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August 29, 2015 14:14
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A simple way of configuring Lua to accept the indexing of nil values
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static int handleNilIndexing (lua_State* luaState) | |
{ | |
return 0; // zero return values is equivalent to returning nil | |
} | |
lua_State* setupLua() | |
{ | |
// Create the new lua state | |
lua_State* luaState = luaL_newstate(); | |
// Set the indexing of nil as a valid operation | |
lua_pushnil(luaState); // <-- nil | |
lua_createtable(luaState, 0, 1); // <-- nil_metatable | |
lua_pushcfunction(luaState, handleNilIndexing); // <-- nil_field_handler | |
lua_setfield(luaState, -2, "__index"); // nil_metatable.__index = nil_field_handler | |
lua_setmetatable(luaState, -2); // nil.metatable = nil_metatable | |
lua_pop(luaState, 1); // -x- nil | |
return luaState; | |
} |
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