Working

luprex/syscpp/lpx-classdb.cpp

@@ -7,56 +7,41 @@
 //   if classname is already present, and is a table, return it.
 //   if classname is already present, and not a table, error.
 //   if classname is not present, create and initialize it.
-// 
+//
 int lpx_classdb_get(lua_State *L) {
-    const int db = lua_gettop(L) - 1;
-    const int cname = lua_gettop(L);
-    
-    luaL_checktype(L, db, LUA_TTABLE);
-    luaL_checktype(L, cname, LUA_TSTRING);
-    lua_pushvalue(L, cname);
-    lua_rawget(L, db);
-    if (lua_istable(L, -1)) {
-        return 1;
-    } else if (!lua_isnil(L, -1)) {
-        lua_pushfstring(L, "%s is not a class", lua_tostring(L, cname));
-        lua_error(L);
-    }
-    lua_pop(L, 1);
-    lua_newtable(L);
-    int cls = lua_gettop(L);
-    lua_pushvalue(L, cname);
-    lua_pushvalue(L, cls);
-    lua_rawset(L, db);
-    lua_pushstring(L, "__index");
-    lua_pushvalue(L, cls);
-    lua_rawset(L, cls);
-    lua_pushstring(L, "__class");
-    lua_pushvalue(L, cname);
-    lua_rawset(L, cls);
-    lua_pushstring(L, "action");
-    lua_newtable(L);
-    lua_rawset(L, cls);
+    LpxArg db, classname;
+    LpxRet classtab;
+    LpxVar action;
+    LpxStackManager LSM(L, db, classname, classtab, action);
 
-    // Remove arguments, leaving new table on stack.
-    lua_replace(L, db);
-    lua_settop(L, db);
-    return 1;
+    LSM.checknometa(db);
+    luaL_checktype(L, classname, LUA_TSTRING);
+    LSM.rawget(classtab, db, classname);
+    if (lua_istable(L, classtab)) {
+        return LSM.retval();
+    } else if (!lua_isnil(L, classtab)) {
+        luaL_error(L, "%s is not a class", lua_tostring(L, classname));
+    }
+    LSM.newtable(classtab);
+    LSM.rawset(db, classname, classtab);
+    LSM.setfield(classtab, "__index", classtab);
+    LSM.setfield(classtab, "__class", classname);
+    LSM.newtable(action);
+    LSM.setfield(classtab, "action", action);
+    return LSM.retval();
 }
 
 // Curried version of classdb.get where db is stored in an upvalue.
 //
 static int lpx_classdb_class(lua_State *L) {
-    const int cname = lua_gettop(L);
     lua_pushvalue(L, lua_upvalueindex(1));
-    lua_insert(L, cname);
+    lua_insert(L, -2);
     return lpx_classdb_get(L);
 }
 
 int lpx_classdb_accessor(lua_State *L) {
-    const int db = lua_gettop(L);
-    luaL_checktype(L, db, LUA_TTABLE);
-    lua_pushcclosure(L, lpx_classdb_class, 1);
+    luaL_checktype(L, -1, LUA_TTABLE);
+    lua_pushcclosure(L, LpxArgCheck<1, lpx_classdb_class>, 1);
     return 1;
 }
 
@@ -69,63 +54,47 @@ int lpx_classdb_accessor(lua_State *L) {
 //   Caution: do not reset the global class database!
 //
 int lpx_classdb_reset(lua_State *L) {
-    const int db = lua_gettop(L);
+    LpxArg db;
+    LpxVar classname, classtab, action, key;
+    LpxStackManager LSM(L, db, classname, classtab, action, key);
+
     luaL_checktype(L, db, LUA_TTABLE);
-    lua_pushnil(L);
-    while (lua_next(L, db) != 0) {
-        int cname = lua_gettop(L) - 1;
-        int cls = lua_gettop(L);
-        if (lua_istable(L, cls)) {
-            lua_pushstring(L, "action");
-            lua_rawget(L, cls);
-            int actn = lua_gettop(L);
-            if (lua_istable(L, actn)) {
-                lua_pushvalue(L, actn);
+    LSM.setnil(classname);
+    while (LSM.next(db, classname, classtab) != 0) {
+        if (lua_istable(L, classtab)) {
+            LSM.setstring(key, "action");
+            LSM.rawget(action, classtab, key);
+            if (lua_istable(L, action)) {
+                lua_pushvalue(L, action);
                 lpx_table_clear(L);
             } else {
-                lua_pop(L, 1);
-                lua_newtable(L);
+                LSM.newtable(action);
             }
-            lua_pushvalue(L, cls);
+            lua_pushvalue(L, classtab);
             lpx_table_clear(L);
-            lua_pushstring(L, "__index");
-            lua_pushvalue(L, cls);
-            lua_rawset(L, cls);
-            lua_pushstring(L, "__class");
-            lua_pushvalue(L, cname);
-            lua_rawset(L, cls);
-            lua_pushstring(L, "action");
-            lua_pushvalue(L, actn);
-            lua_rawset(L, cls);
+            LSM.setfield(classtab, "__index", classtab);
+            LSM.setfield(classtab, "__class", classname);
+            LSM.setfield(classtab, "action", action);
         }
-        lua_settop(L, cname);
     }
-    // Remove arguments, leave nothing on stack.
-    lua_settop(L, db - 1);
-    return 0;
+    return LSM.retval();
 }
 
-// Create the global function 'class'.
-//
-//   This version of 'class' creates classes in the global environment.
-//   Note that this is lua 5.1 specific.
-//
-static int lpx_create_global_class(lua_State *L) {
+// Create a classdb.  That's just an empty table.
+int lpx_classdb_create(lua_State *L) {
+    lua_newtable(L);
+    return 1;
+}
+
+void luaopen_lpx_classdb(lua_State *L) {
+    LpxStackManager::reg(L, "classdb", "get", LpxArgCheck<2, lpx_classdb_get>);
+    LpxStackManager::reg(L, "classdb", "accessor", LpxArgCheck<1, lpx_classdb_accessor>);
+    LpxStackManager::reg(L, "classdb", "reset", LpxArgCheck<1, lpx_classdb_reset>);
+    LpxStackManager::reg(L, "classdb", "create", LpxArgCheck<0, lpx_classdb_create>);
+
+    // Insert the global function 'class', which is a closure with an upvalue.
     lua_pushstring(L, "class");
     lua_pushvalue(L, LUA_GLOBALSINDEX);
     lpx_classdb_accessor(L);
     lua_rawset(L, LUA_GLOBALSINDEX);
 }
-
-static const struct luaL_Reg lpx_classdb_lib [] = {
-    {"get", lpx_classdb_get},
-    {"accessor", lpx_classdb_accessor},
-    {"reset", lpx_classdb_reset},
-    {NULL, NULL}  /* sentinel */
-};
-
-int luaopen_lpx_classdb(lua_State *L) {
-    luaL_openlib(L, "classdb", lpx_classdb_lib, 0);
-    lpx_create_global_class(L);
-    return 1;
-}