grammaranalysis.h

词法分析器

#include <iostream>
#include <string>

using namespace std;

string kind[100];

int counter = 1;

void s(string kind[100], int &bit);
void s1(string kind[100], int &bit);
void c(string kind[100], int &bit);
void c1(string kind[100], int &bit);
void e(string kind[100], int &bit);
void e1(string kind[100], int &bit);
void t(string kind[100], int &bit);
void t1(string kind[100], int &bit);
void f(string kind[100], int &bit);

bool IsDigit(char ch)
{
	return (ch >= '0' && ch <= '9');
}


bool IsAlpha(char ch)
{
	return (ch >= 'a' && ch <= 'z'|| ch >= 'A'&& ch <= 'Z');
}


void s(string kind[100],int &bit)
{
	if(kind[bit] == "IDN")
	{
		bit++;
	    if(kind[bit] == "=")
			bit++;
	    cout<<counter++<<".S	→	id  =  E"<<endl;
	    e(kind, bit) ;
    }
      
	if(kind[bit] == "IF")
	{
		bit++;
		cout<<counter++<<".S	→	if  C  then  S"<<endl;
		c(kind, bit);
		if(kind[bit] == "THEN")
		{
			bit++;
	        s(kind,bit); 
		}
	}

	if(kind[bit] == "WHILE")
	{
		bit++;
		cout<<counter++<<".S	→  while  C  do  S"<<endl;
		c(kind, bit) ;
	    if(kind[bit] == "DO")
		{
			bit++;
	        s(kind, bit) ;
		}
	}
	 
}

void c(string kind[100], int &bit)
{
	cout<<counter++<<".C  → EC`"<<endl;
	e(kind, bit) ;
	c1(kind, bit) ; 
}

void c1(string kind[100], int &bit)
{
	if(kind[bit] == ">")
	{
		bit++;
	    cout<<counter++<<".C`	→	 >  E"<<endl;
	    e(kind,bit) ;
    }

    if(kind[bit] == "<")
	{
		bit++;
	    cout<<counter++<<".C`	→	 <  E"<<endl;
	    e(kind, bit) ;
    }
		 	 
	if(kind[bit] == "=")
	{
		bit++;
	    cout<<counter++<<".C`	→	 =  E"<<endl;
	    e(kind, bit) ;
    }
}


void e(string kind[100],int &bit)
{
	cout<<counter++<<".E  →  TE`"<<endl;
	t(kind, bit) ;
	e1(kind, bit) ;
		
}

void e1(string kind[100],int &bit)
{
	if(kind[bit] == "+")
	{
		bit++;
	    cout<<counter++<<".E`  →  +TE`"<<endl;
	    t(kind, bit) ;
	    e1(kind, bit) ;
	}
		 
	else if(kind[bit]=="-")
	{
		bit++;
	    cout<<counter++<<".E`  →  -TE`"<<endl;
	    t(kind, bit) ;
	    e1(kind, bit) ;
	}
		 
	else	
	{
		cout<<counter++<<".E`  →  ε"<<endl;
    }
}

void t(string kind[100], int &bit)
{
	cout<<counter++<<".T  →  FT`"<<endl;
	f(kind, bit) ;
	t1(kind, bit) ;		
}

void t1(string kind[100], int &bit)
{
	if(kind[bit] == "*")
	{
		bit++;
	    cout<<counter++<<".T`	→	* FT`"<<endl;
	    f(kind, bit) ;
	    t1(kind, bit) ;
	}
		 
	else if(kind[bit] == "/")
	{
		bit++;
	    cout<<counter++<<".T`	→	/ FT`"<<endl;
	    f(kind,bit) ;
	    t1(kind,bit) ;
	}
		 
	else	
	{		      
	    cout<<counter++<<".T` →ε"<<endl;
	}
}

void f(string kind[100], int &bit)
{
	if(kind[bit] == "(")
	{
		bit++;
	    cout<<counter++<<".F	→	(  E  )"<<endl;
	    e(kind, bit) ;
	    if(kind[bit] == ")")
			bit++;
	}

    if(kind[bit] == "IDN")
	{
		bit++;
        cout<<counter++<<".F	→	id"<<endl;
    }
		 	 
	if(kind[bit] == "INT8")
	{
		bit++;
        cout<<counter++<<".F	→	int8"<<endl;
	}
			
	if(kind[bit] == "INT16")
	{
		bit++;
        cout<<counter++<<".F	→	int16"<<endl;
	}
				 	 
	if(kind[bit] == "INT10")
	{
		bit++;
        cout<<counter++<<".F	→	int10"<<endl;
	}
		       
