newline.java

JAVA 数学程序库 提供常规的数值计算程序包

package jmathlib.toolbox.jmathlib.system;

import jmathlib.core.tokens.Token;
import jmathlib.core.tokens.OperandToken;
import jmathlib.core.tokens.numbertokens.DoubleNumberToken;
import jmathlib.core.functions.ExternalFunction;

/**An external function for writing to the main display*/
public class newline extends ExternalFunction
{
	/**write operand to main display
	@param operand[n] = items to display*/
	public OperandToken evaluate(Token[] operands)
	{
		double count = 1;
		
		if((operands.length > 0) && (operands[0] instanceof DoubleNumberToken))
		{
			count = ((DoubleNumberToken)operands[0]).getValueRe();
		}
		
		for(int index = 0; index < count; index++)
		{
			getInterpreter().displayText("");
		}
		
		return new DoubleNumberToken(1);
	}
}

/*
@GROUP
system
@SYNTAX
NEWLINE(lines)
@DOC
Displays number of blank lines equal to the first parameter.
@NOTES
@EXAMPLES
NEWLINE(1)


NEWLINE(2)



@SEE
*/