fun.cpp

词法分析和语法分析的程序

#include"string.h"
#include"iostream.h"
#include"stdio.h"
#include"conio.h"

#define OK 1
#define ERROR 0
#define TRUSE 1
#define FALSE 0
#define MAX 200
#define MAX2
#define YES 1
#define NO 0
#define IF 2
#define ELSE 3
#define WHILE 4
#define DO 5
#define SWITCH 6
#define INT 22
#define CHAR 23
#define FLOAT 24
#define OTC 8
#define DEC 10
#define HEX 16
#define KEY 20
#define ALPHA 21

class word_analyse
{    int ch;
	 char code[MAX][MAX];
public:
	//word_analyse();
	int scan();
	int isletter(int ch);
	int isdigit(int ch);
	int isright(int ch);
	int iskeyword(char * ch);
	int isalpha(char * ch);
	int judge(char * ch);
};

int word_analyse::isletter(int ch)
{
	if(((ch>='a')&&(ch<='z'))||((ch>='A')&&(ch<='Z')))
		return(YES);
	else return(NO);
}

int word_analyse::isalpha(char * ch)
{
	if(((ch[0]>='a')&&(ch[0]<='z'))||((ch[0]>='A')&&(ch[0]<='Z')))
	{ cout<<"\n"<<"The ["<<ch<<"] is a identifier !"<<"\n";
	  return(YES);
	}
	else return(NO);
}

int word_analyse::isdigit(int ch)
{  if(((ch>='0')&&(ch<='9')))
        return(YES);
   else return(NO);
}

int word_analyse::isright(int ch)
{ 
   if(((ch>='0')&&(ch<='9'))||((ch>='a')&&(ch<='z'))
	   ||((ch>='A')&&(ch<='Z'))||(ch=='+')||(ch=='-')
	   ||(ch=='*')||(ch=='/')||(ch=='=')||(ch=='==')
	   ||(ch=='%')||(ch=='<')||(ch=='>')||(ch=='(')||(ch==')'))
	    return(YES);
   else return(NO);
}

int word_analyse::iskeyword(char * ch)
{
  
  if((ch[0]=='i')&&(ch[1]=='n')&&(ch[2]=='t')&&(ch[3]==0))
  { cout<<"\n"<<"The [int] is a keyword !"<<"\n";    return(INT);        }
  if((ch[0]=='c')&&(ch[1]=='h')&&(ch[2]=='a')&&(ch[3]=='r')&&(ch[4]==0))
  { cout<<"\n"<<"The [char] is a keyword !"<<"\n";    return(CHAR);      }
  if((ch[0]=='f')&&(ch[1]=='l')&&(ch[2]=='o')&&(ch[3]=='a')&&(ch[4]=='t')&&(ch[5]==0))
  { cout<<"\n"<<"The [float] is a keyword !"<<"\n";    return(FLOAT);        }
  if((ch[0]=='i')&&(ch[1]=='f')&&(ch[2]==0))
  { cout<<"\n"<<"The [if] is a keyword !"<<"\n";    return(IF);        }
  if((ch[0]=='e')&&(ch[1]=='l')&&(ch[2]=='s')&&(ch[3]=='e')&&(ch[4]==0))
  { cout<<"\n"<<"The [else] is a keyword !"<<"\n";  return(ELSE);      }
  if((ch[0]=='w')&&(ch[1]=='h')&&(ch[2]=='i')&&(ch[3]=='l')&&(ch[4]=='e')&&(ch[5]==0))
  { cout<<"\n"<<"The [while] is a keyword !"<<"\n"; return(WHILE);     }
  if((ch[0]=='d')&&(ch[1]=='o')&&(ch[2]==0))
  { cout<<"\n"<<"The [do] is a keyword !"<<"\n";    return(DO);        }
  if((ch[0]=='s')&&(ch[1]=='w')&&(ch[2]=='i')&&(ch[3]=='t')&&(ch[4]=='c')&&(ch[5]=='h')&&(ch==0))
  { cout<<"\n"<<"It is a keyword [if] !"<<"\n";	return(SWITCH);    }
  return(FALSE);
}

