Is there a more elegant way to do this in D?

[Paul Backus]

On Thursday, 8 April 2021 at 03:57:23 UTC, Brad wrote:
> I am trying to take an array and convert it to a string.  I 
> know that Split will let me easily go the other way.  I 
> searched for the converse of Split but have not been able to 
> locate it.

You need two functions here:

1. `joiner` [1], which lazily joins the elements of a range.
2. `array` [2], which eagerly evaluates a range and returns an 
array of its elements.

The final code looks like this:

     dchar[] b = a.map!(to!string).joiner.array;

You may have noticed that the type of `b` here is `dchar[]`, not 
`string`. This is due to a feature of D's standard library known 
as "auto decoding" [3]. To prevent the strings you get from 
`to!string` from being auto-decoded into ranges of `dchar`, you 
can use the function `std.utf.byCodeUnit` [4], like this:

     string b = a.map!(to!string).map!(byCodeUnit).joiner.array;

[1] 
https://phobos.dpldocs.info/std.algorithm.iteration.joiner.1.html
[2] https://phobos.dpldocs.info/std.array.array.1.html
[3] https://jackstouffer.com/blog/d_auto_decoding_and_you.html
[4] https://phobos.dpldocs.info/std.utf.byCodeUnit.html