Folk's database stores all Wishes, Claims, Whens, and Holds. Essentially, it stores everything that happens in Folk. The database works with Statements, either inserting or removing them. All those verbs I mentioned— Wish, When, etc—are functions that insert a Statement into the database. We'll cover removal later.

So, what is a Statement? A Statement consists of three parts: the Clause, the child matches, and metadata. Let's start with the Clause: a Clause is an array of words, with each word known as a Term. An example Clause, “the sky is blue”, would become [“the”, “sky”, “is”, “blue”]. We'll cover child matches and metadata in a bit.

Let's see what happens when we run Claim.

Claim the sky is blue

The Statement's Clause would become “current-file.folk claims the sky is blue”. Notice there's a part that was prepended to the beginning, “current-file.folk claims”. This is what 1. tells us what file this Claim came from, and 2. tells us that it's a Claim, not a Wish.