Splitting a range into a range of tuples

[Ali Çehreli via Digitalmars-d-learn]

On 06/01/2015 03:31 PM, Adam wrote:
> Hi,
>
> I have a string of pairs of integers, where pairs are delimited from
> each other by commas, and members of the pair are delimited by a space.
> I'd like to end up with something like a range of 2-tuples, which I can
> then sort with a lambda. I'm running into problems trying to do this,
> after splitting on commas:
>
> Tuple!(int,int) coord = to!(int[])(splitter(pairString," ").array[]);
>
> ...which may not even be a good idea, I don't know. I've been following
> D for a long time, but this is the first time I've tried to actually use
> it; this seems like the kind of thing that should take just a few lines,
> if only I knew the libraries and range concepts well enough.
>
> To be clear, this is what I have:
>
> "192 14, 301 3, 578 0, 0 17"
>
> ...and this is what I want:
>
> [(578,0),(301,3),(192,14),(0,17)]
>
> What's the best way to do this? Should I be using map!() somewhere?
>
> Thanks,
> Adam

With no promises on performance and with a bonus mind-blowing format 
string... :) I am sure it can be improved a lot.

import std.stdio;
import std.algorithm;
import std.range;
import std.conv;

void main()
{
     auto input = "192 14, 301 3, 578 0, 0 17";
     auto result = input
                   .splitter(',')
                   .map!splitter
                   .joiner
                   .map!(to!int)
                   .chunks(2)
                   .map!array
                   .array
                   .sort()
                   .retro;

     writeln(result);

     writefln("[%((%(%s,%))%|,%)]", result);
}

Prints both an array of arrays and the same format that you wanted:

[[578, 0], [301, 3], [192, 14], [0, 17]]
[(578,0),(301,3),(192,14),(0,17)]

Ali