Add a search_atleast operation.

[gnulib.git] / lib / gl_oset.h

diff --git a/lib/gl_oset.h b/lib/gl_oset.h
index 6c5d5eb..2a67994 100644 (file)
--- a/lib/gl_oset.h
+++ b/lib/gl_oset.h
@@ -59,6 +59,7 @@ extern "C" {
    gl_oset_add                 O(n)   O(log n)
    gl_oset_remove              O(n)   O(log n)
    gl_oset_search            O(log n) O(log n)
+   gl_oset_search_atleast    O(log n) O(log n)
    gl_oset_iterator            O(1)   O(log n)
    gl_oset_iterator_next       O(1)   O(log n)
  */
@@ -69,6 +70,10 @@ extern "C" {
    NULL denotes pointer comparison.  */
 typedef int (*gl_setelement_compar_fn) (const void *elt1, const void *elt2);
 
+/* Type of function used to compare an element with a threshold.
+   Return true if the element is greater or equal than the threshold.  */
+typedef bool (*gl_setelement_threshold_fn) (const void *elt, const void *threshold);
+
 struct gl_oset_impl;
 /* Type representing an entire ordered set.  */
 typedef struct gl_oset_impl * gl_oset_t;
@@ -90,6 +95,16 @@ extern size_t gl_oset_size (gl_oset_t set);
    Return true if found, or false if not present in the set.  */
 extern bool gl_oset_search (gl_oset_t set, const void *elt);
 
+/* Search the least element in the ordered set that compares greater or equal
+   to the given THRESHOLD.  The representation of the THRESHOLD is defined
+   by the THRESHOLD_FN.
+   Return true and store the found element in *ELTP if found, otherwise return
+   false.  */
+extern bool gl_oset_search_atleast (gl_oset_t set,
+                                   gl_setelement_threshold_fn threshold_fn,
+                                   const void *threshold,
+                                   const void **eltp);
+
 /* Add an element to an ordered set.
    Return true if it was not already in the set and added.  */
 extern bool gl_oset_add (gl_oset_t set, const void *elt);
@@ -143,6 +158,9 @@ struct gl_oset_implementation
                             gl_setelement_compar_fn compar_fn);
   size_t (*size) (gl_oset_t set);
   bool (*search) (gl_oset_t set, const void *elt);
+  bool (*search_atleast) (gl_oset_t set,
+                         gl_setelement_threshold_fn threshold_fn,
+                         const void *threshold, const void **eltp);
   bool (*add) (gl_oset_t set, const void *elt);
   bool (*remove) (gl_oset_t set, const void *elt);
   void (*oset_free) (gl_oset_t set);
@@ -186,6 +204,16 @@ gl_oset_search (gl_oset_t set, const void *elt)
   return ((const struct gl_oset_impl_base *) set)->vtable->search (set, elt);
 }
 
+# define gl_oset_search_atleast gl_oset_search_atleast_inline
+static inline bool
+gl_oset_search_atleast (gl_oset_t set,
+                       gl_setelement_threshold_fn threshold_fn,
+                       const void *threshold, const void **eltp)
+{
+  return ((const struct gl_oset_impl_base *) set)->vtable
+        ->search_atleast (set, threshold_fn, threshold, eltp);
+}
+
 # define gl_oset_add gl_oset_add_inline
 static inline bool
 gl_oset_add (gl_oset_t set, const void *elt)