Containers

Containers are functional like data structures that help provide greater runtime safety and polymorphism.

This package is dependency free. There are some dev only deps, but the package only relies on Elixir.

Protocols

Appendable - A container that provides an interface of append. Safe against nil values. Namely when passing a container with the value nil into either the first of second argument to append, the other value is not change and there is no runtime error.
Mappable - A container that provides an interface to map. When map is called on a container that has a nil value that container just passes through with out the mapping function being called, and this helps prevent runtime errors.
Sequenceable - A container that provides an interface of next. This allows the chaining of computations.
Unwrappable - A container that provides an interface to safe and unsafe unwrapping of inner value. Safe will need a default in case of nil value of container, helping prevent runtime errors. Unsafe will just return the value of the container regardless of a nil value potentially causing runtime errors
Joinable - A container that has a nested container of the same type, and is able to be join down into a single representation of the structure.

Since these are protocols, and highly decoupled, a developer can implement them as needed on their own structs.

The package can be installed by adding containers to your list of dependencies in mix.exs:

def deps do
  [{:containers, "~> 0.7.1"}]
end

Until version 1.0.0 assume minor changes (that is the number in the second spot) to reflect breaking changes.