How about:
julia> for i=1:2
if i>=2; println(z); end
z="Hi"
g(z)= println(z)
g(z)
end
Hi
Hi
Hi
Does this just fall under case 4, or does it change your analysis?
On Wednesday, April 29, 2015 at 11:20:17 AM UTC-4, Sisyphuss wrote:
>
> Please these four versions:
> Version 1:
> for i=1:2
> if i>=2; println(z); end
> z="Hi"
> end
> No error
>
> Version 2:
> for i=1:2
> z="Hi"
> g()= println(z)
> g()
> end
> No error
>
> Version 3:
> for i=1:2
> if i>=2; println(z); end
> z="Hi"
> g()= println(z)
> g()
> end
> ERROR: z not defined
>
> Version 4:
> for i=1:2
> if i>=2; println(z); end
> z="Hi"
> g(x)= println(x)
> g(z)
> end
> No error
>
> My guess is: Version 1 treats `z` in the same way as local variable (let's
> call it *local way*). Version 2 treats `z` in the same way as global
> variable although it's in a local scope (let's call it *global way*).
> Version 3 treats it simultaneously in the local/global way, thus introduce
> an error. Version 4 is a walk around and also a better programming habit.
>
> If my guess is right, I further conclude that the main dilemma of Julia is
> that it depends on the scope (local/global scope) to decide the treatment
> of variables (local/global way); however, when scopes are nested, the
> problem appears.
>
>
>
>
> On Wednesday, April 29, 2015 at 4:53:12 PM UTC+2, Sisyphuss wrote:
>>
>> Here's a variant version of your code:
>> ```
>> for i=1:10
>> if i>=2; println(z); end
>> z=2
>> g()=(*global z*; 2z)
>> println(z)
>> end
>> ```
>> If `z` is defined global, there will not be any error. I would have like
>> to use `nonlocal`, but there isn't this keyword in Julia.
>> In my personal opinion, the magic in your original code is that when the
>> compiler see the definition of `g()`, it will try to do some *amazing
>> *things
>> on the compilation of `z`.
>>
>>
>> On Wednesday, April 29, 2015 at 4:37:24 PM UTC+2, Pooya wrote:
>>>
>>> That's exactly my question: Why should defining a function inside the
>>> loop mess with the variables in the loop?
>>>
>>> On Wednesday, April 29, 2015 at 10:33:03 AM UTC-4, Sisyphuss wrote:
>>>>
>>>> Another *miracle* here is that if you delete "g()=2z", there will be
>>>> no error!
>>>>
>>>>
>>>> On Wednesday, April 29, 2015 at 3:53:23 PM UTC+2, Pooya wrote:
>>>>>
>>>>> Can someone explain why this is the desired behavior? z is defined
>>>>> until the end of first iteration in the for loop, but not in the
>>>>> beginning
>>>>> of the next:
>>>>>
>>>>> julia> for i=1:10
>>>>> if i>=2; println(z); end
>>>>> z=2
>>>>> g()=2z
>>>>> println(z)
>>>>> end
>>>>> 2
>>>>> ERROR: z not defined
>>>>> in anonymous at no file:2
>>>>>
>>>>
