Add a function for selecting a random member of an enum

[xyproto]

This is potentially useful if there is a large selection of possible settings, as an enum.

Mildly related: https://stackoverflow.com/questions/48490049/how-do-i-choose-a-random-value-from-an-enum

[xyproto]

Note that if there are no members, it will panic with panic: invalid argument to Intn.

I have an alternative implementation where it first checks if len(e.members) == 0 and then panics, but it did not feel like an improvement, since both implementations panics if there are no members.

Returning a slice of either 0 or 1 members would also be a possibility.

[MaxBreida]

I don't think that this should ever panic, instead there could be an error returned if it's already known what would cause this panic.

[xyproto]

Imagine if the function could return an Optional[M] instead, and Optional was also provided by this or a similar package. Would something along those lines be feasible?

[orsinium]

Imagine if the function could return an Optional[M] instead

I think it's a good idea to return a pointer to a member and return a nil pointer for an empty enum. Then it will be consistent with the Enum.Parse behavior.

[orsinium]

As a side note, I also thought about adding a method like this and a few similar ones but I'm careful not to reinvent genesis. If you want to have some specific operations on the collection of enum members, you can always do something like genesis.Choice(colors.Members()).

On the other hand, I don't mind any contributions for which you have a use case. After all, "A little copying is better than a little dependency", I wouldn't want people to bring yet another library to just pick a random enum member or something similar. So, it's a good idea to provide some convenient functions that many different people might need.

[orsinium]

golangci-lint complains about using rand. Feel free to suppress the error, I don't think the function needs to be cryptographically secure or something.

[orsinium]

.

[orsinium]

Add // nolint: gosec in the place where golangci-lint reports, and that's it, I'll be happy to merge it :) I can't merge PRs with failing CI.

UPD: run golangci-lint run locally to check.

[orsinium]

Perfect! Thank you for the contribution and for sticking with me through all review comments :)

[xyproto]

Thanks for reviewing and merging. Open source software has the potential to benefit us all. 🙂