SE-0202: Random Unification

[bzamayo (Benjamin Mayo)]

@nnnnnnnn

While integers and even floating-point types make sense to use with just a range, for other types this pattern falls down. While not part of this proposal, extensions to other types could follow the pattern established here:

let myVector = Vector.random(x: 20...50, y: 20...50, using: myGenerator)
let myData = Data.random(byteCount: 400, using: myGenerator)

This justification should be in the proposal honestly. This is great motivation as to why we cannot go 'all in' on ranges.

I am definitely in support of the proposal.

I believe the Swift standard library should offer the base protocols that have the ability to cover most use cases of randomness when extended. I also think that there should be a single RandomNumberGenerator provided for people to use as the default. This generator should not be able to seeded. Extra generators and distributions etcetera should be provided in a third-party module that may eventually become a sanctioned first-party non-standard library.

Luckily, my beliefs line up with the proposal as written, and I therefore have no blocking objections.

The only thing I would say is that Random.default is not a good name for the standard library provided generator. I think it should be DefaultRandomNumberGenerator or SystemRandomNumberGenerator or similar, with the property called shared.