asdasd.cpp

多功能语法分析器。 多功能语法分析器。

#include "stdio.h"
#include "stdlib.h"

#define MaxRuleNum 8
#define MaxVnNum 5
#define MaxVtNum 5
#define MaxStackDepth 20
#define MaxPLength 20
#define MaxStLength 50
/*-----------------main struct define-----------------*/
/*
声明：非终结符序号 = 100 + Vn的下标
  终结符序号 = Vn的下标
*/
/*++++++++++文法结构++++++++++*/
struct pRNode /*产生式右部结构*/
{
 int rCursor; /*右部序号*/
 struct pRNode *next;
};

struct pNode /*产生式结点结构*/
{
 int lCursor; /*左部符号序号*/
 int rLength; /*右部长度*/
 /*注当rLength = 1 时，rCursor = -1为空产生式*/
 struct pRNode *rHead; /*右部结点头指针*/
};

char Vn[MaxVnNum + 1]; /*非终结符集*/
int vnNum;
char Vt[MaxVtNum + 1]; /*终结符集*/
int vtNum;
struct pNode P[MaxRuleNum]; /*产生式*/
int PNum; /*产生式实际个数*/
char buffer[MaxPLength + 1];
char ch; /*符号或string ch;*/
char st[MaxStLength]; /*要分析的符号串*/

/*++first and follow collect struct++*/
struct collectNode /*集合元素结点结构*/
{
 int nVt; /*在终结符集中的下标*/
 struct collectNode *next;
};

struct collectNode* first[MaxVnNum + 1]; /*first集*/
struct collectNode* follow[MaxVnNum + 1]; /*follow集*/

/*+++++++++++++analysis table struct++++++++++++++++*/
int analyseTable[MaxVnNum + 1][MaxVtNum + 1 + 1];
/*预测分析表存放为产生式的编号，+1用于存放结束符，多+1用于存放#(-1)*/

/*+++++++++++++++analysis stack struct++++++++++++++*/
int analyseStack[MaxStackDepth + 1]; /*分析栈*/
int topAnalyse; /*分析栈顶*/
/*int reverseStack[MaxStackDepth + 1]; /*颠倒顺序栈*/
/*int topReverse; /*倒叙栈顶*/

/*------------------function declare---------------*/
void Init();/*初始化*/
int IndexCh(char ch);
/*返回Vn在Vn表中的位置+100、Vt在Vt表中的位置，-1表示未找到*/
void InputVt(); /*输入终结符*/
void InputVn();/*输入非终结符*/
void ShowChArray(char* collect, int num);/*输出Vn或Vt的内容*/
void InputP();/*产生式输入*/
bool CheckP(char * st);/*判断产生式正确性*/
void First(int U);/*计算first集,U->xx...*/
void AddFirst(int U, int nCh); /*加入first集*/
bool HaveEmpty(int nVn); /*判断first集中是否有空(-1)*/
void Follow(int V);/*计算follow集*/
void AddFollow(int V, int nCh, int kind);/*加入follow集，
 kind = 0表加入follow集，kind = 1加入first集*/
void ShowCollect(struct collectNode **collect);/*输出first或follow集*/
void FirstFollow();/*计算first和follow*/
void CreateAT();/*构造预测分析表*/
void ShowAT();/*输出分析表*/
void Identify(char *st);/*主控程序,为操作方便*/
/*分析过程显示操作为本行变换所用，与教程的显示方式不同*/
void InitStack();/*初始化栈及符号串*/
void ShowStack();/*显示符号栈中内容*/
void Pop();/*栈顶出栈*/
void Push(int r);/*使用产生式入栈操作*/

/********************************* LL1.CPP *************************************/

/*-----------------------------------------------*/
//#include "LL1.h"
/*-------------------main function--------------------*/
void main(void)
{
 char todo,ch;
 
 Init();

 InputVn();
 InputVt();
 InputP();

 getchar();

 FirstFollow();
 printf("所得first集为：");
 ShowCollect(first);
 printf("所得follow集为：");
 ShowCollect(follow);

