If and while always evaluate the whole expression

spikey

Yes, excuse me, yet another if post. Consider it as a note, and correct my observation if you know better, please.

a = []
if (len(a) > 0) and (a[0] == 1) then
    // do something 
endif

I wanted to use the while loop like this, because I need to check something inside the array to decide if the loop should go on

a = []
i = 0
while (i < len(a)) and (a[i] == "test") loop
    // do something 
   i += 1
repeat

workaround:

a = []
i = 0
while (i < len(a)) loop
   if (a[i] != "test") then
      break
   endif
    // do something 
   i += 1
endif

Appendix 03/26/2020:
The first two code samples throw an out of bound exception. Thank you @PB____ for linking to the first post about this, I searched for if-then-else posts, so I was not able to find it. So, @Spacemario came to the same workaround.

MikeDX

This definitely shouldn't happen and is a bug, Ill report it to the team 👍

PB____

A similar report was also mentioned in: https://fuzearena.com/forum/topic/644/logical-and-or-do-not-short-circuit

Also and and or cast the result to a boolean value, for example (2 and 3) == 1. I would expect (2 and 3) == 3 and (2 or 3) == 2, but I do think beginning programmers might expect and and or to behave the way they are implemented now.

Maybe it's an idea to add additional operators: && and || to implement short circuiting, without casting the type?

Anyway, that's my opinion on it, do with it as you please...

Martin

I don’t even understand what your report is saying. But it’s ok because Mike seems to so maybe I missed something.

It’s already been stated before that Fuze does not perform short circuiting like some languages do.

As far as I can see, none of your loops will iterate at all. Or is that the point? That the last one does maybe?

PB____

They way I read it, the reasoning is that Fuze will throw an error because it does not perform short circuiting:

even though a is an empty array here, the expression (i < len(a)) and (a[i] == "test") will try to evaluate both i < len(a) and a[i] == "test". So the first check does not 'protect' the second one. It will try to evaluate a[0] == "test" anyway, even though a does not contain any elements.

That's why I linked to the earlier short circuiting post.

Martin

I've not seen the other thread before so I can't say why I know that Fuze doesn't short-circuit, but it's not news to me. So yeah, it doesn't surprise me that a[i] == "test" errors, because Fuze doesn't short-circuit. I wouldn't have know that it evaluates right to left though so that's useful if true.

PB____

Just checked, it does operate right to left (for both or and and), but it will always evaluate both sides regardless.