Getting underlying struct for parseJSON

[via Digitalmars-d-learn]

On Tuesday, 28 February 2017 at 20:27:25 UTC, Alexey H wrote:
> Hello, guys!
>
> I'm working on a project that involves parsing of huge JSON 
> datasets in real-time.
> Just an example of what i'm dealing with is here:
>
> https://gist.githubusercontent.com/gdmka/125014058bb7d7f01b867fac56300a61/raw/f0c6b5be5fb01b16dd83f07c577b72f76f72c855/data.json
>
> Can't think of any tools other that D or Go to solve this 
> problem.
>
> My experience of solving the problem with Go has led me to 
> Stackoverflow and the community out there seemed too reluctant 
> to help so i assumed that the language cannot handle such a set 
> of operations on complex datastructures.
>
> My experience with D was like a charm. Where i have had ~100 
> lines of Go code i did the same  with 12 in with D. But, 
> nevertheless, i did some profiling (unfortunately on OS X) and 
> saw much heavier CPU usage with D than Go. Probably because the 
> Go solution was unpacking all the data strictly to struct.
>
> So, my real question is: can i actually, by any change, get the 
> description of an underlying struct that the call to parseJSON 
> generates?
>
> The goers have this thing https://mholt.github.io/json-to-go/ 
> to generate structs from JSON automatically.
>
> Since D easily parses JSON by type inference, i assume it 
> builds a JSONValue struct which holds all the fields and the 
> data.
>
> If it is possible, then i can build a similar JSON to D tool 
> just for the sake of saving people's time and patience.

If you really care about performance, have a look this: 
http://forum.dlang.org/post/20151014090114.60780ad6@marco-toshiba

std.json is not tuned for performance, so don't expect good 
results from it.