简单编译器设计

采用Java语言对C++语言进行编译，具体的简单编译器设计

词法分析器-扫描器的设计与实现

基本符号表

状态转换图

代码实现


import java.io.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;public class LexicalAnalyzer {/*** 1表示标识符* 2表示常数* 3-9表示界符* 10-40表示关键字* 41-59表示运算符* 60表示字符串* *///关键字static String []keyWord={"class","new","static","break","continue","return","do","while","if","else","for","switch","case","default","char","double","float","int","long","short", "string","null","true","false","void","this","goto","endl","cout","cin","main"};//运算符static String []operation={"+","-","*","-=","*=","/=","<<",">>","==","!=",">","<","=",">=","<=","&&","||","!","."};//界符static String []symbol={",",";",":","(",")","{","}"};//标识符public ArrayList<String> identifer=new ArrayList<>();public ArrayList<String> keyWords=new ArrayList<>();public ArrayList<String> operations=new ArrayList<>();public ArrayList<String> symbols=new ArrayList<>();//指向当前所读到字符串的位置的指针public int p,lines;public static void main(String[] args) throws IOException {PrintStream oldPrintStream = System.out; //将原来的System.out交给printStream 对象保存ByteArrayOutputStream bos = new ByteArrayOutputStream();System.setOut(new PrintStream(bos)); //设置新的outLexicalAnalyzer lexicalAnalyzer = new LexicalAnalyzer();lexicalAnalyzer.init();File file = new File("C:\\Users\\28362\\Desktop\\收集箱\\编译原理\\put.txt");lexicalAnalyzer.lines=1;try(Scanner input=new Scanner(file)) {while (input.hasNextLine()){String str=input.nextLine();lexicalAnalyzer.analyze(str);lexicalAnalyzer.lines++;}}System.setOut(oldPrintStream);System.out.println(bos.toString());saveAsFile(bos.toString());}public void init(){Collections.addAll(keyWords, keyWord);Collections.addAll(operations, operation);Collections.addAll(symbols, symbol);}public void analyze(String str){p=0;char ch;str=str.trim();for (;p<str.length();p++){ch=str.charAt(p);if (Character.isDigit(ch)){digitCheck(str);}else if (Character.isLetter(ch)||ch=='_'){letterCheck(str);}else if (ch=='"'){stringCheck(str);}else if (ch==' '){continue;}else {symbolCheck(str);}}}/*** 数字的识别* 1、识别退出：*   1.1、遇到空格符*   1.2、遇到运算符或者界符* 2、错误情况：*   2.1、两个及以上小数点*   2.2、掺杂字母**/public void digitCheck(String str){String token= String.valueOf(str.charAt(p++));//判断数字的小数点是否有且是否大于1int flag=0;boolean err=false;char ch;for (;p<str.length();p++) {ch = str.charAt(p);if (ch==' '||(!Character.isLetterOrDigit(ch)&&ch!='.')) {break;}else if (err){token+=ch;}else {token+=ch;if (ch == '.') {if (flag == 1) {err = true;} else {flag++;}}else if (Character.isLetter(ch)){err=true;}}}if (token.charAt(token.length()-1)=='.'){err=true;}if (err){System.out.println(lines+"line"+": "+token+" is wrong");}else {//            System.out.println("<"+2+", "+Integer.toBinaryString(Integer.parseInt(token))+">");System.out.println(2+", "+Integer.toBinaryString(Integer.parseInt(token)));}if (p!=str.length()-1||(p==str.length()-1&&!Character.isDigit(str.charAt(p)))){p--;}}/*** 标识符，关键字的识别* 识别退出：*      字符不为字母 数字 下划线* 识别：字符串是否存在关键字里 不为关键字则为标识符* */public void letterCheck(String str){String token= String.valueOf(str.charAt(p++));int num;char ch;for (;p<str.length();p++){ch=str.charAt(p);//isLetterOrDigit 确定指定的字符是否为字母或数字if (!Character.isLetterOrDigit(ch)&&ch!='_'){break;}else{token+=ch;}}if (keyWords.contains(token)){num = keyWords.indexOf(token)+10;
//            System.out.println("<"+num+", "+token+">");System.out.println(num+", "+token);}else {if (!identifer.contains(token))identifer.add(token);//System.out.println("<"+1+", "+"identifer["+identifer.indexOf(token)+"]"+">");System.out.println(1+", "+"identifer["+identifer.indexOf(token)+"]");}if (p!=str.length()-1||(p==str.length()-1&&(!Character.isLetterOrDigit(str.charAt(p))&&str.charAt(p)!='_'))){p--;}}/*** 符号识别* 识别退出*   1、判断是否为界符*   2、双目运算符分开也为存在与运算符中*   3、单个字符为运算符 则往后继续识别添加一个字符*/public void symbolCheck(String str){String token= String.valueOf(str.charAt(p++));char ch;int num;if (symbols.contains(token)){num = symbols.indexOf(token) + 3;
//            System.out.println("<"+num+", "+token+">");System.out.println(num+", "+token);p--;}else {if (operations.contains(token)){if (p<str.length()){ch=str.charAt(p);if (operations.contains(token+ch)){token+=ch;p++;if (p<str.length()){ch=str.charAt(p);if (operations.contains(token+ch)){token+=ch;num = 41+operations.indexOf(token);
//                                System.out.println("<"+num+", "+token+">");System.out.println(num+", "+token);}else{p--;num = 41+operations.indexOf(token);
//                                System.out.println("<"+num+", "+token+">");System.out.println(num+", "+token);}}else{num = 41+operations.indexOf(token);
//                            System.out.println("<"+num+", "+token+">");System.out.println(num+", "+token);}}else {p--;num = 41+operations.indexOf(token);
//                        System.out.println("<"+num+", "+token+">");System.out.println(num+", "+token);}}}else {p--;System.out.println(lines+"line"+": "+token+" is wrong");}}}/*** 字符串检查* 识别 “  ”*/public void stringCheck(String str){String token= String.valueOf(str.charAt(p++));char ch;for (;p<str.length();p++){ch=str.charAt(p);token+=ch;if (ch=='"'){break;}}if (token.charAt(token.length()-1)!='"'){System.out.println(lines+"line"+": "+token+" is wrong");}else {//            System.out.println("<"+60+","+token+">");System.out.println(60+","+"strings");}}//    public void readLine() throws IOException{//        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
//        String str;
//        str = br.readLine();
//        System.out.println(str);
//    }public static void saveAsFile(String str){String fileName = "C:\\Users\\28362\\Desktop\\收集箱\\编译原理\\out.txt";FileWriter fileWriter = null;try {fileWriter = new FileWriter(fileName);fileWriter.write(str);} catch (IOException e) {e.printStackTrace();} finally {try {fileWriter.flush();fileWriter.close();} catch (IOException e) {e.printStackTrace();}}}}

