From 1fa9564916ea9cd92622b5a549693d23fbf35bcb Mon Sep 17 00:00:00 2001
From: Lukas Fleischer <calcurse@cryptocrack.de>
Date: Tue, 4 Oct 2011 09:34:06 +0200
Subject: src/llist.c: Add llist_next_filter()

This convenience function can be used to return the successor of a list
item if it is matched by a filter callback and return NULL otherwise.

We will use this for an improved version of the LLIST_FIND_FOREACH macro
that can be used whenever results are known to be continuous.

Signed-off-by: Lukas Fleischer <calcurse@cryptocrack.de>
---
 src/llist.c    | 13 +++++++++++++
 src/llist.h    |  3 +++
 src/llist_ts.h |  2 ++
 3 files changed, 18 insertions(+)

(limited to 'src')

diff --git a/src/llist.c b/src/llist.c
index 7611595..a85cfa9 100644
--- a/src/llist.c
+++ b/src/llist.c
@@ -114,6 +114,19 @@ llist_next (llist_item_t *i)
   return i ? i->next : NULL;
 }
 
+/*
+ * Return the successor of a list item if it is matched by some filter
+ * callback. Return NULL otherwise.
+ */
+llist_item_t *
+llist_next_filter (llist_item_t *i, long data, llist_fn_match_t fn_match)
+{
+  if (i && i->next && fn_match (i->next->data, data))
+    return i->next;
+  else
+    return NULL;
+}
+
 /*
  * Get the actual data of an item.
  */
diff --git a/src/llist.h b/src/llist.h
index cdab18d..91a8632 100644
--- a/src/llist.h
+++ b/src/llist.h
@@ -65,6 +65,7 @@ void          llist_free_inner (llist_t *, llist_fn_free_t);
 llist_item_t *llist_first (llist_t *);
 llist_item_t *llist_nth (llist_t *, int);
 llist_item_t *llist_next (llist_item_t *);
+llist_item_t *llist_next_filter (llist_item_t *, long, llist_fn_match_t);
 llist_item_t *llist_find_first (llist_t *, long, llist_fn_match_t);
 llist_item_t *llist_find_next (llist_item_t *, long, llist_fn_match_t);
 llist_item_t *llist_find_nth (llist_t *, int, long, llist_fn_match_t);
@@ -72,6 +73,8 @@ llist_item_t *llist_find_nth (llist_t *, int, long, llist_fn_match_t);
 #define LLIST_FIRST(l) llist_first(l)
 #define LLIST_NTH(l, n) llist_nth(l, n)
 #define LLIST_NEXT(i) llist_next(i)
+#define LLIST_NEXT_FILTER(i, data, fn_match)                                  \
+  llist_next_filter(i, data, (llist_fn_match_t)fn_match)
 #define LLIST_FIND_FIRST(l, data, fn_match)                                   \
   llist_find_first(l, data, (llist_fn_match_t)fn_match)
 #define LLIST_FIND_NEXT(i, data, fn_match)                                    \
diff --git a/src/llist_ts.h b/src/llist_ts.h
index e7a6b3c..e152f5d 100644
--- a/src/llist_ts.h
+++ b/src/llist_ts.h
@@ -64,6 +64,8 @@ struct llist_ts {
 #define LLIST_TS_FIRST(l_ts) llist_first ((llist_t *)l_ts)
 #define LLIST_TS_NTH(l_ts, n) llist_nth ((llist_t *)l_ts, n)
 #define LLIST_TS_NEXT(i) llist_next (i)
+#define LLIST_TS_NEXT_FILTER(i, data, fn_match)                               \
+  llist_next_filter (i, data, (llist_fn_match_t)fn_match)
 #define LLIST_TS_FIND_FIRST(l_ts, data, fn_match)                             \
   llist_find_first ((llist_t *)l_ts, data, (llist_fn_match_t)fn_match)
 #define LLIST_TS_FIND_NEXT(i, data, fn_match)                                 \
-- 
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