編譯原理-太原理工大學(xué)

1、編譯原理實(shí)驗(yàn)報(bào)告本科實(shí)驗(yàn)報(bào)告課程名稱： 編譯原理D 實(shí)驗(yàn)地點(diǎn)： 實(shí)驗(yàn)室 專業(yè)班級(jí)： 學(xué) 號(hào)： _學(xué)生姓名： java編譯 指導(dǎo)教師： 成 績(jī)： 2015年 月 日實(shí)驗(yàn)一、 無(wú)符號(hào)數(shù)的詞法分析程序（4學(xué)時(shí)）內(nèi)容：掌握詞法分析的基本思想，并用高級(jí)語(yǔ)言編寫無(wú)符號(hào)數(shù)的詞法分析程序。要求：從鍵盤上輸入一串字符（包括字母、數(shù)字等），最后以“；”結(jié)束，編寫程序識(shí)別出其中的無(wú)符號(hào)數(shù)。無(wú)符號(hào)數(shù)文法規(guī)則可定義如下： .E比例因子E +- 0 1 2 3. 9 讀無(wú)符號(hào)數(shù)的程序流程圖見下圖實(shí)驗(yàn)代碼：package text_1;import java.util.*;public class Text1 public

2、 static void main(String args) int p = 0, w = 0, w1 = 0, j = 0, i = 0, d = 0, e = 1;/定義初值double w2 = 0;String str;System.out.println(請(qǐng)輸入一串字符串(以;結(jié)束)：);Scanner m = new Scanner(System.in);str = m.nextLine();char ch1 = str.toCharArray(); /字符串轉(zhuǎn)化為字符數(shù)組/* * 檢測(cè)字符數(shù)組 for(i=0;ich1.length;i+) System.out.print(ch

3、1i+ ); */while (i 9 | ch1i = 0 & ch1i = 0 & ch1i = 0 & ch1i 1) w2 = w / (Math.pow(10.0, j - 1);System.out.println(實(shí)型數(shù)為：+w2+*10+ +(e*(p-j+1);/科學(xué)計(jì)數(shù)法輸出實(shí)型j = 0;w2 = 0;w = 0;p = 0; elseSystem.out.println(輸入錯(cuò)誤!);if (ch1i = 0 & ch1i = 0 & ch1i 1) w2 = w / (Math.pow(10.0, j - 1);System.out.println(實(shí)型數(shù)為：+w2+

4、*10+ +(e*(p-j+1);j = 0;w2 = 0;w = 0;p = 0; elseSystem.out.println(輸入錯(cuò)誤!);else i+;if (ch1i = 0 & ch1i = 0 & ch1i = 0 & ch1i = 0 & ch1i 1) w2 = w / (Math.pow(10.0, j - 1);System.out.println(實(shí)型數(shù)為： + w2 + *10 + + (e * (p - j + 1);j = 0;w2 = 0;w = 0;p = 0; elseSystem.out.println(輸入錯(cuò)誤!);if (ch1i = 0 & ch1

5、i = 0 & ch1i 1) w2 = w / (Math.pow(10.0, j - 1);System.out.println(實(shí)型數(shù)為：+w2+*10 + +(e*(p-j+1);j = 0;w2 = 0;w = 0;p = 0; elseSystem.out.println(輸入錯(cuò)誤!);else if (ch1i != E) /輸出小數(shù)System.out.println(小數(shù)為： + w + . + w1);w = 0;w1 = 0;j = 0;運(yùn)行結(jié)果：實(shí)驗(yàn)二、 逆波蘭式生成程序內(nèi)容：掌握語(yǔ)法分析的基本思想，并用高級(jí)語(yǔ)言編寫逆波蘭式生成程序（4學(xué)時(shí)）要求：利用逆波蘭式生成算法編

6、寫程序，將從鍵盤上輸入的算術(shù)表達(dá)式（中綴表達(dá)式）轉(zhuǎn)化成逆波蘭式。逆波蘭表達(dá)式的生成過程涉及到運(yùn)算符的優(yōu)先級(jí)，下表中列出幾個(gè)常用運(yùn)算符的優(yōu)先關(guān)系。右關(guān)系左常用運(yùn)算符優(yōu)先關(guān)系矩陣+-*/（）+-*/（）如上表所示的優(yōu)先關(guān)系矩陣表示了+，-，*，/，（，）等七種運(yùn)算符之間的相互優(yōu)先關(guān)系。“、”三種符號(hào)分別代表“大于”、“小于”、“相等”三種優(yōu)先關(guān)系。左邊的“”與右邊的“（”之間沒有優(yōu)先關(guān)系存在，所以表中為空白。逆波蘭表達(dá)式生成算法的關(guān)鍵在于比較當(dāng)前運(yùn)算符與棧頂運(yùn)算符的優(yōu)先關(guān)系，若當(dāng)前運(yùn)算符的優(yōu)先級(jí)高于棧頂運(yùn)算符，則當(dāng)前運(yùn)算符入棧，若當(dāng)前運(yùn)算符的優(yōu)先級(jí)低于棧頂運(yùn)算符，則棧頂運(yùn)算符退棧。下面給出了逆波蘭

