Add u8split()

2 files changed, 18 insertions, 0 deletions

diff --git a/include/mbstring.h b/include/mbstring.h
index 06e32ae..d908284 100644
--- a/include/mbstring.h
+++ b/include/mbstring.h
@@ -52,6 +52,8 @@ int u8prev(rune *, const char8_t **, const char8_t *);
 
 [[nodiscard]] size_t u8len(const char8_t *, size_t);
 
+struct u8view u8split(const char8_t **, size_t *, rune);
+
 #define u8chk(s, n)      _MLIB_Q_PTR(char8_t, u8chk, (s), (s), (n))
 #define u8chr(s, n, ch)  _MLIB_Q_PTR(char8_t, u8chr, (s), (s), (n), (ch))
 #define u8rchr(s, n, ch) _MLIB_Q_PTR(char8_t, u8rchr, (s), (s), (n), (ch))
diff --git a/lib/mbstring/u8split.c b/lib/mbstring/u8split.c
new file mode 100644
index 0000000..5ee3bc0
--- /dev/null
+++ b/lib/mbstring/u8split.c
@@ -0,0 +1,16 @@
+#include "mbstring.h"
+
+struct u8view
+u8split(const char8_t **p, size_t *n, rune ch)
+{
+	struct u8view lhs = {.p = *p};
+	if ((*p = u8chr(*p, *n, ch)) == nullptr) {
+		lhs.len = *n;
+		*n = 0;
+	} else {
+		lhs.len = *p - lhs.p;
+		*n -= lhs.len;
+		u8next(nullptr, p, n);
+	}
+	return lhs;
+}