语法分析器的设计与实现

文法产生式

S‘：程序（语句的组合）S：语句 Q：else语句 L：标识符表 E：表达式

X：条件表达式 R：比较运算符 id：标识符 num：常量

S' -> S S'|ƐS -> A L;|A main(){S'}|id = E;| id(L); | if(X){S}Q|while(X){S}|ƐA -> int|char|short|long|float|doubleQ -> else{S}|ƐL -> id| L,idX -> ERER -> >|>=|<|<=|==|!=E -> +T|-T|E+T|E-TT -> F|T*F|T/FF -> id|num|(E)

提取公共左因子

S' → S S'|ƐS → A A'|id B|if(X){S}Q|while(X){S}|ƐA'→L;|main(){S'}A → int|char|shor|long|doubleB → (L); | =E;L → id | L , idQ → else{S} | ƐX → ERER → > | >= | < | <= | == | !=E → +T | -T | T | EMM → +T | -TT → F | TNN → *F |/FF → id | num | (E)

消除左递归

S’ → S S’
S’ → Ɛ
S → A A'
S → id B
S → if(X){S}Q
S → while(X){S}
S → Ɛ
A'→L;
A'→main(){S'}
B → (L);
B → =E;
L → id L’
L’→ , id L’
L’→ Ɛ
Q → else{S}
Q → Ɛ
X → ERE
E → TE’
E → +TE’
E → -TE’
E’ → ME’
E’ → Ɛ
M → +T
M → -T
T → FT’
T’ → NT’
T’ → Ɛ
N → *F
N → /F
F → id
F → num
F → (E)
R → >
R → >=
R → <
R → <=
R → ==
R → !=
A → char
A → short
A → int
A → long
A → double