}





int scan()
{
	string word;

    int bit = 0;
    char a[200];
    char b = ' ';
    int m = 0;

    cout<<"现在您可以输入您要测试的语句（以！结束）：";

	while(b != '!')
	{
        b = getchar();
        a[m] = b;
        m++;
    }

	word = a;

	int y = 0;
    char arr[200];
    char ch;
    int x = 0;
	int i = 0;
	int j = 0;

    while(1)         //while 1
	{
		ch = word[x];                       //从输入文件中读入一个字符
		if( ch == ' ' || ch == '\t')              //过滤掉空格和tab        if 1
			x++;		
		else if(IsDigit(ch))              //读入的是数字      else if 1
		{
			if(ch == '0' && word[x+1] != ' ' && word[x+1] != '!')               //if 1 1
			{			
				arr[j] = ch;
			    j++;
			    x++;
                ch = word[x];

			    if(ch == 'x')           //if 1 1 1          16进制
				{
					arr[j] = ch;
			        j++;
			        x++;
                    ch = word[x];

                    while(IsDigit(ch) || (IsAlpha(ch) && ((ch >= 'a' && ch <= 'f') || (ch >= 'A'&& ch <= 'F') )))
			        {
                          arr[j] = ch;
				          j++;
				          x++;
                          ch=word[x];
			        }//

			        if(ch != ' ' && ch != '!' && ch != '+' && ch != '-' && ch != '*' && ch != '/' && ch != '(' && ch != ')' && ch != '.' && ch != '>' && ch != '<' && ch != '=' && ch != ',')  // if 1 1 1 1
					{
						cout<<"16进制数输入错误"<<endl;
				        system("pause");

	                    return 0;
				     }//  if 1 1 1 1
			         else   // else 1 1 1 1
					 {
						 cout<<"Token is : ";

						 while(y != j)
					     {
								 cout<<arr[y];
								 y++;
					     }

						 y=0;

						 cout<<endl;
						 kind[bit] = "INT16";
						 cout<<"Class:"<<kind[bit]<<endl;
						 bit++;
						 cout<<endl;

						 j=0;
			           }//else 1 1 1 1
				}  // if 1 1 1
			    else if(IsDigit(ch))          //else if 1 1 1
				{
					while(IsDigit(ch) && ch >= '0' && ch <= '7')
			        {
                        arr[j] = ch;
				        j++;
				        x++;
                        ch=word[x];
			        }
			  
			        if(ch != ' ' && ch != '!' && ch != '+' && ch != '-' && ch != '*' && ch != '/' && ch != '(' && ch != ')' && ch != '.' && ch != '>' && ch != '<' && ch != '=' && ch != ',')
					{
				        cout<<"8进制数输入错误";
				        system("pause");

	                    return 0;

			            j=0;
			        }//if
			        else
					{
				        cout<<"Token is :";

				        while(y != j)
						{
							cout<<arr[y];
							y++;
						}

						y = 0;
						cout<<endl;
						kind[bit] = "INT8";
					    cout<<"Class:"<<kind[bit]<<endl;
					    bit++;

						cout<<endl;
						j=0;
			        }//else
				}   //else if 1 1 1
		    }          // if 1 1
		    else if(ch == '0' && word[x+1] == '!')  //else if 1 1
		    {

			    cout<<"Token is :0"<<endl;
			    kind[bit] = "INT10";
			    cout<<"Class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<0<<endl; 
			    cout<<"End"<<endl;
			    cout<<endl;

		        system("pause");
	            return 0;
		    }// else if 1 1
		    else // else 1 1
			{
				while(IsDigit(ch))
			    {
                    arr[j] = ch;
				    j++;
				    x++;
                    ch = word[x];
			    }
				if(ch != ' ' && ch != '!' && ch != '+' && ch != '-' && ch != '*' && ch != '/' && ch != '(' && ch != ')' && ch != '.' && ch != '>' && ch != '<' && ch != '=' && ch != ',')
				{
				    cout<<"10进制数输入错误";
				    system("pause");
	                return 0;
                    j = 0;
			     }
			     cout<<"Token is :";
				 while(y != j)
				 {
					 cout<<arr[y];
					 y++;
				 }

				 y=0;
				 cout<<endl;
				 kind[bit] = "INT10";
				 cout<<"Class:"<<kind[bit]<<endl;
				 bit++;

				 char* temp1 =(char*)malloc(j+1);
				 memcpy(temp1,arr,j);
				 temp1[j] ='\0';
				 string tempshit=temp1;
				 cout<<"Attribute is :"<<tempshit<<endl;
				 cout<<endl;
			     j = 0;
			}// else 1 1
		}           //else if 1
        
		else if(IsAlpha(ch))//是字母开头的     //else if 2
		{
			while(IsAlpha(ch) || IsDigit(ch))
			{
				arr[i] =ch;
				i++;
				x++;
                ch=word[x];				
			}
			 			
