public static void Extend(Symbol sym, Object val)
{
if (!sym.IsDynamic)
throw new LispException("Dynamic vars must have prefix *");
denv = new DynamicEnvironment(sym, val, denv);
}
//.........................................................................
public static void Restore(DynamicEnvironment olddenv)
{
denv = olddenv;
}
//.........................................................................
protected DynamicEnvironment(Symbol sym, Object val, DynamicEnvironment next)
{
InnerSymbol = sym;
InnerValue = val;
InnerNext = next;
}