GLib.utf8_strdown

function utf8_strdown(str: String, len: Number(gssize)): String {
    // Gjs wrapper for g_utf8_strdown()
}

Converts all Unicode characters in the string that have a case to lowercase. The exact manner that this is done depends on the current locale, and may result in the number of characters in the string changing.

str: a UTF-8 encoded string
len: length of str, in bytes, or -1 if str is nul-terminated.
Returns: a newly allocated string, with all characters converted to lowercase.