public static ILispNode Cond(ILispNode functor, IList <ILispNode> arguments, CallStack callStack, params object[] args)
{
#if TRACE_FLOW
try
{
#endif
var missing = new LispMissing();
if (arguments.Count < 1)
{
throw new Exception("COND requires at least 1 argument");
}
for (var i = 0; i <= arguments.Count; i++)
{
var _case = arguments[i];
if (_case is LispMissing)
{
missing.Merge(_case);
continue;
}
if (!(_case is LispList) && ((_case as LispList).Count != 2))
{
throw new Exception("Each COND case requires exactly 2 arguments");
}
var test = (_case as LispList)[0].Eval(callStack, true);
if (test is LispMissing)
{
missing.Merge(test);
continue;
}
if ((test is LispNil) || (!(test as LispAtom).ValueAsBoolean))
{
continue;
}
return((_case as LispList)[1].Eval(callStack, true));
}
return(new LispNil());
#if TRACE_FLOW
}
catch (Exception ex)
{
Console.WriteLine("cond threw Exception: " + ex.Message);
throw;
}
finally
{
Console.WriteLine("(cond {0}) done", arguments.ToLispArgString());
}
#endif
}
public static ILispNode List(ILispNode functor, IList <ILispNode> arguments, CallStack callStack, params object[] args)
{
#if TRACE_FLOW
try
{
#endif
if (arguments.Count < 1)
{
return(new LispNil());
}
var missing = new LispMissing();
var result = new LispList();
foreach (var xEval in arguments.Select(x => x.Eval(callStack, true)))
{
if (xEval is LispMissing)
{
missing.Merge(xEval);
}
else
{
result.Add(xEval);
}
}
return((missing.Count() > 0)
? missing
: result as ILispNode);
#if TRACE_FLOW
}
catch (Exception ex)
{
Console.WriteLine("list threw Exception: " + ex.Message);
throw;
}
finally
{
Console.WriteLine("(list {0}) done", arguments.ToLispArgString());
}
#endif
}
public static ILispNode Cons(ILispNode functor, IList <ILispNode> arguments, CallStack callStack, params object[] args)
{
#if TRACE_FLOW
try
{
#endif
var missing = new LispMissing();
var result = new LispList();
if (arguments.Count != 2)
{
throw new Exception("CONS requires exactly 2 arguments");
}
do
{
var car = arguments[0].Eval(callStack, true);
if (car is LispMissing)
{
missing.Merge(car);
break;
}
result.Add(car);
var cdr = arguments[1].Eval(callStack, true);
if (cdr is LispNil)
{
break;
}
if ((cdr is LispAtom) && (cdr as LispAtom).IsNil)
{
break;
}
if (cdr is LispMissing)
{
missing.Merge(cdr);
break;
}
if (cdr is LispList)
{
if ((cdr as LispList).IsNil)
{
break;
}
(cdr as LispList).ForEach(
x =>
{
try
{
var xEval = x.Eval(callStack, true);
missing.Merge(xEval);
if (xEval is LispMissing)
{
throw new Exception();
}
result.Add(xEval);
}
catch
{
result.Add(x);
}
});
}
else
{
result.IsImproperList = true;
result.Add(cdr);
}
} while (false);
return((missing.Count() > 0)
? missing
: result as ILispNode);
#if TRACE_FLOW
}
catch (Exception ex)
{
Console.WriteLine("cons threw Exception: " + ex.Message);
throw;
}
finally
{
Console.WriteLine("(cons {0}) done", arguments.ToLispArgString());
}
#endif
}