stack.cpp

一个在linux下的shell的计算器

/*
 *
 *
 *
 */

#include <iostream>
#include <sstream>
#include "stack.h"
#include "exception.h"

using namespace std;

//
//
//
Stack::Stack()
{
 displaymode = DM_DEC;
}

//
//
//
void Stack::Drop()
{
 delete PopItem();
}

//
//
//
void Stack::Duplicate()
{
 Item *p = PopItem();
 Push(p->Clone());
 Push(p->Clone());
 delete p;
}

//
//
//
void Stack::Swap()
{
 Item *a, *b;
 a = PopItem();
 b = PopItem();
 Push(a->Clone());
 Push(b->Clone());
 delete b;
 delete a;
}

//
//
//
void Stack::Push(Item *p)
{
 Add(p);
}

//
//
//
Item *Stack::PopItem()
{
 if (Last() == NULL) throw new StackError();
 Item *q = Last()->Clone();
 Remove(Last());
 return q;
}

//
//
//
long Stack::PopInteger()
{
 return PopItem()->ToInteger();
}

//
//
//
bool Stack::PopBoolean()
{
 return PopItem()->ToBoolean();
}

//
//
//
double Stack::PopDouble()
{
 return PopItem()->ToDouble();
}

//
//
//
string Stack::PopString()
{
 return PopItem()->ToString();
}

//
//
//
void Stack::SetDisplayMode(int mode)
{
 displaymode = mode;
}

//
//
//
void Stack::Display(int levels)
{
 int c, l;
 Item *p, *q = NULL;
 c = 0;
 if (displaymode == DM_HEX) cout << "Hexadecimal mode" << endl;
 else if (displaymode == DM_OCT) cout << "Octal mode" << endl;
 for (p=Last();p!=NULL;p=p->prev)
 {
  c++;
  q = p;
  if (c == levels) break;
 }
 l = c;
 for (p=q;p!=NULL;p=p->next)
 {
  cout << l << ": ";
  if (p->GetType() == INTEGER) 
  {
   if (displaymode == DM_DEC) cout << dec;
   else if (displaymode == DM_HEX) cout << "0x" << hex;
   else if (displaymode == DM_OCT) cout << "0" << oct;
   cout << p->ToInteger();
  }
  else if (p->GetType() == REAL) cout << p->ToDouble();
  else cout << p->ToString();
  cout << endl;
  l--;
 }
}