com.scudata.expression.operator.Assign Maven / Gradle / Ivy

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SPL(Structured Process Language) A programming language specially for structured data computing.

There is a newer version: 20240823

package com.scudata.expression.operator;

import com.scudata.common.MessageManager;
import com.scudata.common.RQException;
import com.scudata.dm.Context;
import com.scudata.expression.Operator;
import com.scudata.resources.EngineMessage;

/**
 * ???????=
 * @author RunQian
 *
 */
public class Assign extends Operator {
	public Assign() {
		priority = PRI_EVL;
	}
	
	/**
	 * ??????ʽ????Ч?ԣ???Ч???׳??쳣
	 */
	public void checkValidity() {
		if (left == null) {
			MessageManager mm = EngineMessage.get();
			throw new RQException("\"=\"" + mm.getMessage("operator.missingLeftOperation"));
		} else if (right == null) {
			MessageManager mm = EngineMessage.get();
			throw new RQException("\"=\"" + mm.getMessage("operator.missingRightOperation"));
		}
		
		left.checkValidity();
		right.checkValidity();
	}

	public Object calculate(Context ctx) {
		return left.assign(right.calculate(ctx), ctx);
	}

	// a = b = c =1
	public Object assign(Object value, Context ctx) {
		return left.assign(right.assign(value, ctx), ctx);
	}

	public byte calcExpValueType(Context ctx) {
		return right.calcExpValueType(ctx);
	}
	
	/**
	 * ?ж??Ƿ???Լ???ȫ????ֵ???и?ֵ????ʱֻ??һ???м???
	 * @return
	 */
	public boolean canCalculateAll() {
		return false;
	}
}