1 files changed, 14 insertions, 6 deletions

diff --git a/dlist.c b/dlist.c
index 5a11c5b..a2a5cfd 100644
--- a/dlist.c
+++ b/dlist.c
@@ -28,6 +28,12 @@ dlist_init(struct dlist *dlist)
         dlist->tail = NULL;
 }
 
+bool
+dlist_empty(struct dlist *dlist)
+{
+        return dlist->head == NULL;
+}
+
 static struct dlist_element *
 create_element(T data)
 {
@@ -50,11 +56,11 @@ dlist_push_front(struct dlist *dlist, T data)
         if ( element != NULL ) {
                 element->prev = NULL; /* Vorgänger ist in jedem Fall NULL */
 
-                if ( dlist->head == NULL ) { /* empty list */
+                if ( dlist_empty(dlist) ) {
                         element->next = NULL;
                         dlist->tail   = element;
                 }
-                else { /* non empty list */
+                else {
                         element->next       = dlist->head;
                         element->next->prev = element;
                 }
@@ -76,11 +82,11 @@ dlist_push_back(struct dlist *dlist, T data)
         if ( element != NULL ) {
                 element->next = NULL; /* Nachfolger ist in jedem Fall NULL */
 
-                if ( dlist->head == NULL ) { /* empty list */
+                if ( dlist_empty(dlist) ) {
                         element->prev = NULL;
                         dlist->head   = element;
                 }
-                else { /* non empty list */
+                else {
                         element->prev       = dlist->tail;
                         element->prev->next = element;
                 }
@@ -238,8 +244,9 @@ dlist_free(struct dlist *dlist)
 void
 dlist_apply_rev(struct dlist *dlist, void (*visit)(T data, void *cl), void *cl)
 {
-        for ( struct dlist_element *elem = dlist->tail; elem; elem = elem->prev )
+        for ( struct dlist_element *elem = dlist->tail; elem; elem = elem->prev ) {
                 visit(elem->data, cl);
+        }
 }
 
 void
@@ -272,8 +279,9 @@ remove_if(struct dlist *list)
         for ( elem = list->head; elem; elem = next ) {
                 next = elem->next;
 
-                if ( (elem->data & 1) == 1 )
+                if ( (elem->data & 1) == 1 ) {
                         dlist_remove(list, elem);
+                }
         }
 }