词法分析程序的设计与实现

标签：记录   ||   char s   存在   实现   har   bsp   pac   int   

#include<iostream>
#include<stdio.h>
#include<string>

using namespace std;

FILE *f;               //定义一个文件变量
static int line = 1;       //表示光标所在的行数
struct IDid[100];//用于存放ID号码
static int I = 0; //用于记录ID存放的数量
int Number[100];         //用于存放数字
static int P = 0;         //用于记录存放数字的个数
int error[100] = ;       //用于记录错误所在的行数
static int K = 0;         //记录错误次数
void Error();           //记录错误
void loginID(char *);       //注册ID号
void loginNumber(int &);     //记录数字
void noteLine(char &);     //记录光标所在的行数
void print();           //输出分析结果
int same(char *chr);       //判断单词是否已经存在

void Error()

void loginID(char *chr)           //注册ID号
{
int k = 0;
int h = 0;
for(int i = 0; i < I; i++)
{
  if(!strcmp(chr,id.name))   //如果单词已经存在
{
id.count++;
   k = 1;
  }
}
if(k == 0)                 //该单词不存在
{  
h = I + 1;  
  //I = h;  
  id[h].count++;
  id[h].name = chr;        
  //strcpy(id[h].name ,chr);
}

}      

void loginNumber(int &nu)

void noteLine(char &ch)
{
if ( ch == ‘ ‘ )
  ++line;
}

void print()//输出部分
{
//cout << "关键字以及变量:" << endl;
//for(int i = 0; i < 100; i++)
//cout << i <<" " << id.name << " " << id.count << endl;
cout << "数字：" << endl;
for(int i = 1; i <= P; i++)
  cout << i << ": " << Number[i-1] << endl;
if(error[0] != 0)
{
  cout << "出现的错误！" << endl;
  for(int i = 1; i <= K; i++)
   cout << "第" << i << "个错误：  " << "第" << error[i-1] << "行" << endl;
}
else cout << "没有错误！" << endl;  
}

//文件处理部分
void noblank( char &ch)   //跳过空格，回车
{
noteLine(ch);
while(ch == ‘ ‘ || ch == ‘ ‘)
  ch = fgetc(f);
}

void identifier(char name[],char &ch)//字母变量
{

int i;
for(i = 0; i < 20; i++)
  name = ‘‘;
i = 0;
while ((‘0‘<= ch && ch <= ‘9‘)||(‘a‘<= ch&&ch <= ‘z‘)||(‘A‘<= ch&&ch <=‘Z‘))
{
  name = ch;
  i++;
  ch = fgetc(f);
}
loginID(name);
//for(int j = 0; j < i; j++)
//
// cout << ‘ ‘;

}

int number(char &ch)//数字
{
int num=0;
while(‘0‘<= ch && ch <= ‘9‘)
{
  num = num* 10 + (ch-‘0‘);
  ch = fgetc(f);
}
if( (‘a‘<= ch&&ch <= ‘z‘)||(‘A‘<= ch&&ch <=‘Z‘))
{
  Error();
}
else if( ch == ‘.‘)

loginNumber(num);   //记录数字
return num;  
}

void test(char &ch)//符号
{
char str[2]=;
if(ch == ‘*‘)

if(ch == ‘.‘)

if(ch == ‘,‘)

if(ch == ‘"‘)

if(ch == ‘/‘)

if(ch == ‘%‘)

if(ch == ‘^‘)

if(ch == ‘-‘)

if(ch == ‘{‘)

if(ch == ‘}‘)

if(ch == ‘[‘)

if(ch == ‘]‘)

if(ch == ‘;‘)

if(ch == ‘:‘)

if(ch == ‘?‘)

if(ch == ‘(‘)

if(ch == ‘)‘)

if(ch ==‘+‘)
{

  str[0] = ch;
  if((ch = fgetc(f)) == ‘+‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }

  //cout << str[0]<< endl;
}
if(ch == ‘-‘)
{

str[0] = ch;
  if((ch = fgetc(f)) == ‘-‘ )
  {
str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }

  //cout << str[0]<< endl;
}
if(ch == ‘&‘)
{

  str[0] = ch;
  if((ch = fgetc(f)) == ‘&‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }

  //cout << str[0]<< endl;
}
if(ch == ‘|‘)
{

  str[0] = ch;
  if((ch = fgetc(f)) == ‘|‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }

  //cout << str[0]<< endl;
}
if(ch == ‘!‘)
{

  str[0] = ch;
  if((ch = fgetc(f)) == ‘=‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }

  //cout << str[0]<< endl;
}
if(ch == ‘=‘)
{

  str[0] = ch;
  if((ch = fgetc(f)) == ‘=‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }

}  
if(ch == ‘>‘)
{

  str[0] = ch;
  if((ch = fgetc(f)) == ‘=‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
   //cout << str[0] << str[1] << endl;
  }
  else
   if(ch == ‘>‘ )
   {
    str[1] = ch;
    ch = fgetc(f);
    //cout << str[0] << str[1] << endl;
   }

}
if(ch == ‘<‘)
{
  str[0] = ch;
  if((ch = fgetc(f)) == ‘=‘ )
  {
   str[1] = ch;
   ch = fgetc(f);
  }
  else
   if(ch == ‘<‘ )
   {
    str[1] = ch;
    ch = fgetc(f);
   }

}

}

int main()
{
char ch;
char name[30];
for(int i = 0; i < 30; i++)
  name = ‘/0‘;
f = fopen("c.txt","r");           //打开指定输入文件
if (f == NULL)
  cout<<"文件不存在！"<<endl;
ch = fgetc(f);
while(!feof(f))
{
  noblank( ch );             //跳过回车，空格
if( ( ch >= ‘a‘ && ch <= ‘z‘ )||( ch >= ‘A‘ && ch <= ‘Z‘ ))
         //处理字母
else if( ch >= ‘0‘&& ch <= ‘9‘)
               //处理数字
else
               //处理符号
}
print();                   //打印词法分析结果
fclose(f);                   //关闭文件
system("pause");
return 0;
}

（此程序为借鉴他人的，并非全部由自己所写）

词法分析程序的设计与实现

标签：记录   ||   char s   存在   实现   har   bsp   pac   int   

原文地址：https://www.cnblogs.com/201706120196y/p/11655667.html