refactor diff wrappers and encoding apis

CHANGELOG.md

@@ -0,0 +1,13 @@
+# 0.2.0
+
+### Fixes
+
+* fixed issue where `DirectedGraph.edges()` returned edges pointing in the wrong direction
+
+### Changes
+
+* moved `Lists.EMPTY`, `Sets.EMPTY`, and `Maps.EMPTY` to `List.EMPTY`, `Set.EMPTY`, and `Map.EMPTY` respectively
+* moved `Lists.VirtualList`, `Sets.VirtualSet`, and `Maps.VirtualMap` to `diffs.DiffList`, `diffs.DiffSet`, and `diffs.DiffMap` respectively
+* moved `Lists.Concat` to `diffs.ConcatList`
+* subsumed `Lists.Slice` into `diffs.DiffList`
+

src/io/lacuna/bifurcan/DirectedAcyclicGraph.java

@@ -9,6 +9,8 @@
 import static io.lacuna.bifurcan.Graphs.MERGE_LAST_WRITE_WINS;
 
 /**
+ * A directed graph which will throw a {@code DirectedAcyclicGraph.CycleException} if any new edge creates a cycle.
+ *
  * @author ztellman
  */
 public class DirectedAcyclicGraph<V, E> implements IGraph<V, E> {

src/io/lacuna/bifurcan/DurableCollections.java

@@ -7,13 +7,13 @@
 
 public class DurableCollections {
 
-  public static IDurableCollection open(Path path, DurableEncoding encoding) {
+  public static IDurableCollection open(Path path, IDurableEncoding encoding) {
     IDurableCollection.Root root = Roots.open(path);
     DurableInput in = root.bytes();
     return Util.decodeCollection(in.readPrefix(), root, encoding, in);
   }
 
-  public static IDurableCollection migrate(Path path, DurableEncoding oldEncoding, DurableEncoding newEncoding) {
+  public static IDurableCollection migrate(Path path, IDurableEncoding oldEncoding, IDurableEncoding newEncoding) {
     return null;
   }