public Functor3(Atom name, object arg1, object arg2, object arg3)
{
_name = name;
_arg1 = arg1;
_arg2 = arg2;
_arg3 = arg3;
}
/// <summary>
/// Return the unique Atom object for name where module is null. You should use this to create
/// an Atom instead of calling the Atom constructor.
/// </summary>
/// <param name="name"></param>
/// <returns></returns>
public static Atom a(string name)
{
Atom atom;
if (!_atomStore.TryGetValue(name, out atom))
{
atom = new Atom(name, null);
_atomStore[name] = atom;
}
return atom;
}
/// <summary>
/// Return an Atom, Functor1, Functor2, Functor3 or Functor depending on the
/// length of args.
/// Note that this is different than the Functor constructor which requires
/// the length of args to be greater than 3.
/// </summary>
/// <param name="name"></param>
/// <param name="args"></param>
/// <returns></returns>
public static object make(Atom name, object[] args)
{
if (args.Length <= 0)
return name;
else if (args.Length == 1)
return new Functor1(name, args[0]);
else if (args.Length == 2)
return new Functor2(name, args[0], args[1]);
else if (args.Length == 3)
return new Functor3(name, args[0], args[1], args[2]);
else
return new Functor(name, args);
}
public Functor(Atom name, object[] args)
{
if (args.Length <= 3)
{
if (args.Length == 0)
throw new Exception("For arity 0 functor, just use name as an Atom");
else if (args.Length == 1)
throw new Exception("For arity 1 functor, use Functor1");
else if (args.Length == 2)
throw new Exception("For arity 2 functor, use Functor2");
else if (args.Length == 3)
throw new Exception("For arity 3 functor, use Functor3");
else
// (This shouldn't happen, but include it for completeness.
throw new Exception("Cannot create a Functor of arity " + args.Length);
}
_name = name;
_args = args;
}
public Functor1(Atom name, object arg1)
{
_name = name;
_arg1 = arg1;
}
/// <summary>
/// Return true if there is a dynamic or static predicate with name and arity.
/// This returns false for built-in predicates.
/// </summary>
/// <param name="name"></param>
/// <param name="arity"></param>
/// <param name="declaringClass">used to resolve references to the default
/// module Atom.a(""). If a declaringClass is needed to resolve the reference but it is
/// null, return false</param>
/// <returns></returns>
public static bool isCurrentPredicate(Atom name, int arity, Type declaringClass)
{
CompilerState state = new CompilerState();
Variable FunctionName = new Variable();
foreach (bool l1 in functorCallFunctionName(state, name, arity, FunctionName))
{
Atom functionNameAtom = ((Atom)FunctionName.getValue());
if (functionNameAtom == Atom.NIL)
// name is for a dynamic predicate.
return YP.isDynamicCurrentPredicate(name, arity);
string methodName = functionNameAtom._name;
if (methodName.StartsWith("YP."))
// current_predicate/1 should fail for built-ins.
return false;
if (methodName.Contains("."))
// We don't support calling inner classes, etc.
return false;
if (declaringClass == null)
return false;
foreach (MemberInfo member in declaringClass.GetMember(methodName))
{
MethodInfo method = member as MethodInfo;
if (method == null)
continue;
if ((method.Attributes | MethodAttributes.Static) == 0)
// Not a static method.
continue;
if (method.GetParameters().Length == arity)
return true;
}
}
return false;
}
/// <summary>
/// If the functor with name and args can be called directly as determined by
/// functorCallFunctionName, then call it and return its iterator. If the predicate is
/// dynamic and undefined, or if static and the method cannot be found, return
/// the result of YP.unknownPredicate.
/// This returns null if the functor has a special form than needs to be compiled
/// (including ,/2 and ;/2).
/// </summary>
/// <param name="name"></param>
/// <param name="args"></param>
/// <param name="declaringClass">used to resolve references to the default
/// module Atom.a(""). If a declaringClass is needed to resolve the reference but it is
/// null, this throws a PrologException for existence_error</param>
/// <returns></returns>
public static IEnumerable<bool> getSimpleIterator(Atom name, object[] args, Type declaringClass)
{
CompilerState state = new CompilerState();
Variable FunctionName = new Variable();
foreach (bool l1 in functorCallFunctionName(state, name, args.Length, FunctionName))
{
Atom functionNameAtom = ((Atom)FunctionName.getValue());
if (functionNameAtom == Atom.NIL)
// name is for a dynamic predicate.
return YP.matchDynamic(name, args);
string methodName = functionNameAtom._name;
// Set the default for the method to call.
Type methodClass = declaringClass;
bool checkMode = false;
if (methodName.StartsWith("YP."))
{
// Assume we only check mode in calls to standard Prolog predicates in YP.
checkMode = true;
// Use the method in class YP.
methodName = methodName.Substring(3);
methodClass = typeof(YP);
}
if (methodName.Contains("."))
// We don't support calling inner classes, etc.
return null;
if (methodClass == null)
return YP.unknownPredicate
(name, args.Length,
"Cannot find predicate function for: " + name + "/" + args.Length +
" because declaringClass is null. Set declaringClass to the class containing " +
methodName);
try
{
if (checkMode)
{
assertYPPred(state);
object functor = Functor.make(name, args);
if (CompilerState.isDetNoneOut(state, functor))
{
methodClass.InvokeMember
(methodName, BindingFlags.InvokeMethod, null, null, args);
return YP.succeed();
}
if (CompilerState.isSemidetNoneOut(state, functor))
{
if ((bool)methodClass.InvokeMember
(methodName, BindingFlags.InvokeMethod, null, null, args))
return YP.succeed();
else
return YP.fail();
}
}
return (IEnumerable<bool>)methodClass.InvokeMember
(methodName, BindingFlags.InvokeMethod, null, null, args);
}
catch (TargetInvocationException exception)
{
throw exception.InnerException;
}
catch (MissingMethodException)
{
return YP.unknownPredicate
(name, args.Length,
"Cannot find predicate function " + methodName + " for " + name + "/" + args.Length +
" in " + methodClass.FullName);
}
}
return null;
}
public TypeErrorInfo(Atom Type, object Culprit, object Message)
{
_Type = Type;
_Culprit = Culprit;
_Message = Message;
}
public Functor2(Atom name, object arg1, object arg2)
{
_name = name;
_arg1 = arg1;
_arg2 = arg2;
}
/// <summary>
/// Return an Atom object with the name and module. If module is null or Atom.NIL,
/// this behaves like Atom.a(name) and returns the unique object where the module is null.
/// If module is not null or Atom.NIL, this may or may not be the same object as another Atom
/// with the same name and module.
/// </summary>
/// <param name="name"></param>
/// <param name="module"></param>
/// <returns></returns>
public static Atom a(string name, Atom module)
{
if (module == null || module == Atom.NIL)
return a(name);
return new Atom(name, module);
}
/// <summary>
/// You should not call this constructor, but use Atom.a instead.
/// </summary>
/// <param name="name"></param>
/// <param name="module"></param>
private Atom(string name, Atom module)
{
_name = name;
_module = module;
}
/// <summary>
/// Return true if _name is lexicographically less than atom._name.
/// </summary>
/// <param name="atom"></param>
/// <returns></returns>
public bool LessThan(Atom atom)
{
return _name.CompareTo(atom._name) < 0;
}