			/*思想和方法与数字的很相似*/
		
			char* temp = (char*)malloc(i+1) ;
			memcpy(temp,arr,i);
			temp[i] ='\0';
			string tempshit=temp;

            if(tempshit == "while")       //查表  if 2 1
		    {
		        cout<<"Token is :";
		        while(y != i)
			    {
				    cout<<arr[y];
				    y++;
			    }

			    y=0;
		        cout<<endl;
			    kind[bit]="WHILE";
				cout<<"class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<"_"<<endl;
			    cout<<endl;
		    }   //if 2 1
		    else if(tempshit == "if")//查表
		    {
		        cout<<"Token is :";
		        while(y != i)
			    {
				    cout<<arr[y];
				    y++;
			    }

			    y=0;
		        cout<<endl;
			    kind[bit]="IF";
				cout<<"class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<"_"<<endl;
			    cout<<endl;
		    }
		    else if(tempshit == "then")//查表
		    {
		        cout<<"Token is :";
		        while(y != i)
			    {
				    cout<<arr[y];
				    y++;
			    }
			    
				y=0;
		        cout<<endl;
			    kind[bit]="THEN";
				cout<<"Class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<"_"<<endl;
			    cout<<endl;
		    }
		    else if(tempshit == "else")//查表
		    {
		        cout<<"Token is :";
		        while(y != i)
			    {
				    cout<<arr[y];
				    y++;
			    }
			    y=0;
		        cout<<endl;
			    kind[bit] = "ELSE";
				cout<<"Class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<"_"<<endl;
			    cout<<endl;
		    }
		    else if(tempshit == "do")//查表   else if 2 1
		    {
		        cout<<"Token is :";
		        while(y != i)
			    {
				    cout<<arr[y];
				    y++;
			    }
			    
				y=0;
		        cout<<endl;
			    kind[bit] = "DO";
				cout<<"Class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<"_"<<endl;
			    cout<<endl;
		    }

		    else       //else 2 1
			{
		        cout<<"Token :";
		        while(y != i)
			    {
				    cout<<arr[y];
				    y++;
			    }
			    
				y=0;
		        cout<<endl;
			    kind[bit] = "IDN";
				cout<<"Class:"<<kind[bit]<<endl;
				bit++;
			    cout<<"Attribute is :"<<"DATA"<<endl;
			    cout<<endl;
		    }//else 2 1
            i = 0;
        }//else if 2

     	else if(ch == '-') //else if 3
		{
			kind[bit] = "-";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"-"<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
		    x++;
            ch = word[x];
			cout<<endl;
		}
		else if(ch == ':') 
		{
			kind[bit] = ":";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
		    cout<<"Class is :"<<":"<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;
		}
	    else if(ch == '+') 
		{
			kind[bit] = "+";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
            cout<<"Class is :"<<"+"<<endl;
		    cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;
		}
	    else if(ch == '*') 
		{
			kind[bit] = "*";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"*"<<endl;
		    cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;
		}
	    else if(ch == ';') 
		{
			kind[bit] = ";";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<";"<<endl;
	        cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;
		}
	    else if(ch == '/') 
		{
			kind[bit] = "/";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"/"<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;}
	    else if(ch == '(')
		{
			kind[bit] = "(";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"("<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;}
	    else if(ch == ')') 
		{
			kind[bit] = ")";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<")"<<endl;
	        cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;
		}
	    else if(ch == '.') 
		{ 
			kind[bit] = ".";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"."<<endl;
		    cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch = word[x];
	        cout<<endl;
		}
	    else if(ch == ',') 
		{
			kind[bit] = ",";
			cout<<"Class:"<<kind[bit]<<endl;
		    bit++;
	        cout<<"Class is :"<<","<<endl;
	        cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch=word[x];
	        cout<<endl;
		}
	    else if(ch == '>') 
		{
			kind[bit] = ">";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<">"<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch=word[x];
	        cout<<endl;
		}
        else if(ch == '<') 
		{
			kind[bit] = "<";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"<"<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch=word[x];
	        cout<<endl;
		}
	    else if(ch == '=') 
		{
			kind[bit] = "=";
			cout<<"Class:"<<kind[bit]<<endl;
			bit++;
	        cout<<"Class is :"<<"="<<endl;
			cout<<"Attribute is :"<<"_ "<<endl;
	        x++;
            ch=word[x];
	        cout<<endl;
		}
        else
	    { 
		    if(ch == '!')
			{
			    cout<<"End"<<endl;

				bit = 0;
			    s(kind, bit);

				break;
		        //system("pause");
	            //return 0;
		    }
		    else
			{
			    cout<<"Token is :"<<ch<<endl;
		        cout<<"字符错误"<<endl;
	            //system("pause");
	            //return 0;
				break;
		    }
		}
	}//while 1
}