Add cancellation to iterators over avltree(n) and genset(dyn)

1 files changed, 13 insertions, 9 deletions

diff --git a/src/libdatastruct/avlnode_iter.c b/src/libdatastruct/avlnode_iter.c
index c6064f3..e1b17de 100644
--- a/src/libdatastruct/avlnode_iter.c
+++ b/src/libdatastruct/avlnode_iter.c
@@ -4,23 +4,27 @@
 
 struct avlnode_iter_s
 {
-  avlnode *s ;
+  avlnode const *s ;
   unsigned int max ;
+  unsigned int cut ;
   avliterfunc_t_ref f ;
   void *p ;
 } ;
 
-static int avlnode_iter_rec (struct avlnode_iter_s const *blah, unsigned int r, unsigned int h)
+static unsigned int avlnode_iter_rec (struct avlnode_iter_s const *blah, unsigned int r, unsigned int h)
 {
-  return (r < blah->max) ?
-    avlnode_iter_rec(blah, blah->s[r].child[0], h+1)
-    && (*blah->f)(blah->s[r].data, h, blah->p)
-    && avlnode_iter_rec(blah, blah->s[r].child[1], h+1)
-   : 1 ;
+  if (r >= blah->max) return blah->max ;
+  {
+    unsigned int res = avlnode_iter_rec(blah, blah->s[r].child[0], h+1) ;
+    if (res != blah->max) return res ;
+  }
+  if (r == blah->cut) return blah->max ;
+  if (!(*blah->f)(blah->s[r].data, h, blah->p)) return r ;
+  return avlnode_iter_rec(blah, blah->s[r].child[1], h+1) ;
 }
 
-int avlnode_iter (avlnode *s, unsigned int max, unsigned int r, avliterfunc_t_ref f, void *p)
+unsigned int avlnode_iter_nocancel (avlnode *s, unsigned int max, unsigned int cut, unsigned int r, avliterfunc_t_ref f, void *p)
 {
-  struct avlnode_iter_s blah = { s, max, f, p } ;
+  struct avlnode_iter_s blah = { .s = s, .max = max, .cut = cut, .f = f, .p = p } ;
   return avlnode_iter_rec(&blah, r, 0) ;
 }