Tue Mar 22 13:54:58 EDT 2016

Sequences vs. folds

For a project, I'm using abstract folds to represent iteration over
possibly infinite sequences.  It meshes well with the actor model:
tail recursion, processing an ordered message stream.

However, it is interesting to see (or re-discover) the distinction
between the two views.

With some hand waving, it seems that I am rarely interested in the
sequence iteself.  The point is almost always a reduction of the
sequence into some form of object that represents a property of the
sequence.  99% of the time, that is best represented as a left fold in
a strict language.