eclipse开发软件
001:加法运算符 + 002:减法运算符 - 003:乘法运算符 * 004:除法运算符 / 005:左括号 （ 013:右括号 ） 008.标识符 010.整数 011.等号运算符 == 012.浮点数 014:错误字段 error 015:赋值运算符 = 016：大于号 > 017：小于号 < 018：不等于号 != 019：小于等于号 <= 020：大于等于号 >= 021:{ 左中括号 { 022:} 右中括号 } 023: ; 分号 ;
import java.util.*; /* 编号规定: 001:加法运算符 002:减法运算符 003:乘法运算符 004:除法运算符 005:左括号 013:右括号 008.标识符 010.整数 011.等号运算符 012.浮点数 014:错误字段 015:赋值运算符 016：大于号 017：小于号 018：不等于号 019：小于等于号 020：大于等于号 021:{ 左中括号 022:} 右中括号 023: ; 分号 */ public class lexicalAnalysis { private static char[] Code;//转化为字符数组 public static ArrayList<String> tokens=new ArrayList<>();//用于之后的语法分析传值使用 public static void main(String[] args) { // String s = "public static void main(String[] args) { // String s = "abc2@e=num2+12.3.23)*123-12.#;#";//输入符号串 // String s = "public static void main(String[] args) { \r\n" + // " String s = \"abc2@e=num2+12.3.23)*123-12.#\";#";//表达式为A1=1.2+3*(4-6/3) String s = "vhguiyv7=-okllpl,-=popl'>=><==#"; StartLexicalAnalysis(s); } public static void StartLexicalAnalysis(String s) {//开始进行语法分析 if (IsCode(s)) {//判断 tokens.add("begin") ; System.out.println("当前输入符号为：" + s.substring(0,s.length()-1)); System.out.println("词法分析结果如下："); StartState(0, 0); } } private static boolean IsCode(String s){//判断源代码是否为空，为空则不能进行词法分析 if (s.isEmpty()||s.toCharArray()[0]=='#') { System.out.println("源代码为空，无法进行词法分析！"); return false; } else { Code = s.toCharArray(); return true; } } private static void StartState(int basicPointer, int currentPointer)//状态0，初始状态 { if (Code[currentPointer] == '#') { System.out.println("词法分析结束"); tokens.add("end") ; } else if (IsEqual(Code[currentPointer]))//如果当前字符是等于号进入EqualState { EqualState(currentPointer,basicPointer); } else if (IsAdd(Code[currentPointer]))//如果当前字符是加号进入AddState { AddState(currentPointer); } else if (IsSub(Code[currentPointer]))//如果当前字符是减号进入SubState { SubState(currentPointer); } else if (IsMul(Code[currentPointer]))//如果当前字符是乘号进入MulState { MulState(currentPointer); } else if (IsDiv(Code[currentPointer]))//如果当前字符是除号进入DivState { DivState(currentPointer); } else if (IsLParent(Code[currentPointer]))//如果当前字符是左括号进入LParentState { LParentState(currentPointer); } else if (IsRParent(Code[currentPointer]))//如果当前字符是右括号进入RParentState { RParentState(currentPointer); } else if (IsAlpha(Code[currentPointer]))//如果当前字符是字母号进入IdentState { IdentState(basicPointer, currentPointer + 1);//是字母就进入状态6 } else if (IsDigit(Code[currentPointer]))//如果当前字符是数字进入IntState { IntState(basicPointer, currentPointer + 1);//是数字就进入状态7 } else if ( IsGreater(Code[currentPointer]) ) { //如果当前字符是大于号 GreaterState(basicPointer, currentPointer + 1); } else if ( IsLess(Code[currentPointer]) ) { //如果当前字符是小于号 LessState(basicPointer, currentPointer + 1); } else if ( IsExc(Code[currentPointer]) ) { //如果当前字符是！ ExcState(basicPointer, currentPointer + 1); } else if ( IsLZKH(Code[currentPointer]) ) { //如果当前字符是{ LZKHState(basicPointer, currentPointer); } else if ( IsRZKH(Code[currentPointer]) ) { //如果当前字符是} RZKHState(basicPointer, currentPointer); } else if ( IsFH(Code[currentPointer]) ) { //如果当前字符是; FHState(basicPointer, currentPointer); } else { System.out.println("(014,错误," + Code[currentPointer] + ")"); String tempSt="014,"+Code[currentPointer]; tokens.add(tempSt); StartState(basicPointer + 1, currentPointer + 1); } } private static void FHState(int basicPointer, int j) { System.out.println("(023，分号，" + Code[j] + ")"); String tempSt="023,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void RZKHState(int basicPointer, int j) { System.out.println("(022，右中括号，" + Code[j] + ")"); String tempSt="022,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void LZKHState(int basicPointer, int j) { System.out.println("(021，左中括号，" + Code[j] + ")"); String tempSt="021,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void ExcState(int basicPointer, int j) { if ( Code[j] == '=' ) { ExcState(basicPointer,j+1); }else { if ( j - basicPointer == 2 ) { System.out.print("(018,不等于号,"); String tempSt = "!" ; printA(basicPointer,j,tempSt); }else { System.out.print("(014,错误," ); String tempSt="014,"; printA(basicPointer,j,tempSt); } } } private static void LessState(int basicPointer, int j) { if ( Code[j] == '=' ) { LessState(basicPointer,j+1); }else { if ( j - basicPointer == 2 ) { System.out.print("(019,小于等于号,"); String tempSt = "<" ; printA(basicPointer,j,tempSt); }else if (j - basicPointer == 1) { System.out.print("017,小于号," + Code[j-1] + ")"); String tempSt="017,"+Code[j-1]; tokens.add(tempSt); StartState(j + 1, j + 1); } else { System.out.print("(014,错误," ); String tempSt="014,"; printA(basicPointer,j,tempSt); } } } private static void GreaterState(int basicPointer, int j) { if ( Code[j] == '=' ) { GreaterState(basicPointer,j+1); }else { if ( j - basicPointer == 2 ) { System.out.print("(020,大于等于号,"); String tempSt = ">" ; printA(basicPointer,j,tempSt); }else if (j - basicPointer == 1) { System.out.println("(016,大于号," + Code[j-1] + ")"); String tempSt="016,"+Code[j-1]; tokens.add(tempSt); StartState(j , j + 1); } else { System.out.print("(014,错误," ); String tempSt="014,"; printA(basicPointer,j,tempSt); } } } private static void EqualState(int j, int basicPointer)//表示字符为等号运算符 { if ( IsEqual(Code[ j+1 ]) ) { EqualState(j+1, basicPointer); }else { if ( j - basicPointer == 1 ) { System.out.print("(011，等于号，"); String tempSt="011," ; printA(basicPointer,j+1,tempSt); }else if (j - basicPointer == 0) { //赋值运算符 System.out.println("(015，赋值运算符，" + Code[j] + ")"); String tempSt="015,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); }else { //错误代码 System.out.print("(014,错误," ); String tempSt="014,"; printA(basicPointer,j+1,tempSt); } } // System.out.println("(011，等于号，" + Code[j] + ")"); // String tempSt="011,"+Code[j]; // tokens.add(tempSt); // StartState(j + 1, j + 1); } private static void AddState(int j)//表示字符为加法运算符 { System.out.println("(001，加号，" + Code[j] + ")"); String tempSt="001,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void SubState(int j)//表示字符为减法运算符 { System.out.println("(002，减号，" + Code[j] + ")"); String tempSt="002,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void MulState(int j)//表示字符为乘法运算符 { System.out.println("(003，乘号，" + Code[j] + ")"); String tempSt="003,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void DivState(int j)//表示字符为除法运算符 { System.out.println("(004，除号，" + Code[j] + ")"); String tempSt="004,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void