text: add text_range_overlap

xoich · Jul 24, 2015 · e57b57e · e57b57e
1 parent 0329e4a
commit e57b57e
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diff --git a/text.c b/text.c
@@ -1496,3 +1496,9 @@ Filerange text_range_new(size_t a, size_t b) {
 		.end = MAX(a, b),
 	};
 }
+
+bool text_range_overlap(Filerange *r1, Filerange *r2) {
+	if (!text_range_valid(r1) || !text_range_valid(r2))
+		return false;
+	return r1->start <= r2->end && r2->start <= r1->end;
+}
diff --git a/text.h b/text.h
@@ -26,6 +26,8 @@ Filerange text_range_empty(void);
 Filerange text_range_union(Filerange*, Filerange*);
 /* create new range [min(a,b), max(a,b)] */
 Filerange text_range_new(size_t a, size_t b);
+/* test whether two ranges overlap */
+bool text_range_overlap(Filerange*, Filerange*);
 
 typedef struct Text Text;
 typedef struct Piece Piece;