/// <summary>
/// Asks the next question or displays the interview results.
/// </summary>
public static Response Investigate(List <Facts.Fact> goals)
{
// Default outputs
bool allDone = true;
int percent = 0;
Facts.Fact theNextFact = new Facts.Fact("", null, null, null);
InitializeProofTree();
// Pre-evaluate each goal in order to cache the results of
// each evaluted function in the FactBase. This will make
// look-ahead short-circuiting work in the interview.
// There will obviously be performance implications to
// evaluating each goal twice. However, a four-line fix
// to a vexing problem feels delightful. And the caching
// may end up making things tolerable after all.
//
// But note that the look-ahead short-circuiting issue is not
// completely solved: it will still fail in large rules where
// the intermediate conditions are not checked/pre-evaluated.
foreach (Facts.Fact g in goals)
{
g.Value();
}
// Console.WriteLine(ShowProofTree());
// Prepare to look for unknown facts
Facts.GetUnknowns = true;
Facts.Unknowns.Clear();
// Iterate through each goal
foreach (Facts.Fact g in goals)
{
if (!g.Value().HasBeenDetermined)
{
allDone = false;
}
}
Facts.GetUnknowns = false;
// Determine the next fact and the percent complete
if (!allDone)
{
theNextFact = Facts.Unknowns[0];
percent = ProgressPercentage(Facts.Count(), Facts.Unknowns.Count);
}
return(new Engine.Response(allDone, theNextFact, percent, goals));
}
/// <summary>
/// Takes an income packet and instantiates a Hammurabi session.
/// </summary>
public Packet Assess(Packet request)
{
// Start timer
DateTime startTime = DateTime.Now;
// Pre-evaluate each goal to enable look-ahead short circuiting.
// See Hammurabi | Core | Engine.cs, line ~81, for an explanation.
foreach (Factoid g in request.Goals)
{
Facts.Fact gb = new Facts.Fact(g.Relationship, g.Arg1, g.Arg2, g.Arg3);
gb.Value();
}
// Start a fresh session
// Facts.Clear();
Facts.GetUnknowns = true;
Facts.Unknowns.Clear();
bool allDone = true;
request.PercentageComplete = 100;
// Assert facts into a Hammurabi session
foreach (Factoid f in request.AssertedFacts)
{
AssertFact(f);
}
// Iterate through each goal
foreach (Factoid g in request.Goals)
{
Facts.Fact gb = new Facts.Fact(g.Relationship, g.Arg1, g.Arg2, g.Arg3);
// Assign to a variable so it's only evaluated once
Tvar gbVal = gb.Value();
// Convert Tvar to timeline object
g.Timeline = TvarToTimeline(gbVal);
// All goals resolved?
if (!gbVal.HasBeenDetermined)
{
allDone = false;
}
}
// Stop looking for unknown facts
Facts.GetUnknowns = false;
// Determine the next fact and the percent complete
if (!allDone)
{
// Factoid neededFact = new Factoid("Tnum","USC.Tit26.Sec151.ThresholdAmount","Jim","","");
// Facts.Fact f = new Facts.Fact("USC.Tit26.Sec151.ThresholdAmount", null, null, null);
// Factoid neededFact = new Factoid(f);
Factoid neededFact = new Factoid(Facts.Unknowns[0]);
request.NeededFacts = new List <Factoid>()
{
neededFact
};
request.PercentageComplete = Interactive.Engine.ProgressPercentage(Facts.Count(), Facts.Unknowns.Count);
}
// Add elapsed time to response object
request.ResponseTimeInMs = Convert.ToInt32((DateTime.Now - startTime).TotalMilliseconds);
return(request);
}
