Sseveral comments regarding the pinholes post, have forced me, against the deepest elements of my nature, to engage in thought. Since that might never happen again, I thought it meet to record the event.
I'm going to say "I" a lot, because this is mostly my opinions.
As pointed out by Christian Schuhegger in a comment on the original post, lenses were originally introduced to computer science in the context of bidirectional programming, rather than as a tool for dealing with deeply nested immutable structures. He points to a good list of papers on the subject on ...more ...