package com.tom_roush.pdfbox.pdmodel.common.function.type4;
import java.util.Stack;
/**
* Makes up the execution context, holding the available operators and the execution stack.
*/
public class ExecutionContext
{
private final Operators operators;
private final Stack<Object> stack = new Stack<Object>();
/**
* Creates a new execution context.
* @param operatorSet the operator set
*/
public ExecutionContext(Operators operatorSet)
{
this.operators = operatorSet;
}
/**
* Returns the stack used by this execution context.
* @return the stack
*/
public Stack<Object> getStack()
{
return this.stack;
}
/**
* Returns the operator set used by this execution context.
* @return the operator set
*/
public Operators getOperators()
{
return this.operators;
}
/**
* Pops a number (int or real) from the stack. If it's neither data type, a
* ClassCastException is thrown.
* @return the number
*/
public Number popNumber()
{
return (Number)stack.pop();
}
/**
* Pops a value of type int from the stack. If the value is not of type int, a
* ClassCastException is thrown.
* @return the int value
*/
public int popInt()
{
return ((Integer)stack.pop());
}
/**
* Pops a number from the stack and returns it as a real value. If the value is not of a
* numeric type, a ClassCastException is thrown.
* @return the real value
*/
public float popReal()
{
return ((Number)stack.pop()).floatValue();
}
}