vector/arraylist in C - c

Question

I am trying to implement a vector or arraylist in C. The code does not have a main, so I am compiling it with gcc -c file.c . I have two questions, the first being how to implement an insert function for the arraylist, and the second being why I receive the error that list-> is not a function.
#include<stdio.h>
#include<stdlib.h>
#include<math.h>
#include<string.h>
typedef struct ArrayList {
int *data;
int capacity;
int size;
ArrayList *list;
ArrayList ArrayList_init(int);
int insert(ArrayList *, int , int);
int set(ArrayList*, int, int);
int destroy(ArrayList *);
int print(ArrayList *);
int append(ArrayList *, int);
int valueOf( ArrayList *, int);
int size(ArrayList *);
int capacity(ArrayList *);
} ArrayList;
ArrayList * ArrayList_Init( int n )
{
ArrayList->data = malloc(sizeof(n) * ArrayList->capacity);
}
int append( ArrayList * list, int val )
{
if (list->size >= list->capacity)
return 1;
else
Arraylist->data[list->size++] = value;
return 0;
}
int print( ArrayList * list )
{
printf("%d\n", list->data);
return 0;
}
int set( ArrayList * list, int val, int index )
{
while(index >= list->size)
append(ArrayList, 0);
return 0;
if (index < 0 || index >= size)
return 1;
}
int destroy( ArrayList * list )
{
free(list->data);
return 0;
}
int insert(ArrayList * list, int val, int index)
{
return 0;
}
int valueOf( ArrayList * list, int element )
{
int x;
x = list->data[element];
return x;
}
int size(ArrayList * list)
{
return list->size;
}
int capacity(ArrayList * list)
{
return list->capacity;
}
int main(void)
{
int n = 3;
int i;
int stat; // Error code
int size;
int val = 0;
int capacity;
// allocate list
ArrayList *list = NULL;
list = ArrayList_Init(n);
printf("ArrayList initialized to %d elements\n", n);
printf("Size of List = %d\n", list->size(list));
printf("Capacity of List = %d\n", list->capacity(list));
// Fill initial values
list->set(list, val++, 0);
list->set(list, val++, 1);
list->set(list, val++, 2);
}
Thank you

Answer 1

First of all if you declare a function that returns something it must do so.
I think your ArrayList_Init should more look like this (I am assuming you want to store integers)
ArrayList * ArrayList_Init( int n )
{
ArrayList * list = malloc(ArrayList);
list->data = malloc(sizeof(int) * n);
list->capacity = n;
list->size=0;
return list;
}
In append as well as in Init you are trying to access a type.
Arraylist->data[list->size++] = value;
but it is supposed to be
list->data[list->size++] = value;
For your insert you can do something similiar to the following:
int insert( ArrayList * list, int val ,int position)
{
if (list->size >= list->capacity){
int * temp = malloc(sizeof(int) * list->capacity *2);
int i;
for(i=0;i<position-1;i++){
temp[i]=list->data[i];
}
for(i=postion-1;i<list->size;i++){
temp[i+1]=list->data[i];
}
free(list->data);
list->data=temp;
list->capacity *=2;
}else{
for(i=list->size;i>postion-1;i--){
list->data[i]=list->data[i-1];
}
}
list->data[position-1]=val;
list->size++;
return 1;
}
You probably want to do something similar in append because otherwise you just have a static array. The idea of a vector is that it grows and shrinks automatically.
Edit:
In C you cannot just declare a prototype of a function inside a struct and than access it.
The only way you can do something similar to what you want to do is by storing a pointer to each of the functions inside your struct. Have a look at the following post.
Define functions in structs