orclausenode.java

是有关解释器的.用JAVA编写.可以解释一般的JAVA程序.

class OrClauseNode extends EvaluatableNode 
{	
	AndClauseNode vAndClauseNode;
	OrClauseNode vOrClauseNode;
	Value vAndClauseValue;
	Value vOrClauseValue;

	static OrClauseNode parserOrClause(Environment env, Scanner s)throws ParserException, ScannerException 
	{
		AndClauseNode tmpAndClauseNode;
		OrClauseNode tmpOrClauseNode = null;
		Token t;

		tmpAndClauseNode = AndClauseNode.parserAndClause(env, s);
		t = s.token();
		if (t.isOperator() && ((OperatorToken) t).isOr()) 
		{
			matchOperator(s, ((OperatorToken) t).content());
			tmpOrClauseNode = OrClauseNode.parserOrClause(env, s);
		}

		return new OrClauseNode(tmpAndClauseNode, tmpOrClauseNode);
	}
	OrClauseNode() 
	{
		vAndClauseNode = null;
		vOrClauseNode = null;
	}
	OrClauseNode(AndClauseNode aAndClauseNode, OrClauseNode aOrClauseNode) 
	{
		vAndClauseNode = aAndClauseNode;
		vOrClauseNode = aOrClauseNode;
	}
	String format(int indent) 
	{
		String str= vAndClauseNode.format(indent);
		if(vOrClauseNode!=null)
			str+= "||"+vOrClauseNode.format(indent);
		return str;
	}
	Value evaluate(Environment env) throws InterpreterException 
	{		
		if(vOrClauseNode==null)return vAndClauseNode.evaluate(env);
			else return vAndClauseNode.evaluate(env).or(vOrClauseNode.evaluate(env));
	}
	boolean typeCheck(Environment env) throws InterpreterException
	{
		if(vAndClauseNode.typeCheck(env))
		{
			vAndClauseValue= vAndClauseNode.evaluate(env);
			if(vOrClauseNode!=null)
				if(vAndClauseValue.isBoolean())
				{	
					if(vOrClauseNode.typeCheck(env))
					{
						vOrClauseValue= vOrClauseNode.evaluate(env);
						if(!vOrClauseValue.isBoolean())ProgramNode.mTypeCheckError(this.format(4));
					}else ProgramNode.mTypeCheckError(this.format(4));
				}else ProgramNode.mTypeCheckError(this.format(4));			
		}else ProgramNode.mTypeCheckError(this.format(4));		
		
		return true;
	}
}