Grabbing a subset of a range if a particular value is found?

[Gary Willoughby]

I'm using std.range.recurrence to generate a range but i want to 
stop it generating and grab the range when a particular value is 
added. e.g.:

    recurrence!("a[n-1] + a[n-2]")(1, 2)
    .take(10)
    .writeln;
This writes ten numbers to the command line which is fair enough 
but what would be the preferred method to keep building the range 
until an element calculated is above a particular value.