int word_analyse::judge(char * ch)
{
     if((ch[0]=='0')&&((ch[1]>='0')&&(ch[1]<='7')))
	  {
		cout<<"\n"<<"This is a OTC number, OTC value is"<<"["<<ch<<"] !"<<"\n";
		return(OTC);
	  }
	  if((ch[0]>='0')&&(ch[0]<='9')&&(ch[0]!='0'))
	  { cout<<"\n"<<"This is a DEC number, DEC value is"<<"["<<ch<<"] !"<<"\n";
	    return(DEC);
	  }
	  if((ch[0]=='0')&&(ch[1]=='x'))
	  { cout<<"\n"<<"This is a HEX number, HEX value is"<<"["<<ch<<"] !"<<"\n";
		return(HEX);
	  }
	return(OK);
}

int word_analyse::scan()
{   int i=0;
    int j=0;
	int x=1;
	clrscr();
	cout<<"Please input !"<<"\n";
	ch=getc(stdin);
	while((ch==' ')||(ch==10))ch=getc(stdin);
	if((isright(ch)==NO)){ cout<<"\n"<<"ERROR"<<"\n"; return(ERROR); }
	ungetc(ch,stdin);
	while(x)
	{ ch=getc(stdin);
	 if((isletter(ch)==YES))
	 {  i=0;
	  while (isletter(ch)||isdigit(ch))
		{
			code[j][i]=ch;
			ch=getc(stdin);
			i++;
		}
		code[j][i]=0;
		ungetc(ch,stdin);
		if(iskeyword(code[j])==0)
		{
			if(isalpha(code[j]))cout<<"The identifier's ID is ["<<j<<"] !"<<"\n";
		}
	    j++;
		if(ch==10)x=0;
	 }
     if((isdigit(ch)==YES))
	 {  i=0;
		while(isdigit(ch)||(ch=='x')||((ch>='a')&&(ch<='f')))
		{
			code[j][i]=ch;
			ch=getc(stdin);
			i++;
		}
		code[j][i]=0;
		ungetc(ch,stdin);
		judge(code[j]);
		cout<<"The number's ID is ["<<j<<"] !"<<"\n";
		j++;
		if(ch==10)x=0;
	 }
	if(ch==':')
	{    i=0;
	     code[j][i]=ch;
		 ch=getc(stdin);
		 if(ch=='='){ code[j][i++]=ch; cout<<"The ["<<"code[j]"<<" is (ASSIGN-OP, -) ."; j++; ch=getc(stdin); if(ch==10)x=0; }
	}
	 if(ch=='+'||ch=='-'||ch=='*'||ch=='/'||ch=='('||ch==')'||ch=='<'||ch=='>'||ch==';')
	 {
	  switch(ch)
	   {
	   case'+':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (PLUS-OP, AND) ."<<"\n"; ch=getc(stdin); if(ch==59)ungetc(ch,stdin); }
		         break;
	   case'-':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (MINUS-OP, SUB) ."<<"\n"; ch=getc(stdin);if(ch==59)ungetc(ch,stdin); }
		         break;
	   case'*':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, MUL) ."<<"\n"; ch=getc(stdin); if(ch==59)ungetc(ch,stdin);}
		         break; 
	   case'/':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, DIV) ."<<"\n"; ch=getc(stdin);if(ch==59)ungetc(ch,stdin); }
		         break;
	   case'=':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, EQ) ."<<"\n"; ch=getc(stdin);if(ch==59)ungetc(ch,stdin); }
		         break;
	   case'>':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, GT) ."<<"\n"; ch=getc(stdin);if(ch==59)ungetc(ch,stdin); }
		         break;
	   case'<':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, LT) ."<<"\n"; ch=getc(stdin);if(ch==59)ungetc(ch,stdin);}
		         break;
	   case'(':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, LP) ."<<"\n"; ch=getc(stdin);if(ch==59)ungetc(ch,stdin); }
		         break;
	   case')':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (RELATION-OP, RP) ."<<"\n"; ch=getc(stdin); if(ch==59)ungetc(ch,stdin); }
		         break;
	   case';':{ i=0; code[j][i]=ch; code[j][i++]=0; cout<<"\n"<<"The ["<<char(ch)<<"] is a identifier (SEMICOLON, -) ."<<"\n"; ch=getc(stdin); }
		         break;
	   }
	 }
	 if(ch==10)x=0;
	}
	return(OK);
}

int main()
{
	char ch1;
	word_analyse word;
	while(ch1!='q')
	{
	 word.scan();
	 ch1=getch();
	}
	return(OK);
}