Dictionary with terms and optionally payload information taken from stored fields in a Lucene index. Similar to DocumentDictionary, except it obtains the weight of the terms in a document based on a ValueSource.
NOTE: In practice the ValueSource will likely be obtained using the lucene expression module. The following example shows how to create a ValueSource from a simple addition of two fields: Expression expression = JavascriptCompiler.compile("f1 + f2"); SimpleBindings bindings = new SimpleBindings(); bindings.add(new SortField("f1", SortField.Type.LONG)); bindings.add(new SortField("f2", SortField.Type.LONG)); ValueSource valueSource = expression.getValueSource(bindings);