Hi there,
In order to become an Irish citizen through naturalization, one of the requirements is a particular length of residence in the country, called 'reckonable residence'. In Ireland, for a non-EU person applying on his/her own (no spouse or kids), it is 5 years. You have to be here legally & properly documented by the immigration authorities in order to have your time counted towards the 5 year time.
One of the rules is that 'in addition, periods of residence in the State will not be reckoned which were covered by a permission to remain if that permission was - for the purposes of study (whether or not that study involved you being in employment during any period of study).'
So, by that, it sounds like the time your friend was here on the student visa will not count towards his reckonable residence.
Check it out on
www.justice.ie. Click on "Site Guide", then on "Immigration, Asylum & Citizenship". Click on "Background Notes", then on "Click here for Citizenship Information Forms". Lastly, click on "Irish Citizenship by Naturalisation". Now, this form was written in 2004 and was supposed to be updated in January 2005 but the changes were mainly due to the issue of Irish-born children. However, contact the Department to be sure.
Regards,
Maria