Lua Gems: Filters, Sources, Sinks and Pumps

["Leo Razoumov" <slonik.az@...>]

Hi List,
I ordered "Lua Gems" on Monday morning from Amazon.com using free
shipping (the slowest shipping option available in the US that costs
nothing). To my great surprise next day (on Tuesday) I found the book
on my door steps!

Now I am reading Diego Nehab's gem on "Filters, Sources, Sinks and Pumps".
To my surprise he does not mention coroutines. I think coroutines with
their "yield" and "resume" are great mechanism to implement filters
and filter chains. They provide an easy and natural way to maintain
filter context while processing chunks of data. Also coroutines all
but eliminate (or rather hide) need for "pumps".
Is there any specific reason they are left out of this gem??

--Leo--