Re: Next Lua (5.2) feature request : slicing

[Asko Kauppi <askok@...>]

Would you be okay in making this via token filters?

For the cases you point out, it could:
	mat[exp1,exp2] --> getmetatable(mat).__index(exp1,exp2)

For a function returning multiple values, it could not, but we can  
rule that out, right?

-asko


On 24.11.2006, at 21.51, Shannon Stewman wrote:

> A straightforward extension to indexing that allowed a library to  
> implement mat[i,j] by allowing multiple arguments to __index and  
> __newindex.  This would eliminate proxy objects (of the sort mat[i] 
> [j] requires) and not require painful manual addressing (the highly  
> annoying mat[j*NCOL+i]).
>
> Slicing can easily be done with the existing syntax:
>
> mat1[ slice(1,3) ] = mat2[ slice(4,6) ]
>
> which extends nicely to 2+ dimensional arrays:
>
> mat1[ slice(1,3) , slice(1,3) ] = mat2[ slice(4,6), slice(5,7) ]