遞歸下降語(yǔ)法制導(dǎo)翻譯

實(shí)現(xiàn)含多條簡(jiǎn)單賦值語(yǔ)句的簡(jiǎn)化語(yǔ)言的語(yǔ)義分析和中間代碼生成。

測(cè)試樣例

begin a:=2; b:=4; c:=c-1; area:=3.14*a*a; s:=2*3.1416*r*(h+r); end #

詞法分析

public class analyzer {public static List<String> llist=new ArrayList<>();static Map<Integer,Integer> map=new HashMap<>();final static String ID = "\\p{Alpha}(\\p{Alpha}|\\d)*";static int countLine=1;/** 整形常數(shù) NUM >> 正則表達(dá)式*/final static String NUM = "\\d\\d*";/** token 詞法單元* <詞符號(hào)， 種別碼> *//** 關(guān)鍵字 token*/static Map<String, Integer> TOKEN_KEYWORDS;/** 運(yùn)算符/界符 token */static Map<String, Integer> TOKEN_OPERATOR_BOUNDARY;/** 其他單詞 token*/static Map<String, Integer> TOKEN_ID_SUM;/** 文件根目錄*/static final String ROOT_DIRECTORY = "program.txt";/*** 初始化 token 單元*/public static void initToken(){//種別碼創(chuàng)建TOKEN_KEYWORDS = new HashMap<String, Integer>(){//關(guān)鍵字{put("begin", 1);put("if", 2);put("then", 3);put("while", 4);put("do", 5);put("end", 6);}};TOKEN_OPERATOR_BOUNDARY= new HashMap<String, Integer>(){//運(yùn)算符和界符{put("+", 13);put("-", 14);put("*", 15);put("/", 16);put(":", 17);put(":=", 18);put("<", 20);put("<>", 21);put("<=", 22);put(">", 23);put(">=", 24);put("=", 25);put(";", 26);put("(", 27);put(")", 28);put("#", 0);}};TOKEN_ID_SUM= new HashMap<String, Integer>(){//標(biāo)識(shí)符和整型常數(shù){put(ID, 10);put(NUM, 11);}};}/*** 讀 源程序 文件*/public static void ReadFile1() {FileInputStream fis = null;InputStreamReader isr = null;BufferedReader br = null;try {fis = new FileInputStream(ROOT_DIRECTORY);isr = new InputStreamReader(fis, "UTF-8"); // 轉(zhuǎn)化類br = new BufferedReader(isr); // 裝飾類String line;/** 記錄 程序 行數(shù) */while ((line = br.readLine()) != null) { // 每次讀取一行，分析一行boolean answer = lexicalAnalysis(line);if(answer == false){System.out.printf("ERROR 編譯錯(cuò)誤=== 第 %d 行出現(xiàn) 詞法錯(cuò)誤 \n", countLine);break;}countLine++;}System.out.printf("===詞法分析完成===\n");} catch (Exception ex) {ex.printStackTrace();} finally {try {br.close(); // 關(guān)閉最后一個(gè)類，會(huì)將所有的底層流都關(guān)閉} catch (Exception ex) {ex.printStackTrace();}}}/** 判斷key是否是其他單詞*/private static boolean isIDOrSUM(String key){if (key.matches(ID) ) {llist.add(key);map.put(llist.size()-1,countLine);System.out.printf("(%d, %s)\n", TOKEN_ID_SUM.get(ID), key);}else if (key.matches(NUM)) {llist.add(key);map.put(llist.size()-1,countLine);System.out.printf("(%d, %s)\n", TOKEN_ID_SUM.get(NUM), key);}else {return false;}return true;}/*** 進(jìn)行 詞法分析* @param word 要分析的字符串* @return 結(jié)果*/public static boolean lexicalAnalysis(String word){word = word.trim(); // 去首尾空格String[] strings = word.split("\\p{Space}+"); // 分割字符串，保證處理的字符串沒(méi)有空格for (String string : strings) {/** 3種情況：* 1. 關(guān)鍵字 == end （關(guān)鍵字的后面一定是空格 ）* 2. 運(yùn)算符/ 分界符 == continue* 3. 其他單詞 == continue*/String key = "";for (int i = 0; i < string.length(); i++){String indexChar = String.valueOf(string.charAt(i)) ;if(i+1<string.length()){if((indexChar+string.charAt(i+1)).equals("//"))return true;}/** 是 運(yùn)算符 或者 關(guān)鍵字*/if (TOKEN_OPERATOR_BOUNDARY.containsKey(indexChar) ||TOKEN_KEYWORDS.containsKey(string.substring(i, string.length()))){if (key.length() > 0) {if (isIDOrSUM(key) == false) {/** 詞法錯(cuò)誤 */return false;}key = "";}if(TOKEN_OPERATOR_BOUNDARY.containsKey(indexChar)) {/** 1. 是 運(yùn)算符/分界符 */key += indexChar;if(i + 1 < string.length() && TOKEN_OPERATOR_BOUNDARY.containsKey(indexChar + string.charAt(i+1))){ // 運(yùn)算分界符key += string.charAt(++i);}llist.add(key);map.put(llist.size()-1,countLine);System.out.printf("(%d, %s)\n",TOKEN_OPERATOR_BOUNDARY.get(key),key);key = "";}else if(TOKEN_KEYWORDS.containsKey(key = string.substring(i, string.length()))) {/** 2. 是關(guān)鍵字*/llist.add(key);map.put(llist.size()-1,countLine);System.out.printf("(%d, %s)\n",TOKEN_KEYWORDS.get(key),key);key = "";break;}}else {/** 是其他單詞*/key += indexChar;/** 其他單詞后面是 1. 換行，2. 運(yùn)算符/界符 3. 其他單詞*/if(i+1 >= string.length()){if (isIDOrSUM(key) == false) {/** 詞法錯(cuò)誤 */return false;}}}}}return true;}public analyzer() {}public static void main(String[] args) {initToken();System.out.println("==詞法分析程序==");System.out.println("從文件中讀取程序");System.out.println("==============");ReadFile1(); for(String s:llist) System.out.println(s);System.out.println();}}

