Files as buffered InputRange

[Les De Ridder]

On Friday, 5 July 2019 at 18:29:36 UTC, berni wrote:
> On Friday, 5 July 2019 at 17:57:39 UTC, Les De Ridder wrote:
>> File.byChunk[1] should do the trick.
>>
>> [1] https://dlang.org/library/std/stdio/file.by_chunk.html
>
> Not sure, if this is, what I'm looking for. I'd like to do 
> something like
>
>> buffered_file.map!(a=>2*a).writeln();
>
> When I understand it right, with byChunk I'll have to take care 
> about the end of the buffer, myself...

You could use `joiner` from std.algorithm, e.g.
     buffered_file.byChunk(4096).joiner.map!(a => 2 * a).writeln;