text-util: constify text_range_* functions

text-util.c

@@ -3,19 +3,19 @@
 #include <wchar.h>
 #include <errno.h>
 
-bool text_range_valid(Filerange *r) {
+bool text_range_valid(const Filerange *r) {
 	return r->start != EPOS && r->end != EPOS && r->start <= r->end;
 }
 
-size_t text_range_size(Filerange *r) {
+size_t text_range_size(const 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) {
+Filerange text_range_union(const Filerange *r1, const Filerange *r2) {
 	if (!text_range_valid(r1))
 		return *r2;
 	if (!text_range_valid(r2))
@@ -33,19 +33,19 @@ Filerange text_range_new(size_t a, size_t b) {
 	};
 }
 
-bool text_range_equal(Filerange *r1, Filerange *r2) {
+bool text_range_equal(const Filerange *r1, const Filerange *r2) {
 	if (!text_range_valid(r1) && !text_range_valid(r2))
 		return true;
 	return r1->start == r2->start && r1->end == r2->end;
 }
 
-bool text_range_overlap(Filerange *r1, Filerange *r2) {
+bool text_range_overlap(const Filerange *r1, const Filerange *r2) {
 	if (!text_range_valid(r1) || !text_range_valid(r2))
 		return false;
 	return r1->start <= r2->end && r2->start <= r1->end;
 }
 
-bool text_range_contains(Filerange *r, size_t pos) {
+bool text_range_contains(const Filerange *r, size_t pos) {
 	return text_range_valid(r) && r->start <= pos && pos <= r->end;
 }
 

text-util.h

@@ -6,21 +6,21 @@
 #include "text.h"
 
 /* test whether the given range is valid (start <= end) */
-bool text_range_valid(Filerange*);
+bool text_range_valid(const Filerange*);
 /* get the size of the range (end-start) or zero if invalid */
-size_t text_range_size(Filerange*);
+size_t text_range_size(const Filerange*);
 /* create an empty / invalid range of size zero */
 Filerange text_range_empty(void);
 /* merge two ranges into a new one which contains both of them */
-Filerange text_range_union(Filerange*, Filerange*);
+Filerange text_range_union(const Filerange*, const Filerange*);
 /* create new range [min(a,b), max(a,b)] */
 Filerange text_range_new(size_t a, size_t b);
 /* test whether two ranges are equal */
-bool text_range_equal(Filerange*, Filerange*);
+bool text_range_equal(const Filerange*, const Filerange*);
 /* test whether two ranges overlap */
-bool text_range_overlap(Filerange*, Filerange*);
+bool text_range_overlap(const Filerange*, const Filerange*);
 /* test whether a given position is within a certain range */
-bool text_range_contains(Filerange*, size_t pos);
+bool text_range_contains(const Filerange*, size_t pos);
 /* count the number of graphemes in data */
 int text_char_count(const char *data, size_t len);