語(yǔ)法分析

public class GrammarAnalysis {static char[] s = new char[100];static int sing;static int i; //用來(lái)記錄數(shù)組s中的下標(biāo)；static int error=0;static void P() {if(Objects.equals(analyzer.llist.get(i), "begin")) {++i;S(); //處理if(Objects.equals(analyzer.llist.get(i), "end")) {++i;}else{System.out.println("error!--------不是結(jié)尾符號(hào)end，"+"程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;++i;}}else {System.out.println("error!--------缺少開(kāi)頭符號(hào)begin，"+"程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;S(); //處理if(Objects.equals(analyzer.llist.get(i), "end")) {++i;}else{System.out.println("error!--------不是結(jié)尾符號(hào)end，"+"程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;++i;}}}static void S() {A();if(Objects.equals(analyzer.llist.get(i), ";")) {++i;// if(s[i]!='e') {S1();// }}else {System.out.println("error!-----------缺少結(jié)尾符號(hào);"+"，程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;++i;S1();}}static void S1() {if(!Objects.equals(analyzer.llist.get(i), "end")) {// ++i;S();}}static void A() {if(i+1<analyzer.llist.size()&&Objects.equals(analyzer.llist.get(i+1), ":=")) {String times=analyzer.llist.get(i),data1;SemanticAnalysis.j=i;SemanticAnalysis.j+=2;data1 = SemanticAnalysis.expression();//表達(dá)式SemanticAnalysis.memset(times,data1,"","");++i;++i;E();if(Objects.equals(analyzer.llist.get(i), ")") || Objects.equals(analyzer.llist.get(i), ";")) {if(Objects.equals(analyzer.llist.get(i), ")")) {++i;}}else {System.out.println("error!--------不是結(jié)尾符號(hào)；或者）"+"，程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;++i;}}else {System.out.println("error!---------不是賦值語(yǔ)句"+"，程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;++i;++i;E();if(Objects.equals(analyzer.llist.get(i), ")") || Objects.equals(analyzer.llist.get(i), ";")) {if(Objects.equals(analyzer.llist.get(i), ")")) {++i;}}else {System.out.println("error!--------不是結(jié)尾符號(hào)；或者）"+"，程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤");error++;++i;}}}static void E() {T();if(Objects.equals(analyzer.llist.get(i), "+") || Objects.equals(analyzer.llist.get(i), "-") || Objects.equals(analyzer.llist.get(i), ";") || Objects.equals(analyzer.llist.get(i), ")")) {E1();}else {System.out.println("error!-----------不是結(jié)尾符號(hào)+或者-或者；或者）"+"，程序第"+analyzer.map.get(i)+"行出現(xiàn)語(yǔ)法錯(cuò)誤"); error++;E1();}}static void T() {F();if(Objects.equals(analyzer.llist.get(i), "+") || Objects.equals(analyzer.llist.get(i), "-") || Objects.equals(analyzer.llist.get(i), ";") || Objects.equals(analyzer.llist.get(i), ")") || Objects.equals(analyzer.llist.get(i), "*") || Objects.equals(analyzer.llist.get(i), "/")) {T1();}}static void F() {if(Objects.equals(analyzer.llist.get(i), "(")) {++i;E();}else {++i;}}static void T1() {if(Objects.equals(analyzer.llist.get(i), "*")) {++i;F();T1();}else if(Objects.equals(analyzer.llist.get(i), "/")){++i;F();T1();}}static void E1() {if(Objects.equals(analyzer.llist.get(i), "+")) {++i;T();E1();}else if(Objects.equals(analyzer.llist.get(i), "-")){++i;T();E1();}}public static void main(String[] args) {Scanner sc=new Scanner(System.in);System.out.println("==詞法分析程序==");System.out.println("從文件中讀取程序");System.out.println("==============");analyzer.initToken();analyzer.ReadFile1();System.out.println("語(yǔ)法分析中....,請(qǐng)稍候");i=0;sing=0;if(Objects.equals(analyzer.llist.get(0), "#")) System.exit(-1);P();if(Objects.equals(analyzer.llist.get(i), "#")) {}else {System.out.println("error!-------不是結(jié)尾符號(hào)#"+analyzer.llist.get(i)+i);error++;}System.out.println("===詞法分析完成===");System.out.println("共檢查出"+error+"個(gè)語(yǔ)法錯(cuò)誤");System.out.println("\n===中間代碼生成結(jié)果===");for(int i = 0;i < SemanticAnalysis.elements.size();i++) {Element e = SemanticAnalysis.elements.get(i);System.out.println(e.times + " = " + e.data1 + " " + e.op + " " + e.data2);}}}

語(yǔ)義分析

public class SemanticAnalysis {static int j=0,t=1;static List<Element> elements = new ArrayList<Element>();static void memset(String times,String data1,String op,String data2) {Element e = new Element(times,data1,op,data2);elements.add(e);}public static String expression() { // 表達(dá)式String times,data1,op,data2;data1 = term();while(analyzer.llist.get(j).equals("+") || analyzer.llist.get(j).equals("-")) {// 當(dāng)前單詞為+、－if(analyzer.llist.get(j).equals("+")) // +op = "+";else // -op = "-";j++;data2 = term();times = "t" + (t++);memset(times,data1,op,data2);data1 = times;}return data1;}private static String term() { // 項(xiàng)String times,data1,op,data2;data1 = factor();while(analyzer.llist.get(j).equals("*") || analyzer.llist.get(j).equals("/") ) { // 當(dāng)前單詞為*、/if(analyzer.llist.get(j).equals("*")) // *op = "*";else // /op = "/";j++;data2 = factor();times = "t" + (t++);memset(times,data1,op,data2);data1 = times;}return data1;}private static String factor() { // 因子String data = "";if(analyzer.map2.get(analyzer.llist.get(j)) == 10) { // IDdata = analyzer.llist.get(j);j++;} else if(analyzer.map2.get(analyzer.llist.get(j)) == 11) { // NUMdata = analyzer.llist.get(j);j++;}else if(analyzer.llist.get(j).equals("(")) { // 左括號(hào)j++;data = expression();if(analyzer.llist.get(j).equals(")"))j++;} else {System.out.println("Error,表達(dá)式錯(cuò)誤");}return data;}} public class Element {String times;String data1;String op;String data2;Element(String times,String data1,String op,String data2) {this.times = times;this.data1 = data1;this.op = op;this.data2 = data2;} }

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