package io.lacuna.bifurcan;

import java.util.Comparator;
import java.util.OptionalLong;
import java.util.function.BiPredicate;
import java.util.function.Function;
import java.util.function.ToLongFunction;

public class SortedSet<V> extends ISortedSet.Mixin<V> {

  final SortedMap<V, Void> m;

  public SortedSet() {
    this.m = new SortedMap<>();
  }

  private SortedSet(SortedMap<V, Void> m) {
    this.m = m;
  }

  @Override
  public Comparator<V> comparator() {
    return m.comparator();
  }

  @Override
  public OptionalLong inclusiveFloorIndex(V val) {
    return m.inclusiveFloorIndex(val);
  }

  @Override
  public OptionalLong ceilIndex(V val) {
    return m.ceilIndex(val);
  }

  @Override
  public SortedSet<V> add(V value) {
    SortedMap<V, Void> mPrime = m.put(value, null);
    if (m == mPrime) {
      super.hash = -1;
      return this;
    } else {
      return new SortedSet<>(mPrime);
    }
  }

  @Override
  public SortedSet<V> remove(V value) {
    SortedMap<V, Void> mPrime = m.remove(value);
    if (m == mPrime) {
      super.hash = -1;
      return this;
    } else {
      return new SortedSet<>(mPrime);
    }
  }

  @Override
  public <U> SortedMap<V, U> zip(Function<V, U> f) {
    return m.mapValues((k, v) -> f.apply(k));
  }

  @Override
  public ToLongFunction<V> valueHash() {
    return m.keyHash();
  }

  @Override
  public BiPredicate<V, V> valueEquality() {
    return m.keyEquality();
  }

  @Override
  public boolean contains(V value) {
    return m.contains(value);
  }

  @Override
  public OptionalLong indexOf(V element) {
    return m.indexOf(element);
  }

  @Override
  public long size() {
    return m.size();
  }

  @Override
  public V nth(long idx) {
    return m.nth(idx).key();
  }

  @Override
  public IList<V> elements() {
    return Lists.lazyMap(m.entries(), IEntry::key);
  }

  @Override
  public SortedSet<V> forked() {
    return isLinear() ? new SortedSet<>(m.forked()) : this;
  }

  @Override
  public SortedSet<V> linear() {
    return isLinear() ? this : new SortedSet<>(m.linear());
  }
}

@@ -1834,32 +1834,104 @@
 try::key);%0A  %7D%0A%0A
+  @Override%0A  public boolean isLinear() %7B%0A    return m.isLinear();%0A  %7D%0A%0A
   @Override%0A  pu

Fix forking SortedSet (#38)