# Here are some examples with headers: note that you can specify both full
# headers (such as In-Reply-To: <469663CB.6080302@localhost>) and partial
# ones (such as Date: 15:30:58), 'cause the IMAP server as usal just does
# a substring search. The email:header string is built so that field and
# value are automatically splitted at the first column, so it' like writing
#
# ?x email:header ?h
# ?h email:hdrnam "In-Reply-To"
# ?h email:hdrval "<469663CB.6080302@localhost>"
#
# The semantics in this case is rather out of standard, but provides an
# easier way to deal with header filters...
#
# When you GET headers, instead, you get all of them and then you can use
# a normal FILTER to have only the messages that satisfy particular header
# conditions. As usual, FILTER is better on a formal point of view but
# requires you to download more data.


PREFIX xsd: <http://www.w3.org/2001/XMLSchema#>
prefix email: <http://davide.eynard.it/rdf/email#>

select * where
{
	?x email:subject 	?subject .
	?x email:header		?headers .
	?x email:header		"Date: 15:30:58" .
	?x email:header		"In-Reply-To: <469663CB.6080302@localhost>" .
	
#	FILTER regex(?headers, "In-Reply-To: <469663CB.6080302@localhost>", "i") .
}