This kata is based on Interactive Development with clojure.spec.
"We want a function that accepts a secret code and a guess, and returns a score for that guess. Codes are made of 4 to 6 colored pegs, selected from six colors: [r]ed, [y]ellow, [g]reen, [c]yan, [b]lack, and [w]hite. The score is based on the number of pegs in the guess that match the secret code. A peg in the guess that matches the color of the peg in the same position in the secret code is considered an exact match, and a peg that matches a peg in a different position in the secret code is considered a loose match.
For example, if the secret code is
[:r :y :g :c]and the guess is[:c :y :g :b], the score would be{:codebreaker/exact-matches 2 :codebreaker/loose-matches 1}because:yand:gappear in the same positions and:cappears in a different position."
Try to spec your code with clojure.spec. The official spec Guide is always a good choice to be kept open in a separate window.
First, the data-structure should be specced. After this, use s/fdef to spec all your functions (you can / should try to spec them first and then implement them!).
Specs can also be used for validation at runtime. You can use s/valid? for verification.