[MOD/FIX] Licensewerk, start counting by codepoint

XEP-0426 came out of the blue, and it *hit* me!

src/Unistr.c

@@ -3,8 +3,10 @@
 #include <Cytoplasm/Memory.h>
 #include <Cytoplasm/Str.h>
 #include <Cytoplasm/Log.h>
+#include <Cytoplasm/Log.h>
 
 #include <string.h>
+#include <stdarg.h>
 
 struct Unistr {
     size_t length;
@@ -222,3 +224,46 @@ UnistrFilter(Unistr *str, UnistrFilterFunc filter)
 
     return unistr;
 }
+
+Unistr *
+UnistrConcat(size_t n, ...)
+{
+    va_list list;
+    size_t i;
+    Unistr *ret = UnistrCreate("");
+
+    va_start(list, n);
+    for (i = 0; i < n; i++)
+    {
+        Unistr *to_concat = va_arg(list, Unistr *);
+        size_t j;
+        for (j = 0; j < UnistrSize(to_concat); j++)
+        {
+            UnistrAddch(ret, UnistrGetch(to_concat, j));
+        }
+    }
+
+    va_end(list);
+    return ret;
+}
+size_t 
+UnistrGetOffset(Unistr *str, uint32_t sep)
+{
+    size_t i;
+    uint32_t prev = 0x0A;
+    if (!str || !sep)
+    {
+        return 0;
+    }
+
+    for (i = 0; i < str->length; i++)
+    {
+        uint32_t curr = str->codepoints[i];
+        if (prev == 0x0A && curr != sep)
+        {
+            return i;
+        }
+        prev = curr;
+    }
+    return 0;
+}