From 501cac0fef258b6038ff5f65fc9b74a965a6e1f0 Mon Sep 17 00:00:00 2001
From: Mathieu Maret <mathieu.maret@gmail.com>
Date: Sun, 21 Apr 2019 21:57:01 +0200
Subject: [PATCH] Implement simple linked list in macro

---
 core/list.h | 92 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 92 insertions(+)

diff --git a/core/list.h b/core/list.h
index 1f4b4d1..aadfdb4 100644
--- a/core/list.h
+++ b/core/list.h
@@ -191,4 +191,96 @@
 #define list_collapse(list,iterator) \
   list_collapse_named(list,iterator,prev,next)
 
+/*
+ */
+#define slist_init_named(list,next) \
+  ((list) = NULL)
+
+#define slist_singleton_named(list,item,next) ({ \
+  (item)->next = (item); \
+  (list) = (item); \
+})
+
+#define slist_is_empty_named(list,next) \
+  ((list) == NULL)
+
+#define slist_is_singleton_named(list,next) \
+  ( ((list) != NULL) && ((list) == (list)->next) )
+
+#define slist_get_head_named(list,next) \
+  (list)
+
+/** @note After_this and item are expected to be valid ! */
+#define slist_insert_after_named(list,after_this,item,next) ({ \
+   (item)->next = (after_this)->next; \
+   (after_this)->next = (item); \
+})
+
+/** @note NO check whether item really is in list ! */
+#define slist_delete_named(list,item,before_item, next) ({ \
+  if ( ((item)->next == (item)) ) \
+    (item)->next = (list) = NULL; \
+  else { \
+    if ((before_item)) (before_item)->next = (item)->next; \
+    if ((item) == (list)) (list) = (item)->next; \
+  } \
+})
+
+#define slist_pop_head_named(list,next) ({ \
+  typeof(list) __ret_elt = (list); \
+  slist_delete_named(list,__ret_elt,NULL, next); \
+  __ret_elt; })
+
+/** Loop statement that iterates through all of its elements, from
+    head to tail */
+#define slist_foreach_named(list,iterator,nb_elements,next) \
+        for (nb_elements=0, (iterator) = (list) ; \
+             (iterator) && (!nb_elements || ((iterator) != (list))) ; \
+             nb_elements++, (iterator) = (iterator)->next )
+
+/** True when we exitted early from the foreach loop (ie break) */
+#define slist_foreach_early_break(list,iterator,nb_elements) \
+  ((list) && ( \
+    ((list) != (iterator)) || \
+    ( ((list) == (iterator)) && (nb_elements == 0)) ))
+
+/*
+ * the same macros : assume that next field is really
+ * named "next"
+ */
+
+#define slist_init(list) \
+  slist_init_named(list,prev,next)
+
+#define slist_singleton(list,item) \
+  slist_singleton_named(list,item,prev,next)
+
+#define slist_is_empty(list) \
+  slist_is_empty_named(list,prev,next)
+
+#define slist_is_singleton(list) \
+  slist_is_singleton_named(list,prev,next)
+
+#define slist_get_head(list) \
+  slist_get_head_named(list,prev,next) \
+
+#define slist_get_tail(list) \
+  slist_get_tail_named(list,prev,next) \
+
+/* @note Before_this and item are expected to be valid ! */
+#define slist_insert_after(list,after_this,item) \
+  slist_insert_after_named(list,after_this,item,prev,next)
+
+/* @note NO check whether item really is in list ! */
+#define slist_delete(list,item,before_item) \
+  slist_delete_named(list,item,before_item,next)
+
+#define slist_pop_head(list) \
+  slist_pop_head_named(list,next)
+
+#define slist_foreach_forward(list,iterator,nb_elements) \
+  slist_foreach_named(list,iterator,nb_elements,prev,next)
+
+#define slist_foreach slist_foreach_forward
+
 #endif /* _SOS_LIST_H_ */