People thinking "Oh god, not another x in y lines of z" (I first thought this as well), be open minded and try to read the code. It might not be in a language you know, but try and see if you can understand the last part:

  (run 1 [q]
    (== q vars)
    (everyo #(infd % (domain 1 2 3 4 5 6 7 8 9)) vars)
    (init vars hints)
    (everyo distinctfd rows)
    (everyo distinctfd cols)
    (everyo distinctfd sqs))

Which, for me, reads "Take one solution and return q, where q is equal to vars, and every var is either 1, 2, 3, 4, 5, 6, 7, 8 or 9. Then initialize the variables with the already placed elements we've been given, and ensure that every row, column and square has only distinct elements."

Now, I don't know about you, but this sounds actually like the rules of Sudoku for me, not some algorithm on how to solve it. That's amazing, and should really get you to think about trying out logic programming if you haven't already. There's a lot of power in it, and using it in production code might not be as far away as it seems.