683c9 -r e3e5bf890aad libraries/json/json.c
--- a/libraries/json/json.c	Sat Jul 26 23:40:43 2014 +0200
+++ b/libraries/json/json.c	Sun Jul 27 01:51:45 2014 +0200
@@ -3,9 +3,9 @@
 #include <stdlib.h>
 #include <string.h>
 
-#define JSON_UPVAL_ARYLEN lua_upvalueindex(1)
+#define JSON_UPVAL_METATABLE lua_upvalueindex(1)
 #define JSON_UPVAL_NULLS lua_upvalueindex(2)
-#define JSON_UPVAL_METATABLE lua_upvalueindex(3)
+#define JSON_UPVAL_ARYLEN lua_upvalueindex(3)
 
 #define JSON_STATE_VALUE 0
 #define JSON_STATE_OBJECT_KEY 1
@@ -44,7 +44,9 @@
     if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
       goto json_import_syntax_error;
     pos++;
-    lua_newtable(L);
+    lua_newtable(L);  // the actual JSON object
+    lua_pushvalue(L, JSON_UPVAL_METATABLE);
+    lua_setmetatable(L, -2);
     lua_newtable(L);  // stores set of NULL values
     lua_pushvalue(L, -2);
     lua_pushvalue(L, -2);
@@ -56,7 +58,9 @@
     if (mode != JSON_STATE_VALUE && mode != JSON_STATE_OBJECT_VALUE && mode != JSON_STATE_ARRAY_VALUE)
       goto json_import_syntax_error;
     pos++;
-    lua_newtable(L);
+    lua_newtable(L);  // the actual JSON array
+    lua_pushvalue(L, JSON_UPVAL_METATABLE);
+    lua_setmetatable(L, -2);
     lua_newtable(L);  // stores set of NULL values
     lua_pushvalue(L, -2);
     lua_pushvalue(L, -2);
@@ -242,8 +246,11 @@
 
 int luaopen_json(lua_State *L) {
   lua_newtable(L);  // library table
+  lua_newtable(L);  // metatable for JSON objects and JSON arrays
+  lua_pushvalue(L, -1);
+  lua_setfield(L, -3, "metatable");
+  lua_newtable(L);  // ephemeron table to store a set of keys associated with JSON-null values
   lua_newtable(L);  // ephemeron table to store the length of arrays (that may contain nil's)
-  lua_newtable(L);  // ephemeron table to store a set of keys associated with JSON-null values
   lua_newtable(L);  // meta table for ephemeron table
   lua_pushliteral(L, "__mode");
   lua_pushliteral(L, "k");
@@ -251,6 +258,6 @@
   lua_pushvalue(L, -1);
   lua_setmetatable(L, -3);
   lua_setmetatable(L, -2);
-  luaL_setfuncs(L, json_module_functions, 2);
+  luaL_setfuncs(L, json_module_functions, 3);
   return 1;
 }