Talk:Pi

"This gives you the chance to shadow (redefine) pi()"
What does that mean? --Bart (talk) 15:05, 24 January 2018 (CET)

You can write in your own program/unit

function pi(): valReal;
begin
	pi := 3.0;
end;

and in the current scope expressions like 3*pi() will result in 9.0. To access “a more precise” definition of π you can/have to write 3*system.pi() (characteristic of shadowing: re-defining identifiers, but the original identifier remains accessible). Kai Burghardt (talk) 16:42, 24 January 2018 (CET)

OK, Wikipedia understands as “shadowing” “variable shadowing”, not necessarily of functions. But “overloading” though, is defining the same identifier with differing formal signatures (accepted parameters). You know a better term, Bart? Kai Burghardt (talk) 16:47, 24 January 2018 (CET)

But this you could also do if Pi was a constant, isn't it?

const pi{: valReal} = 3.0;

Huh, well, indeed. Then I don't know, why pi was implemented as a function and not a as a simple const. Maybe some historical reason? Perhaps some targets, some FPUs provide a pi-function on their own? [which you usually want to use] Kai Burghardt (talk) 17:26, 27 January 2018 (CET)