1 files changed, 23 insertions, 0 deletions
diff --git a/sys/libutf/canfit.c b/sys/libutf/canfit.c
new file mode 100644
index 0000000..4579ab3
--- /dev/null
+++ b/sys/libutf/canfit.c
@@ -0,0 +1,23 @@
+#include "internal.h"
+
+/* returns 1 if string of length n is long enough to be decoded */
+int
+utf8·canfit(byte* s, int n)
+{
+    int  i;
+    rune c;
+
+    if(n <= 0)
+        return 0;
+
+    c = *(ubyte*)s;
+    if(c < TByte1)
+        return 1;
+
+    if(c < TByte3)
+        return n >= 2;
+    if(c < TByte4)
+        return n >= 3;
+
+    return n >= UTFmax;
+}