求FIRST集

First(S’)={ char , short , int , long , float , double , id , if , while , Ɛ }
First(S)={ char , short , int , long , float , double , id , if , while , Ɛ }
First(A')={ id, main}
First(A)={ char , short , int , long, float  , double }
First(L)={ id }
First(L’)={ ，, Ɛ }
First(Q)={ else , Ɛ }
First(X)={ + , - , id , num , ( }
First(R)={ > , >= , < , <= , != , == }
First(E)={ + , - , id , num , ( }
First(E’)={ + , - , Ɛ }
First(M)={ + , - }
First(T)={ id , num , ( }
First(T’)={ * , / , Ɛ }
First(N)={ * , / }
First(F)={ id , num , ( }

求FOLLOW集

Follow (S’)={ #, } }
Follow (S)={ # , } }
Follow(A)={ id, main}
Follow(A')={# , }}
Follow (L)={ # , ) , ; , } }
Follow (L’)={ # , ) , ; , } }
Follow (Q)={#, } }
Follow (X)={ ) }
Follow (R)={ + , - , id , num , ( }
Follow (E)={ ) , ; , > , >= , < , <= , != , == }
Follow (E’)={ ) , ; , > , >= , < , <= , != , == }
Follow (M)={ ) , ; , > , >= , < , <= , != , == , + , - }
Follow (T)={ ) , ; , > , >= , < , <= , != , == , + , - }
Follow (T’)={ ) , ; , > , >= , < , <= , != , == , + , - }
Follow (N)={ ) , ; , > , >= , < , <= , != , == , + , - , * , / }
Follow (F)={ ) , ; , > , >= , < , <= , != , == , + , - , * , / }

LL（1）预测分析表中的数字分别代表的产生式如下：

0：S → A A'
1：S → id B
2：S → if(X){P}Q
3：S → while(X){P}
4：S → Ɛ
5：B → (L);
6：B → =E;
7：L → id L’
8：L’→ ,id L’
9：L’→ Ɛ
10：Q → else{S}
11：Q → Ɛ
12：X → ERE
13：E → +TE’
14：E → -TE’
15：E → TE’
16：E’→ ME’
17：E’→ Ɛ
18：M → +T
19：M → -T
20：T → FT’
21：T’→ NT’
22：T’→ Ɛ
23：N → *F
24：N → /F
25：F → id
26：F → num
27：F → (E)
28：R → >
29：R → >=
30：R → <
31：R → <=
32：R → ==
33：R → !=
34：S’ → S S’
35：S’ → Ɛ
36：A → char
37：A → short
38：A → int
39：A → long
40：A → float
41：A → double
42:A'→main(){S'}
43:A'→L;
44:S → A A'

