nepcmain.c

一个小计算器的实现(编译原理),用Lex和bison

#include <stdio.h>

#include "nepc.tab.h"
#include "nepc.h"
extern int yyparse();
extern FILE * yyin;
void yyerror(char *s) 
{
    fprintf(stdout, "%s\n", s);
}
void motd()
{
    printf("--------------------------------------------------------------\n");
    printf(">> nepc-0.2-r2 - A mini limited precision interpreting calculator.\n");
    printf(">> Copyright (C) 2005 [e-mail]\n");
    printf(">> nepc is open software; you can redistribute it and/or modify\n\
   it under the terms of the version 2.1 of the GNU Lesser \n\
   General Public License as published by the Free Software\n\
   Foundation.\n>> Type 'exit' to quit, type 'help' to get help.\n");
    printf("--------------------------------------------------------------\n");
}
void init()
{
  sysInfo.first=0;
  sysInfo.sysHead=sysInfo.sysTail=NULL;
  sysInfo.G_sys_number=0;
  sentenceArrayLen=0;
}
int main(void) 
{
	nodeType *p;
    nodeType *p2;
    int size;
     nodeType *test[3];
//////////////////////////////////////////////////////////////
   int i=0;
   int result=0;
   nodeType * itp;
   nodeType * itp2;
   init();
    motd();
	i=sizeof(sysType);
	printf("sysType  size::%d\n",i);
	i=sizeof(nodeType);
	printf("nodeType  size::%d\n",i);

    G_line=1;
	G_level=1;
    yyin=fopen("c:\\input.c","r"); /* set parse stream to standard input */
    if(yyin==NULL)
    	{
    	  printf("open error!\n");
	  return 0;
    	}
    result=yyparse(); /* begin parse */
	if(result)
	{
		printf("error happen !!!!!!!!:%d\n",G_line);
	}
    fclose(yyin);
 
    for(i=0;i<sentenceArrayLen;i++)
    	{
    	itp=sentenceArray[i];
    	interpret(itp); 

    	}
    printf("line:%d\n",G_line);
////////////////////////////////////////////////////////////////////////

    return 0;
}