public static bool Unify(object v1, object v2, PrologContext context)
{
object o1 = Deref(v1);
object o2 = Deref(v2);
if (o1 == o2)
{
// Fast path
return(true);
}
var t1 = o1 as Term;
var t2 = o2 as Term;
if (t1 != null)
{
if (t2 != null)
{
return(t1.UnifyWithTerm(t2, context));
}
return(t1.UnifyWithAtomicConstant(o2, context));
}
// o1 isn't a Term
if (t2 != null)
{
// o2 is a Term
return(t2.UnifyWithAtomicConstant(o1, context));
}
// Neither is a Term
if (o1 == null)
{
return(o2 == null);
}
return(o1.Equals(o2));
}
internal static IEnumerable<CutState> SetImplementation(object[] args, PrologContext context)
{
if (args.Length != 2) throw new ArgumentCountException("set", args, new object[] { "Variable", "NewValue"});
object value = Term.CopyInstantiation(args[1]);
if (value is LogicVariable) throw new UninstantiatedVariableException((LogicVariable)args[1], "Value argument should be a data object, not an uninstantiated (unbound) variable.");
var functor = Term.Deref(args[0]) as Symbol;
if (functor == null) throw new ArgumentTypeException("set", "functor", args[0], typeof (Symbol));
List<KnowledgeBaseEntry> entries = context.KnowledgeBase.EntryListForStoring(new PredicateIndicator(functor, 1));
switch (entries.Count)
{
case 0:
entries.Add(new KnowledgeBaseVariable(value));
return CutStateSequencer.Succeed();
case 1:
var v = entries[0] as KnowledgeBaseVariable;
if (v==null)
throw new ArgumentException("Functor is not a variable; it has another entry defined for it.");
v.CurrentValue = value;
return CutStateSequencer.Succeed();
default:
throw new ArgumentException("Functor is not a variable; it has multiple entries defined for it.");
}
}
public static bool TryChildQuery(
out ELNode foundNode,
out ELNodeEnumerator enumerator,
object parentExpression,
object keyExpression,
bool isExclusive,
PrologContext context)
{
// Decode the parent expression
ELNode parentNode;
ELNodeEnumerator parentEnumerator;
if (!TryQuery(parentExpression, context, out parentNode, out parentEnumerator))
{
// Parent failed, so we fail
enumerator = null;
foundNode = null;
return false;
}
//
// Decode the key argument
//
var key = keyExpression;
var v = key as LogicVariable;
return isExclusive?TryExclusiveQuery(out foundNode, out enumerator, parentNode, parentEnumerator, key, v)
: TryNonExclusiveQuery(out foundNode, out enumerator, parentNode, key, v, parentEnumerator);
}
public static bool TryQueryStructure(
Structure term,
PrologContext context,
out ELNode foundNode,
out ELNodeEnumerator enumerator)
{
//
// Dispatch based on the functor and arity.
//
// Handle root queries, i.e. /Key
if (term.IsFunctor(Symbol.Slash, 1))
return TryRootQuery(term, context, out foundNode, out enumerator);
if (!IsELTerm(term))
throw new Exception("Malformed EL query: " + ISOPrologWriter.WriteToString(term));
if (term.IsFunctor(SBindNodeOperator, 2))
{
var variableToBind = term.Argument(1) as LogicVariable;
if (variableToBind == null)
throw new ArgumentException("RHS of >> must be an uninstantiated variable: "+ ISOPrologWriter.WriteToString(term.Argument(1)));
foundNode = null;
return TryNodeBindingQuery(out enumerator, term.Argument(0), variableToBind, context);
}
return TryChildQuery(
out foundNode,
out enumerator,
term.Argument(0),
term.Argument(1),
term.Functor == Symbol.Colon,
context);
}
public static bool TryQuery(object term, PrologContext context, out ELNode foundNode, out ELNodeEnumerator enumerator)
{
// Dereference any top-level variables.
var t = Term.Deref(term);
// Dereference indexicals
var i = t as Indexical;
if (i != null)
t = i.GetValue(context);
// A game object means the gameobject's EL KB.
var g = t as GameObject;
if (g != null)
t = g.KnowledgeBase().ELRoot;
// If it's already an ELNode, use that.
var n = t as ELNode;
if (n != null)
{
foundNode = n;
enumerator = null;
return true;
}
// Otherwise, it's an expression, so evaluate it.
var s = t as Structure;
if (s != null)
return TryQueryStructure(s, context, out foundNode, out enumerator);
var v = t as LogicVariable;
if (v != null && !v.IsBound)
throw new Exception("EL query root is an unbound variable: " + v);
throw new Exception("Malformed EL query: " + ISOPrologWriter.WriteToString(term));
}
public static bool TryChildQuery(
out ELNode foundNode,
out ELNodeEnumerator enumerator,
object parentExpression,
object keyExpression,
bool isExclusive,
PrologContext context)
{
// Decode the parent expression
ELNode parentNode;
ELNodeEnumerator parentEnumerator;
if (!TryQuery(parentExpression, context, out parentNode, out parentEnumerator))
{
// Parent failed, so we fail
enumerator = null;
foundNode = null;
return false;
}
//
// Decode the key argument
//
var key = keyExpression;
var v = key as LogicVariable;
return isExclusive?TryExclusiveQuery(out foundNode, out enumerator, parentNode, parentEnumerator, key, v)
: TryNonExclusiveQuery(out foundNode, out enumerator, parentNode, key, v, parentEnumerator);
}
public static bool TryQuery(object term, PrologContext context, out ELNode foundNode, out ELNodeEnumerator enumerator)
{
// Dereference any top-level variables.
var t = Term.Deref(term);
// Dereference indexicals
var i = t as Indexical;
if (i != null)
t = i.GetValue(context);
// A game object means the gameobject's EL KB.
