org.nutz.el.parse.OptParse Maven / Gradle / Ivy

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Nutz, which is a collections of lightweight frameworks, each of them can be used independently
There is a newer version: 1.r.72
package org.nutz.el.parse;

import org.nutz.el.ElException;
import org.nutz.el.Parse;
import org.nutz.el.opt.arithmetic.LBracketOpt;
import org.nutz.el.opt.arithmetic.ModOpt;
import org.nutz.el.opt.arithmetic.MulOpt;
import org.nutz.el.opt.arithmetic.PlusOpt;
import org.nutz.el.opt.arithmetic.RBracketOpt;
import org.nutz.el.opt.arithmetic.SubOpt;
import org.nutz.el.opt.bit.BitNot;
import org.nutz.el.opt.bit.BitOr;
import org.nutz.el.opt.bit.BitXro;
import org.nutz.el.opt.bit.LeftShift;
import org.nutz.el.opt.bit.RightShift;
import org.nutz.el.opt.bit.UnsignedLeftShift;
import org.nutz.el.opt.logic.AndOpt;
import org.nutz.el.opt.logic.GTEOpt;
import org.nutz.el.opt.logic.GTOpt;
import org.nutz.el.opt.logic.LTEOpt;
import org.nutz.el.opt.logic.LTOpt;
import org.nutz.el.opt.logic.NEQOpt;
import org.nutz.el.opt.logic.NotOpt;
import org.nutz.el.opt.logic.OrOpt;
import org.nutz.el.opt.logic.QuestionOpt;
import org.nutz.el.opt.logic.QuestionSelectOpt;
import org.nutz.el.opt.object.ArrayOpt;
import org.nutz.el.opt.object.CommaOpt;
import org.nutz.el.opt.object.FetchArrayOpt;
import org.nutz.el.opt.arithmetic.DivOpt;
import org.nutz.el.opt.bit.BitAnd;
import org.nutz.el.opt.logic.EQOpt;
import org.nutz.el.opt.object.AccessOpt;

/**
 * 操作符转换器
 * @author juqkai([email protected])
 *
 */
public class OptParse implements Parse {

	public Object fetchItem(CharQueue exp){
		switch(exp.peek()){
		case '+':
			exp.poll();
			return new PlusOpt();
		case '-':
			exp.poll();
			return new SubOpt();
		case '*':
			exp.poll();
			return new MulOpt();
		case '/':
			exp.poll();
			return new DivOpt();
		case '%':
			exp.poll();
			return new ModOpt();
		case '(':
			exp.poll();
			return new LBracketOpt();
		case ')':
			exp.poll();
			return new RBracketOpt();
		case '>':
			exp.poll();
			switch(exp.peek()){
			case '=':
				exp.poll();
				return new GTEOpt();
			case '>':
				exp.poll();
				if(exp.peek() == '>'){
					exp.poll();
					return new UnsignedLeftShift();
				}
				return new RightShift();
			}
			return new GTOpt();
		case '<':
			exp.poll();
			switch(exp.peek()){
			case '=':
				exp.poll();
				return new LTEOpt();
			case '<':
				exp.poll();
				return new LeftShift();
			}
			return new LTOpt();
		case '=':
			exp.poll();
			switch(exp.peek()){
			case '=':
				exp.poll();
				return new EQOpt();
			}
			throw new ElException("表达式错误,请检查'='后是否有非法字符!");
		case '!':
			exp.poll();
			switch(exp.peek()){
			case '=':
				exp.poll();
				return new NEQOpt();
			}
			return new NotOpt();
		case '|':
			exp.poll();
			switch(exp.peek()){
			case '|':
				exp.poll();
				return new OrOpt();
			}
			return new BitOr();
		case '&':
			exp.poll();
			switch(exp.peek()){
			case '&':
				exp.poll();
				return new AndOpt();
			}
			return new BitAnd();
		case '~':
			exp.poll();
			return new BitNot();
		case '^':
			exp.poll();
			return new BitXro();
		case '?':
			exp.poll();
			return new QuestionOpt();
		case ':':
			exp.poll();
			return new QuestionSelectOpt();
		
		case '.':
			if(!Character.isJavaIdentifierStart(exp.peek(1))){
				return nullobj;
			}
			exp.poll();
			return new AccessOpt();
		case ',':
			exp.poll();
			return new CommaOpt();
		case '[':
			exp.poll();
			return new Object[]{new ArrayOpt(),new LBracketOpt()};
		case ']':
			exp.poll();
			return new Object[]{new RBracketOpt(), new FetchArrayOpt()};
		}
		return nullobj;
	}

}