going backwards with multiple procedures..

[mooki3]

delete this topic please, was posted on the wrong forum

mod edit: moved to Turing Help since there are already a few replies with content.

[Insectoid]

'going back' is simply ending the procedure. If slide 1 calls slide 2, and slide 2 ends, slide 1 will continue at the next line of code. Basically, it will look like this:

code:

proc slide1     loop        if (next button pushed)           slide2        else if (back button pushed)            quit slide1        end if     end loop end slide1

Of course, if you have 500 slides you'll end up with a procedure in a procedure in a procedure, etc. And then your computer will eventually give up.

A better way would be to use functions instead of procedures and return the number of the slide to go to. You have a main procedure that runs slide1, then slide1 will run until 'back' or 'next' is clicked. If 'next' is clicked, slide1 will return 2, then the main proc will run procedure 2. If 'back' is clicked, slide1 will return 0, and the main proc will quit. Similarly, slide2 will return 3 if 'next' is clicked, and 1 if 'back' is clicked. This way, only 2 procedures are ever running at the same time- the main proc, and a slide. This method will also greatly simplify adding extra controls. For example, you could add functionality to enter a slide number and instantly go to that slide.

[mooki3]

I'm not that familiar with functions, I've always used procedures simply because they are easier to make.
Can you please give me an example of how to do it with functions? A basic outline of 3 slides would be great
Thanks for being so helpful!!

[Insectoid]

Functions are exactly like procedures, except they return a value.

code:

function foo (a:int) : int //this function returns an integer     result 2*a // 'result' ends the function and returns a value. In this case, we just return 2*a end foo int bar = foo (5) put bar //output will be 10

EDIT: My Turing's a bit rusty so the syntax might be a bit off.

[Zren]

Insectoid @ Wed Jan 04, 2012 9:03 pm wrote:

Functions are exactly like procedures, except they return a value.

Turing:

function foo (a:int) : int %this function returns an integer     result 2*a % 'result' ends the function and returns a value. In this case, we just return 2*a end foo var bar := foo (5) put bar %output will be 10

EDIT: My Turing's a bit rusty so the syntax might be a bit off.