var g = t as GameObject;
if (g != null)
t = g.KnowledgeBase().ELRoot;
// If it's already an ELNode, use that.
var n = t as ELNode;
if (n != null)
{
foundNode = n;
enumerator = null;
return true;
}
// Otherwise, it's an expression, so evaluate it.
var s = t as Structure;
if (s != null)
return TryQueryStructure(s, context, out foundNode, out enumerator);
var v = t as LogicVariable;
if (v != null && !v.IsBound)
throw new Exception("EL query root is an unbound variable: " + v);
throw new Exception("Malformed EL query: " + ISOPrologWriter.WriteToString(term));
}
private void DumpPrologStack(PrologContext context)
{
if (context.GoalStackDepth > 0)
{
for (ushort i = 0; i <= context.CurrentFrame; i++)
{
Structure g = context.GoalStackGoal(i);
if (g != null)
{
ushort frame = i;
while (frame != 0)
{
//Output.Write("{0}/", frame);
Output.Write(" ");
frame = context.GoalStackParent(frame);
}
//Output.Write(' ');
//Output.Write("{0}<{1}: ", i, PrologContext.GoalStackParent(i));
Output.WriteLine(Term.ToStringInPrologFormat(g));
}
}
}
else
{
Output.WriteLine("Goal stack is empty.");
}
}
/// <summary>
/// True if the specified goal is provable within this KnowledgeBase.
/// </summary>
/// <param name="goal">Goal to attempt to prove</param>
/// <param name="thisValue">The value to give ot the $this indexical while running the goal</param>
/// <returns>Success</returns>
public bool IsTrue(object goal, object thisValue = null)
{
var t = Term.Structurify(goal, "Argument to IsTrue() should be a valid Prolog goal.");
bool result;
using (var prologContext = PrologContext.Allocate(this, thisValue))
{
try
{
result = Prove(t.Functor, t.Arguments, prologContext, 0).GetEnumerator().MoveNext();
}
catch (InferenceStepsExceededException)
{
throw;
}
catch (Exception e)
{
throw new PrologError(
e,
prologContext.StackTrace(
Prolog.CurrentSourceFile,
Prolog.CurrentSourceLineNumber,
"IsTrue()",
false) + e.StackTrace);
}
}
return(result);
}
internal override IEnumerable <CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
object[] goal1Args = null;
var newVars = new LogicVariable[FreeVariables.Count];
object[] newArgs = Term.AlphaConvertArglist(HeadArgs, FreeVariables, newVars, context, true);
// ReSharper disable UnusedVariable
#pragma warning disable 414, 168, 219
foreach (bool ignore in Term.UnifyArraysFast(args, newArgs, context))
#pragma warning restore 414, 168, 219
{
if (goal1Args == null)
{
goal1Args = Term.AlphaConvertArglist(BodyGoals[0].Arguments, FreeVariables, newVars, context, false);
}
#pragma warning disable 414, 168, 219
foreach (CutState ignoreFreeze in context.ProveAllWokenGoals())
#pragma warning restore 414, 168, 219
{
// ReSharper restore UnusedVariable
foreach (CutState state1 in context.KnowledgeBase.Prove(BodyGoals[0].Functor, goal1Args, context, parentFrame))
{
yield return(state1);
}
}
}
}
internal override Metastructure MetaVarUnify(LogicVariable l, PrologContext context)
{
if (DelayedGoal != null)
{
context.WakeUpGoal(DelayedGoal);
}
return(MakeSuspension(null, FrozenGoal));
}
internal override bool UnifyWithStructure(Structure value, PrologContext context)
{
if (value == null || value.Functor != Functor || value.Arguments.Length != Arguments.Length)
{
return(false);
}
return(UnifyArrays(Arguments, value.Arguments, context));
}
internal override IEnumerable <CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
if (args.Length != 1)
{
throw new ArgumentCountException("variable", args, new object[] { "Value" });
}
return(Term.UnifyAndReturnCutState(CurrentValue, args[0]));
}
internal IEnumerable <CutState> StackCall(PrologContext context)
{
if (Compiled)
{
return(TestCompiledClauses(context));
}
return(Prove(context.GetCallArgumentsAsArray(Arity), context));
}
internal override Metastructure MetaMetaUnify(Metastructure theirMetaStructure, PrologContext context)
{
var s = theirMetaStructure as Suspension;
if (s == null) throw new ArgumentTypeException("MetaMetaUnify", "theirMetaStructure", theirMetaStructure, typeof(Suspension));
if (context != s.context) throw new ArgumentException("Can't unify suspended goals across PrologContexts.");
context.WakeUpGoal(CombineGoals(DelayedGoal, s.DelayedGoal));
return MakeSuspension(null, CombineGoals(FrozenGoal, s.FrozenGoal));
}
internal static IEnumerable <bool> UnifyArraysFast(object[] a1, object[] a2, PrologContext context)
{
int mark = context.MarkTrail();
if (UnifyArrays(a1, a2, context))
{
yield return(false);
}
context.RestoreVariables(mark);
}
internal static void RetractAll(object term, PrologContext context)
{
ELNode foundNode;
ELNodeEnumerator enumerator;
if (!TryQuery(term, context, out foundNode, out enumerator))
return;
if (foundNode != null)
foundNode.DeleteSelf();
else
while (enumerator.MoveNext()) enumerator.Current.DeleteSelf();
}
/// <summary>
/// Attempts to prove the specified goal.
