On 11/26/19 2:08 PM, Taylor R Hillegeist wrote:> On Tuesday, 26 November 2019 at 16:33:06 UTC, Timon Gehr wrote:
>>     int[][] y=x.chunkBy!((a,b)=>a==b).map!array.array;
>
>
> how did you know to do that?

Ranges don't have elements. They either generate elements according to an algorithm, provide access to elements (or copies of elements) that belong to other containers.

In this case, chunkBy() is like an engine that knows how to present the input range in chunks but does not start working automatically. This is a great feature because you can start accessing chunks, deciding it's enough, and stop; potentially avoiding a lot of eager work (potentially infinite).

std.array.array pulls all elemenst of a range and places them inside an array. That is eager but sometimes necessary work. For example, std.algorithm.sort cannot sort just any range because it needs the elements to be layed out as array elements:

  someAlgorithmRange.sort;      <-- Does not work
  someAlgorithmRange.array.sort <-- Works

Ali

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