text: move utility functions to separate file

1 files changed, 38 insertions, 0 deletions

diff --git a/text-util.c b/text-util.c
new file mode 100644
index 0000000..4139454
--- /dev/null
+++ b/text-util.c
@@ -0,0 +1,38 @@
+#include "text-util.h"
+#include "util.h"
+
+bool text_range_valid(Filerange *r) {
+	return r->start != EPOS && r->end != EPOS && r->start <= r->end;
+}
+
+size_t text_range_size(Filerange *r) {
+	return text_range_valid(r) ? r->end - r->start : 0;
+}
+
+Filerange text_range_empty(void) {
+	return (Filerange){ .start = EPOS, .end = EPOS };
+}
+
+Filerange text_range_union(Filerange *r1, Filerange *r2) {
+	if (!text_range_valid(r1))
+		return *r2;
+	if (!text_range_valid(r2))
+		return *r1;
+	return (Filerange) {
+		.start = MIN(r1->start, r2->start),
+		.end = MAX(r1->end, r2->end),
+	};
+}
+
+Filerange text_range_new(size_t a, size_t b) {
+	return (Filerange) {
+		.start = MIN(a, 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;
+}