static Object.Environment extendFunctionEnv(Object.Function fn, List <Object.Object> args)
{
Object.Environment env = Object.Environment.NewEnclosedEnvironment(fn.Env);
for (int paramIdx = 0; paramIdx < args.Count; paramIdx++)
{
env.Set(fn.Parameters[paramIdx].Value, args[paramIdx]);
}
return(env);
}
private static Object.Environment ExtendFuncitonEnv(Object.Function function, IEnumerable <Object.Object> args)
{
var env = new Object.Environment(function.Env);
var idx = 0;
foreach (var arg in args)
{
env.Set(function.Parameters[idx].Value, arg);
idx++;
}
return(env);
}
private static Object.Object ApplyFunction(Object.Object fn, IEnumerable <Object.Object> args)
{
if (fn.GetType() == typeof(Object.Function))
{
Object.Function function = fn as Object.Function;
var extendedEnv = ExtendFuncitonEnv(function, args);
var evaluated = Eval(function.Body, extendedEnv);
return(unwrapReturnValue(evaluated));
}
if (fn.GetType() == typeof(Object.Builtin))
{
return(((Object.Builtin)fn).Fn(args.ToArray()));
}
return(new Object.Error()
{
Message = $"not a funciton. {fn.Type()}"
});
}