/// </summary>
internal IEnumerable <CutState> Prove(Symbol functor, object[] args, PrologContext context, ushort parentFrame)
{
context.PushGoalStack(functor, args, parentFrame);
context.NewStep();
PrologPrimitives.PrimitiveImplementation prim;
if (PrologPrimitives.Implementations.TryGetValue(functor, out prim))
{
return(CallPrimitive(functor, prim, args, context));
}
return(ProveFromDB(functor, args, context));
}
public static IEnumerable <CutState> SucceedAndRestoreTrail(PrologContext context, int trailMark)
{
try
{
yield return(CutState.Continue);
}
finally
{
context.RestoreVariables(trailMark);
}
}
private void PushCallArgs(PrologContext context, int framePointer, int arity, ref ushort pc)
{
for (int i = 0; i < arity; i++)
{
byte maybeReg = code[pc++];
object argumentValue = (maybeReg < 0x80) ?
context.GetStack(framePointer, maybeReg & 0x7f)
: GlobalLiteralTable[((maybeReg & 0x7f) << 8) + code[pc++]];
context.SetCallArg(i, argumentValue);
}
}
// ReSharper disable once InconsistentNaming
IEnumerable<CutState> ProveFromDB(Symbol functor, object[] args, PrologContext context)
{
PredicateInfo info = GetPredicateInfo(this, new PredicateIndicator(functor, args.Length));
if (info == null)
{
if (ErrorOnUndefined)
throw new UndefinedPredicateException(functor, args.Length);
return PrologPrimitives.FailImplementation;
}
return info.Prove(args, context);
}
private static bool TryRootQuery(Structure term, PrologContext context, out ELNode foundNode, out ELNodeEnumerator enumerator)
{
// Expression is /Key.
var arg0 = term.Argument(0);
// This is a "/constant" expression, i.e. a top-level lookup.
if (arg0 is LogicVariable)
{
throw new NotImplementedException("Lookups of the form /Variable are not supported.");
}
enumerator = null;
return context.KnowledgeBase.ELRoot.TryLookup(arg0, out foundNode);
}
/// <summary>
/// Merge the information from two Metastructures into one new metastructure.
/// </summary>
/// <param name="theirMetaStructure">The Metastructure to merge with.</param>
/// <param name="context">Context in which to execute suspended goals.</param>
/// <returns>The merged Metastructure.</returns>
public Metastructure MetaMetaUnify(Metastructure theirMetaStructure, PrologContext context)
{
if (theirMetaStructure == null)
{
throw new ArgumentTypeException("MetaMetaUnify", "theirMetaStructure", theirMetaStructure, typeof(Metastructure));
}
if (context != theirMetaStructure.Context)
{
throw new ArgumentException("Can't unify suspended goals across PrologContexts.");
}
context.WakeUpGoal(CombineGoals(DelayedGoal, theirMetaStructure.DelayedGoal));
return(MakeSuspension(null, CombineGoals(FrozenGoal, theirMetaStructure.FrozenGoal)));
}
internal IEnumerable <CutState> AddSuspendedGoal(Structure goal, PrologContext context)
{
var old = MetaBinding;
mValue = new Metastructure(goal, null, context, old);
try
{
yield return(CutState.Continue);
}
finally
{
mValue = (object)old ?? this;
}
}
internal IEnumerable <CutState> AddFrozenGoal(Structure goal, PrologContext context)
{
var old = MetaBinding;
mValue = new Metastructure(null, goal, context, old);
try
{
yield return(CutState.Continue);
}
finally
{
mValue = old;
}
}
internal override IEnumerable <CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
var newVars = new LogicVariable[FreeVariables.Count];
object[] newArgs = Term.AlphaConvertArglist(HeadArgs, FreeVariables, newVars, context, true);
// ReSharper disable UnusedVariable
#pragma warning disable 414, 168, 219
foreach (bool ignore in Term.UnifyArrays(args, newArgs))
#pragma warning restore 414, 168, 219
{
// ReSharper restore UnusedVariable
yield return(CutState.Continue);
}
}
#pragma warning disable 414, 168, 219
/// <summary>
/// Unifies arrays using trailing
/// </summary>
/// <returns>Success</returns>
internal static bool UnifyArrays(object[] a1, object[] a2, PrologContext context)
{
if (a1.Length != a2.Length)
{
return(false);
}
for (int i = 0; i < a1.Length; i++)
{
if (!Unify(a1[i], a2[i], context))
{
return(false);
}
}
return(true);
}
internal static IEnumerable <CutState> Retract(object term, PrologContext context)
{
ELNode foundNode;
ELNodeEnumerator enumerator;
if (!TryQuery(term, context, out foundNode, out enumerator))
{
return(CutStateSequencer.Fail());
}
if (foundNode != null)
{
foundNode.DeleteSelf();
return(CutStateSequencer.Succeed());
}
return(DeleteSuccessive(enumerator));
}
/// <summary>
/// Tests clauses in a randomized order (but still exhaustively).
/// Uses Shuffler to generate a random permutation.
/// </summary>
IEnumerable <CutState> TestShuffledClauses(object[] args, PrologContext context, ushort myFrame)
{
entriesListUsed = true;
var mark = context.MarkTrace();
var shuffler = new Shuffler((ushort)Entries.Count);
var argIndexers = PredicateArgumentIndexer.ArglistIndexers(args);
while (!shuffler.Done)
{
var entry = Entries[shuffler.Next()];
if (entry.Prematch(argIndexers))
{
// This shouldn't be here...
