A Lamdera package. It is not on package.elm-lang.org: the Lamdera compiler provides it, from static.lamdera.com, so lamdera install works and elm install does not.
Lamdera.Wire2 contains all the built-in codecs used by Lamdera
It is the second version for generalised usage, and is more compact than the first iteration.
floor is one of few functions that turn integer floats in js into typed integers in Elm, e.g. the Float 3 into the Int 3.