public static ILispNode ApplyDynamicFunction(Lambda lambda, LispList arguments, CallStack callStack, params object [] args)
{
try
{
callStack.PushFrame();
var functionBodyStatements = lambda.Body;
var fOptional = false;
for (var iParam = 0; iParam < lambda.FormalParameters.Count; iParam++)
{
var param = lambda.FormalParameters[iParam];
Debug.Assert(param is LispAtom, "Formal Parameter should be an Atom");
var paramName = (param as LispAtom).ValueAsString;
Debug.Assert(paramName != String.Empty, "Formal Parameter name cannot be a null string");
fOptional |= paramName.EndsWith("?");
paramName = paramName.TrimEnd('?');
ILispNode paramValue = null;
try
{
paramValue = arguments[iParam].Eval(callStack, true);
if (paramValue is LispMissing)
{
throw new Exception("Value to be bound cannot be evaluated");
}
}
catch
{
if (!fOptional)
{
throw new Exception(String.Format("Cannot find value to bind to {0}", paramName));
}
paramValue = new LispNil();
}
finally
{
Debug.Assert(paramValue != null, paramName + " is bound to null");
var invocationParamName = String.Format("{0}_{1}", paramName, callStack.NumberOfFrames);
callStack[invocationParamName] = paramValue;
functionBodyStatements = functionBodyStatements.Select(x => ReplaceParamName(x, paramName, invocationParamName)).ToList();
}
}
ILispNode result = new LispNil();
foreach (var statement in functionBodyStatements)
{
result = statement.Eval(callStack);
}
return(result);
}
finally
{
callStack.PopFrame();
}
}
public ILispNode Clone()
{
var result = new LispList();
ForEach(x => result.Add(x.Clone()));
return(result);
}
public LispList(LispList parent)
{
Parent = parent;
if (Parent != null)
{
Parent.Add(this);
}
}
public LispAtom(LispList parent, string tokenValue, Token token)
{
Parent = parent;
TokenValue = tokenValue;
Token = token;
SetValue(tokenValue as object);
if (Parent != null)
{
Parent.Add(this);
}
}
public ILispNode Eval(CallStack callStack, params object [] args)
{
try
{
// ()
if (Count == 0)
{
return(_nil);
}
var functor = this[0].Eval(callStack, false);
// ( =>nil )
if (functor is LispNil)
{
return(_nil);
}
// ( =>missing )
if (functor is LispMissing)
{
return(functor);
}
var arguments = new LispList();
do
{
if (IsImproperList)
{
arguments.Add(this[1] as LispAtom);
continue;
}
arguments = new LispList(null, this.Skip(1));
}while (false);
// ( =>(lambda) ) and ( =>'funcname' )
return(Functor.Apply(functor, arguments, callStack, args));
}
catch (LispException)
{
throw;
}
catch (Exception ex)
{
throw new LispException(this, "Exception while applying functor to arguments", ex);
}
}
public LispList(LispList parent, IEnumerable <ILispNode> value) : base(value)
{
Parent = parent;
}
public LispAtom(LispList parent, object value) : this(parent, String.Empty, Token.MAX)
{
SetValue(value);
}
public Defun(string functionName, LispList formalParameters, IList <ILispNode> body) : base(formalParameters, body)
{
FunctionName = functionName;
}
public Lambda(LispList formalParameters, IList <ILispNode> body)
{
FormalParameters = formalParameters;
Body = body;
}
public static ILispNode Apply(ILispNode functor, LispList arguments, CallStack callStack, params object [] args)
{
if (functor is LispNil)
{
return(new LispNil());
}
if (functor is LispMissing)
{
throw new Exception("Cannot apply a Functor of type Missing!");
}
Lambda lambda = null;
do
{
if (functor is LispAtom)
{
var functionName = (functor as LispAtom).ValueAsString;
if (functionName == String.Empty)
{
throw new Exception("functor's ValueAsString is Empty!");
}
var resolvedFunctor = ResolveFunctor(functionName, callStack, args);
if (resolvedFunctor.DynamicFunction != null)
{
lambda = resolvedFunctor.DynamicFunction;
break;
}
foreach (var nativeFunction in resolvedFunctor.NativeFunctions)
{
try
{
#if TRACE_FLOW
var strTrace = String.Format("{0}({1} {2})", new String(' ', callStack.NumberOfFrames), functionName, arguments.ToString().Unlist());
_calls.Push(strTrace);
#endif
var result = nativeFunction.Invoke(functor, arguments, callStack, args);
#if TRACE_FLOW
#if TRACE_FLOW_VERBOSE
Console.WriteLine("{0} => {1}\n{2}", Calls.Pop(), result.ToString(), callStack.ToString());
#else
Console.WriteLine("{0} => {1}", _calls.Pop(), result);
#endif
#endif
return(result);
}
#if TRACE_FLOW
catch (Exception ex)
{
Console.WriteLine(
"({0} {1}) throws: {2}",
nativeFunction.GetType().FullName + "." + nativeFunction.Method.Name,
arguments.ToLispArgString(),
ex.Message);
Console.WriteLine("Stack:\n{0}", _calls.ToList().Aggregate(String.Empty, (r, x) => r + ("\n" + x)));
continue;
}
#else
catch
{
continue;
}
#endif
}
}
if (functor is LispList)
{
var lambdaExpression = (functor as LispList);
lambda = new Lambda(lambdaExpression.Car as LispList, lambdaExpression.Cdr as IList <ILispNode>);
}
}while (false);
try
{
return(ApplyDynamicFunction(lambda, arguments, callStack, args));
}
catch (Exception ex)
{
Console.WriteLine("({0} {1}) throws: {2}", lambda, arguments.ToLispArgString(), ex.Message);
}
throw new LispException(functor, String.Format("{0} : All known implementations have failed: ", functor));
}