Filter and sort associative array

[Head Scratcher]

On Friday, 11 January 2019 at 16:06:48 UTC, Alex wrote:
> On Friday, 11 January 2019 at 16:02:27 UTC, Head Scratcher 
> wrote:
>> Thank you. This works great. What I don't understand is how a 
>> key-value pair ends up being a set of strings. Where did the 
>> value of the key-value pair get removed?  According to the 
>> library documentation, the array function "allocates an array 
>> and initializes it with copies of the elements of range r." So 
>> wouldn't the resulting array contain pairs? And if so, how 
>> does the sort work on pairs?
>
> By map you map the pair to its key resp. its first element. The 
> result of the map contains the right-hand side of the "=>" 
> expression only.

Ah, that makes sense. Thank you for the explanation.