lispptr.java

来自「计算机代数系统」· Java 代码 · 共 43 行

package net.sf.yacas;


/** class LispPtr. This class is a smart pointer type class to Lisp
 *  objects that can be inserted into linked lists. They do the actual
 *  reference counting, and consequent destruction of the object if
 *  nothing points to it. LispPtr is used in LispObject as a pointer
 *  to the next object, and in diverse parts of the built-in internal
 *  functions to hold temporary values.
 */
class LispPtr 
{
    public LispPtr()
	{
		iNext = null;
	}
    public LispPtr(LispPtr aOther)
	{
		iNext = aOther.iNext;
	}
    public LispPtr(LispObject aOther)
	{
		iNext = aOther;
	}
    public void Set(LispObject aNext)
	{
		iNext = aNext;
	}
    public LispObject Get()
	{
		return iNext;
	}
    public void GoNext()
	{
		iNext = iNext.iNext.iNext;
	}
    void DoSet(LispObject aNext)
	{
		iNext = aNext;
	}
    LispObject iNext;
};