/// <summary>
/// Add a term (fact or rule) to the KB.
/// </summary>
public void AssertA(Structure structure)
{
Assert(structure, false, false);
}
/// <summary>
/// Add a term (fact or rule) to the KB.
/// </summary>
public void Assert(Structure structure, bool atEnd, bool checkSingletons)
{
if (structure == null)
{
throw new ArgumentNullException("structure", "Term to add to KB may not be null.");
}
//structure = structure.Expand();
if (structure == null)
{
throw new ArgumentNullException("structure");
}
Structure head = structure.IsFunctor(Symbol.Implication, 2)
? Term.Structurify(structure.Argument(0),
"Head of :- must be a valid proposition or predicate.")
: structure;
if (head.IsFunctor(Symbol.ColonColon, 2))
{
var argument = head.Argument(0);
var kb = argument as KnowledgeBase;
if (kb == null)
{
var o = argument as GameObject;
if (o != null)
{
kb = o.KnowledgeBase();
}
else
{
var c = argument as Component;
if (c != null)
{
kb = c.KnowledgeBase();
}
else
{
throw new ArgumentTypeException(
"assert",
"knowledgebase",
argument,
typeof(KnowledgeBase));
}
}
}
if (structure.IsFunctor(Symbol.Implication, 2))
{
kb.Assert(
new Structure(Symbol.Implication, head.Argument(1), structure.Argument(1)),
atEnd,
checkSingletons);
}
else
{
kb.Assert(structure.Argument(1), atEnd, checkSingletons);
}
}
else
{
if (PrologPrimitives.Implementations.ContainsKey(head.Functor))
{
throw new PrologException(
new Structure(
"error",
new Structure(
"permission_error",
Symbol.Intern("modify"),
Symbol.Intern("static_procedure"),
Term.PredicateIndicatorExpression(head))));
}
KnowledgeBaseRule assertion = KnowledgeBaseRule.FromTerm(
structure,
checkSingletons,
Prolog.CurrentSourceFile,
Prolog.CurrentSourceLineNumber);
PredicateInfo info = EntryForStoring(head.PredicateIndicator);
PredicateInfo parentInfo;
if (!info.Shadow && this.Parent != null &&
(parentInfo = this.Parent.CheckForPredicateInfoInThisKB(head.PredicateIndicator)) != null &&
!parentInfo.External)
{
throw new PrologException(
new Structure(
"error",
new Structure(
"permission_error",
Symbol.Intern("shadow"),
Term.PredicateIndicatorExpression(head))));
}
info.Assert(assertion, atEnd);
}
}
/// <summary>
/// Add a term (fact or rule) to the KB.
/// </summary>
public void AssertZ(Structure structure)
{
Assert(structure, true, false);
}
public Suspension(Structure delayedGoal, Structure frozenGoal, PrologContext prologContext)
{
DelayedGoal = delayedGoal;
FrozenGoal = frozenGoal;
context = prologContext;
}
internal IEnumerable <CutState> FindClauses(Structure head, object body)
{
PredicateInfo i = CheckForPredicateInfo(head.PredicateIndicator);
return((i == null)?CutStateSequencer.Fail():i.FindClauses(head, body));
}
/// <summary>
/// Test whether GOAL is provable
/// </summary>
/// <param name="goal">Goal to prove</param>
/// <returns>True if provable, else false.</returns>
public bool IsTrue(Structure goal)
{
return(Prove(goal).GetEnumerator().MoveNext());
}
internal override IEnumerable <bool> UnifyWithStructure(Structure value)
{
return(UnifyWithCanonicalValue(value));
}
/// <summary>
/// Adds ASSERTION to GAMEOBJECT's knowledgebase.
/// </summary>
/// <param name="gameObject">Object whose knowledge base it should be added to</param>
/// <param name="assertion">Assertion to add</param>
public static void Assert(this GameObject gameObject, Structure assertion)
{
gameObject.KnowledgeBase().AssertZ(assertion);
}
/// <summary>
/// Adds ASSERTION to COMPONENT's knowledgebase.
/// </summary>
/// <param name="component">Object whose knowledge base it should be added to</param>
/// <param name="assertion">Assertion to add</param>
public static void Assert(this Component component, Structure assertion)
{
component.KnowledgeBase().AssertZ(assertion);
}
public void AddSuspendedGoalSavingToTrail(Structure goal, PrologContext context)
{
SaveAndUpdate(new Metastructure(goal, null, context, MetaBinding), context);
}
private void CompileGoal(Structure goal, ref ushort failAddress, ref ushort backPatchAddress)
{
byte continuationRegister = env.GetRegister();
// Allocate registers to goal arguments.
var argRegisters = new byte[goal.Arity];
for (int i = 0; i < goal.Arity; i++)
{
object arg = goal.Argument(i);
if (arg is Structure)
{
argRegisters[i] = env.GetRegister();
}
else
{
var @var = arg as LogicVariable;
if (@var != null)
{
argRegisters[i] = this.env.InsureRegisterAndLock(@var);
}
else
{
// It's a literal.
argRegisters[i] = NoRegister;
}
}
}
// Build goal arguments into registers.
