编译原理实验一：词法分析实验

编译原理词法分析器-ll1-lr0-python实现代码计算机科学与通信工程学院编译原理实验报告题目： 1.词法分析器2. LL(1)分析器3. LR(0)分析器班级：姓名:学号：指导老师：2017年月目录一、实验题目 (1)二、实验目的和要求 (1)三、代码实现 (2)四、总结 (25)一、实验题目1.词法分析器分析一段程序代码，将代码中的单词符号分解出来，并对其进行检查，输出token表和error表2.LL(1)文法分析器分析给定文法。

求出文法的FIRST集，FOLLOW集，并构建分析表，对给定输入串进行分析。

3.LR(0)文法分析器分析给定文法。

用Ꜫ_CLOSURE方法构造文法的LR(0)项目集规范族，根据状态转换函数GO构造出文法的DFA,并转换为分析表，对给定输入串进行分析。

二、实验目的和要求1.学会词法分析器的实现思路。

2.学会求解FIRST集， FOLLOW集，构造LL(1)分析表。

3.学会Ꜫ_CLOSURE方法，状态转换函数GO, 构造LR(0)分析表。

三、代码实现1.词法分析器program.txt 中存放要分析的文法：E->TRR->+TR|-TR|~T->FGG->*FG|/FG|~F->(E)|i代码：KEYWORD_LIST = ['while', 'if', 'else', 'switch', 'case']SEPARATOR_LIST = [';', ':', ',', '(', ')', '[', ']', '{', '}']OPERATOR_LIST1 = ['+', '-', '*']OPERATOR_LIST2 = ['<=', '<', '==', '=', '>', '>=']CATEGORY_DICT = {# KEYWORD"while": {"while": ""},"if": {"if": ""},"else": {"else": ""},"switch": {"switch": ""},"case": {"case": ""},# OPERATOR"+": {"+": ""},"-": {"-": ""},"*": {"*": ""},"<=": {"relop": "LE"},"<": {"relop": "LT"},">=": {"relop": "GE"},">": {"relop": "GT"},"==": {"relop": "EQ"},"=": {"=": ""},# SEPARATOR";": {";": ""},":": {":": ""},",": {",": ""},"(": {"(": ""},")": {")": ""},"[": {"]": ""},"]": {"]": ""},"{": {"{": ""},"}": {"}": ""},}CONSTANTTABLE = []TOKENTABLE = []OPERATORTABLE = []KEYWORDTABLE = []SEPARATORTABLE = []UNDEFINEDTABLE = []# READ FILEdef read_file(path, method):temp_str = ""try:file = open(path, method)for line in file:line = line.replace('\n', " ") temp_str += linetemp_str = str(temp_str)except IOError as e:print(e)exit()finally:file.close()return temp_str.strip() + " "# GETBEdef getbe():global tokengetchar()token = ""return# GETCHARdef getchar():global characterglobal locationwhile all_string[location] == " ":location = location + 1character = all_string[location]return character# LINK TOKENdef concatenation():global tokenglobal charactertoken = token + character# IS NUMBERdef digit():if '0' <= character <= '9':return Truereturn False# IS ALPHABETdef letter():if 'A' <= character <= 'Z' or 'a' <= character <= 'z': return Truereturn False# IS IDENTIFIERdef reserve():if token in KEYWORD_LIST:return CATEGORY_DICT[token]else:return 0# RETRACTdef retract():global locationglobal character# location = location - 1character = ""return# MAIN FUNCTIONdef main():global tokenglobal characters = getchar()getbe()if 'a' <= s <= 'z' or 'A' <= s <= 'Z':while letter() or digit():concatenation()location = location + 1character = all_string[location]retract()c = reserve()if c == 0:TOKENTABLE.append(token)print("这是标识符：{'", token, "':'", TOKENTABLE.index(token), "'}") else:KEYWORDTABLE.append(token)print("这是保留字：", CATEGORY_DICT[token])elif '0' <= s <= '9':while digit():concatenation()location = location + 1character = all_string[location]retract()CONSTANTTABLE.append(token)print("这是常数：{'", token, "':'", CONSTANTTABLE.index(token), "'}") elif s in OPERATOR_LIST1:location = location + 1OPERATORTABLE.append(s)print("这是单操作符：", CATEGORY_DICT[s])elif s in OPERATOR_LIST2:location = location + 1character = all_string[location]if character == '=':OPERATORTABLE.append(s + character)print("这是双操作符：", CATEGORY_DICT[s + character])else:retract()location = location + 1OPERATORTABLE.append(s)print("这是单操作符:", CATEGORY_DICT[s])elif s in SEPARATOR_LIST:location = location + 1SEPARATORTABLE.append(s)print("这是分隔符：", CATEGORY_DICT[s])else:UNDEFINEDTABLE.append(s)print("error:undefined identity :'", s, "'")if __name__ == '__main__':character = ""token = ""all_string = read_file("program.txt", "r")location = 0while location + 1 < len(all_string):main()print('KEYWORDTABLE:', KEYWORDTABLE)print('TOKENTABLE:', TOKENTABLE)print('CONSTANTTABLE:', CONSTANTTABLE)print('OPERATORTABLE:', OPERATORTABLE)print('SEPARATORTABLE:', SEPARATORTABLE)运行结果：2.LL(1)分析器program.txt 中存放要分析的文法：E->TRR->+TR|-TR|~T->FGG->*FG|/FG|~F->(E)|i输入串：i+i*i代码：NonTermSet = set() # 非终结符集合TermSet = set() # 终结符集合First = {} # First集Follow = {} # Follow集GramaDict = {} # 处理过的产生式Code = [] # 读入的产生式AnalysisList = {} # 分析表StartSym = "" # 开始符号EndSym = '#' # 结束符号为“#“Epsilon = "~" # 由于没有epsilon符号用“~”代替# 构造First集def getFirst():global NonTermSet, TermSet, First, Follow, FirstAfor X in NonTermSet:First[X] = set() # 初始化非终结符First集为空for X in TermSet:First[X] = set(X) # 初始化终结符First集为自己Change = Truewhile Change: # 当First集没有更新则算法结束Change = Falsefor X in NonTermSet:for Y in GramaDict[X]:k = 0Continue = Truewhile Continue and k < len(Y):if not First[Y[k]] - set(Epsilon) <= First[X]: # 没有一样的就添加，并且改变标志if Epsilon not in First[Y[k]] and Y[k] in NonTermSet and k > 0: # Y1到Yi候选式都有~存在Continue = Falseelse:First[X] |= First[Y[k]] - set(Epsilon)Change = Trueif Epsilon not in First[Y[k]]:Continue = Falsek += 1if Continue: # X->~或者Y1到Yk均有~产生式First[X] |= set(Epsilon)# FirstA[Y] |= set(Epsilon)# 构造Follow集def getFollow():global NonTermSet, TermSet, First, Follow, StartSymfor A in NonTermSet:Follow[A] = set()Follow[StartSym].add(EndSym) # 将结束符号加入Follow[开始符号]中Change = Truewhile Change: # 当Follow集没有更新算法结束Change = Falsefor X in NonTermSet:for Y in GramaDict[X]:for i in range(len(Y)):if Y[i] in TermSet:continueFlag = Truefor j in range(i + 1, len(Y)): # continueif not First[Y[j]] - set(Epsilon) <= Follow[Y[i]]:Follow[Y[i]] |= First[Y[j]] - set(Epsilon) # 步骤2 FIRST(β)/~ 加入到FOLLOW(B)中。

