public override void print(int n)
{
// there got to be a more efficient way to print n spaces
for (int i = 0; i < n; i++)
{
Console.Write(' ');
}
Console.WriteLine("#{Environment");
if (frame != null)
{
frame.print(Math.Abs(n) + 4);
}
if (env != null)
{
env.print(Math.Abs(n) + 4);
}
for (int i = 0; i < Math.Abs(n); i++)
{
Console.Write(' ');
}
Console.WriteLine('}');
}
public override Node apply(Node args)
{
if (args == null)
{
return(null);
}
String symbolType = symbol.getName();
Node arg1 = args.getCar();
Node arg2 = args.getCdr();
if (arg1.isNull())
{
arg1 = Nil.getInstance();
}
if (arg2.isNull())
{
arg2 = Nil.getInstance();
}
else
{
arg2 = args.getCdr().getCar();
}
if (symbolType.Equals("b+"))
{
if (arg1.isNumber() & arg2.isNumber())
{
return(new IntLit(arg1.getValue() + arg2.getValue()));
}
else
{
return(new StringLit("Error: Both arguments must be numbers for b+"));
}
}
if (symbolType.Equals("b-"))
{
if (arg1.isNumber() & arg2.isNumber())
{
return(new IntLit(arg1.getValue() - arg2.getValue()));
}
else
{
return(new StringLit("Error: Both arguments must be numbers for b-"));
}
}
if (symbolType.Equals("b*"))
{
if (arg1.isNumber() & arg2.isNumber())
{
return(new IntLit(arg1.getValue() * arg2.getValue()));
}
else
{
return(new StringLit("Error: Both arguments must be numbers for b*"));
}
}
if (symbolType.Equals("b/"))
{
if (arg1.isNumber() & arg2.isNumber())
{
return(new IntLit(arg1.getValue() / arg2.getValue()));
}
else
{
return(new StringLit("Error: Both arguments must be numbers for b/"));
}
}
if (symbolType.Equals("b="))
{
if (arg1.isNumber() & arg2.isNumber())
{
return(new BoolLit(arg1.getValue() == arg2.getValue()));
}
else
{
return(new StringLit("Error: Both arguments must be numbers for b="));
}
}
if (symbolType.Equals("b<"))
{
if (arg1.isNumber() & arg2.isNumber())
{
return(new BoolLit(arg1.getValue() < arg2.getValue()));
}
else
{
return(new StringLit("Error: Both arguments must be numbers for b<"));
}
}
if (symbolType.Equals("null?"))
{
return(new BoolLit(arg1.isNull()));
}
if (symbolType.Equals("number?"))
{
return(new BoolLit(arg1.isNumber()));
}
if (symbolType.Equals("pair?"))
{
return(new BoolLit(arg1.isPair()));
}
if (symbolType.Equals("symbol?"))
{
return(new BoolLit(arg1.isSymbol()));
}
if (symbolType.Equals("procedure?"))
{
return(new BoolLit(arg1.isProcedure()));
}
if (symbolType.Equals("car"))
{
if (arg1.isNull())
{
return(arg1);
}
return(arg1.getCar());
}
if (symbolType.Equals("cdr"))
{
if (arg1.isNull())
{
return(arg1);
}
return(arg1.getCdr());
}
if (symbolType.Equals("set-car!"))
{
arg1.setCar(arg2);
return(arg1);
}
if (symbolType.Equals("set-cdr!"))
{
arg1.setCdr(arg2);
return(arg1);
}
if (symbolType.Equals("cons"))
{
return(new Cons(arg1, arg2));
}
if (symbolType.Equals("eq?"))
{
return(new BoolLit(arg1 == arg2));
}
if (symbolType.Equals("display"))
{
return(arg1);
}
if (symbolType.Equals("write"))
{
//write calls your pretting printer
arg1.print(0);
return(new StringLit(""));
}
if (symbolType.Equals("eval"))
{
//eval calls your C# eval() function
return(eval(arg1, env));
}
if (symbolType.Equals("apply"))
{
//apply calls your C# apply function
return(arg1.apply(arg2));
}
if (symbolType.Equals("newline"))
{
return(new StringLit(""));
}
if (symbolType.Equals("read"))
{
Scanner io = new Scanner(Console.In);
TreeBuilder tree = new TreeBuilder();
Parser parse = new Parser(io, tree);
Node theNode = (Node)parse.parseExp();
return(theNode);
}
if (symbolType.Equals("interaction-environment"))
{
env.print(0);
}
else
{
arg1.print(0);
return(Nil.getInstance());
}
return(Nil.getInstance());
}