Including Ring in the Namespace
Add the ring-adaptor-jetty namespace from the ring library, so we can use the functions from that library.
Require the ring-adaptor
Delete all code in src/todo_list/core.clj and replace it with the following code.
(ns todo-list.core
(:require [ring.adapter.jetty :as webserver]))
The ns expression defines the current namespace as todo-list.core, providing a scope for all the functions and data structures we define within it.
The :require expression makes the ring.adaptor.jetty namespace accessible within the todo-list.core namespace. We can now call any of the public functions in the ring.adaptor.jetty namespace.
In ring.adapter.jetty namespace is bound to the webserver alias, providing a short name to refer to functions from that namespace.
For example, the run-jetty function is called using webserver/run-jetty rather than the fully qualified namespace of ring.adaptor.jetty/run-jetty
Using aliases for namespaces
Using :require we can use the :as keyword to specify an alias for a namespace, a short-hand way of refering to a library. You can specify any valid Clojure name for a namespace alias, however please consider the readability of your code and choose a meaningful alias name.
Later in the workshop we will show other options for including functions from other namespaces.