//context.PushGoalStack(Name, args, myFrame);
context.SetCurrentRule(entry);
foreach (var cutState in entry.Prove(args, context, myFrame))
{
if (cutState == CutState.ForceFail)
{
if (KnowledgeBase.Trace || Trace)
{
context.TraceOutput("Cut: {0}", new Structure(Name, args));
}
goto fail;
}
if (KnowledgeBase.Trace || Trace)
{
context.TraceOutput("Succeed: {0}", new Structure(Name, args));
}
yield return(CutState.Continue);
if (KnowledgeBase.Trace || Trace)
{
context.TraceOutput("Retry: {0}", new Structure(Name, args));
}
}
}
}
fail:
context.RestoreVariables(mark);
if (KnowledgeBase.Trace || Trace)
{
context.TraceOutput("Fail: {0}", new Structure(Name, args));
}
//context.UnwindStack(Name, args);
context.UnwindStack(myFrame);
}
private ushort StartCallInstruction(PrologContext context, int framePointer, ref ushort pc, out ushort succeedPC,
out IEnumerator <CutState> iterator)
{
int iteratorRegister = code[pc++];
ushort failPC = GetUShort(ref pc);
succeedPC = GetUShort(ref pc);
iterator = null;
// Make the iterator. How we do this depends on the opcode, so re-fetch it.
switch ((Opcode)code[pc - CallTargetOffset])
{
case Opcode.CallWokenGoals:
{
if (context.GoalsHaveWoken)
{
iterator = context.ProveAllWokenGoals().GetEnumerator();
}
}
break;
case Opcode.Call:
{
// It's a user-defined predicate call
PredicateInfo calledPredicate = GetPredicate(ref pc);
PushCallArgs(context, framePointer, predicate.Arity, ref pc);
iterator = calledPredicate.StackCall(context).GetEnumerator();
}
break;
case Opcode.CallPrimitive:
{
// It's a primitive call
PrologPrimitives.PrimitiveImplementation implementation = GetPrimitive(ref pc);
int arity = code[pc++];
PushCallArgs(context, framePointer, arity, ref pc);
iterator =
PrologPrimitives.StackCall(implementation, arity, context).GetEnumerator();
}
break;
default:
Debug.Assert(false, "Bad call opcode");
break;
}
context.SetStack(framePointer, iteratorRegister, iterator);
return(failPC);
}
private IEnumerable <CutState> TestCompiledClauses(PrologContext context)
{
foreach (var knowledgeBaseEntry in Entries)
{
var rule = (ByteCompiledRule)knowledgeBaseEntry;
foreach (var result in rule.StackCall(context))
{
if (result == CutState.ForceFail)
{
yield break;
}
else
{
yield return(result);
}
}
}
}
private object DecodeOperand(PrologContext context, int framePointer, ref ushort pc)
{
int registerNumber = code[pc++];
object value = Term.Deref(context.GetStack(framePointer, registerNumber & 0x7f));
if (registerNumber < 0x80)
{
return(value);
}
int argNumber = code[pc++];
value = ((Structure)value).Argument(argNumber & 0x7f);
if (argNumber >= 0x80)
{
context.SetStack(framePointer, code[pc++], value);
}
return(value);
}
internal bool UnifyWithCanonicalValue(object value, PrologContext context)
{
if (!IsBound)
{
Metastructure m = MetaBinding;
if (m == null)
{
// We're binding a truly unbound variable to something.
if (value != this)
{
var xl = value as LogicVariable;
if (xl != null)
{
Metastructure xm2;
if ((xm2 = xl.MetaBinding) != null)
{
// We're binding a truly unbound variable to a meta-bound variable
xl.UnifyMetaVar(xm2, this, context);
return(true);
}
}
SaveAndUpdate(value, context); // sets IsBound
}
return(true);
}
// This is an attributed (metabound) variable
var l = value as LogicVariable;
if (l == null)
{
UnifyMetaTerm(m, value, context);
return(true);
}
Metastructure m2 = l.MetaBinding;
if (m2 == null)
{
// Need to alias l to this, that's most easily done by letting l unify to this.
UnifyMetaVar(m, l, context);
return(true);
}
UnifyMetaMeta(m, m2, l, context);
return(true);
}
return(Value.Equals(value));
}
private void SetOperand(PrologContext context, int framePointer, ref ushort pc, object newValue)
{
int registerNumber = code[pc++];
if (registerNumber < 0x80)
{
context.SetStack(framePointer, registerNumber, newValue);
}
else
{
object s = Term.Deref(context.GetStack(framePointer, registerNumber & 0x7f));
int argNumber = code[pc++];
object value = ((Structure)s).Arguments[argNumber & 0x7f] = newValue;
if (argNumber >= 0x80)
{
context.SetStack(framePointer, code[pc++], value);
}
}
}
public static bool TryNodeBindingQuery(
out ELNodeEnumerator enumerator,
object nodeExpression,
LogicVariable variableToBind,
PrologContext context)
{
// Decode the node expression
ELNode foundNode;
ELNodeEnumerator nodeEnumerator;
if (!TryQuery(nodeExpression, context, out foundNode, out nodeEnumerator))
{
// Parent failed, so we fail
enumerator = null;
return false;
}
enumerator = (foundNode != null)
? (ELNodeEnumerator)new ELNodeEnumeratorBindFixedNodeToVariable(foundNode, variableToBind)
: new ELNodeEnumeratorBindEnumeratedNodesToVariable(nodeEnumerator, variableToBind);
return true;
}
/// <summary>
/// Merge the information from two Metastructures into one new metastructure.
/// </summary>
/// <param name="theirMetaStructure">The Metastructure to merge with.</param>
/// <param name="context">Context in which to execute suspended goals.</param>
/// <returns>The merged Metastructure.</returns>
public Metastructure MetaMetaUnify(Metastructure theirMetaStructure, PrologContext context)
{
if (theirMetaStructure == null) throw new ArgumentTypeException("MetaMetaUnify", "theirMetaStructure", theirMetaStructure, typeof(Metastructure));
if (context != theirMetaStructure.Context) throw new ArgumentException("Can't unify suspended goals across PrologContexts.");
context.WakeUpGoal(CombineGoals(DelayedGoal, theirMetaStructure.DelayedGoal));
return MakeSuspension(null, CombineGoals(FrozenGoal, theirMetaStructure.FrozenGoal));
}
private static IEnumerable<CutState> IfThenElseImplementation(object test, object consequent, object alternative, PrologContext context)
{
#pragma warning disable 414, 168, 219
// ReSharper disable UnusedVariable
foreach (var ignore in context.Prove(test, "Arguments to -> must be valid subgoals."))
