map! filter! and range algorithm

[H. S. Teoh]

On Mon, Mar 04, 2013 at 09:06:18PM +0100, Andrea Fontana wrote:
> If I understand it correctly something like:
> 
> range.filter!(...).map!(...)
> 
> browse range 2 times, one for filter and one for mapping doesn't it?

No, these algorithms are evaluated lazily (unless you put .array at the
end). The range is only traversed once.


> Is there a way to "parallelize" this kind of operations?

What do you mean by "parallelize"? Run in multiple threads? I don't
think you can do that, because the result of filter depends on what it
gets from map.


T

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