预测分析表

代码实现

package parser;import java.io.*;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Scanner;public class Parser {private static ArrayList<String> stack = new ArrayList<>(); // 当前栈private static ArrayList<Integer> reader = new ArrayList<>(); // 待读队列private static Production[] productions = new Production[45]; // 产生式数组private static HashMap<Integer, String> map_i2s; // 种别码Map，种别码为键，单词为值private static HashMap<String, Integer> map_s2i; // 种别码Map，单词为键，种别码为值public static void main(String[] args) {int stackTop = 1;int readerTop = 0;int index = 0; // 当前步骤数initMap(); // 初始化种别码MapinitProductions(); // 产生式初始化stack.add(0, String.valueOf(map_s2i.get("#"))); // 在stack底部加上#stack.add(stackTop, "S'"); // 将S'压入栈System.out.print("请输入词法分析结果的文件路径：");Scanner scanner = new Scanner(System.in);String filepath = scanner.next();StringBuffer outputBuffer = new StringBuffer(); // 输出到文件的StringBuffer// 通过词法分析器的输出结果，初始化readertry {readToReader(filepath);} catch (IOException e) {e.printStackTrace();}reader.add(map_s2i.get("#")); // 在reader末尾加上#while (stackTop >= 0) {System.out.printf("%-6s", "第" + ++index + "步：");System.out.printf("%-10s", "当前栈：");outputBuffer.append("第" + index + "步： 当前栈：");StringBuffer sb = new StringBuffer(); // 引入StringBuffer仅为控制在控制台的输出格式对齐//获取当前栈的字符 用于显示for (int i = 0; i <= stackTop; i++) {String str = null;try {str = map_i2s.get(Integer.valueOf(stack.get(i)));if (str != null) {sb.append(str + " ");outputBuffer.append(str + " ");}} catch (NumberFormatException e) {sb.append(stack.get(i) + " ");outputBuffer.append(stack.get(i) + " ");}}System.out.printf("%-30s", sb.toString());System.out.print("待读队列：");outputBuffer.append("        待读队列：");sb = new StringBuffer();//获取当前队列的字符 用于显示for (int i = 0; i < reader.size(); i++) {sb.append(map_i2s.get(reader.get(i)) + " ");outputBuffer.append(map_i2s.get(reader.get(i)) + " ");}System.out.printf("%-55s", sb.toString());//比较栈顶和队底的元素if (match(stackTop, readerTop)) {stackTop--;System.out.print("\n");outputBuffer.append("\n");} else {int i = ll1_table(stackTop, readerTop);stackTop += stackPush(stackTop, productions[i]); // 压栈System.out.printf("%-30s", "下一步所用产生式：" + productions[i].prod);System.out.println();outputBuffer.append("         下一步所用产生式：" + productions[i].prod + "\n");}}if (stackTop == -1) {System.out.println("语法分析成功");outputBuffer.append("Accept");}System.out.print("请输入语法分析结果文件的保存路径：");String outputPath = scanner.next();// 将StringBuffer的内容输出到文件File outputFile = new File(outputPath);if (outputFile.exists()) {outputFile.delete();}PrintWriter writer = null;try {outputFile.createNewFile();writer = new PrintWriter(new FileOutputStream(outputFile));writer.write(outputBuffer.toString());} catch (IOException e1) {e1.printStackTrace();} finally {if (writer != null) {writer.close();}}}/*** 读取文件内容，词法分析结果* @param filePath* @throws IOException*/public static void readToReader(String filePath) throws IOException {InputStream is = new FileInputStream(filePath);String line; // 用来保存每行读取的内容BufferedReader br = new BufferedReader(new InputStreamReader(is));line = br.readLine(); // 读取第一行while (line != null) { // 如果 line 为空说明读完了int pos = line.indexOf(",");reader.add(Integer.valueOf(line.substring(0, pos)));line = br.readLine(); // 读取下一行}br.close();is.close();}/*** 压栈，将对应的文法产生式压入栈* @param stackTop* @param production* @return*/private static int stackPush(int stackTop, Production production) {int len = production.r_str.length;stack.remove(stackTop);if ("ε".equals(production.r_str[0])) {}else {for (int i = len - 1; i >= 0; i--) {stack.add(production.r_str[i]);}return len - 1;}return -1;}/*** ll(1)预测分析表* 通过 栈顶的元素和读入的元素 返回对应的文法产生式* @param stackTop* @param readerTop* @return*/private static int ll1_table(int stackTop, int readerTop) {if ("S".equals(stack.get(stackTop))) {if ("char".equals(map_i2s.get(reader.get(readerTop)))) {return 0;} else if ("short".equals(map_i2s.get(reader.get(readerTop)))) {return 0;} else if ("int".equals(map_i2s.get(reader.get(readerTop)))) {return 0;} else if ("long".equals(map_i2s.get(reader.get(readerTop)))) {return 0;} else if ("float".equals(map_i2s.get(reader.get(readerTop)))) {return 0;} else if ("double".equals(map_i2s.get(reader.get(readerTop)))) {return 0;} else if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 1;} else if ("if".equals(map_i2s.get(reader.get(readerTop)))) {return 2;} else if ("while".equals(map_i2s.get(reader.get(readerTop)))) {return 3;} else if ("}".equals(map_i2s.get(reader.get(readerTop)))) {return 4;} else if ("#".equals(map_i2s.get(reader.get(readerTop)))) {return 4;} else {return -1;}} else if ("B".equals(stack.get(stackTop))) {if ("(".equals(map_i2s.get(reader.get(readerTop)))) {return 5;} else if ("=".equals(map_i2s.get(reader.get(readerTop)))) {return 6;} else {return -1;}} else if ("L".equals(stack.get(stackTop))) {if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 7;}
//            else if("main".equals(map_i2s.get(reader.get(readerTop))))
//            {//                return 42;
//            }else {return -1;}} else if ("L'".equals(stack.get(stackTop))) {if (";".equals(map_i2s.get(reader.get(readerTop)))) {return 9;} else if (")".equals(map_i2s.get(reader.get(readerTop)))) {return 9;} else if ("}".equals(map_i2s.get(reader.get(readerTop)))) {return 9;} else if ("#".equals(map_i2s.get(reader.get(readerTop)))) {return 9;} else if (",".equals(map_i2s.get(reader.get(readerTop)))) {return 8;} else {return -1;}} else if ("Q".equals(stack.get(stackTop))) {if ("}".equals(map_i2s.get(reader.get(readerTop)))) {return 11;} else if ("$".equals(map_i2s.get(reader.get(readerTop)))) {return 11;} else if ("else".equals(map_i2s.get(reader.get(readerTop)))) {return 10;} else {return -1;}} else if ("X".equals(stack.get(stackTop))) {if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 12;} else if ("num".equals(map_i2s.get(reader.get(readerTop)))) {return 12;} else if ("+".equals(map_i2s.get(reader.get(readerTop)))) {return 12;} else if ("-".equals(map_i2s.get(reader.get(readerTop)))) {return 12;} else if ("(".equals(map_i2s.get(reader.get(readerTop)))) {return 12;} else {return -1;}} else if ("E".equals(stack.get(stackTop))) {if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 15;} else if ("num".equals(map_i2s.get(reader.get(readerTop)))) {return 15;} else if ("(".equals(map_i2s.get(reader.get(readerTop)))) {return 15;} else if ("+".equals(map_i2s.get(reader.get(readerTop)))) {return 13;} else if ("-".equals(map_i2s.get(reader.get(readerTop)))) {return 14;} else {return -1;}} else if ("E'".equals(stack.get(stackTop))) {if ("+".equals(map_i2s.get(reader.get(readerTop)))) {return 16;} else if ("-".equals(map_i2s.get(reader.get(readerTop)))) {return 16;} else if (">".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if (">=".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if ("<".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if ("<=".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if ("==".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if ("!=".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if (";".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else if (")".equals(map_i2s.get(reader.get(readerTop)))) {return 17;} else {return -1;}} else if ("M".equals(stack.get(stackTop))) {if ("+".equals(map_i2s.get(reader.get(readerTop)))) {return 18;} else if ("-".equals(map_i2s.get(reader.get(readerTop)))) {return 19;} else {return -1;}} else if ("T".equals(stack.get(stackTop))) {if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 20;} else if ("num".equals(map_i2s.get(reader.get(readerTop)))) {return 20;} else if ("(".equals(map_i2s.get(reader.get(readerTop)))) {return 20;}} else if ("T'".equals(stack.get(stackTop))) {if ("+".