Recommendation: Mad Pascal Recursion

[zbyti]

uses crt;

function sum_algo(n: byte): integer;
begin
  result := (n * (n + 1)) shr 1;
end;

//---------------------------------------------

function sum(n: byte): integer;
begin
  if n = 1 then result := 1
  else result := n + sum(n - 1);
end;

//---------------------------------------------

function tail_call(n: byte; i: integer): integer;
begin
  if n = 0 then result := i
  else result := tail_call(n - 1, i + n);
end;

function tail_sum(n: byte): integer;
begin
  result := tail_call(n,0);
end;

//---------------------------------------------

// big n crash the system ;)
begin
  writeln(sum(10));
  writeln(sum_algo(10));

  writeln(tail_sum(20));
  writeln(sum_algo(20));

  repeat until keypressed;
end.

Recursion can go beyond Mad Pascal's software stack. I strongly recommend provide info about this possibility due to small software stack or maybe you can try to implement tail recursion optimization.

[zbyti]

But in general I find recursion useless on 8-bit systems ;)

[GSoftwareDevelopment]

Don't take away the ability to create recursion. Allow it, however, let it be known that it has its limitations.

Finally, MAD Pascal, allows you to call other procedures/functions from procedures/functions, repeatedly going deep into the "call tree".
After all, this is the same as recursion, except that different procedures/functions are called.

The call stack is small (I don't know what kind - maybe you can write about it?), but it allows to do that in the simplest form (without optimization).

In general, if recursion is used, it's mostly with a small number of parameters - which is also important for the number of iterations.

I think that recursion is one of the most important features of a language - if you deprive Pascal's MAD of it, it can lose its usefulness.

Translated with www.DeepL.com/Translator (free version)

[zbyti]

Most important for me is more space on ZP than ability to use recursion on relatively big (on 8-bit) stack on ZP.

I proposed tail recursion witch is fine on small systems.

[zbyti]

doesn't matter anymore