学生学号实验课成绩武汉理工大学学生实验报告书实验课程名称《编译原理》开课学院计算机科学与技术学院指导老师姓名何九周学生姓名小灰灰的爸爸学生专业班级中国好学长系列2013 —2014 学年第一学期实验课程名称：编译原理实验项目名称单词的词法分析器的设计实验成绩实验者专业班级组别同组者实验日期年月日第一部分：实验分析与设计（可加页）一、实验内容描述（问题域描述）1．实验目的：设计，编制并调试一个词法分析程序，加深对词法分析原理的理解。

2．实验要求要求：在上机前应认真做好各种准备工作，熟悉机器的操作系统和语言的集成环境，独立完成算法编制和程序代码的编写；上机时应随带有关的高级语言教材或参考书；要学会程序调试与纠错；每次实验后要交实验报告。

3．实验报告的内容（1）实验题目、班级、学号、姓名、完成日期；（2）待分析的某种语言子集的词法描述；（3）词法分析程序的功能；（4）详细的算法描述；（5）程序清单；（6）运行结果(给3组典型输入数据进行测试)；（7）收获与体会。

二、实验基本原理与设计（包括实验方案设计，实验手段的确定，试验步骤等，用硬件逻辑或者算法描述）1．待分析的简单语言的词法：（1）关键字：bengin if then while do end所有的关键字都是小写。

（2）运算符和界符：：= + - * / < <= <> > >= = ; ( ) #（3）其他单词是标志符（ID）和整形常数（NUM），通过以下正规式定义：ID=letter（letter|digit）* NUM=digit digit*（4）空格空白、制表符和换行符组成。

空格一般用来分隔ID、NUM、运算符、界符和关键字，词法分析阶段通常被忽略。

2．各种单词符号对应的种别码单词符号种别码单词符号种别码begin 1 ：17if 2 ：= 18then 3 < 20while 4 <> 21do 5 <= 22end 6 > 23 Letter(letter|digit) 10 >= 24digit digit * 11 = 25 + 13 ; 26- 14 ( 27* 15 ) 28/ 16 # 03．实验源代码如下：#include<stdio.h>#include<string.h>char prog[80],token[6];char ch;int syn,p,m,n,sum;char * rwtab[6]={"begin","if","then","while","do","end"};main(){p=0;printf("\nplease intput string:");do{ch=getchar();prog[p++]=ch;}while(ch!='#');p=0;do{scaner();switch(syn){case 11:printf("(%d,%d)\n",syn,sum);break;case -1:printf("input error\n"); break;default:printf("(%d,%s)\n",syn,token);}}while(syn!=0);getch();}scaner(){for(n=0;n<8;n++)token[n]=NULL;m=0;ch=prog[p++];while(ch==' ')ch=prog[p++];if((ch<='z'&&ch>='a')||(ch<='Z'&&ch>='A')){while((ch<='z'&&ch>='a')||(ch<='Z'&&ch>='A')||(ch<='9'&&ch>='0')) {token[m++]=ch;ch=prog[p++];}token[m++]='\0';ch=prog[--p];syn=10;for(n=0;n<6;n++)if(strcmp(token,rwtab[n])==0){syn=n+1;break;}}elseif((ch<='9'&&ch>='0')){sum=0;while((ch<='9'&&ch>='0')){sum=sum*10+ch-'0';ch=prog[p++];}ch=prog[--p];syn=11;}elseswitch(ch){case '<':m=0;token[m++]=ch;ch=prog[p++];if(ch=='>'){syn=21;token[m++]=ch;}elseif(ch=='='){syn=22;token[m++]=ch;}else{syn=20;ch=prog[--p];}break;case '>':token[m++]=ch;ch=prog[p++];if(ch=='='){syn=24;token[m++]=ch;}else{syn=23;ch=prog[--p];}break;case ':':token[m++]=ch;ch=prog[p++];if(ch=='='){syn=18;token[m++]=ch;}else{syn=17;ch=prog[--p];}break;case '+':syn=13;token[0]=ch;break; case '-':syn=14;token[0]=ch;break; case '*':syn=15;token[0]=ch;break; case '/':syn=16;token[0]=ch;break;case ':=':syn=18;token[0]=ch;break;case '<>':syn=21;token[0]=ch;break;case '<=':syn=22;token[0]=ch;break;case '>=':syn=24;token[0]=ch;break;case '=':syn=25;token[0]=ch;break;case ';':syn=26;token[0]=ch;break;case '(':syn=27;token[0]=ch;break;case ')':syn=28;token[0]=ch;break;case '#':syn=0;token[0]=ch;break;default:syn=-1;}}三、主要仪器设备及耗材PC机一台，Miscrosoft VisualC++6.0第二部分：实验调试与结果分析（可加页）一、调试过程（包括调试方法描述、实验数据记录，实验现象记录，实验过程发现的问题等）按照要求编写完代码之后，首先检查一下有没有错误语法错误，然后编译连接运行，输入所给文法的源程序字符串，经此法分析之后，程序就会输出如下结果所示的二元组构成的序列：二、实验结果及分析（包括结果描述、实验现象分析、影响因素讨论、综合分析和结论等）（1）输入字符串begin x:=9; if x>0 then x:= 2*x+1/3; end #其结果如下图所示（2）输入字符串hello#其输出结果如下图所示：（3）输入字符串if x>2; y=3; end #其结果如下图所示：三．实验小结、建议及体会词法分析是编译的第一个阶段，它的主要任务是从左至右逐个字符地对源程序进行扫描，产生一个单词序列，用以语法分析，执行词法分析的程序成为词法分析程序或扫描程序。

