==== ARQ ToDo

+ Separate out QueryIterators from engine1

+ Compare engine1 and engine for speed

+ Property function to property path expression

+ AltMatcher - Remove bnodes in QueryIterBlockTriplesAlt

+ RootBinding should be empty
    System variables need to look in the context (add version while about it)
    Remove .getCurrentBinding
    "Expr" and "Function" get Context, not ExecContext
    jfn:now() is not in the test suite
    Dymanic version: jfn:system(stringname) => Context

+ testing QE1 and QE2 in the same test run

+ Initial binding by substitution (engine2)
    QEngine2/QEBase
    QEBase => .engine
  Return of "Plan" in .engine.
  
+ Determination of safe streaming.
  "well-designed" test
   core.OptNesting

+ Tidy table implementations.

+ Convenient: Get the version ID (property function?)
  Generalize to system functions.
    
+ Split tests into
   Pure SPARQL
   ARQ/SPARQL (property functions, functions)
   ARQ/ARQ

+ Filter fn:listMember, :listIndex, bagMember, seqMember, altMember
  PF:s list:first, list:last, list:index (N, ?m)
    Gotta go!
  
  These access the current (group scoped) graph.
  Must remove - and remove ExecutionContext from the filter interface
  to allow quad store getting everything at once.

+ LARQ
    Incremental update

+ java: general redirection.
  PREFIX apf:     <http://jena.hpl.hp.com/ARQ/pfunction#> 
    Change the java: lookup to add this case.
    ==> PFuncOps.isMagicProperty
        PropertyFunctionRegistry.manages/.get
          Also FunctionRegistry
   

Missing java:function causes:
Caused by: java.lang.NullPointerException
	at java.lang.Class.isAssignableFrom(Native Method)
	at com.hp.hpl.jena.query.function.FunctionRegistry.put(FunctionRegistry.java:65)
	at com.hp.hpl.jena.query.function.FunctionRegistry.get(FunctionRegistry.java:90)
	at com.hp.hpl.jena.query.expr.E_Function.bindFunction(E_Function.java:78)
	at com.hp.hpl.jena.query.expr.E_Function.buildFunction(E_Function.java:53)
Tidy up.
Also registered function errors?
Check property function as well.

+ Commands
  + qtest to use modules.

+ Access rdfs direct forms of subClassOf and subPropertyOf by writing a property function to call
  find(?, directForm,?). The direct form must be used explicitly to see the inferred direct triples.

+ Use DatasetDesc more widely.
    See TODO in DatasetDesc
    FROM/FROM NAME
 
+ ResultSetRewindable could be a delayed evaluation wrapper.
    .hasPrevious(), .previous()

+ Graph version of interface?

+ Documentation
	Writing filter functions
	Writing property functions
    Creating datasets
    MediaWiki?

== Documentation

+ Document API (more)
  Document lists
  Document symbols and configuration
  Document writing PF's
  Describe interactions of transactions and query.
  Document making and using datasets
  Document configuration (?)
  javadoc for extensions
    And on writing_functions.html say what the interfaces are.
  location-mapping and FROM/FROM NAMED
  
== Testing

+ TestManifestX property: plainGraphTest, valueSameAsTest etc 
  as subclasses of QueryTest.
    mildly tricky as affects reading results and external datasets
    so must be per-test and tests don't have contexts.

+ Organise
  Split into SPARQL/Features/ARQ tests
  Utility to find duplicate tests (hash the query)

== Core

+ XML results: process xml:lang on other elements than just <literal>
  Documentation for XML result set processing

+ Serialization
  + Need to take into account subject width across multiple chunks
  + Using [] for bNodes
  + Lists (not important)
  + Expressions - outer level does not need () - also SortCondition