 CreateAT();
 ShowAT();

 todo = 'y';
 while('y' == todo)
 {
  printf("\n是否继续进行句型分析？(y / n):");
  todo = getchar();
  while('y' != todo && 'n' != todo)
  {
   printf("\n(y / n)? ");
   todo = getchar();
  }
  if('y' == todo)
  {
   int i;
   InitStack();
   printf("请输入符号串(以#结束) : ");
   ch = getchar();
   i = 0;
   while('#' != ch && i < MaxStLength)
   {
    if(' ' != ch && '\n' != ch)
    {
     st[i++] = ch;
    }
    ch = getchar();
   }
   if('#' == ch && i < MaxStLength)
   {
    st[i] = ch;
    Identify(st);
   }
   else 
    printf("输入出错！\n");
  }
 }

 getchar();
}
/*---------------function definition------------------*/
void Init()
{
 int i,j;
 vnNum = 0;
 vtNum = 0;
 PNum = 0;
 for(i = 0; i <= MaxVnNum; i++)
  Vn[i] = '\0';
 for(i = 0; i <= MaxVtNum; i++)
  Vt[i] = '\0';
 for(i = 0; i < MaxRuleNum; i++)
 {
  P[i].lCursor = NULL;
  P[i].rHead = NULL;
  P[i].rLength = 0;
 }
 PNum = 0;
 for(i = 0; i <= MaxPLength; i++)
  buffer[i] = '\0';
 for(i = 0; i < MaxVnNum; i++)
 {
  first[i] = NULL;
  follow[i] = NULL;
 }
 for(i = 0; i <= MaxVnNum; i++)
 {
  for(j = 0; j <= MaxVnNum + 1; j++)
   analyseTable[i][j] = -1;
 }
}
/*返回Vn在Vn表中的位置+100、Vt在Vt表中的位置，-1表示未找到*/
int IndexCh(char ch) 
{
 int n;
 n = 0; /*is Vn?*/
 while(ch != Vn[n] && '\0' != Vn[n])
  n++;
 if('\0' != Vn[n])
  return 100 + n;
 n = 0; /*is Vt?*/
 while(ch != Vt[n] && '\0' != Vt[n])
  n++;
 if('\0' != Vt[n])
  return n;
 return -1;
}
/*输出Vn或Vt的内容*/
void ShowChArray(char* collect)
{
 int k = 0;
 while('\0' != collect[k])
 {
  printf(" %c ", collect[k++]);
 }
 printf("\n");
}
/*输入非终结符*/
void InputVn()
{
 int inErr = 1;
 int n,k;
 char ch;
 while(inErr)
 {
  printf("\n请输入所有的非终结符，注意：");
  printf("请将开始符放在第一位，并以#号结束:\n"); 
  ch = ' ';
  n = 0;
  /*初始化数组*/
  while(n < MaxVnNum)
  {
   Vn[n++] = '\0';
  }
  n = 0;
  while(('#' != ch) && (n < MaxVnNum))
  {
   if(' ' != ch && '\n' != ch && -1 == IndexCh(ch))
   {
    Vn[n++] = ch;
    vnNum++;
   }
   ch = getchar();
  }
  Vn[n] = '#'; /*以“#”标志结束用于判断长度是否合法*/
  k = n; /*k用于记录n以便改Vn[n]='\0'*/
  if('#' != ch)
  {
   if( '#' != (ch = getchar()))
   {
    while('#' != (ch = getchar()))
     ;
    printf("\n符号数目超过限制！\n");
    inErr = 1;
    continue;
   }
  }
  /*正确性确认，正确则，执行下下面，否则重新输入*/
  Vn[k] = '\0';
  ShowChArray(Vn);
  ch = ' ';
  while('y' != ch && 'n' != ch)
  {
   if('\n' != ch)
   {
    printf("输入正确确认?(y/n):");
   }
   scanf("%c", &ch);
  }
  if('n' == ch)
  {
   printf("录入错误重新输入！\n");
   inErr = 1;
  }
  else
  {
   inErr = 0;
  }
 }
}
/*输入终结符*/
void InputVt()
{
 int inErr = 1;
 int n,k;
 char ch;
 while(inErr)
 {
  printf("\n请输入所有的终结符，注意：");
  printf("以#号结束:\n"); 
  ch = ' ';
  n = 0;
  /*初始化数组*/
  while(n < MaxVtNum)
  {
   Vt[n++] = '\0';
  }
  n = 0;
  while(('#' != ch) && (n < MaxVtNum))
  {
   if(' ' != ch && '\n' != ch && -1 == IndexCh(ch))