北京科技大学计算机与通信工程学院实验报告实验名称：_________编译原理实验报告_______学生姓名：_________ ________________专业：_________ _________________班级：_________ _________________学号：_________________________指导教师：_________ _________________实验成绩：________________________________实验地点：________________________________实验时间：____2015___年___07__月_______日一、实验目的与实验要求1、实验目的通过一个词法分析程序将一段给出的C语言代码的词法部分分析出来；通过一个语法分析程序将一段给出的C语言代码的语法分析出来。

2、实验要求二、实验设备（环境）及要求Win7家庭普通版；Visual Studio 2013；三、实验内容与步骤1、实验1（1）实验内容对于给定一段代码，通过词法分析程序将程序中的各个类型的字表分析，包括保留字、分隔符表、运算符表、标识符、整型数、浮点类型数、字符类型、字符串类型等表文件。

（2）主要步骤通过读入程序的文本文件，然后将分析的结果一次保存在本地文本文件。

然后通过指定的命令来将分析的结果读取出来。

附录：源码#include<stdio.h>#include<string.h>#include<stdlib.h>char*key0[] = { " ", "auto", "break", "case", "char", "const", "continue", "default", "do", "double", "else", "enum", "extern", "float", "for", "goto", "if", "int", "long", "register", "return", "short", "signed", "sizeof", "static", "struct", "switch", "typedef", "_Complex", "_Imaginary", "union", "unsigned", "void", "volatile", "while" };/*保留字表*/char *key1[] = { " ", "(", ")", "[", "]", "{", "}", ",", ";", "'" };/*分隔符表*/char *key2[] = { " ", "+", "-", "*", "/", "%", "<", ">", "==", ">=", "<=", "!=", "!", "&&", "||", "<<", ">>", "~", "|", "^", "&", "=", "?:", "->", "++", "--", ".", "+=", "-=", "*=", "/=" };/*运算符表*/int xx0[35], xx1[10], xx2[31];int temp_key3 = 0, temp_c40 = 0, temp_c41 = 0, temp_c42 = 0, temp_c43 = 0;/******* 初始化函数 *******/void load(){int mm;for (mm = 0; mm <= 34; mm++){xx0[mm] = 0;}for (mm = 0; mm <= 9; mm++){xx1[mm] = 0;}for (mm = 0; mm <= 30; mm++){xx2[mm] = 0;}FILE *floading;if ((floading = fopen("key0.txt", "w")) == NULL){printf("Error! Can't create file : key0.txt");return;}fclose(floading);/*建立保留字表文件：key0.txt*/if ((floading = fopen("key1.txt", "w")) == NULL){printf("Error! Can't create file : key1.txt");return;}/*建立分隔符表文件：key1.txt*/if ((floading = fopen("key2.txt", "w")) == NULL){printf("Error! Can't create file : key2.txt");return;}fclose(floading);/*建立运算符表文件：key2.txt*/if ((floading = fopen("key3.txt", "w")) == NULL){printf("Error! Can't create file : key3.txt");return;}fclose(floading);/*建立标识符表文件：key3.txt*/if ((floading = fopen("c40.txt", "w")) == NULL){printf("Error! Can't create file : c40.txt");return;}fclose(floading);/*建立整数类型常量表文件：c40.txt*/if ((floading = fopen("c41.txt", "w")) == NULL){printf("Error! Can't create file : c41.txt");return;}fclose(floading);/*建立浮点类型常量表文件：c41.txt*/if ((floading = fopen("c42.txt", "w")) == NULL){printf("Error! Can't create file : c42.txt");return;}fclose(floading);/*建立字符类型常量表文件：c42.txt*/if ((floading = fopen("c43.txt", "w")) == NULL){printf("Error! Can't create file : c43.txt");return;}fclose(floading);/*建立字符串类型常量表文件：c43.txt*/if ((floading = fopen("defination.txt", "w")) == NULL) {printf("Error! Can't create file : defination.txt");return;}fclose(floading);/*建立注释文件：defination.txt*/if ((floading = fopen("output.txt", "w")) == NULL){printf("Error! Can't create file : output.txt");return;}fclose(floading);/*建立内部码文件：output.txt*/if ((floading = fopen("temp_key1", "w")) == NULL){printf("Error! Can't create file : temp_key1");return;}fclose(floading);/*建立保留字临时表文件：temp_key1*/if ((floading = fopen("temp_key3", "w")) == NULL){printf("Error! Can't create file : temp_key3");return;}fclose(floading);/*建立标识符临时文件：temp_key3*/if ((floading = fopen("temp_c40", "w")) == NULL){printf("Error! Can't create file : temp_c40");return;}fclose(floading);/*建立整数类型常量临时文件：temp_c40*/if ((floading = fopen("temp_c41", "w")) == NULL){printf("Error! Can't create file : temp_c41");return;}fclose(floading);/*建立浮点类型常量临时文件：temp_c41*/if ((floading = fopen("temp_c42", "w")) == NULL){printf("Error! Can't create file : temp_c42");return;}fclose(floading);/*建立字符类型常量临时文件：temp_c42*/if ((floading = fopen("temp_c43", "w")) == NULL){printf("Error! Can't create file : temp_c43");return;}fclose(floading);/*建立字符串类型常量临时文件：temp_c43*/}/******* 保留字及标识符判断函数 *******/void char_search(char *word){int m, line = 0, csi = 0;int value = 0;int value2 = 0;char c, cs[100];FILE *foutput, *finput;for (m = 1; m <= 34; m++){if (strcmp(word, key0[m]) == 0){value = 1;break;}}if (value == 1){if (xx0[m] == 0){foutput = fopen("key0.txt", "a");fprintf(foutput, "0\t%d\t\t%s\n", m, word);fclose(foutput);xx0[m] = 1;}foutput = fopen("output.txt", "a");fprintf(foutput, "0\t%d\t\t%s\n", m, word);fclose(foutput);}else{if (temp_key3 == 0){foutput = fopen("temp_key3", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_key3++;foutput = fopen("key3.txt", "a");fprintf(foutput, "3\t1\t\t%s\n", word);fclose(foutput);}finput = fopen("temp_key3", "r");c = fgetc(finput);while (c != EOF){while (c != '\n'){cs[csi++] = c;c = fgetc(finput);}cs[csi] = '\0';csi = 0;line++;if ((strcmp(cs, word)) == 0){value2 = 1;break;}else{value2 = 0;c = fgetc(finput);}}fclose(finput);if (value2 == 1){foutput = fopen("output.txt", "a");fprintf(foutput, "3\t%d\t\t%s\n", line, word);fclose(foutput);}else{foutput = fopen("temp_key3", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_key3++;foutput = fopen("output.txt", "a");fprintf(foutput, "3\t%d\t\t%s\n", temp_key3, word);fclose(foutput);foutput = fopen("key3.txt", "a");fprintf(foutput, "3\t%d\t\t%s\n", temp_key3, word);fclose(foutput);}}}/******* 整数类型判断函数 *******/void inta_search(char *word){FILE *foutput, *finput;char c;char cs[100];int csi = 0;int line = 0;int value2 = 0;if (temp_c40 == 0){foutput = fopen("temp_c40", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c40++;foutput = fopen("c40.txt", "a");fprintf(foutput, "4\t0\t1\t%s\n", word);fclose(foutput);}finput = fopen("temp_c40", "r");c = fgetc(finput);while (c != EOF){while (c != '\n'){cs[csi++] = c;c = fgetc(finput);}cs[csi] = '\0';csi = 0;line++;if (strcmp(cs, word) == 0){value2 = 1;break;}c = fgetc(finput);}fclose(finput);if (value2 == 1){foutput = fopen("output.txt", "a");fprintf(foutput, "4\t0\t%d\t%s\n", line, word);fclose(foutput);}else{foutput = fopen("temp_c40", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c40++;foutput = fopen("output.txt", "a");fprintf(foutput, "4\t0\t%d\t%s\n", temp_c40, word);fclose(foutput);foutput = fopen("c40.txt", "a");fprintf(foutput, "4\t0\t%d\t%s\n", temp_c40, word);fclose(foutput);}}/******* 浮点类型判断函数 *******/void intb_search(char *word){FILE *foutput, *finput;char c;char cs[100];int csi = 0;int line = 0;int value2 = 0;if (temp_c41 == 0){foutput = fopen("temp_c41", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c41++;foutput = fopen("c41.txt", "a");fprintf(foutput, "4\t1\t1\t%s\n", word);fclose(foutput);}finput = fopen("temp_c41", "r");c = fgetc(finput);while (c != EOF){while (c != '\n'){cs[csi++] = c;c = fgetc(finput);}cs[csi] = '\0';csi = 0;line++;if (strcmp(cs, word) == 0){value2 = 1;break;}c = fgetc(finput);}fclose(finput);if (value2 == 1){foutput = fopen("output.txt", "a");fprintf(foutput, "4\t1\t%d\t%s\n", line, word);fclose(foutput);}else{foutput = fopen("temp_c41", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c41++;foutput = fopen("output.txt", "a");fprintf(foutput, "4\t1\t%d\t%s\n", temp_c41, word);fclose(foutput);foutput = fopen("c40.txt", "a");fprintf(foutput, "4\t1\t%d\t%s\n", temp_c41, word);fclose(foutput);}}/******* 字符串常量判断函数 *******/void cc_search(char *word){FILE *foutput, *finput;char c;char cs[100];int csi = 0;int line = 0;int value2 = 0;if (temp_c43 == 0){foutput = fopen("temp_c43", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c43++;foutput = fopen("c43.txt", "a");fprintf(foutput, "4\t3\t1\t%s\n", word);fclose(foutput);}finput = fopen("temp_c43", "r");c = fgetc(finput);while (c != EOF){while (c != '\n'){cs[csi++] = c;c = fgetc(finput);}cs[csi] = '\0';csi = 0;line++;if (strcmp(cs, word) == 0){value2 = 1;break;}c = fgetc(finput);}fclose(finput);if (value2 == 1){foutput = fopen("output.txt", "a");fprintf(foutput, "4\t3\t%d\t%s\n", line, word);fclose(foutput);}else{foutput = fopen("temp_c43", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c43++;foutput = fopen("output.txt", "a");fprintf(foutput, "4\t3\t%d\t%s\n", temp_c43, word);fclose(foutput);foutput = fopen("c43.txt", "a");fprintf(foutput, "4\t3\t%d\t%s\n", temp_c43, word);fclose(foutput);}}/******* 字符常量判断函数 *******/void c_search(char *word){FILE *foutput, *finput;char c;char cs[100];int csi = 0;int line = 0;int value2 = 0;if (temp_c42 == 0){foutput = fopen("temp_c42", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c42++;foutput = fopen("c42.txt", "a");fprintf(foutput, "4\t2\t1\t%s\n", word);fclose(foutput);}finput = fopen("temp_c42", "r");c = fgetc(finput);while (c != EOF){while (c != '\n'){cs[csi++] = c;c = fgetc(finput);}cs[csi] = '\0';csi = 0;line++;if (strcmp(cs, word) == 0){value2 = 1;break;}c = fgetc(finput);}fclose(finput);if (value2 == 1){foutput = fopen("output.txt", "a");fprintf(foutput, "4\t2\t%d\t%s\n", line, word);fclose(foutput);}else{foutput = fopen("temp_c42", "a");fprintf(foutput, "%s\n", word);fclose(foutput);temp_c42++;foutput = fopen("output.txt", "a");fprintf(foutput, "4\t2\t%d\t%s\n", temp_c42, word);fclose(foutput);foutput = fopen("c42.txt", "a");fprintf(foutput, "4\t2\t%d\t%s\n", temp_c42, word);fclose(foutput);}}/******* 主扫描函数 *******/void scan(){int count;char chin;FILE *fin;FILE *fout;char filename[50];char temp[100];char target[3] = "'";printf("请输入文件名：");scanf("%s", filename);if ((fin = fopen(filename, "r")) == NULL){printf("Error! Can't open file : %s\n", filename);return;}chin = fgetc(fin);while (chin != EOF){/*对文件包含、宏定义进行处理*/if (chin == '#'){while (chin != '>')chin = fgetc(fin);/*chin=fgetc(fin);*/}/*对空格符、水平制表符进行处理*/else if ((chin == ' ') || (chin == '\t')){;}/*对回车符进行处理*/else if (chin == '\n'){;}/*对单引号内的字符常量进行处理*/else if (chin == target[0]){if (xx1[9] == 0){fout = fopen("key1.txt", "a");fprintf(fout, "1\t9\t\t%c\n", target[0]);fclose(fout);xx1[9] = 1;}temp[0] = chin;chin = fgetc(fin);temp[1] = chin;chin = fgetc(fin);if (chin != target[0]){temp[2] = chin;chin = fgetc(fin);temp[3] = chin;temp[4] = '\0';}else{temp[2] = chin;temp[3] = '\0';}c_search(temp);}/*对双引号内的字符串常量进行处理*/else if (chin == '"'){int i = 0;temp[i++] = '"';chin = fgetc(fin);while (chin != '"'){temp[i++] = chin;chin = fgetc(fin);}temp[i] = '"';temp[i + 1] = '\0';cc_search(temp);}/*对保留字、标识符进行处理*/else if (((chin >= 'A') && (chin <= 'Z')) || ((chin >= 'a') && (chin <= 'z')) || (chin == '_')){int i = 0;while (((chin >= 'A') && (chin <= 'Z')) || ((chin >= 'a') && (chin <= 'z')) || (chin == '_') || ((chin >= '0') && (chin <= '9'))){temp[i++] = chin;chin = fgetc(fin);}temp[i] = '\0';char_search(temp);if (chin != EOF)fseek(fin, -1L, SEEK_CUR);}/*对整型、浮点型数据进行处理*/else if ((chin >= '0') && (chin <= '9')){int dotcount = 0;int i = 0;while (((chin >= '0') && (chin <= '9')) || (chin == '.')){if (chin == '.')dotcount++;if (dotcount == 2)break;temp[i++] = chin;chin = fgetc(fin);}temp[i] = '\0';if (dotcount == 1)intb_search(temp);elseinta_search(temp);if (chin != EOF)fseek(fin, -1L, SEEK_CUR);}/*对注释进行处理*/else if (chin == '/'){chin = fgetc(fin);if (chin == '='){fout = fopen("output.txt", "a");fprintf(fout, "2\t30\t\t/=\n");fclose(fout);}else if (chin != '*'){fout = fopen("output.txt", "a");fprintf(fout, "2\t4\t\t/\n");fclose(fout);fseek(fin, -1L, SEEK_CUR);}else if (chin == '*'){count = 0;chin = fgetc(fin);fout = fopen("defination.txt", "a");fprintf(fout, "/*");while (count != 2){count = 0;while (chin != '*'){fprintf(fout, "%c", chin);chin = fgetc(fin);}count++;fprintf(fout, "%c", chin);chin = fgetc(fin);if (chin == '/'){count++;fprintf(fout, "%c\n", chin);}else{fprintf(fout, "%c", chin);chin = fgetc(fin);}}}}/*对运算符、分隔符进行处理*/else{int time = 0;int firstblood = 0;temp[0] = chin;chin = fgetc(fin);if (chin != EOF){temp[1] = chin;temp[2] = '\0';for (time = 1; time <= 30; time++){if (strcmp(temp, key2[time]) == 