generativity.clj

(ns generativity 
  (:use [cascalog api]))

(defn one_of [seq] (vec (map vector seq)))
(deffilterop forbid
    ([var comparator val]
      (not (comparator var val)))
    ([var op val comparator comparee]
      (not (comparator (op var val) comparee))))

(def generativity 
  (<- 
    [?alice ?bob ?claire]
    ((one_of [1 2 3]) ?alice)
    ((one_of [1 2 3]) ?bob)
    ((one_of [1 2 3]) ?claire)
    (cross-join)

    (forbid ?alice = ?bob) (forbid ?bob = ?claire) (forbid ?alice = ?claire)
    (forbid ?bob = 3)
    (forbid ?alice - ?claire = 1) (forbid ?claire - ?alice = 1)
    (forbid ?claire < ?bob)))

; (?- (stdout) generativity)
; 
; RESULTS
; -----------------------
; 1       2        3
; -----------------------

project.clj

(defproject generativity "0.0.1"
  :source-path "src"
  :dependencies [[cascalog "1.8.8-SNAPSHOT"]]
  :profiles {
    :provided {
      :dependencies [[org.apache.hadoop/hadoop-core "0.20.2-dev"]]
    }
  })