Take a look at Boomerang programming language: https://alliance.seas.upenn.edu/~harmony/ https://alliance.seas.upenn.edu/~harmony/ and its documentation, they h

Take a look at Boomerang programming language: https://alliance.seas.upenn.edu/~harmony/ https://alliance.seas.upenn.edu/~harmony/ and its documentation, they have a bit of explanation of lenses there. Also, on the frontend/in JS we also have some implementations of lenses, most notably in Bilby.js: http://bilby.brianmckenna.org/#lenses http://bilby.brianmckenna.org/#lenses