7、表達(dá)式生成算法的流程圖。（為了便于比較相鄰運(yùn)算符的優(yōu)先級(jí)，需要設(shè)立一個(gè)工作棧，用來(lái)存放暫時(shí)不能處理的運(yùn)算符，所以又稱運(yùn)算符棧。實(shí)驗(yàn)代碼：package text_2import java.util.*;public class Text2 private char Operator_Precedence_Relation_Matrix = , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , ;private char Infix_Expression; / 字符串infix用于表示要

8、處理的中綴表達(dá)式private String Reverse_Polish_Expression = new String();/ 字符串reversePlishExpression用于表示處理結(jié)果逆波蘭式private String Analysis_Stack = new String();/字符串a(chǎn)nalysisStack用于表示分析棧private int Length_Infix_Expression = 0;/ 中綴表達(dá)式的長(zhǎng)度,初始值為0private int match_Parentheses = 1;/ 用來(lái)查看左右括號(hào)是否配對(duì)正確private int count = 0;

9、private void init(String str) Infix_Expression = str.toCharArray();Length_Infix_Expression = Infix_Expression.length;private int Operator_Judgement(char currentOperator) int flag = -1;switch (currentOperator) case +:flag = 0;break;case -:flag = 1;break;case *:flag = 2;break;case /:flag = 3;case :fla

10、g = 4;break;case (:flag = 5;break;case ):flag = 6;break;return flag;void convert_Process(String str) init(str);while (true) match_Parentheses = 0;if (count = Length_Infix_Expression) / 檢測(cè)輸入串為空while (Analysis_Stack.length() != 0) / 檢測(cè)分析棧if (Analysis_Stack.charAt(Analysis_Stack.length() - 1) = () Syst

11、em.out.println(n您輸入的中綴表達(dá)式中有無(wú)法配對(duì)的（括號(hào)，請(qǐng)仔細(xì)核實(shí)!);System.exit(0); else Reverse_Polish_Expression += Analysis_Stack.charAt(Analysis_Stack.length() - 1);Analysis_Stack = Analysis_Stack.substring(0,Analysis_Stack.length() - 1);/ 退棧輸出System.out.println(逆波蘭式為：+ Reverse_Polish_Expression);System.exit(0); else i

12、f (Operator_Judgement(Infix_Expressioncount) = -1) Reverse_Polish_Expression += Infix_Expressioncount; else while (Analysis_Stack.length() != 0) / 檢測(cè)分析棧if (Operator_Precedence_Relation_MatrixOperator_Judgement(Analysis_Stack.charAt(Analysis_Stack.length() - 1)Operator_Judgement(Infix_Expressioncount

13、) = ) Analysis_Stack += Infix_Expressioncount;break; else if (Infix_Expressioncount != ) Reverse_Polish_Expression += Analysis_Stack.charAt(Analysis_Stack.length() - 1);Analysis_Stack = Analysis_Stack.substring(0,Analysis_Stack.length() - 1); else while (Analysis_Stack.length() = 0| Analysis_Stack.c

14、harAt(Analysis_Stack.length() - 1) != () if (Analysis_Stack.length() = 0) System.out.println(n您輸入的中綴表達(dá)式中有無(wú)法配對(duì)的）括號(hào)，請(qǐng)仔細(xì)核實(shí)！);System.exit(0); else Reverse_Polish_Expression += Analysis_Stack.charAt(Analysis_Stack.length() - 1);Analysis_Stack = Analysis_Stack.substring(0,Analysis_Stack.length() - 1);if (

15、Analysis_Stack.charAt(Analysis_Stack.length() - 1) = () Analysis_Stack = Analysis_Stack.substring(0, Analysis_Stack.length() - 1);match_Parentheses = 1;break;if (Analysis_Stack.length() = 0)if (Infix_Expressioncount != )Analysis_Stack += Infix_Expressioncount;else if (match_Parentheses != 1) System.out.println(