trying to flesh out the array implementation before I proceed to heap

c/arraylist.c

@@ -1,24 +1,23 @@
+#include <stdint.h>
 #include <stdio.h>
 #include <stdlib.h>
 
-typedef struct ArrayList {
-    int capacity;
-    int index;
-    int data[];
-} ArrayList;
+typedef struct i32_ArrayList {
+    int     capacity;  // capacity of the array
+    int     index;     // the current location the list that is to be written to
+    int32_t data[];    // the data
+} i32_ArrayList;
 
-ArrayList* new_arraylist(int cap) {
-    ArrayList* arr = malloc(sizeof(ArrayList) + cap * sizeof(int));
+i32_ArrayList* new_arraylist(int cap) {
+    i32_ArrayList* arr = malloc(sizeof(i32_ArrayList) + cap * sizeof(int));
     arr->capacity = cap;
     arr->index = 0;
-    for (int i = 0; i < cap; i++) {
-        arr->data[i] = 0;
-    }
 
     return arr;
 }
 
-void push_to_array(ArrayList* s, int v) {
+// add to end of the array
+void array_append(i32_ArrayList* s, int v) {
     if (s->index == s->capacity) {
         printf("you attempted to insert %d, but array is at capacity cannot add mode values\n", v);
     } else {
@@ -27,18 +26,33 @@ void push_to_array(ArrayList* s, int v) {
     }
 }
 
-void pop_from_array(ArrayList* s) {
-    if (s->index == 0) {
-        printf("there is nothing to remove!\n");
-    } else {
-        s->index--;
+// insert value at index
+void array_insert_at(i32_ArrayList* arr, int index, int32_t value) {
+    for (int i = index; i > arr->index; i--) {
+        arr->data[i] = arr->data[i - 1];
     }
 }
 
-void grow_array_list(ArrayList* s, int amount) {
+int32_t array_get_at(i32_ArrayList* arr, int index) {
+    return (arr->data[index]);
 }
 
-void print_array_list(ArrayList* arr) {
+int32_t pop_from_array(i32_ArrayList* s) {
+    if (s->index == 0) {
+        printf("there is nothing to remove!\n");
+        return (-99);
+    } else {
+        int32_t val = s->data[s->index - 1];
+        s->index--;
+
+        return (val);
+    }
+}
+
+void grow_array_list(i32_ArrayList* s, int amount) {
+}
+
+void print_array_list(i32_ArrayList* arr) {
     printf("[");
     for (int i = 0; i < arr->index; i++) {
         printf(" %d ", arr->data[i]);
@@ -47,15 +61,22 @@ void print_array_list(ArrayList* arr) {
 }
 
 int main() {
-    ArrayList* a = new_arraylist(5);
-    push_to_array(a, 10);
-    push_to_array(a, 11);
-    push_to_array(a, 12);
-    push_to_array(a, 12);
-    push_to_array(a, 12);
-    push_to_array(a, 12);
-    push_to_array(a, 12);
-    pop_from_array(a);
-    push_to_array(a, 155);
+    i32_ArrayList* a = new_arraylist(5);
+    array_append(a, 10);
     print_array_list(a);
+    array_append(a, 11);
+    print_array_list(a);
+    array_append(a, 12);
+    print_array_list(a);
+    array_append(a, 13);
+    print_array_list(a);
+    array_append(a, 14);
+    print_array_list(a);
+    pop_from_array(a);
+    print_array_list(a);
+    array_append(a, 15);
+    print_array_list(a);
+    array_insert_at(a, 3, 55);
+    print_array_list(a);
+    printf("%d\n", array_get_at(a, 3));
 }