// ReSharper restore UnusedVariable
{
// ReSharper disable UnusedVariable
foreach (var ignore2 in context.Prove(consequent, "Arguments to -> must be valid subgoals."))
// ReSharper restore UnusedVariable
{
yield return CutState.Continue;
}
yield break;
}
// ReSharper disable UnusedVariable
foreach (var ignore in context.Prove(alternative, "Arguments to -> must be valid subgoals."))
// ReSharper restore UnusedVariable
{
yield return CutState.Continue;
}
#pragma warning restore 414, 168, 219
}
private static IEnumerable<CutState> RealOrImplementation(object[] args, PrologContext context)
{
foreach (var status1 in context.Prove(args[0], "Arguments to ; (or) must be valid subgoals."))
{
if (status1 == CutState.ForceFail)
{
//yield return status1;
yield break;
}
yield return CutState.Continue;
}
foreach (var status2 in context.Prove(args[1], "Arguments to ; (or) must be valid subgoals."))
{
if (status2 == CutState.ForceFail)
{
//yield return status2;
yield break;
}
yield return CutState.Continue;
}
}
internal override bool UnifyWithTerm(Term value, PrologContext context)
{
return value.UnifyWithAtomicConstant(this, context);
}
// ReSharper restore InconsistentNaming
private static IEnumerable<CutState> MapListInternal(Symbol functor, object[] args, object list1, object list2,
PrologContext context)
{
// maplist(_, [], []).
// ReSharper disable UnusedVariable
#pragma warning disable 414, 168, 219
foreach (var ignore in Term.Unify(null, list1))
foreach (var ignore2 in Term.Unify(null, list2))
#pragma warning restore 414, 168, 219
// ReSharper restore UnusedVariable
yield return CutState.Continue;
// maplist(P, [X | XT], [Y | YT]) :- call(P, X, Y), maplist(P, XT, YT).
var x = new LogicVariable(SX);
var xT = new LogicVariable(SXt);
var y = new LogicVariable(SY);
var yT = new LogicVariable(SYt);
// ReSharper disable UnusedVariable
#pragma warning disable 414, 168, 219
foreach (var ignore in Term.Unify(list1, new Structure(Symbol.PrologListConstructor, x, xT)))
foreach (var ignore2 in Term.Unify(list2, new Structure(Symbol.PrologListConstructor, y, yT)))
#pragma warning restore 414, 168, 219
{
// call(P, X, Y)
var realArgs = new object[args.Length + 2];
args.CopyTo(realArgs, 0);
realArgs[realArgs.Length - 2] = x;
realArgs[realArgs.Length - 1] = y;
#pragma warning disable 414, 168, 219
foreach (
var ignore3 in context.KnowledgeBase.Prove(functor, realArgs, context, context.CurrentFrame))
// maplist(P, XT, YT)
foreach (var ignore4 in MapListInternal(functor, args, xT, yT, context))
#pragma warning restore 414, 168, 219
// ReSharper restore UnusedVariable
yield return CutState.Continue;
}
}
/// <summary>
/// Recopy the term to replace variables. If term contains no variables, no recopying is done.
/// </summary>
/// <param name="oldVars">Variables to be replaced</param>
/// <param name="newVars">The corresponding variables that are replacing the oldVars</param>
/// <param name="context">PrologContext to evaluating indexicals</param>
/// <param name="evalIndexicals">If true, any indexicals will be replaced with their values.</param>
/// <returns>Converted term or original term if not conversion necessary</returns>
public abstract object AlphaConvert(
List<LogicVariable> oldVars,
LogicVariable[] newVars,
PrologContext context,
bool evalIndexicals);
internal override IEnumerable<CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
object[] goal1Args = null;
object[] goal2Args = null;
var newVars = new LogicVariable[FreeVariables.Count];
object[] newArgs = Term.AlphaConvertArglist(HeadArgs, FreeVariables, newVars, context, true);
// ReSharper disable UnusedVariable
#pragma warning disable 414, 168, 219
foreach (bool ignore in Term.UnifyArraysFast(args, newArgs, context))
#pragma warning restore 414, 168, 219
{
if (goal1Args == null)
goal1Args = Term.AlphaConvertArglist(BodyGoals[0].Arguments, FreeVariables, newVars, context, false);
#pragma warning disable 414, 168, 219
foreach (CutState ignoreFreeze in context.ProveAllWokenGoals())
// ReSharper restore UnusedVariable
foreach (CutState state1 in context.KnowledgeBase.Prove(BodyGoals[0].Functor, goal1Args, context, parentFrame))
#pragma warning restore 414, 168, 219
{
if (state1 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal2Args == null)
goal2Args = Term.AlphaConvertArglist(BodyGoals[1].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state2 in context.KnowledgeBase.Prove(BodyGoals[1].Functor, goal2Args, context, parentFrame))
yield return state2;
}
}
}
/// <summary>
/// Called after the variable bound to this Metastructure is unified with a non-variable term.
/// </summary>
/// <param name="value">The term to which to unify</param>
/// <param name="contextOfBinding">Context in which to execute suspended goals.</param>
public void MetaTermUnify(object value, PrologContext contextOfBinding)
{
Debug.Assert(contextOfBinding == Context, "Delayed goal woken in a different context than it was created in.");
contextOfBinding.WakeUpGoal(CombineGoals(DelayedGoal, FrozenGoal));
}
/// <summary>
/// Create a new set of suspended goals.