0){firstblood = 1;if (xx2[time] == 0){fout = fopen("key2.txt", "a");fprintf(fout, "2\t%d\t\t%s\n", time, temp);fclose(fout);xx2[time] = 1;}fout = fopen("output.txt", "a");fprintf(fout, "2\t%d\t\t%s\n", time, temp);fclose(fout);break;}}if (firstblood != 1){fseek(fin, -1L, SEEK_CUR);temp[1] = '\0';for (time = 1; time <= 9; time++){if (strcmp(temp, key1[time]) == 0){if (xx1[time] == 0){fout = fopen("key1.txt", "a");fprintf(fout, "1\t%d\t\t%s\n", time, temp);fclose(fout);xx1[time] = 1;}fout = fopen("output.txt", "a");fprintf(fout, "1\t%d\t\t%s\n", time, temp);fclose(fout);break;}}for (time = 1; time <= 30; time++){if (strcmp(temp, key2[time]) == 0){if (xx2[time] == 0){fout = fopen("key2.txt", "a");fprintf(fout, "2\t%d\t\t%s\n", time, temp);fclose(fout);xx2[time] = 1;}fout = fopen("output.txt", "a");fprintf(fout, "2\t%d\t\t%s\n", time, temp);fclose(fout);break;}}}}}chin = fgetc(fin);}fout = fopen("output.txt", "a");fprintf(fout, "1\t6\t\t}\n");fclose(fout);}/******* Main函数 *******/void main(){FILE *fread;char charin;char command = 'Q';printf("\n");printf("******************** 词法分析 ********************\n");printf("* *\n");printf("* *\n");printf("* 0 --> 查看保留字表文件 *\n");printf("* 1 --> 查看分隔符表文件 *\n");printf("* 2 --> 查看运算符表文件 *\n");printf("* 3 --> 查看标识符表文件 *\n");printf("* 4 --> 查看整数类型常量表 *\n");printf("* 5 --> 查看浮点类型常量表 *\n");printf("* 6 --> 查看字符类型常量表 *\n");printf("* 7 --> 查看字符串类型常量表 *\n");//printf("* 8 --> 查看注释文件 *\n");printf("* 9 --> 查看内部码文件 *\n");printf("* -------------------------- *\n");printf("* Q --> 退出 *\n");printf("***************************************************************\n");printf("\n");load();scan();printf("\n");printf("分析完成！\n");getchar();printf("\n");printf("请输入命令：");command = getchar();while ((command != 'Q') && (command != 'q')){switch (command){case'0':{printf("*************************\n");printf("\n");fread = fopen("key0.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'1':{printf("*************************\n");printf("\n");fread = fopen("key1.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'2':{printf("*************************\n");printf("\n");fread = fopen("key2.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'3':{printf("*************************\n");printf("\n");fread = fopen("key3.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'4':{printf("*************************\n");printf("\n");fread = fopen("c40.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'5':{printf("*************************\n");printf("\n");fread = fopen("c41.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'6':{printf("*************************\n");printf("\n");fread = fopen("c42.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'7':{printf("*************************\n");printf("\n");fread = fopen("c43.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'8':{printf("*************************\n");printf("\n");fread = fopen("defination.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}case'9':{printf("*************************\n");printf("\n");fread = fopen("output.txt", "r");charin = fgetc(fread);while (charin != EOF){putchar(charin);charin = fgetc(fread);}printf("\n");printf("*************************\n");printf("\n");printf("请输入命令：");break;}}command = getchar();}}2、实验2（1）实验内容输入单词串，以”#”结束，如果是文法正确的句子，则输出成功信息，打印“success”,否则输出”error”例如:输入： begin a:=9;b:=0 end #输出： success输入： begin a=9 end #输出： error（2）主要步骤附录：源码#include<stdio.h>#include<string.h>#include<ctype.h>#include<stdlib.h>char GetChar(char *input, int *index, int length);int ClearBlank(char *input, int(*index), int length);int reserve(char *s);void lrparser(char *input, int inputLength, int *index);void yucu(char *input, int inputLength, int *index);void factor(char *input, int inputLength, int *index);void statement(char *input, int inputLength, int *index);void expression(char *input, int inputLength, int *index);void term(char *input, int inputLength, int *index);char *retab[6] = { "begin", "if", "then", "while", "do", "end" };//关键字int syn = 0;int myIsAlpha(char ch){if (islower(ch) == 2 || isupper(ch) == 1){return 1;}else{return 0;}}void scaner(char *input, int inputLength, int *index){char s[256] = ""; //保存当前的字符char ch = GetChar(input, index, inputLength);int nowPosition = 0;int j = 0;if (myIsAlpha(ch) == 1) //如果是字母{while(((ch >= '0'&& ch <= '9') || (myIsAlpha(ch) == 1)) && *index<= inputLength) {s[nowPosition] = ch; //添加到当前字符串中nowPosition++;ch = GetChar(input, index, inputLength);}if ((ch <'0' || ch>'9') && (myIsAlpha(ch) == 0))//进行回退操作，并输出结果{s[nowPosition] = '\0';//添加结束标志j = reserve(s);if (j == 0){syn = 10;}else{syn = j;}(*index)--;return;}else//超过范围{s[nowPosition++] = ch;s[nowPosition] = '\0';//添加结束标志j = reserve(s);if (j == 0){syn = 10;}else{syn = j;}getchar();exit(0);return;}}elseif (ch >= '0' && ch <= '9') //如果是数字{while (ch >= '0' && ch <= '9'&& *index <= inputLength) {s[nowPosition] = ch; //添加到当前字符串中nowPosition++;ch = GetChar(input, index, inputLength);}if (ch<'0' || ch>'9')//进行回退操作{(*index)--;syn = 11;return;}else//超过范围时{s[nowPosition] = ch;syn = 11;return;}}else{switch (ch){case'+':{syn = 13;return;}case'-':{syn = 14;return;}case'*':{syn = 15;return;}case'/':{syn = 16;return;}case'<':{ch = GetChar(input, index, inputLength);if (ch == '='){syn = 22;return;}elseif (ch == '>'){syn = 21;return;}else{syn = 20;if (*index>inputLength){return;}else{(*index)--;return;}}case'>':{ch = GetChar(input, index, inputLength);if (ch == '='){syn = 24;return;}else{syn = 23;if (*index>inputLength){return;}else{(*index)--;return;}}}case':':{ch = GetChar(input, index, inputLength);if (ch == '='){syn = 18;return;}else{if (*index>inputLength){return;}else(*index)--;return;}}}case'=':{syn = 25;return;}case';':{syn = 26;return;}case'(':{syn = 27;return;}case')':{syn = 28;return;}case'#':{syn = 0;return;}case' ':{syn = -1;return;}default:{printf("(非法符号)");。

