From: Srinivas Jonnalagadda <srinivas.j@...>
Date: 2005-11-04T18:41:32+09:00
Subject: Lazy evaluation

I was just looking at lazy.rb (http://moonbase.rydia.net/software/lazy/).

The example 'rjust_lines' on that page is very interesting for several 
numerical computation scenarios, as well, where _not every_ computed 
result is actually used.  However, the computation could involve 
multiplication of two vectors, and in the absence of any lazy 
evaluation, the cost of entire set of computations would be incurred 
right then!

I do not know Scheme, hence cannot perhaps appreciate just how routine 
such programming could be, but expression templates technique in C++ 
was used to a similar effect in libraries such as Blitz++.

Very nice feature -- thank you!

Best regards,

JS