/// </summary>
/// <param name="delayedGoal">Goal to run upon unification with any value.</param>
/// <param name="frozenGoal">Goal to run upon unification with a non-variable term.</param>
/// <param name="prologContext">Context in which to run goals.</param>
public Metastructure(Structure delayedGoal, Structure frozenGoal, PrologContext prologContext)
{
DelayedGoal = delayedGoal;
FrozenGoal = frozenGoal;
Context = prologContext;
}
private static IEnumerable<CutState> NotImplementation(object[] args, PrologContext context)
{
if (args.Length != 1) throw new ArgumentCountException("not", args, "goal");
LogicVariable v = Term.FindUninstantiatedVariable(args[0]);
if (v != null)
throw new InstantiationException(v, "Argument to not must be a ground literal (i.e. contain no unbound variables).");
using (var e = context.Prove(args[0], "Argument to not must be a valid term to prove.").GetEnumerator())
{
if (!e.MoveNext() || e.Current == CutState.ForceFail)
yield return CutState.Continue;
}
}
private static IEnumerable<CutState> OnceImplementation(object[] args, PrologContext context)
{
if (args.Length != 1) throw new ArgumentCountException("once", args, "goal");
#pragma warning disable 414, 168, 219
// ReSharper disable UnusedVariable
foreach (var ignore in context.Prove(args[0], "Argument to once/1 must be a valid subgoal."))
#pragma warning restore 414, 168, 219
{
// ReSharper restore UnusedVariable
yield return CutState.Continue;
yield break;
}
}
private static IEnumerable<CutState> IgnoreImplementation(object[] args, PrologContext context)
{
if (args.Length != 1) throw new ArgumentCountException("ignore", args, "goal");
using (var e = context.Prove(args[0], "Argument to ignore/n must be a valid subgoal.").GetEnumerator())
{
e.MoveNext(); // Ignore whether it succeeded.
yield return CutState.Continue;
}
}
public static object EvalMemberExpression(object obj, object memberExpression, PrologContext context)
{
obj = Eval(obj, context);
memberExpression = Term.Deref(memberExpression);
var methodCall = memberExpression as Structure;
if (methodCall != null)
{
// Method call
var args = new object[methodCall.Arity];
for (var i = 0; i < args.Length; i++)
{
args[i] = Eval(methodCall.Argument(i), context);
}
return obj.InvokeMethod(methodCall.Functor.Name, args);
}
var propName = memberExpression as Symbol;
if (propName != null)
{
// Field or property reference
return obj.GetPropertyOrField(propName.Name);
}
throw new ArgumentException(
"Invalid member expression: " + ISOPrologWriter.WriteToString(new Structure(Symbol.Dot, obj, memberExpression)));
}
public static object Eval(object term, PrologContext context)
{
term = Term.Deref(term);
var indexical = term as Indexical;
if (indexical != null)
return indexical.GetValue(context);
var offendingVariable = term as LogicVariable;
if (offendingVariable != null)
throw new InstantiationException(offendingVariable,
"arithmetic expression cannot be evaluated because it includes an uninstantiated variable.");
var t = term as Structure;
if (t == null)
{
//var s = term as Symbol;
//if (s != null)
// throw new BadProcedureException(s, 0);
//throw new BadProcedureException(term);
return term; // It's a literal.
}
switch (t.Functor.Name)
{
case "+":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("+", t.Arguments, "number1", "number2");
return GenericArithmetic.Add(Eval(t.Arguments[0], context), Eval(t.Arguments[1], context));
case "-":
if (t.Arguments.Length == 2)
return GenericArithmetic.Subtract(Eval(t.Arguments[0], context),
Eval(t.Arguments[1], context));
if (t.Arguments.Length == 1)
return GenericArithmetic.Subtract(Eval(t.Arguments[0], context));
throw new ArgumentException("Wrong number of arguments in - expression; should be 1 or 2.");
case "*":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("*", t.Arguments, "number1", "number2");
return GenericArithmetic.Multiply(Eval(t.Arguments[0], context),
Eval(t.Arguments[1], context));
case "/":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("/", t.Arguments, "number1", "number2");
return GenericArithmetic.Divide(Eval(t.Arguments[0], context),
Eval(t.Arguments[1], context));
case "mod":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("mod", t.Arguments, "number1", "number2");
return Convert.ToInt32(Eval(t.Arguments[0], context))%
Convert.ToInt32((Eval(t.Arguments[1], context)));
case "//":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("//", t.Arguments, "number1", "number2");
return Convert.ToInt32(Eval(t.Arguments[0], context))/
Convert.ToInt32(Eval(t.Arguments[1], context));
case "sqrt":
if (t.Arguments.Length != 1) throw new ArgumentCountException("sqrt", t.Arguments, "number");
return Math.Sqrt(Convert.ToDouble(Eval(t.Arguments[0], context)));
case "abs":
if (t.Arguments.Length != 1) throw new ArgumentCountException("abs", t.Arguments, "number");
return Math.Abs(Convert.ToDouble(Eval(t.Arguments[0], context)));
case "log":
if (t.Arguments.Length != 1) throw new ArgumentCountException("log", t.Arguments, "number");
return Math.Log(Convert.ToDouble(Eval(t.Arguments[0], context)));
case "exp":
if (t.Arguments.Length != 1) throw new ArgumentCountException("exp", t.Arguments, "number");
return Math.Exp(Convert.ToDouble(Eval(t.Arguments[0], context)));
case "floor":
if (t.Arguments.Length != 1) throw new ArgumentCountException("floor", t.Arguments, "number");
return Math.Floor(Convert.ToDouble(Eval(t.Arguments[0], context)));
case "float":
if (t.Arguments.Length != 1) throw new ArgumentCountException("floor", t.Arguments, "number");
return Convert.ToSingle(Eval(t.Arguments[0], context));
case "min":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("min", t.Arguments, "number1", "number2");
return GenericArithmetic.Min(Eval(t.Arguments[0], context), Eval(t.Arguments[1], context));
case "max":
if (t.Arguments.Length != 2)
