splay tree map w/ values as comparators

splaytreevaluemap.dart

import 'dart:core';
import 'dart:collection';

class Test {
  SplayTreeMap m;
  Test() {
    m = new SplayTreeMap<String, RTest>(_compare);
  }

  int _compare(String s1, String s2) {
    return m[s1].compareTo(m[s2]);
  }
  void add(String s, RTest t){
    m[s] = t;
  }
  void printAll() {
    for (String s in m.keys) {
      print(s);
    }
  }
}

class RTest implements Comparable {
  int z;
  RTest(int z) {
    this.z = z;
  }
  int compareTo(RTest other) {
    return this.z - other.z;
  }
}
void main() {
  Test t = new Test();

  RTest r1 = new RTest(6);
  RTest r2 = new RTest(-5);
  RTest r3 = new RTest(4);
  RTest r4 = new RTest(-20);

  t.add("a",r1);
  t.add("b",r2);
  t.add("c",r3);
  t.add("d",r4);
  // order should be "d", "b", "c", "a"
  t.printAll();
}