LParentState(int j)//字符为左括号 { System.out.println("(005，左括号，" + Code[j] + ")"); String tempSt="005,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void RParentState(int j)//字符为右括号 { System.out.println("(013，右括号，" + Code[j] + ")"); String tempSt="013,"+Code[j]; tokens.add(tempSt); StartState(j + 1, j + 1); } private static void IdentState(int i, int j)//标识符 { //Code[i]为准标识符的第一个字符，是个字母 ,而Code[j-1]是字母或数字 if (IsDigit(Code[j]) || IsAlpha(Code[j])) //如果当前字符仍然为字母或数字则再次进入IdentState { IdentState(i, j + 1); } else//如果当前字符为非数字及字母字符，则表明Code[i]~Code[j-1]这一段是标识符 { System.out.print("(008,标识符，"); String tempSt="008,"; printA(i, j, tempSt); } } private static void IntState(int i, int j)//状态7，准实数 { //Code[i]为准实数的第一个字符，是个字母 ,而Code[j-1]是数字或小数点 if (IsDigit(Code[j]))//如果当前字符仍然是数字，则再次进入IntState { IntState(i, j + 1); } if (Code[j] == '.')//如果当前字符是小数点，进入PointState { PointState(i, j + 1); } if ((Code[j] != '.') && !IsDigit(Code[j])) //如果当前字符既不为小数点也不是数字 ，则表明Code[i]~Code[j-1]这一段是个实数 { System.out.print("(010,整数，"); String tempSt="010,"; printA(i, j, tempSt); } } private static void PointState(int i, int j)//整数后接个小数点的中间态 { //Code[i]~Code[j-1]之中含有小数点 if (!IsDigit(Code[j])) {//小数点后还是小数点或者不是数字时报错 System.out.print("(014,错误，"); String tempSt="014,"; int q = i;//从Code[i]开始算起 while ((IsDigit(Code[q])) || (Code[q]) == '.') //直接相连的数字或小数点都属于这个无效字段的一部分 { tempSt=tempSt+Code[q]; System.out.print(Code[q]); q++; } System.out.println(")"); tokens.add(tempSt); //Code[q]此时为无效字段的下一个字符 StartState(q, q); } if (IsDigit(Code[j]))//如果当前字符是数字，则进入FloatState { FloatState(i, j + 1); } } private static void FloatState(int i,int j){ if (IsDigit(Code[j]))//如果当前字符是数字，则再次进入FloatState { FloatState(i, j + 1); } if (!IsDigit(Code[j])) //如果当前字符是非数字字符，说明Code[i]~Code[j-1]这一段是浮点数 { System.out.print("(012,浮点数，"); String tempSt="012,"; printA(i, j, tempSt); } } private static void printA(int i, int j, String tempSt) {//用于输出非单一字符 for (int k = i; k < j; k++) { tempSt = tempSt + Code[k]; System.out.print(Code[k]); } System.out.println(")"); tokens.add(tempSt); StartState(j, j); } private static boolean IsEqual(char ch) {//判断是否是字符'=' return ch == '='; } private static boolean IsAdd(char ch)//判断是否是字符'+' { return ch == '+'; } private static boolean IsSub(char ch)//判断是否是字符'-' { return ch == '-'; } private static boolean IsMul(char ch)//判断是否是字符'*' { return ch == '*'; } private static boolean IsDiv(char ch)//判断是否是字符'/' { return ch == '/'; } private static boolean IsLParent(char ch)//判断是否左括号 { return ch == '('; } private static boolean IsRParent(char ch)//判断是否是有括号 { return ch == ')'; } private static boolean IsDigit(char ch) {//判断是否是数字 return Character.isDigit(ch); } private static boolean IsAlpha(char ch) {//判断是否是字母 return Character.isLetter(ch); } private static boolean IsExc(char ch) { return ch == '!'; } private static boolean IsLess(char ch) { return ch == '<'; } private static boolean IsGreater(char ch) { return ch == '>'; } private static boolean IsFH(char ch) { return ch == ';'; } private static boolean IsRZKH(char ch) { return ch == '}'; } private static boolean IsLZKH(char ch) { return ch == '{'; } }
源代码下载https://download.csdn.net/download/Simple__Code/12809398
