Does D have a tool like pySnooper?

[Taylor Hillegeist]

On Friday, 26 April 2019 at 10:22:49 UTC, Bastiaan Veelo wrote:
> On Friday, 26 April 2019 at 08:35:57 UTC, Bastiaan Veelo wrote:
>> On Thursday, 25 April 2019 at 08:44:14 UTC, Dennis wrote:
>>> On Monday, 22 April 2019 at 16:24:53 UTC, Taylor Hillegeist 
>>> wrote:
>>>> Or would this not be easy at all with D?
>>>
>>> I don't think so. While there are lots of traits for 
>>> introspection of declarations, there is no way to introspect 
>>> lines of code. The whole function
>>> would need to be wrapped into a mixin, and the D code would 
>>> need to be parsed
>>> at compile time for this to work.
>>
>> Yes, but I think that might be doable. You wouldn't need a 
>> full blown D parser, just one that can identify statements 
>> (`;` being an important clue). Not sure whether __LINE__ will 
>> be meaningful inside a mixin, though, but that might also be 
>> fixable. It would be an interesting challenge.
>>
>> Bastiaan.
>
> Proofing the concept:
> ---
> mixin(snoop(q{
>     int fun(int a, int b)
>     {
>         int c = 3;
>         foreach (i; 1 .. 5)
>         {
>             a += i;
>         }
>         int d = a + b + c;
>         return d;
>     }
> }));
> ---
>
> Output:
> 2019-Apr-26 10:33:46.0935135 executed line 7:	        int c = 3;
> 2019-Apr-26 10:33:46.0936716 executed line 10:	            a += 
> i;
> 2019-Apr-26 10:33:46.0937348 executed line 10:	            a += 
> i;
> 2019-Apr-26 10:33:46.0937963 executed line 10:	            a += 
> i;
> 2019-Apr-26 10:33:46.0938583 executed line 10:	            a += 
> i;
> 2019-Apr-26 10:33:46.0939622 executed line 12:	        int d = 
> a + b + c;
>
> https://run.dlang.io/is/Go97hQ
>
> Bastiaan.

Hey, that's a pretty cool demo. I saw the idea and wondered 
rather it could be possible with D. I has some very cool 
introspection properties. The Link seems to be broken right now. 
But I think this might be worth some development. Tools like this 
can really help new users, especially when they are doing things 
the o'l fashion way, printf for debugging. I doubt it would be 
too much help for things like ranges, but one must pick their 
battles.

Thanks.