refresh

du6/list_ops.c

@@ -74,4 +74,64 @@ list_t *filter_list(list_t *list, bool (*filter)(list_element_t)) {
     return new;
 }
 
+list_t *map_list(list_t *lst, list_element_t (*func)(list_element_t)) {
+    if (lst == NULL || func == NULL) return NULL;
+
+    size_t n = lst->length;
+    list_t *mapped = malloc(sizeof(list_t) + n * sizeof(list_element_t));
+    if (mapped == NULL) return NULL;
+
+    mapped->length = n;
+
+    for (size_t i = 0; i < n; ++i) {
+        list_element_t val = lst->elements[i];
+        mapped->elements[i] = func(val);
+    }
+
+    return mapped;
+}
+
+list_element_t foldl_list(list_t *lst, list_element_t init,
+    list_element_t (*folder)(list_element_t, list_element_t)) {
+list_element_t acc = init;
+
+if (lst && folder) {
+for (size_t i = 0; i < lst->length; ++i) {
+acc = folder(acc, lst->elements[i]);
+}
+}
+
+return acc;
+}
+
+list_element_t foldr_list(list_t *lst, list_element_t init,
+    list_element_t (*folder)(list_element_t, list_element_t)) {
+list_element_t acc = init;
+
+if (lst && folder) {
+for (size_t i = lst->length; i > 0; --i) {
+acc = folder(lst->elements[i - 1], acc);
+}
+}
+
+return acc;
+}
+
+list_t *reverse_list(list_t *lst) {
+    if (!lst) return NULL;
+
+    size_t n = lst->length;
+    list_t *reversed = malloc(sizeof(list_t) + n * sizeof(list_element_t));
+    if (!reversed) return NULL;
+
+    
+
+    for (size_t i = 0; i < n; ++i) {
+        reversed->elements[i] = lst->elements[n - i - 1];
+    }
+
+    return reversed;
+}
+
+