More on "Component Programming"

[Peter Alexander]

On Monday, 27 May 2013 at 21:36:12 UTC, bearophile wrote:
> "pairwise" is a very useful lazy range similar to 
> cartesianProduct, but it yields only the ordered pairs, so they 
> cover only about half (a triangle) of the square matrix of the 
> possibilities.

This will be part of my combinatorics library, but is more 
general. pairWise is just a specific case of k-subsets (with 
k=2). By default, it currently provides the subsets in 
colexicographic order instead of lexicographic, but I intend to 
make the ordering a policy before I'm done.