3 files changed, 35 insertions, 0 deletions
diff --git a/src/include/skalibs/bitarray.h b/src/include/skalibs/bitarray.h
index ed44fed..fc9b16d 100644
--- a/src/include/skalibs/bitarray.h
+++ b/src/include/skalibs/bitarray.h
@@ -24,6 +24,11 @@ extern int bitarray_testandpoke (unsigned char *, unsigned int, int) ;
 extern unsigned int bitarray_firstclear (unsigned char const *, unsigned int) gccattr_pure ;
 extern unsigned int bitarray_firstset (unsigned char const *, unsigned int) gccattr_pure ;
 #define bitarray_first(s, n, h) ((h) ? bitarray_firstset(s, n) : bitarray_firstclear(s, n))
+
+extern unsigned int bitarray_firstclear_skip (unsigned char const *, unsigned int, unsigned int) gccattr_pure ;
+extern unsigned int bitarray_firstset_skip (unsigned char const *, unsigned int, unsigned int) gccattr_pure ;
+#define bitarray_first_skip(s, n, k, h) ((h) ? bitarray_firstset_skip(s, n, k) : bitarray_firstclear_skip(s, n, k))
+
 extern unsigned int bitarray_countones (unsigned char const *, unsigned int) gccattr_pure ;
 
 extern void bitarray_not (unsigned char *, unsigned int, unsigned int) ;
diff --git a/src/libstddjb/bitarray_firstclear_skip.c b/src/libstddjb/bitarray_firstclear_skip.c
new file mode 100644
index 0000000..8a32dba
--- /dev/null
+++ b/src/libstddjb/bitarray_firstclear_skip.c
@@ -0,0 +1,15 @@
+/* ISC license. */
+
+#include <skalibs/bitarray.h>
+
+unsigned int bitarray_firstclear_skip (register unsigned char const *s, unsigned int max, unsigned int skip)
+{
+  register unsigned int i = bitarray_div8(skip) ;
+  register unsigned int j = i << 3 > max ? max : i << 3 ;
+  if (i && s[i-1] != 0xffU)
+  {
+    while ((skip < j) && bitarray_peek(s, skip)) skip++ ;
+    if (skip < j) return skip ;
+  }
+  return j + bitarray_firstclear(s + i, max - j) ;
+}
diff --git a/src/libstddjb/bitarray_firstset_skip.c b/src/libstddjb/bitarray_firstset_skip.c
new file mode 100644
index 0000000..2f269cf
--- /dev/null
+++ b/src/libstddjb/bitarray_firstset_skip.c
@@ -0,0 +1,15 @@
+/* ISC license. */
+
+#include <skalibs/bitarray.h>
+
+unsigned int bitarray_firstset_skip (register unsigned char const *s, unsigned int max, unsigned int skip)
+{
+  register unsigned int i = bitarray_div8(skip) ;
+  register unsigned int j = i << 3 > max ? max : i << 3 ;
+  if (i && s[i-1])
+  {
+    while ((skip < j) && !bitarray_peek(s, skip)) skip++ ;
+    if (skip < j) return skip ;
+  }
+  return j + bitarray_firstset(s + i, max - j) ;
+}