Aktualizovat du6/list_ops.c

du6/list_ops.c

@@ -1,10 +1,15 @@
 #include "list_ops.h"
 #include <string.h>
 
-list_t *new_list(size_t length, list_element_t elements[]) {
+static list_t *allocate_list(size_t length) {
     list_t *list = malloc(sizeof(list_t) + sizeof(list_element_t) * length);
+    if (list) list->length = length;
+    return list;
+}
+
+list_t *new_list(size_t length, list_element_t elements[]) {
+    list_t *list = allocate_list(length);
     if (!list) return NULL;
-    list->length = length;
     if (length && elements)
         memcpy(list->elements, elements, sizeof(list_element_t) * length);
     return list;
@@ -15,42 +20,28 @@ void delete_list(list_t *list) {
 }
 
 list_t *append_list(list_t *list1, list_t *list2) {
-    size_t new_length = list1->length + list2->length;
+    list_t *result = allocate_list(list1->length + list2->length);
-    list_t *new_list_ptr = malloc(sizeof(list_t) + sizeof(list_element_t) * new_length);
+    if (!result) return NULL;
-    if (!new_list_ptr) return NULL;
 
-    new_list_ptr->length = new_length;
+    memcpy(result->elements, list1->elements, sizeof(list_element_t) * list1->length);
+    memcpy(result->elements + list1->length, list2->elements, sizeof(list_element_t) * list2->length);
 
-    for (size_t i = 0; i < list1->length; i++) {
+    return result;
-        new_list_ptr->elements[i] = list1->elements[i];
-    }
-    for (size_t i = 0; i < list2->length; i++) {
-        new_list_ptr->elements[list1->length + i] = list2->elements[i];
-    }
-
-    return new_list_ptr;
 }
 
 list_t *filter_list(list_t *list, bool (*filter)(list_element_t)) {
     size_t count = 0;
-
+    for (size_t i = 0; i < list->length; i++)
-    for (size_t i = 0; i < list->length; i++) {
         if (filter(list->elements[i])) count++;
-    }
 
-    list_t *new_list_ptr = malloc(sizeof(list_t) + sizeof(list_element_t) * count);
+    list_t *result = allocate_list(count);
-    if (!new_list_ptr) return NULL;
+    if (!result) return NULL;
 
-    new_list_ptr->length = count;
+    for (size_t i = 0, j = 0; i < list->length; i++)
+        if (filter(list->elements[i]))
+            result->elements[j++] = list->elements[i];
 
-    size_t index = 0;
+    return result;
-    for (size_t i = 0; i < list->length; i++) {
-        if (filter(list->elements[i])) {
-            new_list_ptr->elements[index++] = list->elements[i];
-        }
-    }
-
-    return new_list_ptr;
 }
 
 size_t length_list(list_t *list) {
@@ -58,45 +49,35 @@ size_t length_list(list_t *list) {
 }
 
 list_t *map_list(list_t *list, list_element_t (*map)(list_element_t)) {
-    list_t *new_list_ptr = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
+    list_t *result = allocate_list(list->length);
-    if (!new_list_ptr) return NULL;
+    if (!result) return NULL;
 
-    new_list_ptr->length = list->length;
+    for (size_t i = 0; i < list->length; i++)
+        result->elements[i] = map(list->elements[i]);
 
-    for (size_t i = 0; i < list->length; i++) {
+    return result;
-        new_list_ptr->elements[i] = map(list->elements[i]);
-    }
-
-    return new_list_ptr;
 }
 
 list_element_t foldl_list(list_t *list, list_element_t initial,
                           list_element_t (*foldl)(list_element_t, list_element_t)) {
-    list_element_t result = initial;
+    for (size_t i = 0; i < list->length; i++)
-    for (size_t i = 0; i < list->length; i++) {
+        initial = foldl(initial, list->elements[i]);
-        result = foldl(result, list->elements[i]);
+    return initial;
-    }
-    return result;
 }
 
 list_element_t foldr_list(list_t *list, list_element_t initial,
                           list_element_t (*foldr)(list_element_t, list_element_t)) {
-    list_element_t result = initial;
+    for (size_t i = list->length; i-- > 0;)
-    for (int i = (int)list->length - 1; i >= 0; i--) {
+        initial = foldr(list->elements[i], initial);
-        result = foldr(list->elements[i], result);
+    return initial;
-    }
-    return result;
 }
 
 list_t *reverse_list(list_t *list) {
-    list_t *new_list_ptr = malloc(sizeof(list_t) + sizeof(list_element_t) * list->length);
+    list_t *result = allocate_list(list->length);
-    if (!new_list_ptr) return NULL;
+    if (!result) return NULL;
 
-    new_list_ptr->length = list->length;
+    for (size_t i = 0; i < list->length; i++)
+        result->elements[i] = list->elements[list->length - 1 - i];
 
-    for (size_t i = 0; i < list->length; i++) {
+    return result;
-        new_list_ptr->elements[i] = list->elements[list->length - i - 1];
-    }
-
-    return new_list_ptr;
 }