made work: removeAtIndex(x);

src/list.c

@@ -214,3 +214,12 @@ listInsertAt(list_t* l, int index, dataType_e type, void* element) {
         }
     }
 }
+
+void
+listRemoveAt(list_t* l, int index) {
+    vectorRemoveAt(l->data, index);
+    l->size -= 1;
+    if (l->size == l->capacity) {
+        l->capacity /= 2;
+    }
+}

src/vector.c

@@ -430,3 +430,52 @@ vectorInsertAt(vector_t* v, int index, void* element) {
             exit(EXIT_FAILURE);
     }
 }
+
+void
+vectorRemoveAt(vector_t* v, int index) {
+    if (v->size == 0) {
+        fprintf(stderr, "cannot remove from empty vector\n");
+        exit(EXIT_FAILURE);
+    } else if (index >= v->size || index < 0) {
+        fprintf(stderr, "index out of range\n");
+        exit(EXIT_FAILURE);
+    }
+
+    switch (v->type) {
+        case INT:
+            // move all elements to the right by one
+            for (int i = index; i < v->size; i++) {
+                *((int *)(v->data) + i) = *((int *)(v->data) + i+1);
+            }
+            break;
+        case FLOAT:
+            for (int i = index; i < v->size; i++) {
+                *((float *)(v->data) + i) = *((float *)(v->data) + i+1);
+            }
+            break;
+        case CHAR:
+            for (int i = index; i < v->size; i++) {
+                *((char *)(v->data) + i) = *((char *)(v->data) + i+1);
+            }
+            break;
+        case VECTOR:
+            for (int i = index; i < v->size; i++) {
+                *((vector_t*)(v->data) + i) = *((vector_t*)(v->data) + i+1);
+            }
+            break;
+        case LIST:
+            for (int i = index; i < v->size; i++) {
+                *((list_t*)(v->data) + i) = *((list_t*)(v->data) + i+1);
+            }
+            break;
+        default:
+            fprintf(stderr, "specify a valid vector type\n");
+            exit(EXIT_FAILURE);
+    }
+
+    v->size -= 1;
+    if (v->size < v->capacity/2) {
+        v->capacity /= 2;
+        v->data = realloc(v->data, v->elementSize * v->capacity);
+    }
+}