#include<stdlib.h>

#include "Stack.h"

struct _Stack {
  int size;
  int top;
  void **storage;
};

Stack stack_create(int size) {
  Stack p = (Stack) malloc (sizeof *p);
  p->size = size;
  p->top = 0;
  p->storage = (void **) malloc(size*(sizeof(void *)));
  return p;
}

void stack_destroy(Stack p) {
  free(p->storage);
  free(p);
}

int stack_get_size(Stack p) {
  return p->top;
}

int stack_is_empty(Stack p) {
  return p->top == 0;
}

void stack_push(Stack p, void *data) {
  p->storage[p->top] = data;
  p->top = p->top+1;
}

void *stack_pop(Stack p) {
  p->top = p->top-1;
  return p->storage[p->top];
}

void *stack_peep(Stack p) {
  return p->storage[p->top-1];
}