optional process

[Paul Backus]

On Friday, 29 November 2019 at 15:17:35 UTC, Taylor R Hillegeist 
wrote:
> I know phobos has choose which is close.
> But what I want is something like:
>
> bool sortOutput;
>
> if(sortOutput){
> read(Textfile)
>    .splitter("\n")
>    .filter(a=>a.contains("data))
>    .doif(sortOutput,sort!("a < b"))
>    .writeln();

import std.functional: pipe;

bool sortOutput;

read(Textfile)
    .splitter("\n")
    .filter!(a=>a.contains("data))
    .pipe!((output) {
       if (sortOutput)
          return output.sort!("a < b");
       else
          return output;
    })
    .writeln(); // maybe you meant each!writeln ?