Re: [ANN] Lua 5.4.0 (work1) now available

[KHMan <keinhong@...>]

On 3/16/2018 4:16 AM, albertmcchan wrote:
> On Mar 15, 2018, at 3:55 PM, Sean Conner wrote:
>
> > It was thus said that the Great Roberto Ierusalimschy once stated:
> > > Many years ago, we added booleans to the language exactly 
> > > because we
> > > could not store nil in tables. 'false' is just a 'nil' that we 
> > > can store
> > > in tables. ('true' is useless in Lua.) If tables could store 
> > > nils, the
> > > language would not need 'false'.
> >
> >  I've been using Lua since late 2009, and this is the first time 
> > I even
> > *heard* of this.  Why did you not bring this up the previous 
> > n-times that
> > the issue of holes came up?  Is there some sort of FAQ we can 
> > add this to?
> > Like:
>
> I had been saying this all along (false = nil in table)

So it's an impedance matching issue between programming languages 
and we're adding more duct tape? :-p


> Quote from Evolution of Lua, sec 6.1: https://www.lua.org/doc/hopl.pdf
>
> For a long time we resisted introducing boolean values in Lua: nil 
> was false and anything else was true. This state of affairs was 
> simple and seemed sufficient for our purposes. However, nil was 
> also used for absent fields in tables and for undefined variables. 
> In some applications, it is important to allow table fields to be 
> marked as false but still be seen as present; an explicit false 
> value can be used for this. In Lua 5.0 we finally introduced 
> boolean values true and false. Nil is still treated as false.


--
Cheers,
Kein-Hong Man (esq.)
Selangor, Malaysia