.编译原理实验报告实验名称：分析调试语义分析程序TEST抽象机模拟器完整程序保证能用！！！！！一、实验目的通过分析调试TEST语言的语义分析和中间代码生成程序，加深对语法制导翻译思想的理解，掌握将语法分析所识别的语法畴变换为中间代码的语义翻译方法。

二、实验设计程序流程图.Statement_list()开始es=0读入一个token=}符号 es=0Y{Nes=1Tooken=ifToken=ifNYToken=whilees=0NNToken=for declaration_list()NYes=0Token=readNN N Statement_list()Token=writeNY es=0Token={ YNN}N es=2Token=ID|NUM|(Y N返回token=}YReturn(es)语法分析YYYYYYYIf_stat()while_stat()for_stat()read_stat()N write_stat()Compound_state()expression_stat()开始Es=0词法分析输出词法Es>0Y分析失败N输出词法分析成功语法分析输出语法Es=0Y分析成功N输出语法分析错误结束程序代码：Main.cpp#include<stdio.h>#include<ctype.h>extern bool TESTparse(char *pFileName);extern int TESTScan(FILE *fin,FILE *fout);FILE *fin,*fout;//用于指定输入输出文件的指针int main(){char szFinName[300];char szFoutName[300];printf("请输入源程序文件名（包括路径）:");scanf("%s",szFinName);printf("请输入词法分析输出文件名（包括路径）：");scanf("%s",szFoutName);if( (fin = fopen(szFinName,"r")) == NULL){printf("\n打开词法分析输入文件出错！\n");return 0;}if( (fout = fopen(szFoutName,"w")) == NULL){printf("\n创建词法分析输出文件出错！\n");return 0;}int es = TESTScan(fin,fout);fclose(fin);fclose(fout);if(es > 0)printf("词法分析有错，编译停止！共有%d个错误！ \n",es);else if(es == 0){printf("词法分析成功！\n");int es=0;es =TESTparse(szFoutName);//调语法分析if(es== true) printf("语法分析成功！\n");else printf("语法分析错误！\n");}elseprintf("词法分析出现未知错误!\n");}Parse.cpp#include<stdio.h>#include<string.h>#include<ctype.h>#include<conio.h>#include<vector>// functionbool TESTparse();bool compound_Stat();bool program();bool statement();bool expression_stat();bool expression();bool bool_expr();bool additive_expr();bool term();bool factor();bool if_stat();bool while_stat();bool for_stat();bool write_stat();bool read_stat();bool declaration_stat();bool declaration_list();bool statement_list();bool compound_stat();char token[20],token1[40];//token保存单词符号，token1保存单词值FILE *fp;// 用于指向输入文件的指针int EsLine=0;typedef struct{int es;int line;}EsInf;std::vector<EsInf>StackEs;//语法分析程序void ProcessError(int es){EsInf temp;temp.es=es;temp.line=EsLine;StackEs.push_back(temp);}bool ReadFile(char *tok, char *tok1){if(feof(fp))return false;fscanf(fp,"%s\t%s\n",tok,tok1);printf("%s\t%s\n",tok,tok1);EsLine++;return true;}bool TESTparse(char *pFileName){bool es =true;if((fp=fopen(pFileName,"r"))==NULL){printf("\n打开 %s错误 !\n",pFileName);return false;}elseprogram();if(!feof(fp))ProcessError(9);fclose(fp);printf("===== 语法分析结果！=====\n");if(StackEs.size() == 0){printf("语法分析成功！\n");return true;}else{int i;for(i = 0; i < StackEs.size(); i++){printf("在第 %d行 ",StackEs[i].line);switch(StackEs[i].es){case 1:printf("缺少{！\n");break;case 2:printf("缺少}！\n");break;case 3:printf("缺少标识符！\n");break;case 4:printf("缺少分号！\n");break;case 5:printf("缺少(！\n");break;case 6:printf("缺少)！\n");break;case 7:printf("缺少操作数！\n");break;case 8:printf("文件为空！\n");break;case 9:printf("文件尾有多余字符！\n");break;case 10:printf("\n打开%s错误!\n",pFileName);break;}}return false;}}//《程序》 ::={< 声明序列 ><语句序列 >}//program::={<declaration_;list><statement_list>}bool program(){bool es = true;if( ReadFile(token,token1) == false ){ProcessError(8);//文件结束return false;}if(strcmp(token,"{"))// 判断是否为‘{ ’ProcessError(1);if( ReadFile(token,token1) == false )//文件中仅有｛ProcessError(2);es =declaration_list();if(es == false)return false;es =statement_list();if(es == false)return false;if(strcmp(token,"}"))// 判断是否为‘ } ’ ProcessError(2);return true;}//< 声明序列 >::=< 声明序列 ><声明语句 >|< 声明语句 >//<declaration>::=//<declaration_list><declaration_stat>|ε//改成 <declaration_list>::={<declaration_stat>}bool declaration_list(){bool es = true;while (strcmp(token,"int")==0){es = declaration_stat(); if(es== false)return false;}return es;}//< 声明语句 >::=int<变量>;//<declaration_stat>::=int ID;bool declaration_stat(){bool es = true;if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}if(strcmp(token,"ID"))ProcessError(3); //不是标识符if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}if(strcmp(token,";"))ProcessError(4);if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}return(es);}//< 语句序列 >::=< 语句序列 ><语句 >| ε//<statement_list>::=<statement_list><statement>|ε//改成 <statement_list>::={<statement>}bool statement_list(){bool es =true;if(feof(fp))return false;.while(strcmp(token,"}")){es =statement();if(es == false)return(es);}return(es);}//< 语句 >::=<if语句>|<while语句>|<for语句>|<read语句>//|<write语句>|<复合语句>|<表达式语句>//<statement>::=<if_sttat>|<while_stat>|<for_stat>//|<compound_stat>|<expression_stat>bool statement(){bool es =true;if(strcmp(token,"if")==0 )es=if_stat();//<if语句>else if(strcmp(token,"while")==0 )es=while_stat();//<while语句>else if(strcmp(token,"for")==0 )es=for_stat();//<for语句>else if(strcmp(token,"read")==0 )es=read_stat();//<read语句>else if(strcmp(token,"write")==0 )es=write_stat();//<write语句>else if(strcmp(token,"{")==0 )es=compound_stat();//< 复合语句 >else if(strcmp(token,"ID")==0||strcmp(token,"NUM")==0|| strcmp(token,"(")==0 )es=expression_stat();//< 表达式语句 >return(es);}.