--- /dev/null
+#include "unicode-util.h"
+
+/* Based on Xapian::Unicode::is_wordchar, to avoid forcing clients to
+ link directly to libxapian.
+*/
+
+static bool
+unicode_is_wordchar (notmuch_unichar ch)
+{
+ switch (g_unichar_type (ch)) {
+ case G_UNICODE_UPPERCASE_LETTER:
+ case G_UNICODE_LOWERCASE_LETTER:
+ case G_UNICODE_TITLECASE_LETTER:
+ case G_UNICODE_MODIFIER_LETTER:
+ case G_UNICODE_OTHER_LETTER:
+ case G_UNICODE_NON_SPACING_MARK:
+ case G_UNICODE_ENCLOSING_MARK:
+ case G_UNICODE_SPACING_MARK:
+ case G_UNICODE_DECIMAL_NUMBER:
+ case G_UNICODE_LETTER_NUMBER:
+ case G_UNICODE_OTHER_NUMBER:
+ case G_UNICODE_CONNECT_PUNCTUATION:
+ return true;
+ default:
+ return false;
+ }
+}
+
+bool
+unicode_word_utf8 (const char *utf8_str)
+{
+ gunichar *decoded = g_utf8_to_ucs4_fast (utf8_str, -1, NULL);
+ const gunichar *p = decoded;
+ bool ret;
+
+ while (*p && unicode_is_wordchar (*p))
+ p++;
+
+ ret = (*p == '\0');
+
+ g_free (decoded);
+ return ret;
+}