public static AccumulWriter <A> Restore <A>
(this AccumulWriter <A> src)
{
src.Paper.Pop();
src.Value.Pop();
return(src);
}
internal AccumulWriter(A value, string txt, AccumulWriter <A> past)
{
if (value == null)
{
throw new ArgumentException(nameof(value));
}
Value = past.Value;
Value.Push(value);
Paper = past.Paper;
Writer = past.Writer;
Paper.Push(Paper.First() + Writer(txt));
}
public static A GetLastValue <A>
(this AccumulWriter <A> self)
=> self.Value.First();
public static string GetLastPaper <A>
(this AccumulWriter <A> self)
=> self.Paper.First();
// Func => new M<A> ( val , txt , self )
public static AccumulWriter <A> Add <A>
(this AccumulWriter <A> self, Func <A, A> f, string txt)
=> new AccumulWriter <A>(f(self.Value.First()), txt, self);
public static A Lift <A>
(this AccumulWriter <A> self, Func <A, A> f)
=> f(self.Value.First());
public static int Count <A>
(this AccumulWriter <A> src)
=> src.Value.Count;