for (int i = 0; i < goal.Arity; i++)
{
if (argRegisters[i] != NoRegister)
{
CompileBuild(goal.Argument(i), NoRegister, argRegisters[i]);
}
}
// Emit call instruction
ushort startOfCallInstruction = CurrentPC;
BackPatch(backPatchAddress, startOfCallInstruction);
PrologPrimitives.PrimitiveImplementation primitiveImplementation;
bool isPrimitive = PrologPrimitives.Implementations.TryGetValue(goal.Functor,
out primitiveImplementation);
// Call header
Emit(isPrimitive?Opcode.CallPrimitive : Opcode.Call, continuationRegister);
EmitUShort(failAddress);
backPatchAddress = CurrentPC;
EmitUShort(0); // This will get backpatched
// Call target
if (isPrimitive)
{
EmitUShort(PrimitiveTable.IndexOf(primitiveImplementation));
EmitByte((byte)goal.Arity);
}
else
{
EmitUShort(PredicateTable.IndexOf(this.knowledgeBase.EntryForStoring(goal.PredicateIndicator)));
}
// Call arguments
for (int i = 0; i < goal.Arity; i++)
{
byte reg = argRegisters[i];
if (reg == NoRegister)
{
EmitUShort((ushort)(0x8000 + GlobalLiteralTable.IndexOf(goal.Argument(i))));
}
else
{
EmitByte(reg);
}
}
failAddress = startOfCallInstruction;
}
// ReSharper disable once InconsistentNaming
void LoadCSVRow(int rowNumber, Structure row)
{
if (!this.IsTrue(new Structure("load_csv_row", rowNumber, row)))
throw new Exception(string.Format("Failed to load CSV row number {0} : {1}", rowNumber, Term.ToStringInPrologFormat(row)));
}
/// <summary>
/// Proves the specified goal, throwing an exception with badGoalErrorMessage if the goal is ill-formed.
/// </summary>
internal IEnumerable <CutState> Prove(object goal, string badGoalErrorMessage)
{
Structure s = Term.Structurify(goal, badGoalErrorMessage);
return(KnowledgeBase.Prove(s.Functor, s.Arguments, this, CurrentFrame));
}
/// <summary>
/// Proves the goal in the specified structure.
/// </summary>
internal IEnumerable <CutState> Prove(Structure goal)
{
return(KnowledgeBase.Prove(goal.Functor, goal.Arguments, this, CurrentFrame));
}
/// <summary>
/// Remove all terms matching head
/// </summary>
public void RetractAll(Structure head)
{
EntryForStoring(head.PredicateIndicator).RetractAll(head);
}
internal override bool UnifyWithStructure(Structure value, PrologContext context)
{
return(UnifyWithCanonicalValue(value, context));
}
internal IEnumerable <CutState> Retract(Structure head, object body)
{
return(EntryForStoring(head.PredicateIndicator).Retract(head, body));
}
private void WalkGoal(KnowledgeBase kb, KnowledgeBaseRule rule, Structure goal)
{
var predicateIndicator = goal.PredicateIndicator;
Symbol functor = goal.Functor;
int arity = goal.Arity;
switch (functor.Name)
{
case "begin":
foreach (var arg in goal.Arguments)
{
WalkGoal(kb, rule, arg);
}
break;
case "once":
case "check":
case "randomize":
case "not":
case "\\+":
if (arity == 1)
{
WalkGoal(kb, rule, goal.Argument(0));
}
else
{
WarnUndefined(rule, functor, arity);
}
break;
case ",":
case ";":
case "->":
if (arity == 2)
{
WalkGoal(kb, rule, goal.Argument(0));
WalkGoal(kb, rule, goal.Argument(1));
}
else
{
WarnUndefined(rule, functor, arity);
}
break;
case "call":
case "maplist":
if (arity < 1)
{
WarnUndefined(rule, functor, arity);
}
else
{
object goalToCall = goal.Argument(0);
var goalToCallAsStructure = goalToCall as Structure;
if (goalToCallAsStructure != null)
{
var newArgs = new object[arity - 1 + goalToCallAsStructure.Arity];
goalToCallAsStructure.Arguments.CopyTo(newArgs, 0);
WalkGoal(kb, rule, new Structure(goalToCallAsStructure.Functor, newArgs));
}
else
{
var call = goalToCall as Symbol;
if (call != null)
{
this.WalkGoal(kb, rule, new Structure(call, new object[arity - 1]));
}
}
}
break;
case "arg_min":
case "arg_max":
if (arity == 3)
{
WalkGoal(kb, rule, goal.Argument(2));
}
else
{
WarnUndefined(rule, functor, arity);
}
break;
case "find_all":
if (arity == 3)
{
WalkGoal(kb, rule, goal.Argument(1));
}
else
{
WarnUndefined(rule, functor, arity);
}
break;
default:
if (PrologPrimitives.IsDefined(predicateIndicator))
{
var arglist = PrologPrimitives.Arglist(predicateIndicator.Functor);
for (int i = 0; i < Math.Min(predicateIndicator.Arity, arglist.Count); i++)
{
var argSym = arglist[i] as Symbol;
if (argSym != null)
{
var arg = argSym.Name;
if (arg[0] == ':')
{
WalkGoal(kb, rule, goal.Argument(i));
}
else if (arg == "..." && arglist[i - 1] is string && ((string)arglist[i - 1])[0] == ':')
{
// Predicate accepts a rest arg of goals
for (int j = i; j < predicateIndicator.Arity; j++)
{
WalkGoal(kb, rule, goal.Argument(j));
}
}
}
}
}
else
{
var predicate = kb.CheckForPredicateInfo(predicateIndicator);
if (predicate == null)
{
WarnUndefined(rule, functor, arity);
}
else
{
MarkReferenced(predicate);
if (predicate.HigherOrderArguments != null)
{
foreach (int argIndex in predicate.HigherOrderArguments)
{
WalkGoal(kb, rule, goal.Argument(argIndex));
}
}
}
}
break;
}
}