You're working away in a Clojure REPL, when you realise you need to add a dependency. You add the dependency to your leiningen project.clj file and then? Instead of shutting down your REPL, loosing whatever state you have built up, you can use Alembic to load the new dependencies. Simply call (alembic.still/load-project).
Of course, it still has to work within the confines of the JVM's classloaders, so you can only add dependencies, and not modify versions or remove dependencies, but this should still cover a lot of use cases.
To use alembic on a single project, simply add it as a dependency in your :dev profile in project.clj:
:profiles {:dev {:dependencies [[alembic "0.2.0"]]}}
To make alembic available in all your projects, and it to the :user profile in ~/.lein/profiles.clj instead:
{:user {:dependencies [[alembic "0.2.0"]]}}
Alembic also allows you to directly add dependencies without editing your project.clj file, using the distill function. Use this if you are just exploring libraries, for example.
Finally a big thank you to Anthony Grimes and the other flatland developers for removing classlojure's dependency on useful, which should make this all much more robust.
Discuss this post here.
Published: 2013-08-29