nat.c

压缩包里面的都是精致的基本C语言小程序

#include <stdio.h>
#include <stdlib.h>
#include "mystdlib.h"
#include "error.h"
#include "commonInter.h"
#include "myint.h"
#include "nat.h"

static int flag = 1;

struct nat
{
  tyVft vft;
  
  int i;
  plist pplist;
};

struct tyVft natVft;

nat newNat (int i)
{
  if (i<0)
  {
    printf ("%d\n", i);
    exception ("invalid argument in file nat.c: i = ");
    
    return NULL;
  }
  
  if (flag)
  {
    flag--;
    natVft.equals = natEquals;
    natVft.hashCode = hashCode;
    natVft.toString = natToString;
    natVft.getPlist = natPlist;
  }

  nat n = checkedMalloc (sizeof (*n));
  
  n->vft = &natVft;
  n->i = i;
  n->pplist = newPlist ();
  
  return n;
}

nat natAdd (nat n1, nat n2)
{
  int i1 = n1->i;
  int i2 = n2->i;
  return newNat (i1+i2);
}

nat natSub (nat n1, nat n2)
{
  int i1 = n1->i;
  int i2 = n2->i;
  return newNat (i1-i2);
}

nat natTimes (nat n1, nat n2)
{
  int i1 = n1->i;
  int i2 = n2->i;
  return newNat (i1*i2);
}

int hashCode (poly n)
{
  return ((nat)n) -> i;
}

plist natPlist (poly n)
{
  return ((nat)n)->pplist;
}

int natToInt (nat n)
{
  return n->i;
}

void natOutput (poly n)
{
  printf ("%d", ((nat)n)->i);
}

int natEquals (poly n1, poly n2)
{
  return (((nat)n1)->i == ((nat)n2)->i);
}

str natToString (poly n)
{
  return intToString (((nat)n)->i);
}