net.sandius.rembulan.impl.DefaultSavedState 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.impl;
import java.util.Arrays;
/**
* A generic, immutable implementation of the suspended state of a function call, used primarily
* by compiled Lua functions.
*
* The class provides a uniform structured representation of the saved state consisting
* of
*
* - a resumption point, an integer value, used to select the appropriate
* continuation point;
* - the register state, a sequence of arbitrary objects, typically used to restore
* the local variables of the call.
*
*
* The exact meaning of the values stored in these fields is left to the discretion
* of the class instantiating this object.
*/
@SuppressWarnings("unused")
public class DefaultSavedState {
private final int resumptionPoint;
private final Object[] registers;
/**
* Constructs a new instance of {@code DefaultSavedState} with the specified
* {@code resumptionPoint} and {@code registers}.
*
* @param resumptionPoint the resumption point
* @param registers the registers, may be {@code null}
*/
@SuppressWarnings("unused")
public DefaultSavedState(int resumptionPoint, Object[] registers) {
this.resumptionPoint = resumptionPoint;
this.registers = registers != null ? Arrays.copyOf(registers, registers.length) : null;
}
/**
* Returns the resumption point stored in this saved state.
*
* @return the resumption point
*/
@SuppressWarnings("unused")
public int resumptionPoint() {
return resumptionPoint;
}
/**
* Returns a copy of the register state stored in this saved state, or {@code null}
* if the register state array stored in this saved state was {@code null}.
*
* @return the registers stored in this saved state, possibly {@code null}
*/
@SuppressWarnings("unused")
public Object[] registers() {
return registers != null
? Arrays.copyOf(registers, registers.length)
: null;
}
}