made popping with lists work. yay! (also new demo to show the thing)

src/list.c

@@ -106,3 +106,15 @@ listCleanup(list_t* l) {
     vectorCleanup((vector_t *)l->data);
     free(l);
 }
+
+void*
+listPop(list_t* l) {
+    vector_t *first_ptr = (vector_t *)vectorPop((vector_t *)l->data);
+    void *ptr = vectorPop(first_ptr);
+    l->size -= 1;
+
+    if (l->size <= l->capacity / 2) l->capacity /= 2;
+    if (l->capacity == 0) l->capacity = 1;
+
+    return ptr;
+}

src/vector.c

@@ -216,30 +216,27 @@ vectorPop(vector_t* v) {
             int *iretval = (int *)(v->data) + v->size-1;
             v->size -= 1;
             if (v->size <= v->capacity / 2) v->capacity /= 2;
-            v->data = realloc(v->data, v->elementSize * v->capacity);
-        if (v->capacity == 0) v->capacity = 1;
-        return iretval;
+            if (v->capacity == 0) v->capacity = 1;
+            return iretval;
         case FLOAT:
             float *fretval = (float *)(v->data) + v->size-1;
             v->size -= 1;
             if (v->size <= v->capacity / 2) v->capacity /= 2;
             if (v->capacity == 0) v->capacity = 1;
-            v->data = realloc(v->data, v->elementSize * v->capacity);
-        return fretval;
+            return fretval;
         case CHAR:
             char *cretval = (char *)(v->data) + v->size-1;
             v->size -= 1;
             if (v->size <= v->capacity / 2) v->capacity /= 2;
             if (v->capacity == 0) v->capacity = 1;
-            v->data = realloc(v->data, v->elementSize * v->capacity);
-        return cretval;
+            return cretval;
         case VECTOR:
             vector_t *vretval = (vector_t *)(v->data) + v->size-1;
             v->size -= 1;
             if (v->size <= v->capacity / 2) v->capacity /= 2;
             if (v->capacity == 0) v->capacity = 1;
-            v->data = realloc(v->data, v->elementSize * v->capacity);
-        return vretval;
+
+            return vretval;
         default:
             perror("specify a valid vector type\n");
             exit(EXIT_FAILURE);