/// <summary>
/// Instantiates a new function predicate.
/// </summary>
/// <param name="resolutionType">The type of resolution for the function.</param>
/// <param name="predicate">The predicate value, i.e. the string representation of the function predicate.</param>
/// <param name="bob">The business object binder to use when evaluating the function, or null.</param>
/// <param name="name">The name of the function, as it was analyzed by the binder.</param>
/// <param name="arguments">The array of arguments of the function, as it was analyzed by the binder.</param>
public Function(FunctionResolutionType resolutionType, string predicate, IBinder bob, string name, params string[] arguments)
: base(predicate)
{
this.resolutionType = resolutionType;
this.bob = bob;
this.name = name;
this.arguments = arguments;
HashCodeBuilder hcb = new HashCodeBuilder(base.GetHashCode()).Append(resolutionType).Append(bob).Append(name);
foreach(string argument in arguments) hcb.Append(argument);
hashCode = hcb.Value;
// precalculate the function signature to use in the binder to evaluate the function
functionSignature = Parameter.BuildFunctionSignature(name, arguments);
}
/// <summary>
/// Instantiates a new atom group.
/// </summary>
/// <param name="logicalOperator">The operator that characterizes the relationship between the atoms and atoms group.</param>
/// <param name="members">An array containing atoms and atom groups.</param>
/// <param name="runningMembers">An array containing atoms and atom groups that will actually be run (they can be different
/// from the members because of atom equivalence).</param>
internal AtomGroup(LogicalOperator logicalOperator, object[] members, object[] runningMembers)
{
this.logicalOperator = logicalOperator;
this.members = members;
HashCodeBuilder hcb = new HashCodeBuilder();
hcb.Append(logicalOperator);
SortedList<int, object> sortedMembers = new SortedList<int, object>(Comparer<int>.Default);
// check the members, compute hashcode and build sorted members list
for(int i=0; i < members.Length; i++) {
object member =members[i];
if (member == null) {
throw new BREException("An atom group can not contain a null member");
}
else if (member is AtomGroup) {
if (((AtomGroup)member).logicalOperator == logicalOperator)
throw new BREException("An atom group can not contain another group with the same logical operator");
}
else if (member is Atom) {
if (((Atom)member).HasFormula)
throw new BREException("An atom group can not contain an atom that contains a formula");
}
else {
throw new BREException("An atom group can not hold objects of type: " + member.GetType());
}
hcb.Append(member);
if (runningMembers == null) sortedMembers.Add(GetMemberSortedIndex(members, i), member);
}
hashCode = hcb.Value;
// the members actually used when processing the atom group are not the ones defined in the rule file (usually because of equivalent atoms definitions)
if (runningMembers != null) {
for(int i=0; i < runningMembers.Length; i++) sortedMembers.Add(GetMemberSortedIndex(runningMembers, i), runningMembers[i]);
}
orderedMembers = sortedMembers.Values;
allAtoms = new List<Atom>();
foreach(object member in orderedMembers) {
if (member is Atom) allAtoms.Add((Atom)member);
else if (member is AtomGroup) allAtoms.AddRange(((AtomGroup)member).AllAtoms);
}
}
/// <summary>
/// Instantiates a new Atom.
/// </summary>
/// <param name="negative">Negative Atom.</param>
/// <param name="type">The relation type of the Atom.</param>
/// <param name="members">Array of predicates associated in the Atom.</param>
/// <remarks>This is the principal constructor for Atom and descendant objects.</remarks>
public Atom(bool negative, string type, params IPredicate[] members)
{
this.negative = negative;
this.type = type;
// load the predicates, extracting the slot names if any
predicates = new IPredicate[members.Length];
slotNames = new string[members.Length];
hasSlot = false;
for(int i=0; i<members.Length; i++) {
if (members[i] is Slot) {
hasSlot = true;
Slot slot = (Slot)members[i];
predicates[i] = slot.Predicate;
slotNames[i] = slot.Name;
}
else {
predicates[i] = members[i];
slotNames[i] = String.Empty;
}
}
// initialize long hashcode & other characteristics
HashCodeBuilder hcb = new HashCodeBuilder().Append(type);
isFact = true;
hasFunction = false;
hasFormula = false;
hasIndividual = false;
onlyVariables = true;
foreach(IPredicate member in predicates) {
hcb.Append(member);
if (member is Individual) hasIndividual = true;
else isFact = false;
if (!(member is Variable)) onlyVariables = false;
if (member is Function) hasFunction = true;
else if (member is Formula) hasFormula = true;
}
hashCode = hcb.Value;
// initialize signature
signature = type + predicates.Length;
}
