Allow eggos implementations to programatically set log levels

[jspc]

When running applications on platforms where there is no environment, calls to os.Setenv to set a loglevel have inconsistent results. Similarly, setting this environment variable before the first log event, and thus making that call moot, is racy.

Instead, then, export log levels, drop the potential stutter in log.LogLvl to log.Level, and allow implementations/ callers of this package to set a log level accordingly, while maintaining the default behaviour

[icexin]

Maybe a setter would be better, like SetLogLevel?

[jspc]

Sure thing, if that's the way you'd prefer it. It'd still be nice to have this public to be able to inspect the value- would you prefer a getter, or the naked var?

[icexin]

Gopher prefer naked var 😄

[jspc]

My worry is that adding the setter, then, adds complexity and can be bypassed by setting directly on the naked value.

I'll make sure that the setter is well documented to explain that it does additional checking to make sure the specified level is a valid level. That's probably the best of all worlds!

[icexin]

The current log package implementation is relatively simple, I think there is no problem if you implement it in a simple way.

[jspc]

@icexin ♻️

I've written a setter with bounds checking (with some tests) and made it accept an explicit log level type. I've left the init() function alone, so it still sets log.Level directly, since it does it's own bounds checking1

[icexin]

LGTM