//<if 语句 >::=if(<表达式>)<语句>[else<语句>]//<if_stat>::=if(<expressiion>)<statement>[else<statement>]bool if_stat(){bool es =true;//ifif( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}if(strcmp(token,"("))ProcessError(5);// 少左括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es = expression();if(es == false)return(es);if(strcmp(token,")"))ProcessError(6);// 少右括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es=statement();if(es == false)return(es);if(strcmp(token,"else")==0)//else部分处理{if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}es=statement();if(es == false)return(es);}return(es);}//<while 语句 >::=while(<表达式>)<语句>//<while_stat>::=while<espr><statement>bool while_stat(){bool es = true;if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}if(strcmp(token,"("))ProcessError(5);// 少左括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es =expression();if(es == false)return(es);if(strcmp(token,")"))ProcessError(6);// 少右括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es = statement();if(es == false)return es;return(es);}//<for 语句 >::=for(<表达式>；<表达式>;<表达式>)<语句>//<for_stat>::=for(<expression>;<expression>;<expression>)<statement> bool for_stat(){bool es =true;if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}if(strcmp(token,"(")) ProcessError(5);//少左括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es=expression();if(es == false) return (es);if(strcmp(token,";")) ProcessError(4); //少分号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少 }return false;//文件结束}es=expression();if(es == false) return (es);if(strcmp(token,";"))ProcessError(4);//少分号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少 }return false;//文件结束}es=expression();if(es == false) return (es);if(strcmp(token,")"))ProcessError(6);//少右括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少 }return false;//文件结束}es=statement();if(es == false) return (es);return es;}//<write_语句>::=write<表达式>;//<write_stat>::=write<expression>bool write_stat(){bool es = true;if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es=expression();if(es == false) return (es);if(strcmp(token,";")) ProcessError(4); //少分号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}return es;}//<read_语句>::=read<变量>//<read_stat>::=read Id;bool read_stat(){bool es =true;if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}if(strcmp(token,"ID"))ProcessError(3); //少标识符if(strcmp(token,";"))ProcessError(4); //少分号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}return es;}//< 复合语句 >::{< 语句序列 >}//<compound_stat>::={<statement_list>}bool compound_stat()//复合语句函数{bool es =true;if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}es =statement_list();if(es == false)return es;//-------------- new----------if(strcmp(token1,"}") != 0)ProcessError(2);else{if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}}//--------------- new ----------return es;}//< 表达式语句 >::=<< 表达式 >； |;//<expression_stat>::=<expression>;|;bool expression_stat(){bool es =true;if(strcmp(token,";")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}return es;}es=expression();if(es == false) return es;if(strcmp(token,";")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}return es;}else{ProcessError(4);//少分号}return es;}//< 表达式 >::=< 标识符 >=<布尔表达式 >|< 布尔表达式 >//<expression>::=ID=<bool_expr>|<bool_expr>bool expression(){bool es =true;int fileadd;char token2[20],token3[40];if(strcmp(token,"ID")==0){fileadd=ftell(fp);//记住当前文件位置if( ReadFile(token2,token3) == false ){ProcessError(2);//缺少}return false;//文件结束.}if(strcmp(token2,"=")==0)//'='{if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}es=bool_expr();if(es == false) return es;}else{fseek(fp,fileadd,0); //若非‘ =’，则文件指针回到‘=’前的标识符EsLine--;es=bool_expr();if(es == false) return es;}}else{es=bool_expr();if(es == false) return es;}return es;}//< 布尔表达式 >::=<算术表达式 >[(>|<|>=|<=|==|!=)<算数表达式>]//<bool_expr>::=<additive_expr> [(>|<|>=|<=|==|!=)<additive_expr>]bool bool_expr(){bool es =true;es=additive_expr();if(es == false) return es;.if(strcmp(token,">")==0||strcmp(token,">=")==0||strcmp(token,"<")==0||strcmp(token,"<=")==0||strcmp(token,"!