編譯原理-實驗報告實驗三--語法分析(LR分析程序

1、精選優(yōu)質(zhì)文檔-傾情為你奉上華北水利水電學院 編譯原理 實驗報告20122013學年 第 一 學期 2011 級 計算機科學與技術(shù) 專業(yè)班級： 學號： 姓名： 一、 實驗題目：語法分析（LR分析程序）（1）選擇最有代表性的語法分析方法LR分析法；（2）選擇對各種常見程序語言都用的語法結(jié)構(gòu)，如賦值語句（尤指表達式）作為分析對象，并且與所選語法分析方法要比較貼切。二、 實驗內(nèi)容（1）根據(jù)給定文法，先求出FirstVt和LastVt集合，構(gòu)造算符優(yōu)先關(guān)系表（要求算符優(yōu)先關(guān)系表輸出到屏幕或者輸出到文件）；（2）根據(jù)算法和優(yōu)先關(guān)系表分析給定表達式是否是該文法識別的正確的算術(shù)表達式（要求輸出歸約過程）（3）

2、給定表達式文法為：G(E): E#E#EE+T | TTT*F |FF(E)|i(4) 分析的句子為: (i+i)*i和i+i)*i三、 根據(jù)以上文法構(gòu)造出的LR(1)分析表為：+*()I#ETF0S4S51231S6Acc2R2S7R2R23R4R4R4R44S4S58235R6R6R6R66S4S5937S4S5108S6S119R1S7R1R110R3R3R3R311R5R5R5R5四、程序源代using System;using System.Text;using System.IO;namespace Syntax_Analyzerclass SyntaxStreamReader m

3、yStreamReader;int t;int lengh;int l =0;string grammar;int s=0;string Word;int w=0;int wordNum ;int n =0;int, LR;public Syntax() lengh = new int7; grammar=new string7; Word=new string100; wordNum = new int100; LR=new int30,30;public void analyzer()/讀入grammarSyntax myTextRead=new Syntax();Console.Writ

4、eLine("-語法分析開始-n");/*/循環(huán)讀取文法/*string strStart;strStart="grammar.txt"myTextRead.myStreamReader=new StreamReader(strStart);string strBufferStart;int uu=0;dostrBufferStart =myTextRead.myStreamReader.ReadLine();if(strBufferStart=null)break;foreach (String subString in strBufferStart.

5、Split()grammaruu=subString; /每行文法存入grammaruu+;while (strBufferStart!=null);myTextRead.myStreamReader.Close();/*/循環(huán)讀取lengh/*strStart="lengh.txt"myTextRead.myStreamReader=new StreamReader(strStart);uu=0;dostrBufferStart =myTextRead.myStreamReader.ReadLine();if(strBufferStart=null)break;forea

6、ch (String subString in strBufferStart.Split()lenghuu=Convert.ToInt32(subString); /每行文法存入grammaruu+;while (strBufferStart!=null);myTextRead.myStreamReader.Close();/*/ 讀入文件，進行語法分析/*string strReadFile;strReadFile="input.txt"myTextRead.myStreamReader=new StreamReader(strReadFile);string strBu

7、fferText;int wid =0;Console.WriteLine("分析讀入程序（記號ID）：n");dostrBufferText =myTextRead.myStreamReader.ReadLine();if(strBufferText=null)break;foreach (String subString in strBufferText.Split()if(subString!="")int ll;if(subString!=null)ll= subString.Length; /每一個長度elsebreak;int a=ll+1;

8、char b = new chara;StringReader sr = new StringReader(subString);sr.Read(b, 0, ll); /把substring 讀到char數(shù)組里int sort=(int)b0;/ wordi 和wordNumi對應(yīng)/先識別出一整個串，再根據(jù)開頭識別是數(shù)字還是字母Wordwid=subString;if(subString.Equals("+")wordNumwid=0;else if(subString.Equals("*")wordNumwid=1;else if(subString.

9、Equals("(")wordNumwid=2;else if(subString.Equals(")")wordNumwid=3;else if(subString.Equals("i")wordNumwid=4;Console.Write(subString+"("+wordNumwid+")"+" ");wid+;Console.WriteLine("n");while (strBufferText!=null);wordNumwid=5;myTex

10、tRead.myStreamReader.Close();/*/讀入LR分析表/*string strLR;strLR="LR-table.txt"myTextRead.myStreamReader=new StreamReader(strLR);string strBufferLR;int pp=0;dostrBufferLR =myTextRead.myStreamReader.ReadLine();if(strBufferLR=null)break;elseint j=0;foreach (String subString in strBufferLR.Split()

11、if(subString!=null)int lllr=Convert.ToInt16(subString);LRpp,j=lllr; /把行與列讀入數(shù)組j+;pp+;while (strBufferLR!=null);myTextRead.myStreamReader.Close();int state = new int100;string symbol =new string100;state0=0;symbol0="#"int p1=0;int p2=0;Console.WriteLine("n按文法規(guī)則歸約順序如下:n");/*/歸約算法/*w

12、hile(true)int j,k;j=statep2;k=wordNump1;t=LRj,k; /當出現(xiàn)t為的時候if(t=0)/錯誤類型 string error = "" ; if (k = 0) error = "+" else if (k = 1) error = "*" else if (k = 2) error = "(" else if (k = 3) error = ")" else if (k = 4) error = "i" else error = &

13、quot; 其它錯誤！"Console.WriteLine("n檢測結(jié)果:");Console.WriteLine("代碼中存在語法錯誤");Console.WriteLine("錯誤狀況:錯誤狀態(tài)編號為"+j+" 讀頭下符號為"+error);break;elseif(t=-100) /-100為達到接受狀態(tài)Console.WriteLine("n");Console.WriteLine("n檢測結(jié)果:");Console.WriteLine("代碼通過

14、語法檢測");break;if(t<0&&t!=-100) /歸約string m=grammar-t;Console.Write(m+" "); /輸出開始符int length=lengh-t; p2=p2-(length-1); Search mySearch=new Search();int right=mySearch.search(m);if(right=0)Console.WriteLine("n");Console.WriteLine("代碼中有語法錯誤");break;int a=st

15、atep2-1;int LRresult= LRa,right;statep2=LRresult;symbolp2=m;if(t>0)p2=p2+1;statep2=t;symbolp2=Convert.ToString(wordNump1);p1=p1+1;myTextRead.myStreamReader.Close();Console.WriteLine("-語法分析結(jié)束-n");Console.Read();class Searchpublic int search(string x)string mysymbol=new string3;mysymbol0="E"mysymbol1="T"mysymbol2="F" int r = 0;for(int s=0;s<=2;s+)if(mysymbols.Equals(