throw new ArgumentCountException("max", t.Arguments, "number1", "number2");
return GenericArithmetic.Max(Eval(t.Arguments[0], context), Eval(t.Arguments[1], context));
case "magnitude":
{
if (t.Arguments.Length != 1)
throw new ArgumentCountException("magnitude", t.Arguments, "Vector3");
object v = Eval(t.Argument(0), context);
if (!(v is Vector3))
throw new ArgumentTypeException("magnitude", "vector", v, typeof (Vector3));
return ((Vector3) v).magnitude;
}
case "magnitude_squared":
{
if (t.Arguments.Length != 1)
throw new ArgumentCountException("magnitude_squared", t.Arguments, "Vector3");
object v = Eval(t.Argument(0), context);
if (!(v is Vector3))
throw new ArgumentTypeException("magnitude_squared", "vector", v, typeof (Vector3));
return ((Vector3) v).sqrMagnitude;
}
case "distance":
{
if (t.Arguments.Length != 2)
throw new ArgumentCountException("distance", t.Arguments, "v1", "v2");
object v1 = Eval(t.Argument(0), context);
if (v1 is GameObject)
v1 = ((GameObject)v1).transform.position;
object v2 = Eval(t.Argument(1), context);
if (v2 is GameObject)
v2 = ((GameObject)v2).transform.position;
if (!(v1 is Vector3))
throw new ArgumentTypeException("distance", "v1", v1, typeof (Vector3));
if (!(v2 is Vector3))
throw new ArgumentTypeException("distance", "v2", v2, typeof (Vector3));
return Vector3.Distance((Vector3) v1, (Vector3) v2);
}
case "distance_squared":
{
if (t.Arguments.Length != 2)
throw new ArgumentCountException("distance_squared", t.Arguments, "v1", "v2");
object v1 = Eval(t.Argument(0), context);
if (v1 is GameObject)
v1 = ((GameObject)v1).transform.position;
object v2 = Eval(t.Argument(1), context);
if (v2 is GameObject)
v2 = ((GameObject)v2).transform.position;
if (!(v1 is Vector3))
throw new ArgumentTypeException("distance_squared", "v1", v1, typeof (Vector3));
if (!(v2 is Vector3))
throw new ArgumentTypeException("distance_squared", "v2", v2, typeof (Vector3));
return Vector3.SqrMagnitude((Vector3) v1 - (Vector3) v2);
}
case "position":
{
if (t.Arguments.Length != 1)
throw new ArgumentCountException("position", t.Arguments, "gameObject");
var gameObject = Eval(t.Argument(0), context);
var go = gameObject as GameObject;
if (go==null)
throw new ArgumentTypeException("position", "gameObject", gameObject, typeof(GameObject));
return go.transform.position;
}
case ".":
if (t.Arguments.Length != 2)
{
throw new ArgumentCountException(".", t.Arguments, "object");
}
return EvalMemberExpression(t.Arguments[0], t.Arguments[1], context);
case "property":
{
if (t.Arguments.Length != 2)
throw new ArgumentCountException("property", t.Arguments, "object", "property_name");
object o = t.Argument(0);
if (o is Structure)
o = Eval(o, context);
var name = t.Argument(1) as Symbol;
if (name == null)
throw new ArgumentTypeException("property", "property_name", t.Argument(1), typeof(Symbol));
return o.GetPropertyOrField(name.Name);
}
case "vector":
{
if (t.Arguments.Length != 3)
throw new ArgumentCountException("vector", t.Arguments, "x", "y", "z");
return new Vector3(Convert.ToSingle(Eval(t.Argument(0), context)),
Convert.ToSingle(Eval(t.Argument(1), context)),
Convert.ToSingle(Eval(t.Argument(2), context)));
}
case "instance_id":
{
if (t.Arguments.Length != 1)
throw new ArgumentCountException("instance_id", t.Arguments, "game_object");
var arg = t.Argument(0) as UnityEngine.Object;
if (arg == null)
throw new ArgumentTypeException("instance_id", "object", t.Argument(0), typeof(UnityEngine.Object));
return arg.GetInstanceID();
}
default:
throw new BadProcedureException(t.Functor, t.Arguments.Length);
}
}
/// <summary>
/// Called after the variable bound to this Metastructure is unified with an unbound variable
/// that is not (itself) bound to a Metastructure.
/// </summary>
/// <param name="l">The logic variable with which to Unify.</param>
/// <param name="context">Context in which to execute suspended goals.</param>
/// <returns>The Metastructure to bind to the newly aliased variables.</returns>
public Metastructure MetaVarUnify(LogicVariable l, PrologContext context)
{
if (DelayedGoal != null)
context.WakeUpGoal(DelayedGoal);
return MakeSuspension(null, FrozenGoal);
}
internal static System.Collections.Generic.IEnumerable<CutState> Retract(object term, PrologContext context)
{
ELNode foundNode;
ELNodeEnumerator enumerator;
if (!TryQuery(term, context, out foundNode, out enumerator))
return PrologPrimitives.FailDriver();
if (foundNode != null)
{
foundNode.DeleteSelf();
return PrologPrimitives.SucceedDriver();
}
return DeleteSuccessive(enumerator);
}
public Metastructure(Structure delayedGoal, Structure frozenGoal, PrologContext prologContext, Metastructure old)
: this(CombineGoals(delayedGoal, old?.DelayedGoal),
CombineGoals(frozenGoal, old?.FrozenGoal),
prologContext)
{
}
internal static void RetractAll(object term, PrologContext context)
{
ELNode foundNode;
ELNodeEnumerator enumerator;
if (!TryQuery(term, context, out foundNode, out enumerator))
return;
if (foundNode != null)
foundNode.DeleteSelf();
else
while (enumerator.MoveNext()) enumerator.Current.DeleteSelf();
}
internal override IEnumerable<CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
var newVars = new LogicVariable[FreeVariables.Count];
object[] newArgs = Term.AlphaConvertArglist(HeadArgs, FreeVariables, newVars, context, true);
// ReSharper disable UnusedVariable
#pragma warning disable 414, 168, 219
foreach (bool ignore in Term.UnifyArrays(args, newArgs))
#pragma warning restore 414, 168, 219
// ReSharper restore UnusedVariable
yield return CutState.Continue;
}
private static IEnumerable<CutState> IfThenImplementation(object[] args, PrologContext context)
{
if (args.Length != 2) throw new ArgumentCountException("->", args, "if_condition", "then_result");
#pragma warning disable 414, 168, 219
// ReSharper disable UnusedVariable
foreach (var ignore in context.Prove(args[0], "Arguments to -> must be valid subgoals."))
