Lots of work on LuaStack

luprex/syscpp/globaldb.cpp

@@ -0,0 +1,43 @@
+#include "globaldb.hpp"
+#include "table.hpp"
+
+// Get a table from the global database.
+//
+//   GLOBALNAME
+//   if globalname is already present, and is a table, return it.
+//   if globalname is already present, and not a table, error.
+//   if globalname is not present, create and initialize it.
+//
+int lpx_globaldb_global(lua_State *L) {
+    LuaArg globalname;
+    LuaRet globaltab;
+    LuaVar globaldb;
+    LuaStack LS(L, globalname, globaltab, globaldb);
+
+    LS.checktype(globalname, LUA_TSTRING);
+
+    // Get a pointer to the globaldb.
+    LS.getfield(globaldb, LUA_REGISTRYINDEX, "globaldb");
+    if (!LS.istable(globaldb)) {
+        LS.newtable(globaldb);
+        LS.setfield(LUA_REGISTRYINDEX, "globaldb", globaldb);
+    }
+
+    // Get the globaltab from the globaldb, sanity check it.
+    LS.rawget(globaltab, globaldb, globalname);
+    if (LS.istable(globaltab)) {
+        return LS.result();
+    } else if (!LS.isnil(globaltab)) {
+        luaL_error(L, "%s is not a global", LS.tostring(globalname).c_str());
+    }
+
+    // Create a new globaltab and store it in the globaldb.
+    LS.newtable(globaltab);
+    LS.rawset(globaldb, globalname, globaltab);
+    LS.setfield(globaltab, "__global", globalname);
+    return LS.result();
+}
+
+void luaopen_lpx_globaldb(lua_State *L) {
+    LuaStack::reg(L, 0, "global", LuaArgCheck<1, lpx_globaldb_global>);
+}