idna_convert::_utf8_to_ucs4

This converts an UTF-8 encoded string to its UCS-4 representation By talking about UCS-4 "strings" we mean arrays of 32bit integers representing each of the "chars". This is due to PHP not being able to handle strings with bit depth different from 8. This apllies to the reverse method _ucs4_to_utf8(), too.

The following UTF-8 encodings are supported: bytes bits representation 1 7 0xxxxxxx 2 11 110xxxxx 10xxxxxx 3 16 1110xxxx 10xxxxxx 10xxxxxx 4 21 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx 5 26 111110xx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 6 31 1111110x 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx 10xxxxxx Each x represents a bit that can be used to store character data. The five and six byte sequences are part of Annex D of ISO/IEC 10646-1:2000