net.sandius.rembulan.MetatableAccessor Maven / Gradle / Ivy
/*
* Copyright 2016 Miroslav Janíček
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package net.sandius.rembulan;
/**
* A metatable accessor, an interface for getting and setting object metatables.
*
* In Lua, only tables and (full) userdata carry their own metatables; for all other
* types of values T, all values of type T share a metatable. This interface
* provides a uniform setter for metatables of all types.
*/
public interface MetatableAccessor extends MetatableProvider {
/**
* Sets the metatable for nil (i.e., the {@code nil} type) to {@code table}.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for the {@code nil} type, may be {@code null}
* @return the previous metatable for the {@code nil} type
*/
Table setNilMetatable(Table table);
/**
* Sets the metatable for the {@code boolean} type.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for the {@code boolean} type, may be {@code null}
* @return the previous metatable for the {@code boolean} type
*/
Table setBooleanMetatable(Table table);
/**
* Sets the metatable for the {@code number} type.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for the {@code number} type, may be {@code null}
* @return the previous metatable for the {@code number} type
*/
Table setNumberMetatable(Table table);
/**
* Sets the metatable for the {@code string} type.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for the {@code string} type, may be {@code null}
* @return the previous metatable for the {@code string} type
*/
Table setStringMetatable(Table table);
/**
* Sets the metatable for the {@code function} type.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for the {@code function} type, may be {@code null}
* @return the previous metatable for the {@code function} type
*/
Table setFunctionMetatable(Table table);
/**
* Sets the metatable for the {@code thread} type.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for the {@code thread} type, may be {@code null}
* @return the previous metatable for the {@code thread} type
*/
Table setThreadMetatable(Table table);
/**
* Sets the metatable for light userdata.
* {@code table} may be {@code null}: in that case, clears the metatable. Returns
* the previous metatable.
*
* @param table new metatable for light userdata, may be {@code null}
* @return the previous metatable for light userdata
*/
Table setLightUserdataMetatable(Table table);
/**
* Sets the metatable of the object {@code instance} to {@code table}.
* {@code table} may be {@code null}: in that case, clears {@code instance}'s metatable.
* Returns the previous metatable.
*
* Note that {@code instance} may share the metatable with other instances of the same
* (Lua) type. This method provides a uniform interface for setting the metatables
* of all types.
*
* @param instance object to set the metatable of, may be {@code null}
* @param table new metatable of {@code instance}, may be {@code null}
* @return the previous metatable of {@code instance}
*/
Table setMetatable(Object instance, Table table);
}