Github user spmallette commented on a diff in the pull request:
https://github.com/apache/tinkerpop/pull/882#discussion_r206188786
--- Diff:
gremlin-core/src/main/java/org/apache/tinkerpop/gremlin/process/computer/search/path/ShortestPathVertexProgram.java
---
@@ -0,0 +1,581 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+package org.apache.tinkerpop.gremlin.process.computer.search.path;
+
+import org.apache.commons.configuration.Configuration;
+import org.apache.tinkerpop.gremlin.process.computer.GraphComputer;
+import org.apache.tinkerpop.gremlin.process.computer.Memory;
+import org.apache.tinkerpop.gremlin.process.computer.MemoryComputeKey;
+import org.apache.tinkerpop.gremlin.process.computer.MessageScope;
+import org.apache.tinkerpop.gremlin.process.computer.Messenger;
+import org.apache.tinkerpop.gremlin.process.computer.VertexComputeKey;
+import org.apache.tinkerpop.gremlin.process.computer.VertexProgram;
+import
org.apache.tinkerpop.gremlin.process.computer.traversal.TraversalVertexProgram;
+import
org.apache.tinkerpop.gremlin.process.computer.traversal.step.map.ProgramVertexProgramStep;
+import
org.apache.tinkerpop.gremlin.process.computer.traversal.step.map.VertexProgramStep;
+import
org.apache.tinkerpop.gremlin.process.computer.util.AbstractVertexProgramBuilder;
+import org.apache.tinkerpop.gremlin.process.traversal.Operator;
+import org.apache.tinkerpop.gremlin.process.traversal.Path;
+import org.apache.tinkerpop.gremlin.process.traversal.Step;
+import org.apache.tinkerpop.gremlin.process.traversal.Traversal;
+import org.apache.tinkerpop.gremlin.process.traversal.Traverser;
+import org.apache.tinkerpop.gremlin.process.traversal.dsl.graph.__;
+import
org.apache.tinkerpop.gremlin.process.traversal.step.util.ImmutablePath;
+import
org.apache.tinkerpop.gremlin.process.traversal.traverser.util.IndexedTraverserSet;
+import
org.apache.tinkerpop.gremlin.process.traversal.traverser.util.TraverserSet;
+import org.apache.tinkerpop.gremlin.process.traversal.util.PureTraversal;
+import org.apache.tinkerpop.gremlin.structure.Direction;
+import org.apache.tinkerpop.gremlin.structure.Edge;
+import org.apache.tinkerpop.gremlin.structure.Element;
+import org.apache.tinkerpop.gremlin.structure.Graph;
+import org.apache.tinkerpop.gremlin.structure.Vertex;
+import org.apache.tinkerpop.gremlin.structure.VertexProperty;
+import org.apache.tinkerpop.gremlin.structure.util.StringFactory;
+import
org.apache.tinkerpop.gremlin.structure.util.reference.ReferenceFactory;
+import org.apache.tinkerpop.gremlin.util.NumberHelper;
+import org.javatuples.Pair;
+import org.javatuples.Triplet;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+
+/**
+ * @author Daniel Kuppitz (http://gremlin.guru)
--- End diff --
It would be nice to see more javadoc and inline comments in here. I'd like
to know more about "why" in a lot of the stuff i see here, especially in
`execute()`, `storeState()` and `loadState()`. Similar to the inline comments i
have in `connectedComponent()` -
https://github.com/apache/tinkerpop/pull/897/files#diff-b0b5f3644f5f656c492f3f6ddae2c7feR117
it would be also nice to know why halted traversers are setup the way that
they are if you figured that out somehow because it's still mysterious to me.
---