   {
    Vt[n++] = ch;
    vtNum++;
   }
   ch = getchar();
  }
  Vt[n] = '#'; /*以“#”标志结束*/
  k = n; /*k用于记录n以便改Vt[n]='\0'*/
  if('#' != ch)
  {
   if( '#' != (ch = getchar()))
   {
    while('#' != (ch = getchar()))
     ;
    printf("\n符号数目超过限制！\n");
    inErr = 1;
    continue;
   }
  }
  /*正确性确认，正确则，执行下下面，否则重新输入*/
  Vt[k] = '\0';
  ShowChArray(Vt);
  ch = ' ';
  while('y' != ch && 'n' != ch)
  {
   if('\n' != ch)
   {
    printf("输入正确确认?(y/n):");
   }
   scanf("%c", &ch);
  }
  if('n' == ch)
  {
   printf("录入错误重新输入！\n");
   inErr = 1;
  }
  else
  {
   inErr = 0;
  }
 }
}
/*产生式输入*/
void InputP()
{
 char ch;
 int i = 0, n,num;
 printf("请输入文法产生式的个数：");
 scanf("%d", &num);
 PNum = num;
 getchar(); /*消除回车符*/
 printf("\n请输入文法的%d个产生式,并以回车分隔每个产生式：", num);
 printf("\n");
 while(i < num)
 {
  printf("第%d个：", i);
  /*初始化*/
  for(n =0; n < MaxPLength; n++)
   buffer[n] = '\0';
  /*输入产生式串*/
  ch = ' ';
  n = 0;
  while('\n' != (ch = getchar()) && n < MaxPLength)
  {
   if(' ' != ch)
    buffer[n++] = ch;    
  }
  buffer[n] = '\0';
/*  printf("%s", buffer);*/
  if(CheckP(buffer))
  {
   /*填写入产生式结构体*/
   pRNode *pt, *qt;
   P[i].lCursor = IndexCh(buffer[0]);
   pt = (pRNode*)malloc(sizeof(pRNode));
   pt->rCursor = IndexCh(buffer[3]);
   pt->next = NULL;
   P[i].rHead = pt;
   n = 4;
   while('\0' != buffer[n])
   {
    qt = (pRNode*)malloc(sizeof(pRNode));
    qt->rCursor = IndexCh(buffer[n]);
    qt->next = NULL;
    pt->next = qt;
    pt = qt;
    n++;
   }
   P[i].rLength = n - 3;
   i++;
   /*调试时使用*/
  }
  else
   printf("输入符号含非法在成分，请重新输入！\n");
 }
}
/*判断产生式正确性*/
bool CheckP(char * st)
{
 int n;
 if(100 > IndexCh(st[0]))
  return false;
 if('-' != st[1])
  return false;
 if('>' != st[2])
  return false;
 for(n = 3; '\0' != st[n]; n ++)
 {
  if(-1 == IndexCh(st[n]))
   return false;
 }
 return true;
}
/*====================first & follow======================*/
/*计算first集,U->xx...*/
void First(int U)
{
 int i,j;
 for(i = 0; i < PNum; i++)
 {
  if(P[i].lCursor == U)
  {
   struct pRNode* pt;
   pt = P[i].rHead;
   j = 0;
   while(j < P[i].rLength)
   {
    if(100 > pt->rCursor)
    {
     /*注:此处因编程出错,使空产生式时
     rlength同样是1,故此处同样可处理空产生式*/
     AddFirst(U, pt->rCursor);
     break;
    }
    else
    {
     if(NULL == first[pt->rCursor - 100])
     {
      First(pt->rCursor);
     }     
     AddFirst(U, pt->rCursor);
     if(!HaveEmpty(pt->rCursor))
     {
      break;
     }
     else
     {
      pt = pt->next;
     }
    }
    j++;
   }
   if(j >= P[i].rLength) /*当产生式右部都能推出空时*/
    AddFirst(U, -1);
  }
 }
}
/*加入first集*/
void AddFirst(int U, int nCh) /*当数值小于100时nCh为Vt*/
/*当处理非终结符时,AddFirst不添加空项(-1)*/
{
 struct collectNode *pt, *qt;
 int ch; /*用于处理Vn*/
 pt = NULL;
 qt = NULL;
 if(nCh < 100)
 {
  pt = first[U - 100];
  while(NULL != pt)
  {