# HG changeset patch
# User jbe
# Date 1406493772 -7200
# Node ID a1507b499fa52bbfc93fee42c0a212d44326c387
# Parent  214e11b729078aac3c4c963fe3bf8b611161e044
Implemented ipairs metamethod for sparse JSON arrays

diff -r 214e11b72907 -r a1507b499fa5 libraries/json/json.c
--- a/libraries/json/json.c	Sun Jul 27 22:10:28 2014 +0200
+++ b/libraries/json/json.c	Sun Jul 27 22:42:52 2014 +0200
@@ -7,6 +7,7 @@
 #define JSON_UPVAL_SHADOWTBL lua_upvalueindex(2)
 #define JSON_UPVAL_TYPES     lua_upvalueindex(3)
 #define JSON_UPVAL_METATABLE lua_upvalueindex(4)
+#define JSON_UPVAL_IPAIRS_ITERFUNC lua_upvalueindex(5)
 
 #define JSON_STATE_VALUE 0
 #define JSON_STATE_OBJECT_KEY 1
@@ -354,6 +355,28 @@
   return 1;
 }
 
+static int json_ipairs_iterfunc(lua_State *L) {
+  int idx;
+  lua_settop(L, 2);
+  idx = lua_tointeger(L, 2) + 1;
+  lua_pushvalue(L, 1);
+  lua_rawget(L, JSON_UPVAL_SHADOWTBL);
+  if (lua_isnil(L, -1)) return luaL_error(L, "Shadow table not found");
+  lua_rawgeti(L, -1, idx);
+  if (lua_isnil(L, -1)) return 0;
+  lua_pushinteger(L, idx);
+  if (lua_rawequal(L, -2, JSON_UPVAL_NULLMARK)) lua_pushnil(L);
+  else lua_pushvalue(L, -2);
+  return 2;
+}
+
+static int json_ipairs(lua_State *L) {
+  lua_pushvalue(L, JSON_UPVAL_IPAIRS_ITERFUNC);
+  lua_pushvalue(L, 1);
+  lua_pushinteger(L, 0);
+  return 3;
+}
+
 static const struct luaL_Reg json_module_functions[] = {
   {"object", json_object},
   {"array", json_array},
@@ -369,6 +392,7 @@
   {"__len", json_len},
   {"__index", json_index},
   {"__newindex", json_newindex},
+  {"__ipairs", json_ipairs},
   {NULL, NULL}
 };
 
@@ -392,7 +416,15 @@
   lua_pushvalue(L, 3);
   lua_pushvalue(L, 4);
   lua_pushvalue(L, 5);
-  luaL_setfuncs(L, json_metatable_functions, 4);
-  luaL_setfuncs(L, json_module_functions, 4);
+  lua_pushcclosure(L, json_ipairs_iterfunc, 4);  // 6: iteration function for ipairs
+  lua_pushvalue(L, 5);
+  lua_pushvalue(L, 2);
+  lua_pushvalue(L, 3);
+  lua_pushvalue(L, 4);
+  lua_pushvalue(L, 5);
+  lua_pushvalue(L, 6);
+  luaL_setfuncs(L, json_metatable_functions, 5);
+  lua_pop(L, 1);
+  luaL_setfuncs(L, json_module_functions, 5);
   return 1;
 }