allow rand with zero value

[kostya]

this is useful in such code:

def delay(interval : Float64)
  sleep(rand(interval))
end

# when you want just not to sleep
delay(0.0)

[RX14]

This is quite useful but i'm concerned that it could mask logic bugs in code that would otherwise raise.

[kostya]

why not?
also it already works for range: rand(0..0) => 0, rand(0.0..0.0) => 0.0, why not to work for zero itself?

[trans]

This should definitely work. It provides an inherit on/off behavior, removing the need for extra conditionals, allowing code to be more succinct.

but i'm concerned that it could mask logic bugs in code that would otherwise raise.

That's what tests are for. Besides, if you are expecting behavior based on the generation of random numbers, it's usually pretty obvious when you just keep getting zeros.

[kostya]

👍

[straight-shoota]

@kostya This PR needs a rebase. Otherwise it looks good to me

[kostya]

rebased

[Sija]

@asterite @mverzilli @RX14 🏓