I thought this was going to be about lenses implemented in JavaScript, if it was I didn't get it. The Haskell lens[1] package (which implements a type of lense

I thought this was going to be about lenses implemented in JavaScript, if it was I didn't get it. The Haskell lens[1] package (which implements a type of lenses referred to as van Laarhoven lenses after their discoverer Twan van Laarhoven) builds up a hierarchy (pyramid if you will) of lenses with varying degrees of generality and power. [1]: http://hackage.haskell.org/package/lens-4.17#readme http://hackage.haskell.org/package/lens-4.17#readme