wordpars.cpp

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// WordPars.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"
#include <stdio.h>
#include <io.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <stdlib.h>
#include <iostream.h>
#include <fstream.h>
#include <malloc.h>

FILE *fp;
char cbuffer;
char *key[21]={"AND","BEGIN","CONST","DIV","DO","ELSE","END",
	       "FUNCTION","IF","INTEGER","NOT","OR","PROCEDURE",
	       "PROGRAM","READ","REAL","THEN","TYPE","VAR","WHILE",
	       "WRITE"};
char *border[8]={",",";",":",".","(",")","[","]"};
char *arithmetic[4]={"+","-","*","/"};
char *relation[10]={"=","<",">","<>","<=",">=",":=","{","}","#"};
char *consts[20];
char *label[20];
int constnum=0,labelnum=0;

int search(char searchchar[],int wordtype)
{
     int i=0;
     switch (wordtype) 
	 {
       case 1:for (i=0;i<=20;i++)
		{
		   if (strcmp(key[i],searchchar)==0)
		    return(i+1);
		};
       case 2:
		{
			 for (i=0;i<=7;i++)
			{
				 if (strcmp(border[i],searchchar)==0)
					 return(i+24);
			}
	       return(0);
	     };
       case 3:
		   {
			   for (i=0;i<=3;i++)
				{
					if (strcmp(arithmetic[i],searchchar)==0)
					 {
					 return(i+35);
					 }
				}
				return(0);
	      };
       case 4:
		   {
			   for (i=0;i<=9;i++)
				{
					if (strcmp(relation[i],searchchar)==0)
					 {
						  return(i+39);
					 }
				}
				 return(0);
	      };
       case 5:
		   {
			   for (i=0;i<=constnum;i++)
				{
					if (strcmp(consts[i],searchchar)==0)
					   {
							return(23);
					   }

			   }
				 consts[i-1]=(char *)malloc(sizeof(searchchar));
				 strcpy(consts[i-1],searchchar);
				 constnum++;
				 return(23);
	      };
       case 6:
		   {
		   //printf("%s",searchchar); 
			   for (i=0;i<=labelnum;i++)
				 {
				   // printf("%s",searchchar);
					  if (strcmp(label[i],searchchar)==0)
					  {
						 
						return(22);
					  }
					  
				 }
		   
			    label[i-1]=(char *)malloc(sizeof(searchchar));
				strcpy(label[i-1],searchchar);
				labelnum++;
				return(22);
	      };
      };
	return 0;
 };

char alphaprocess(char buffer)
     {
      int atype;
      int i=-1;
      char alphatp[20];

      while ((isalpha(buffer))||(isdigit(buffer)))
	    {
//		  printf("%c",buffer);
	    alphatp[++i]=buffer;
	    buffer=fgetc(fp);
	    };

      alphatp[i+1]='\0';
	  //printf("%s",alphatp);     
      if (atype=search(alphatp,1))
	  {
		 printf("       %-10s,      %-5d\n",alphatp,atype-1);
		 buffer=fgetc(fp);
		 //	printf("%c",buffer);
	  }
      else
	 {
		  
		 atype=search(alphatp,6);
		 printf("       %-10s,      %-5d\n",alphatp,atype-1);
		 //buffer=fgetc(fp);
	 
	 }
//	 printf("%c",buffer); 
      return(buffer);
}

char digitprocess(char buffer)
     {
      int i=-1;
      char digittp[20];
      int dtype;
      while ((isdigit(buffer)))
	    {
	    digittp[++i]=buffer;
	    buffer=fgetc(fp);
	    }
      digittp[i+1]='\0';
      dtype=search(digittp,5);
      printf("       %-10s,      %-5d\n",digittp,dtype-1);
      return(buffer);
     }

char otherprocess(char buffer)
     {

      int i=-1;
      char othertp[20];
      int otype,otypetp;
      othertp[0]=buffer;
      othertp[1]='\0';
      if (otype=search(othertp,3))
	 {
	 printf("       %-10s,      %-5d\n",othertp,otype-1);
	 buffer=fgetc(fp);
	 goto out;
	 };

      if (otype=search(othertp,4))
	      {
	      buffer=fgetc(fp);
	      othertp[1]=buffer;
	      othertp[2]='\0';
	      if (otypetp=search(othertp,4))
		 {
		 printf("       %-10s,      %-5d\n",othertp,otypetp-1);
		 goto out;
		 }
	      else
		 othertp[1]='\0';
		 printf("       %-10s,      %-5d\n",othertp,otypetp-1);
		 goto out;
	      };

      if(buffer==':')
	      {
	      buffer=fgetc(fp);
	      if (buffer=='=')
		 printf("       :=        ,      44   \n");
		 buffer=fgetc(fp);
		 goto out;
	      }
	   else
	      {
	      if (otype=search(othertp,2))
		 {
		 printf("       %-10s,      %-5d\n",othertp,otype-1);
		 buffer=fgetc(fp);
		 goto out;
		 }
	      };

	  if ((buffer!='\n')&&(buffer!=' '))
		  printf("%c error,not a word\n",buffer);
	  buffer=fgetc(fp);
out:      return(buffer);
     };

int main(int argc, char* argv[])
{
	 int i;
     printf("     The Result :\n");
      for (i=0;i<=20;i++)
	  {
	   label[i]="";//不能用NULL
	   consts[i]="";//不能用NULL
	  };
      if ((fp=fopen("pas.PAS","r"))==NULL)
		 printf("error");
      else
	{
	cbuffer = fgetc(fp);
	while (cbuffer!=EOF)
	 {
		  if (isalpha(cbuffer))
		  {
			cbuffer=alphaprocess(cbuffer);
			
		  }
			else if (isdigit(cbuffer))
				cbuffer=digitprocess(cbuffer);
			else cbuffer=otherprocess(cbuffer);
//		  cbuffer=fgetc(fp);
			//printf("       %c", cbuffer);
	  };
	 printf("     OVER !\n");
	};
	return 0;
}