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if ("-".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if ("*".equals(map_i2s.get(reader.get(readerTop)))) {return 21;} else if ("/".equals(map_i2s.get(reader.get(readerTop)))) {return 21;} else if (">".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if (">=".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if ("<".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if ("<=".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if ("==".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if ("!=".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if (";".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else if (")".equals(map_i2s.get(reader.get(readerTop)))) {return 22;} else {return -1;}} else if ("N".equals(stack.get(stackTop))) {if ("*".equals(map_i2s.get(reader.get(readerTop)))) {return 23;} else if ("/".equals(map_i2s.get(reader.get(readerTop)))) {return 24;} else {return -1;}} else if ("F".equals(stack.get(stackTop))) {if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 25;} else if ("num".equals(map_i2s.get(reader.get(readerTop)))) {return 26;} else if ("(".equals(map_i2s.get(reader.get(readerTop)))) {return 27;} else {return -1;}} else if ("R".equals(stack.get(stackTop))) {if (">".equals(map_i2s.get(reader.get(readerTop)))) {return 28;} else if (">=".equals(map_i2s.get(reader.get(readerTop)))) {return 29;} else if ("<".equals(map_i2s.get(reader.get(readerTop)))) {return 30;} else if ("<=".equals(map_i2s.get(reader.get(readerTop)))) {return 31;} else if ("==".equals(map_i2s.get(reader.get(readerTop)))) {return 32;} else if ("!=".equals(map_i2s.get(reader.get(readerTop)))) {return 33;} else {return -1;}} else if ("S'".equals(stack.get(stackTop))) {if ("char".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("short".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("int".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("long".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("float".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("double".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("if".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("while".equals(map_i2s.get(reader.get(readerTop)))) {return 34;} else if ("#".equals(map_i2s.get(reader.get(readerTop)))) {return 35;}else if ("}".equals(map_i2s.get(reader.get(readerTop)))) {return 35;}else {return -1;}} else if ("A".equals(stack.get(stackTop))) {if ("char".equals(map_i2s.get(reader.get(readerTop)))) {return 36;} else if ("short".equals(map_i2s.get(reader.get(readerTop)))) {return 37;} else if ("int".equals(map_i2s.get(reader.get(readerTop)))) {return 38;} else if ("long".equals(map_i2s.get(reader.get(readerTop)))) {return 39;} else if ("float".equals(map_i2s.get(reader.get(readerTop)))) {return 40;} else if ("double".equals(map_i2s.get(reader.get(readerTop)))) {return 41;} else if("id".equals(map_i2s.get(reader.get(readerTop)))){return 43;}else {return -1;}}else if("A'".equals(stack.get(stackTop))){if ("id".equals(map_i2s.get(reader.get(readerTop)))) {return 43;} else if ("main".equals(map_i2s.get(reader.get(readerTop)))) {return 42;} else{return -1;}} else {System.out.println("语法错误");}return -1;}/*** 比较栈里面的符号* @param stackTop* @param readerTop* @return*/private static boolean match(int stackTop, int readerTop) {try {int stackTopVal = Integer.valueOf(stack.get(stackTop)); // 未抛出异常说明是终结符if (stackTopVal == reader.get(0)) {stack.remove(stackTop);reader.remove(readerTop);return true;} else {return false;}} catch (NumberFormatException e) {// 抛出异常说明是非终结符return false;}}/*** 初始化产生式*/private static void initProductions() {productions[0] = new Production("S",new String[]{"A", "A'"},"S --> AA'");productions[1] = new Production("S",new String[]{String.valueOf(map_s2i.get("id")), "B"},"S --> id B");productions[2] = new Production("S",new