Mir Random [WIP]

[Ilya Yaroshenko via Digitalmars-d]

On Thursday, 24 November 2016 at 13:45:40 UTC, Jonathan M Davis 
wrote:
> Alternatively, you could just do rndGen().take(1).front, and as 
> long as rndGen() gives you a reference type, it works just 
> fine. Unfortunately, std.random did not use reference types for 
> its ranges. _That_ is the big mistake of std.random and the 
> main item that needs to be fixed. There are some other 
> subtleties (e.g. it's useful to be able to save the state of a 
> random number generating range, but you don't necessarily 
> really want it to be a forward range), but those are minor in 
> comparison to the mistake of std.random using value types 
> rather than reference types for ranges.
>
> - Jonathan M Davis

The fix is opCall syntax. Reference types are classes, which 
would not work without linking DRuntime and Phobos (BetterC). 
Refcounting is to slow to implement for users.
Note, that Engines is only backend RNGs. There are also 
nonuniform distributions (WIP). See the example of users code: 
https://forum.dlang.org/post/nyvtoejvmsaolzaqyche@forum.dlang.org 
.

It is very difficult to implement both user random variable and 
Engine using Range API. Note, that code should work without 
DRuntime and should be simple (the example is user code).

Ilya