=")==0||strcmp(token,"==")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}es=additive_expr();if(es == false) return es;}return es;}//< 算数表达式 >::=< 项 >{(+|-)<项>}//<additive_expr>::=<term>{(+|-)<term>}bool additive_expr(){bool es =true;es=term();if(es == false) return es;while(strcmp(token,"+")==0||strcmp(token,"-")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}es=term();if(es== false) return es;}return es;}//< 项 >::=< 因子 >{(*|/)<因子>}//<term>::=<factor>{(*|/)<factor>}bool term(){bool es =true;es=factor();if(es == false) return es;while(strcmp(token,"*")==0||strcmp(token,"/")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}es=factor();if(es == false) return es;}return es;}//< 因子 >::=(< 表达式 >)|< 标识符 >|< 无符号整数 >//<factor>::=(<expression>)|ID|NUMbool factor(){bool es =true;if(strcmp(token,"(")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少} return false;//文件结束}es=expression();if(es==false)return es;if(strcmp(token,")")) ProcessError(6);//少右括号if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}}else{if(strcmp(token,"ID")==0||strcmp(token,"NUM")==0){if( ReadFile(token,token1) == false ){ProcessError(2);//缺少}return false;//文件结束}return es;}else{ProcessError(7);//缺少操作数}}return es;}Scan.cpp#include<ctype.h>#include<cstring>#include<stdio.h>//保留字#define KEYWORDNUM 8char*pKeyword[KEYWORDNUM] ={"if","else","for","while","do", "int", "read", "write"};//单分界符char szSingleWord[50]="+-(){};,:";//双分界符char szDoubleWord[10]="<>!";//其他符char*szDivide="/";char*szStar="*";char*szEqual="=";#define STATUSNUM16// 状态个数#define DATANUM10//数据流个数// 数据流类型typedef unsigned int DATA;#define OTHER0// wrong input#define LETTER1//字母#define DIGIT2//数字#define SINGLEWORD3//单分界符#define DOUBLEWORD4//双分界符#define DIVIDE5// /#define EQUAL6// =#define STAR7// *#define SPACE8//空白#define FILEOVER9//状态类型typedef unsigned int STATUS;#define NOSTATUS0// wrong input#define START1#define CASE_ID2#define END_ID3#define CASE_NUM4#define END_NUM5#define CASE_SINGLE6#define END_SINGLE7#define CASE_DOUBLE8#define CASE_DOUBLE29#define END_DOUBLE10#define CASE_DIVIDE11#define CASE_NOTE12#define END_NOTE13#define CASE_ERROR14#define END_ERROR15//状态转换表//: 到达终结状态的数据不保存在输出串中int reflect[STATUSNUM][DATANUM] ={//OTHER LETTER DIGIT SINGLEWORDDOUBLEWORD DIVIDE EQUAL STAR SPACE FILEOVER/*NOSTATUS*/{NOSTATUS,NOSTATUS,NOSTATUS,NOSTATUS,NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS},/*START*/{CASE_ERROR,CASE_ID,CASE_NUM,CASE_SINGLE,CASE_DOUBLE,CASE_DIVIDE,CASE_DOUBLE,CASE_SINGLE,START, START},/*CADE_ID*/{END_ID,CASE_ID,CASE_ID,END_ID,END_ID,END_ID,END_ID,END_ID,END_ID,END_ID},/*END_ID*/{NOSTATUS,NOSTATUS,NOSTATUS,NOSTATUS,NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS},/*CASE_NUM*/{END_NUM,END_NUM,CASE_NUM,END_NUM, END_NUM, END_NUM,END_NUM, END_NUM, END_NUM, END_NUM},/*END_NUM*/{NOSTATUS,NOSTATUS,NOSTATUS,NOSTATUS,NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS},/*CASE_SINGLE*/ {END_SINGLE,END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE},/*END_SINGLE*/ {NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS},/*CASE_DOUBLE*/ {END_SINGLE,END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, CASE_DOUBLE2,END_SINGLE,END_SINGLE, END_SINGLE},/*CASE_DOUBLE2*/{END_DOUBLE,END_DOUBLE, END_DOUBLE, END_DOUBLE, END_DOUBLE, END_DOUBLE, END_DOUBLE, END_DOUBLE, END_DOUBLE, END_DOUBLE},/*END_DOUBLE*/ {NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS},/*CASE_DIVIDE*/ {END_SINGLE,END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, END_SINGLE, CASE_NOTE, END_SINGLE, END_SINGLE},/*CASE_NOTE*/{END_NOTE, END_NOTE, END_NOTE, END_NOTE, END_NOTE, END_NOTE, END_NOTE, END_NOTE, END_NOTE, END_NOTE},/*END_NOTE*/{NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS},/*CASE_ERROR*/{END_ERROR, END_ERROR,END_ERROR, END_ERROR, END_ERROR, END_ERROR, END_ERROR, END_ERROR, END_ERROR, END_ERROR},/*END_ERROR*/ {NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS, NOSTATUS} };//若在 pString 中找到 word 则返回 true ，否则，返回 false boolSearchChar(char word,const char *pString){int n=strlen(pString);for(int i = 0; i < n; i++){if( word == pString[i])return true;}return false;}//得到 word 的数据流类型DATA GetDataByword(char word){if(word == EOF)return FILEOVER;if(isalpha(word))return LETTER;if(isdigit(word))return DIGIT;if(SearchChar(word,szSingleWord))return SINGLEWORD;if(SearchChar(word,szDoubleWord))return DOUBLEWORD;if(SearchChar(word,szDivide))return DIVIDE;if(SearchChar(word,szEqual))return EQUAL;if(SearchChar(word,szStar))return STAR;if(isspace(word))return SPACE;return OTHER;}//得到从 status 状态输入 word 后到达的状态STATUS GetNextStatus(STATUS status, DATA word){return reflect[status][word];}// 返回值表示错误个数。