Add vect_each, VECT_EACH for iteration over vectors

3 files changed, 48 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index c08f83d..93f613f 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,10 @@
 2012-09-25  Petr Machata  <pmachata@redhat.com>
 
+	* vect.h, vect.c (vect_each): New function.
+	* vect.h (VECT_EACH): New wrapper macro.
+
+2012-09-25  Petr Machata  <pmachata@redhat.com>
+
 	* callback.h: New file.
 	* proc.h (enum callback_status): Move to callback.h.
 
diff --git a/vect.c b/vect.c
index f2e58b2..7dae847 100644
--- a/vect.c
+++ b/vect.c
@@ -134,3 +134,25 @@ vect_destroy(struct vect *vec, void (*dtor)(void *emt, void *data), void *data)
 	}
 	free(vec->data);
 }
+
+void *
+vect_each(struct vect *vec, void *start_after,
+	  enum callback_status (*cb)(void *, void *), void *data)
+{
+	size_t i = start_after == NULL ? 0
+		: ((start_after - vec->data) / vec->elt_size) + 1;
+
+	for (; i < vec->size; ++i) {
+		void *slt = slot(vec, i);
+		switch ((*cb)(slt, data)) {
+		case CBS_FAIL:
+			/* XXX handle me */
+		case CBS_STOP:
+			return slt;
+		case CBS_CONT:
+			break;
+		}
+	}
+
+	return NULL;
+}
diff --git a/vect.h b/vect.h
index 50401bb..c07235f 100644
--- a/vect.h
+++ b/vect.h
@@ -22,6 +22,9 @@
 #define VECT_H
 
 #include <stddef.h>
+#include <assert.h>
+
+#include "callback.h"
 
 /* Vector is an array that can grow as needed to accommodate the data
  * that it needs to hold.  ELT_SIZE is also used as an elementary
@@ -122,4 +125,22 @@ void vect_destroy(struct vect *vec,
 			     DATA);					\
 	} while (0)
 
+/* Iterate through vector VEC.  See callback.h for notes on iteration
+ * interfaces.  */
+void *vect_each(struct vect *vec, void *start_after,
+		enum callback_status (*cb)(void *, void *), void *data);
+
+#define VECT_EACH(VECP, ELT_TYPE, START_AFTER, CB, DATA)		\
+	/* xxx GCC-ism necessary to get in the safety latches.  */	\
+	({								\
+		assert((VECP)->elt_size == sizeof(ELT_TYPE));		\
+		/* Check that CB is typed properly.  */			\
+		enum callback_status (*_cb)(ELT_TYPE *, void *) = CB;	\
+		ELT_TYPE *start_after = (START_AFTER);			\
+		(ELT_TYPE *)vect_each((VECP), start_after,		\
+				      (enum callback_status		\
+				       (*)(void *, void *))_cb,		\
+				      DATA);				\
+	})
+
 #endif /* VECT_H */