Pass a tabsize to ucswdth()

2 files changed, 10 insertions, 6 deletions

diff --git a/include/unicode/string.h b/include/unicode/string.h
index ed082a1..6908fe7 100644
--- a/include/unicode/string.h
+++ b/include/unicode/string.h
@@ -30,7 +30,7 @@ enum normform {
 
 /* clang-format on */
 
-[[nodiscard]] size_t u8wdth(struct u8view);
+[[nodiscard]] size_t u8wdth(struct u8view, int);
 [[nodiscard]] size_t u8gcnt(struct u8view);
 [[nodiscard]] size_t u8wcnt(struct u8view);
 [[nodiscard]] size_t u8wcnt_human(struct u8view);
@@ -49,7 +49,7 @@ size_t u8wnext_human(struct u8view *, struct u8view *);
                               enum normform);
 
 /* Encoding-generic macros */
-#define ucswdth(sv)       _Generic((sv), struct u8view: u8wdth)((sv))
+#define ucswdth(sv, ts)   _Generic((sv), struct u8view: u8wdth)((sv), (ts))
 #define ucsgcnt(sv)       _Generic((sv), struct u8view: u8gcnt)((sv))
 #define ucswcnt(sv)       _Generic((sv), struct u8view: u8wcnt)((sv))
 #define ucswcnt_human(sv) _Generic((sv), struct u8view: u8wcnt_human)((sv))
diff --git a/lib/unicode/string/u8wdth.c b/lib/unicode/string/u8wdth.c
index 503ff7c..7a58069 100644
--- a/lib/unicode/string/u8wdth.c
+++ b/lib/unicode/string/u8wdth.c
@@ -3,15 +3,19 @@
 #include "unicode/string.h"
 
 size_t
-u8wdth(struct u8view sv)
+u8wdth(struct u8view sv, int ts)
 {
 	rune ch;
 	size_t n = 0;
 
 	while (ucsnext(&ch, &sv) != 0) {
-		int w = uprop_get_wdth(ch);
-		if (w > 0)
-			n += w;
+		if (ch == '\t')
+			n += ts - n % ts;
+		else {
+			int w = uprop_get_wdth(ch);
+			if (w > 0)
+				n += w;
+		}
 	}
 
 	return n;