iRule : matching 2 patterns in the query string but in order

of course it's possible. following lines are from tclsh for demo. you can use same if expression in irule.

% set uri_list {"/test?pattern1=value1&pattern2=value2" "/test?pattern2=value2" "/test?pattern1=value1" "/test?pattern2=value2&pattern1=value1"}

"/test?pattern1=value1&pattern2=value2" "/test?pattern2=value2" "/test?pattern1=value1" "/test?pattern2=value2&pattern1=value1"

% foreach uri $uri_list {
    unset -nocomplain p1pos p2pos
     For logging only because p2pos is not set if first condition fails in next line.
    set p2pos [string first "pattern2=" $uri]
    if {([set p1pos [string first "pattern1=" $uri]] != -1) && ([set p2pos [string first "pattern2=" $uri]] != -1) && ($p1pos < $p2pos)} { 
        puts "ok : $p1pos / $p2pos / [expr {$p1pos < $p2pos}]"
    } else {
        puts "Not ok : $p1pos / $p2pos / [expr {$p1pos < $p2pos}]"
    }
}
% 
ok : 6 / 22 / 1
Not ok : -1 / 6 / 1
Not ok : 6 / -1 / 0
Not ok : 22 / 6 / 0
%