snakeyaml

core.clj

(ns snakeyaml-example.core
  (:require [clojure.string :refer (split)])
  (:import [org.yaml.snakeyaml.constructor SafeConstructor
            AbstractConstruct Construct]
           [org.yaml.snakeyaml.nodes Tag Node ScalarNode NodeId]
           [snakeyaml-example.core Dice ConstructDice DiceConstructor]))

(set! *warn-on-reflection* true)

(gen-class
 :name snakeyaml-example.core.Dice
 :prefix dice-
 :state state
 :init init
 :constructors {[Integer Integer] []})

(gen-class
 :name snakeyaml-example.core.ConstructDice
 :prefix construct-dice-
 :extends org.yaml.snakeyaml.constructor.AbstractConstruct)

(gen-class
 :name snakeyaml-example.core.DiceConstructor
 :prefix dice-constructor-
 :post-init initialize
 :extends org.yaml.snakeyaml.constructor.SafeConstructor)

(defn dice-init
  [a b]
  [[] {:a a :b b}])

(defn construct-dice-construct
  [^ScalarNode node]
  (let [^String val (.constructScalar node)
        [as bs] (split val #"d" 2)
        a (Integer/parseInt as)
        b (Integer/parseInt bs)]
    (Dice. a b)))

(defn dice-constructor-initialize
  [this]
  ;; (println "Initialize DiceConstructor!")
  ;; (throw (RuntimeException. "OK!"))
  (let [yc (.yamlConstructors this)]
    (.put yc (Tag. "!dice") (ConstructDice.))))

(defn -main [& args]
  (Dice. (int 3) (int 5))
  (DiceConstructor.)
  (ConstructDice.))

;; class DiceConstructor extends SafeConstructor {
;;     public DiceConstructor() {
;;         this.yamlConstructors.put(new Tag("!dice"), new ConstructDice());
;;     }

;;     private class ConstructDice extends AbstractConstruct {
;;         public Object construct(Node node) {
;;             String val = (String) constructScalar((ScalarNode) node);
;;             int position = val.indexOf('d');
;;             Integer a = new Integer(val.substring(0, position));
;;             Integer b = new Integer(val.substring(position + 1));
;;             return new Dice(a, b);
;;         }
;;     }
;; }

project.clj

(defproject snakeyaml-example "0.1.0-SNAPSHOT"
  :description "FIXME: write description"
  :url "http://example.com/FIXME"
  :license {:name "Eclipse Public License"
            :url "http://www.eclipse.org/legal/epl-v10.html"}
  :dependencies [[org.clojure/clojure "1.5.1"]
                 [org.yaml/snakeyaml "1.13"]]
  :main snakeyaml-example.core
  :aot [snakeyaml-example.core])