Re: Issue with bit shift in Lua 5.4 Work releases

[Lorenzo Donati <lorenzodonatibz@...>]

On 06/07/2018 17:58, Dirk Laurie wrote:
> 2018-07-06 17:55 GMT+02:00 Roberto Ierusalimschy <roberto@inf.puc-rio.br>:
> > > The following three lines runs without errors in Lua 5.3.
> > >
> > > local foo = 13.37
> > > local bar = foo // 1
> > > type( bar <<  8 )
> > >
> > > The shift on the third line fails with Lua 5.4 with the following error:
> > > "number (local 'bar') has no integer representation".
> > >
> > > It still fails with the error "attempt to perform bitwise operation on a nil
> > > value (local 'bar')" when 'bar' is explicit converted to an integer.
> > >
> > > local foo = 13.37
> > > local bar = math.tointeger( foo // 1 )
> > > type( bar <<  8 )
> > >
> > > Is this a bug or did I use the wrong method?
> >
> > It is a (stupid) bug, but not in bit shift:
> >
> > > foo = 13.37
> > > print(foo // 1)     --> 13.7
>
> When is a bug not stupid?

It somewhat depends on your reaction when you find it.

Stupid bug:

"doh!!!" (*palm-face*)	


Not-so-stupid bug:

"aha!!!"
(*mumbling: "I found you! You little dirty <add your favourite expletive 
here>"*)


Of course this is somewhat relative: it depends on the "doh"-threshold 
of the specific programmer with the specific language.

:-)

There are no bug-free programs.
Any program has at least one unavoidable big bug: its end-user.

:-D