Writing a Custom Lens with http4k
http4k and lenses http4k is a lightweight web framework written in and designed for use with Kotlin. One of the many features I love is the simplicity of marshalling and validating http requests using its Lens api. For anyone (like me) not from a functional programming background, here, a lens is used to get a particular value from, or set a particular value onto, an http message, without the need for marshalling.
