I am working on an implementation of a forth-like language on top of Elixir.
One of the things that is a major part of any forth-like language, is the dictionary of defined functions (called words). This is usually implemented as a linked list, so that multiple vocabularies (i.e. execution contexts) might coexist without conflicting definitions (they are re-using the same tail of the list, but each context might have its own head).

I wanted to build this in Elixir using a list. But now I found out that functions like Keyword.get, Keyword.put, etc. only work if the key is an atom. Why is this restriction on atom keys there?

The foo: 1, bar: 2 syntactic sugar of course desugars to a ‘keyword list’, but even without using this syntactic sugar it would be useful to use Keyword.get, Keyword.get_values etc. with different types of keys.