On 23 July 2010 01:41, Moritz Lenz <[email protected]> wrote:
> Use the right tool for the right job:
>
>> square numbers: 0, 1, 4, 9, 16, 25, 36, etc.
>
> (1..10).map(* ** 2)
Or even just:
(1..10) »**» 2
Note that you can also get most of the effects you want by using
@_ in the series' generator block. For example, here are all the
square numbers:
0, { @_**2 } ... *
and all the factorials:
1, { (@_+1) * @_[*-1] } ... *
or all the factorials more prettily but less inefficiently:
1, { [*] 1...@_ } ... *
However, those *are* clunky and nigh unreadable, so I certainly wouldn't
object to having the index of the next generated element readily
available as an explicit variable in a series' generator block.
That would make all manner of evil both easier and cleaner. >;-)
Damian