String[]{String.valueOf(map_s2i.get("if")), String.valueOf(map_s2i.get("(")), "X", String.valueOf(map_s2i.get(")")), String.valueOf(map_s2i.get("{")), "S", String.valueOf(map_s2i.get("}")), "Q"},"S --> if(X){S}Q");productions[3] = new Production("S",new String[]{String.valueOf(map_s2i.get("while")), String.valueOf(map_s2i.get("(")), "X", String.valueOf(map_s2i.get(")")), String.valueOf(map_s2i.get("{")), "S", String.valueOf(map_s2i.get("}"))},"S --> while(X){S}");productions[4] = new Production("S",new String[]{"ε"},"S --> ε");productions[5] = new Production("B",new String[]{String.valueOf(map_s2i.get("(")), "L", String.valueOf(map_s2i.get(")")), String.valueOf(map_s2i.get(";"))},"B --> (L);");productions[6] = new Production("B",new String[]{String.valueOf(map_s2i.get("=")), "E", String.valueOf(map_s2i.get(";"))},"B --> =E;");productions[7] = new Production("L",new String[]{String.valueOf(map_s2i.get("id")), "L'"},"L --> id L'");productions[8] = new Production("L'",new String[]{String.valueOf(map_s2i.get(",")), String.valueOf(map_s2i.get("id")), "L'"},"L' --> ,id L'");productions[9] = new Production("L'",new String[]{"ε"},"L' --> ε");productions[10] = new Production("Q",new String[]{String.valueOf(map_s2i.get("else")), String.valueOf(map_s2i.get("{")), "S", String.valueOf(map_s2i.get("}"))},"Q --> else{S}");productions[11] = new Production("Q",new String[]{"ε"},"Q --> ε");productions[12] = new Production("X",new String[]{"E", "R", "E"},"X --> ERE");productions[13] = new Production("E",new String[]{String.valueOf(map_s2i.get("+")), "T", "E'"},"E --> +TE'");productions[14] = new Production("E",new String[]{String.valueOf(map_s2i.get("-")), "T", "E'"},"E --> -TE'");productions[15] = new Production("E",new String[]{"T", "E'"},"E --> TE'");productions[16] = new Production("E'",new String[]{"M", "E'"},"E' --> ME'");productions[17] = new Production("E'",new String[]{"ε"},"E' --> ε");productions[18] = new Production("M",new String[]{String.valueOf(map_s2i.get("+")), "T"},"M --> +T");productions[19] = new Production("M",new String[]{String.valueOf(map_s2i.get("-")), "T"},"M --> -T");productions[20] = new Production("T",new String[]{"F", "T'"},"T --> FT'");productions[21] = new Production("T'",new String[]{"N", "T'"},"T' --> NT'");productions[22] = new Production("T'",new String[]{"ε"},"T' --> ε");productions[23] = new Production("N",new String[]{String.valueOf(map_s2i.get("*")), "F"},"N --> *F");productions[24] = new Production("N",new String[]{String.valueOf(map_s2i.get("/")), "F"},"N --> /F");productions[25] = new Production("F",new String[]{String.valueOf(map_s2i.get("id"))},"F --> id");productions[26] = new Production("F",new String[]{String.valueOf(map_s2i.get("num"))},"F --> num");productions[27] = new Production("F",new String[]{String.valueOf(map_s2i.get("(")), "E", String.valueOf(map_s2i.get(")"))},"F --> (E)");productions[28] = new Production("R",new String[]{String.valueOf(map_s2i.get(">"))},"R --> >");productions[29] = new Production("R",new String[]{String.valueOf(map_s2i.get(">="))},"R --> >=");productions[30] = new Production("R",new String[]{String.valueOf(map_s2i.get("<"))},"R --> <");productions[31] = new Production("R",new String[]{String.valueOf(map_s2i.get("<="))},"R --> <=");productions[32] = new Production("R",new String[]{String.valueOf(map_s2i.get("=="))},"R --> ==");productions[33] = new Production("R",new String[]{String.valueOf(map_s2i.get("!="))},"R --> !