private static ILispValue EvaluateSet(IList <ILispValue> args, ILispEnvironment environment)
{
if (args.Count < 2)
{
throw new SignatureMismatchException("too few arguments supplied");
}
if (args.Count > 2)
{
throw new SignatureMismatchException("too many arguments supplied");
}
// this is a special form since we do not evaluate the first argument, which must be a symbol
if (args[0].Type != LispValueType.Symbol)
{
throw new TypeMismatchException(new Symbol("variable"), LispValueType.Symbol, args[0].Type);
}
ILispValue value = Evaluate(args[1], environment);
environment.Set((Symbol)args[0], value);
return(value);
}
