lua-users home
lua-l archive

[Date Prev][Date Next][Thread Prev][Thread Next] [Date Index] [Thread Index]

On Wed, Dec 21, 2011 at 19:29, Joshua Jensen <> wrote:
> ----- Original Message -----
> From: Alexander Gladysh
> Date: 12/21/2011 7:42 AM
>> On Wed, Dec 21, 2011 at 18:25, Joshua Jensen<>
>>  wrote:
>>> ----- Original Message -----
>>> From: Philippe Lhoste
>>> Date: 12/21/2011 6:19 AM
>>>> On 17/12/2011 13:47, Jeff Smith wrote:
>>>>> 6) I dont like long if else blocks, so a select case construct would
>>>>> have
>>>>> been nice IMHO.
>>>> This is usually done with a table of functions, no? A bit verbose, but
>>>> quite usable.
>>> And MUCH slower.
>> Only about 15 times slower (with vanilla Lua), AFAIR, but much more
>> readable.
>> In rare cases where that 15 times matter, you always can rewrite to
>> whatever is more efficient .
> I publish games.  I care about performance.

Well, I'm in games too :-)

> I am willing to sacrifice some
> performance by using a scripting language,

If a piece code takes only 0.1% of execution time, you wouldn't speed
up your program more by 0.1% no matter that you do with it.

Do you really have that many if-elseif blocks so that matters?

> but when a construct can be
> created that enhances performance over the alternative, like a switch
> statement over a table of functions, I am for it.

*Language* constructs are rarely about performance only, especially in Lua.

> The Lua C source code itself uses switch in dozens of places.  The result is
> plenty readable and arguably far more readable than a table of functions
> that have to be defined elsewhere in the file.

Well, I replied to the post on if-elseif vs. function tables. As for
introducing switch construct to Lua, I said all I could for in my
first letter in this thread — I *personally* do not care much for this
feature. The rest was milled over and over in the past.