Re: ipairs and extending numeric for loop

[M Joonas Pihlaja <jpihlaja@...>]

On Mon, 24 May 2010, James Graves wrote:

> This is what I've got in my "utilities.lua" file which I use with all
> my own projects:

[snip implementation of ipairs]

Thanks for posting this.  Clearly it's not a lot of code to carry 
around if you miss ipairs, and your version even has __ipairs support 
to boot.

> Questions:
> 
> Should I be using rawget(a, i) instead of a[i]?  

I like the a[i] table access since it means your ipairs is more 
flexible than the 5.1 one and can use it on suitable userdata even.  
Using a[i] from Lua is also much faster than calling rawget() for 
normal tables.  Having said that, the 5.1 ipairs() does use rawget(), 
so I guess it depends on how closely you want to emulate it.

> Since I want ipairs() to be universally accessible, is there any
> practical difference to declaring the function as it is now, versus
> inserting it explicitly in the _G table?

I think it's fine as it is.  There's only a practical difference if 
someone's messed with your environment or removed _G from it.

Joonas