public bool Lookup(Symbol ident)
{
if (Variables.ContainsKey(ident.Name))
{
return(true);
}
return(Parent != null && Parent.Lookup(ident));
}
public Cons MacroProcessing(Cons seq) // TODO
{
var rseq = new Cons();
foreach (var o in seq.GetIterator())
{
var exp = o.Car();
if (exp is Cons)
{
var op = exp.Car() as Symbol;
var arguments = exp.Cdr() as Cons;
if (op?.Name == "define-syntax")
{
DefineMacro(arguments);
continue;
}
else if (Macro.Lookup(op))
{
foreach (var o1 in (Macro.Get(op).Expand(arguments)).GetIterator())
{
if (o1.Car() is Cons)
{
rseq.Add(MacroProcessing(o1.Car()));
}
else
{
rseq.Add(o1.Car());
}
}
continue;
}
rseq.Add(MacroProcessing(exp));
}
else
{
rseq.Add(exp);
var rest = o?.Cdr();
if (!(rest is Cons))
{
rseq.Add(rest, true);
}
}
}
return(rseq);
}
public static Cons MExpand(Cons seq) // TODO
{
var rseq = new Cons();
foreach (var o in seq.GetIterator())
{
var exp = o.Car();
if (exp is Cons)
{
var op = exp.Car() as Symbol;
var arguments = exp.Cdr() as Cons;
if (op?.Name == "defmacro")
{
var mName = arguments?.Car().Car() as Symbol;
var mArg = arguments?.Car().Cdr() as Cons;
var mBody = arguments?.Cdr() as Cons;
macro.Define(mName, new Macro(mArg, mBody));
continue;
}
else if (macro.Lookup(op))
{
foreach (var o1 in (macro.Get(op).Expand(arguments)).GetIterator())
{
rseq.Add(o1.Car());
}
continue;
}
}
rseq.Add(exp);
}
return(rseq);
}