Sudoku with core.logic

A small Sudoku solver in Clojure, written with core.logic for tonight’s Got.clj meetup. There is no search algorithm in it: I create 81 logic variables, give each one the domain 1 to 9, unify them with the puzzle (empty cells, written as zeros, become fresh variables), and require every row, column and 3×3 square to be distinct. core.logic does the rest. It comes with a “super hard” puzzle to try it on.

(run 1 [q]
  (everyg #(infd % sudoku-domain) cells)
  (== cells constraints)
  (== q rows)
  (everyg distinctfd rows)
  (everyg distinctfd columns)
  (everyg distinctfd squares))

Source on GitHub: sudoku-core-logic