Answers to Ovid's programmer questions:

1. This is a problem because although efficient on short arrays, it does not scale (i.e. O(n-squared) type algorithm). Better to sort the arrays (or copies of the arrays) first (assuming sortable elements), then you can simply hopscotch along them both comparing elements, and shuttling matches to a new array. Depends on arrays being sorted efficiently.

2.
#!/usr/bin/ruby -w class Array def my_reverse tmp = self.dup #function is destructive new = [] while tmp.size > 0 new.push( tmp.pop ) end return new end end a = ['foo', 'bar', 'baz', 'cheeze whiz'] puts a.my_reverse
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3. Request manager gets request, asks translator for standard query form, gives that to DB interface, gives result to output translator. As much as possible the input/output handlers are subclasses of main input and output superclasses . Request manager sets up a queue (FIFO) of requests, each one containing it's own "blackboard" space to be used at will by each of the components. Of course, if the database is a bottleneck, it might be wise to do I/O with one program/thread and queue them to the db program/thread so that request fetching/output is not blocked by this step. Of course output is still throttled by the db, but assuming variable input rate, it should "catch up" during slow request times.