translateword.java

算术表达式的词法分析和语法分析,编译原理的实验

package Word;

public class TranslateWord {
	public TranslateWord(String str){
		toTranslate = str;
		wordInside = new WordInside();
		String info = translate();
		System.out.println("Translate   " + info);
	}
	public WordInside getWordInside(){
		return wordInside;
	}
	private String translate(){
		boolean succeed = true;
		char current;
		int fence=0;
		int length = toTranslate.length();
		System.out.println("toTranslate" + toTranslate.length());
		while(fence!=length&&succeed){
			succeed = false;
			current = toTranslate.charAt(fence);
			if('a'<=current&&current<='z'){
				String temp="";
				fence++;
				while('a'<=current&&current<='z'||'0'<=current&&current<='9'){
					temp += current;
					current = toTranslate.charAt(fence);
					fence++;
				}
				fence--;
				addWord(VARIABLE,temp);
				succeed = true;
			}
			if('1'<=current&&current<='9'){
				String temp="";
				fence++;
				while('0'<=current&&current<='9'){
					temp +=current;
					current = toTranslate.charAt(fence);
					fence++;
				}
				fence--;
				addWord(FIGURE,temp);
				succeed = true;
			}
			switch(current){
			case '=':addWord(EQUAL);succeed = true;break;
			case '+':addWord(ADD);succeed = true;break;
			case '-':addWord(SUBTRACT);succeed = true;break;
			case '*':addWord(MULT);succeed = true;break;
			case '/':addWord(DIVIDE);succeed = true;break;
			}
			fence++;
		}
		if(succeed)
			return "succeed";
		else return "the wrong word lies in " + fence;
	}
	private void addWord(byte byt){
		OneWord word = new OneWord(byt);
		wordInside.add(word);
	}
	private void addWord(byte byt,String str){
		OneWord word = new OneWord(byt,str);
		wordInside.add(word);
	}
	private String toTranslate;
	private WordInside wordInside;
	private static final byte EQUAL = 1;
	private static final byte ADD = 2;
	private static final byte SUBTRACT = 3;
	private static final byte MULT = 4;
	private static final byte DIVIDE = 5;
	private static final byte VARIABLE = 6;
	private static final byte FIGURE = 7;

}