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

[Patrick Donnelly <batrick@...>]

On Thu, Jun 20, 2019 at 2:07 PM Dibyendu Majumdar
<mobile@majumdar.org.uk> wrote:
>
> On Thu, 20 Jun 2019 at 21:59, Patrick Donnelly <batrick@batbytes.com> wrote:
> >
> => > 2) With regards to the 'toclose' variable declaration, introducing a
> > > 'with' statement is the nicest approach.
> > >
> > > with <vars> = <initializers> do
> > >
> > > end
> > >
> > > This idiom is familiar to most programmers who use Python.
> > > BTW @Patrick Donnelly this has nothing to do with Python's reasons for it etc.
> >
> > Quoting myself from the prior thread:
> >
> > "I want to point out the reasons why Python requires a control
> > structure but Lua would not: Python's locals are function-scoped.
> > Declaring a local in Python means it doesn't go out of scope until the
> > function returns. For this reason, Python requires an explicit control
> > structure to define the lifetime of the variable. Lua does not have
> > this limitation."
> >
> > They absolutely needed another control structure to implement their
> > flavor of RAII.
> >
>
> And I repeat that the suggestion to use this syntax doesn't have
> anything to do with why Python had to have it. It is a nice idiom used
> in many languages. C# calls it 'using'. In Java we have try with
> resources. But all are the same construct.

Fine, but I haven't seen a good argument for __enter so a "with"
construct looks unnecessary, distracting, and unnecessary indentation.

-- 
Patrick Donnelly