=");productions[34] = new Production("S'",new String[]{"S", "S'"},"S' --> SS'");productions[35] = new Production("S'",new String[]{"ε"},"S' --> ε");productions[36] = new Production("A",new String[]{String.valueOf(map_s2i.get("char"))},"A --> char");productions[37] = new Production("A",new String[]{String.valueOf(map_s2i.get("short"))},"A --> short");productions[38] = new Production("A",new String[]{String.valueOf(map_s2i.get("int"))},"A --> int");productions[39] = new Production("A",new String[]{String.valueOf(map_s2i.get("long"))},"A --> long");productions[40] = new Production("A'",new String[]{String.valueOf(map_s2i.get("float"))},"A --> float");productions[41] = new Production("A",new String[]{String.valueOf(map_s2i.get("double"))},"A --> double");productions[42] = new Production("A'",new String[]{String.valueOf(map_s2i.get("main")),String.valueOf(map_s2i.get("(")),String.valueOf(map_s2i.get(")")), String.valueOf(map_s2i.get("{")), "S'", String.valueOf(map_s2i.get("}"))},"A' --> main(){S'}");productions[43] = new Production("A'",new String[]{"L", String.valueOf(map_s2i.get(";"))},"A' --> L;");productions[44] = new Production("S",new String[]{"A","A'"},"S --> AA'");}/*** 存储符号表，散列表*/private static void initMap(){//HashMap 散列表map_s2i = new HashMap<>();map_s2i.put("id",1);//标识符map_s2i.put("num",2);//常数map_s2i.put(",",3);map_s2i.put(";",4);map_s2i.put(":",5);map_s2i.put("(",6);map_s2i.put(")",7);map_s2i.put("{",8);map_s2i.put("}",9);map_s2i.put("class",10);map_s2i.put("new",11);map_s2i.put("static",12);map_s2i.put("break",13);map_s2i.put("continue",14);map_s2i.put("return",15);map_s2i.put("do",16);map_s2i.put("while",17);map_s2i.put("if",18);map_s2i.put("else",19);map_s2i.put("for",20);map_s2i.put("switch",21);map_s2i.put("case",22);map_s2i.put("default",23);map_s2i.put("char",24);map_s2i.put("double",25);map_s2i.put("float",26);map_s2i.put("int",27);map_s2i.put("long",28);map_s2i.put("short",29);map_s2i.put("string",30);map_s2i.put("null",31);map_s2i.put("true",32);map_s2i.put("false",33);map_s2i.put("void",34);map_s2i.put("this",35);map_s2i.put("goto",36);map_s2i.put("endl",37);map_s2i.put("cout",38);map_s2i.put("cin",39);map_s2i.put("main",40);map_s2i.put("+",41);map_s2i.put("-",42);map_s2i.put("*",43);map_s2i.put("-=",44);map_s2i.put("*=",45);map_s2i.put("/=",46);map_s2i.put("<<",47);map_s2i.put(">>",48);map_s2i.put("==",49);map_s2i.put("!=",50);map_s2i.put(">",51);map_s2i.put("<",52);map_s2i.put("=",53);map_s2i.put(">=",54);map_s2i.put("<=",55);map_s2i.put("&&",56);map_s2i.put("||",56);map_s2i.put("!",58);map_s2i.put(".",59);map_s2i.put("strings",60);//字符串map_s2i.put("#",61);map_i2s = new HashMap<>();map_i2s.put(1,"id");//标识符map_i2s.put(2,"num");//常数map_i2s.put(3,",");map_i2s.put(4,";");map_i2s.put(5,":");map_i2s.put(6,"(");map_i2s.put(7,")");map_i2s.put(8,"{");map_i2s.put(9,"}");map_i2s.put(10,"class");map_i2s.put(11,"new");map_i2s.put(12,"static");map_i2s.put(13,"break");map_i2s.put(14,"continue");map_i2s.put(15,"return");map_i2s.put(16,"do");map_i2s.put(17,"while");map_i2s.put(18,"if");map_i2s.put(19,"else");map_i2s.put(20,"for");map_i2s.put(21,"switch");map_i2s.put(22,"case");map_i2s.put(23,"default");map_i2s.put(24,"char");map_i2s.put(25,"double");map_i2s.put(26,"float");map_i2s.put(27,"int");map_i2s.put(28,"long");map_i2s.put(29,"short");map_i2s.put(30,"string");map_i2s.put(31,"null");map_i2s.put(32,"true");map_i2s.put(33,"false");map_i2s.put(34,"void");map_i2s.put(35,"this");map_i2s.put(36,"goto");map_i2s.put(37,"endl");map_i2s.put(38,"cout");map_i2s.put(39,"cin");map_i2s.put(40,"main");map_i2s.put(41,"+");map_i2s.put(42,"-");map_i2s.put(43,"*");map_i2s.put(44,"-=");map_i2s.put(45,"*=");map_i2s.put(46,"/=");map_i2s.put(47,"<<");map_i2s.put(48,">>");map_i2s.put(49,"==");map_i2s.put(50,"!=");map_i2s.put(51,">");map_i2s.put(52,"<");map_i2s.put(53,"=");map_i2s.put(54,">=");map_i2s.put(55,"<=");map_i2s.put(56,"&&");map_i2s.put(57,"||");map_i2s.put(58,"!");map_i2s.put(59,".");map_i2s.put(60,"strings");//字符串map_i2s.put(61,"#");}/*** 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【编译原理】词法分析器语法分析器

简单编译器设计

词法分析器-扫描器的设计与实现

基本符号表

状态转换图

代码实现

语法分析器的设计与实现

文法产生式

提取公共左因子

消除左递归

求FIRST集

求FOLLOW集

预测分析表

代码实现

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