fix the handling of 'pre' in the C runtime

2 files changed, 40 insertions, 7 deletions

diff --git a/src/runtime/c/gu/seq.c b/src/runtime/c/gu/seq.c
index b798d2923..8ec6480cc 100644
--- a/src/runtime/c/gu/seq.c
+++ b/src/runtime/c/gu/seq.c
@@ -255,7 +255,7 @@ gu_buf_sort(GuBuf *buf, GuOrder *order)
 }
 
 void*
-gu_seq_binsearch_(GuSeq *seq, GuOrder *order, size_t elem_size, size_t field_offset, void *key)
+gu_seq_binsearch_(GuSeq *seq, GuOrder *order, size_t elem_size, void *key)
 {
 	size_t i = 0;
 	size_t j = seq->len-1;
@@ -263,8 +263,8 @@ gu_seq_binsearch_(GuSeq *seq, GuOrder *order, size_t elem_size, size_t field_off
 	while (i <= j) {
 		size_t k = (i+j) / 2;
 		uint8_t* elem_p = &seq->data[elem_size * k];
-		int cmp = order->compare(order, key, elem_p + field_offset);
-	
+		int cmp = order->compare(order, key, elem_p);
+
 		if (cmp < 0) {
 			j = k-1;
 		} else if (cmp > 0) {
@@ -273,10 +273,36 @@ gu_seq_binsearch_(GuSeq *seq, GuOrder *order, size_t elem_size, size_t field_off
 			return elem_p;
 		}
 	}
-	
+
 	return NULL;
 }
 
+bool
+gu_seq_binsearch_index_(GuSeq *seq, GuOrder *order, size_t elem_size,
+                        void *key, size_t *pindex)
+{
+	size_t i = 0;
+	size_t j = seq->len-1;
+	
+	while (i <= j) {
+		size_t k = (i+j) / 2;
+		uint8_t* elem_p = &seq->data[elem_size * k];
+		int cmp = order->compare(order, key, elem_p);
+	
+		if (cmp < 0) {
+			j = k-1;
+		} else if (cmp > 0) {
+			i = k+1;
+		} else {
+			*pindex = k;
+			return true;
+		}
+	}
+
+	*pindex = j;
+	return false;
+}
+
 static void
 gu_heap_siftdown(GuBuf *buf, GuOrder *order, 
                  const void *value, int startpos, int pos)
diff --git a/src/runtime/c/gu/seq.h b/src/runtime/c/gu/seq.h
index cb18a90b5..2b0020bab 100644
--- a/src/runtime/c/gu/seq.h
+++ b/src/runtime/c/gu/seq.h
@@ -114,11 +114,18 @@ gu_seq_resize_tail(GuSeq seq, ptrdiff_t change);
 void
 gu_buf_sort(GuBuf *buf, GuOrder *order);
 
-#define gu_seq_binsearch(S, O, T, N, V) \
-	((T*) gu_seq_binsearch_(S, O, sizeof(T), offsetof(T,N), V))
+#define gu_seq_binsearch(S, O, T, V) \
+	((T*) gu_seq_binsearch_(S, O, sizeof(T), V))
 
 void*
-gu_seq_binsearch_(GuSeq *seq, GuOrder *order, size_t elem_size, size_t field_offset, void *key);
+gu_seq_binsearch_(GuSeq *seq, GuOrder *order, size_t elem_size, void *key);
+
+#define gu_seq_binsearch_index(S, O, T, V, PI) \
+	gu_seq_binsearch_index_(S, O, sizeof(T), V, PI)
+
+bool
+gu_seq_binsearch_index_(GuSeq *seq, GuOrder *order, size_t elem_size, 
+                        void *key, size_t *pindex);
 
 // Using a buffer as a heap
 void