// ReSharper restore UnusedVariable
{
// ReSharper disable UnusedVariable
foreach (var ignore2 in context.Prove(args[1], "Arguments to -> must be valid subgoals."))
// ReSharper restore UnusedVariable
#pragma warning restore 414, 168, 219
{
yield return CutState.Continue;
}
yield break;
}
}
internal override IEnumerable<CutState> Prove(object[] args, PrologContext context, ushort parentFrame)
{
object[] goal1Args = null;
object[] goal2Args = null;
object[] goal3Args = null;
object[] goal4Args = null;
object[] goal5Args = null;
object[] goal6Args = null;
object[] goal7Args = null;
object[] goal8Args = null;
var newVars = new LogicVariable[FreeVariables.Count];
object[] newArgs = Term.AlphaConvertArglist(HeadArgs, FreeVariables, newVars, context, true);
// ReSharper disable UnusedVariable
foreach (bool ignore in Term.UnifyArraysFast(args, newArgs, context))
{
if (goal1Args == null)
goal1Args = Term.AlphaConvertArglist(BodyGoals[0].Arguments, FreeVariables, newVars, context, false);
foreach (CutState ignoreFreeze in context.ProveAllWokenGoals())
// ReSharper restore UnusedVariable
foreach (CutState state1 in context.KnowledgeBase.Prove(BodyGoals[0].Functor, goal1Args, context, parentFrame))
{
if (state1 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal2Args == null)
goal2Args = Term.AlphaConvertArglist(BodyGoals[1].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state2 in context.KnowledgeBase.Prove(BodyGoals[1].Functor, goal2Args, context, parentFrame))
{
if (state2 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal3Args == null)
goal3Args = Term.AlphaConvertArglist(BodyGoals[2].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state3 in context.KnowledgeBase.Prove(BodyGoals[2].Functor, goal3Args, context, parentFrame))
{
if (state3 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal4Args == null)
goal4Args = Term.AlphaConvertArglist(BodyGoals[3].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state4 in context.KnowledgeBase.Prove(BodyGoals[3].Functor, goal4Args, context, parentFrame))
{
if (state4 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal5Args == null)
goal5Args = Term.AlphaConvertArglist(BodyGoals[4].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state5 in context.KnowledgeBase.Prove(BodyGoals[4].Functor, goal5Args, context, parentFrame))
{
if (state5 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal6Args == null)
goal6Args = Term.AlphaConvertArglist(BodyGoals[5].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state6 in context.KnowledgeBase.Prove(BodyGoals[5].Functor, goal6Args, context, parentFrame))
{
if (state6 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal7Args == null)
goal7Args = Term.AlphaConvertArglist(BodyGoals[6].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state7 in context.KnowledgeBase.Prove(BodyGoals[6].Functor, goal7Args, context, parentFrame))
{
if (state7 == CutState.ForceFail) yield return CutState.ForceFail;
if (goal8Args == null)
goal8Args = Term.AlphaConvertArglist(BodyGoals[7].Arguments, FreeVariables, newVars, context, false);
foreach (CutState state8 in context.KnowledgeBase.Prove(BodyGoals[7].Functor, goal8Args, context, parentFrame))
{
yield return state8;
}
}
}
}
}
}
}
}
}
}
private static bool TryRootQuery(Structure term, PrologContext context, out ELNode foundNode, out ELNodeEnumerator enumerator)
{
// Expression is /Key.
var arg0 = term.Argument(0);
// This is a "/constant" expression, i.e. a top-level lookup.
if (arg0 is LogicVariable)
{
throw new NotImplementedException("Lookups of the form /Variable are not supported.");
}
enumerator = null;
return context.KnowledgeBase.ELRoot.TryLookup(arg0, out foundNode);
}
private static IEnumerable<CutState> NotPlusImplementation(object[] args, PrologContext context)
{
if (args.Length != 1) throw new ArgumentCountException("\\+", args, "goal");
using (var e = context.Prove(args[0], "Argument to \\+ must be a valid term to prove.").GetEnumerator())
{
if (!e.MoveNext() || e.Current == CutState.ForceFail)
yield return CutState.Continue;
}
}
private static IEnumerable<CutState> MapListImplementation(object[] args, PrologContext context)
{
if (args.Length != 3)
throw new ArgumentCountException("maplist", args, "predicate", "list1", "list2");
object predicate = Term.Deref(args[0]);
var functor = predicate as Symbol;
object[] arguments;
if (functor != null)
{
arguments = NoArgs;
}
else
{
var t = predicate as Structure;
if (t != null)
{
functor = t.Functor;
arguments = t.Arguments;
}
else
throw new ArgumentTypeException("maplist", "predicate", predicate, typeof (Symbol));
}
return MapListInternal(functor, arguments, args[1], args[2], context);
}
