what are the reasons to clone files?

[yairEO]

I don't get the first example..why would you do such a thing?

[mariocasciaro]

The purpose of gulp-clone is mainly performance and convenience. You could almost always replicate its functionality by re-reading and reprocessing the same source files, or executing some intermediate save.
Look at this discussion for a real-life example: ben-eb/gulp-rsvg#2
I report the code here for convenience:

var svg = gulp
    .src('images/svg/*.svg');

  var png32 = svg
    .pipe(clone())
    .pipe(rsvg({ width: 32, height: 32 }))
    .pipe(gulp.dest('images/png-32'));

  var png64 = svg
     .pipe(clone())
     .pipe(rsvg({ width: 64, height: 64 }))
     .pipe(gulp.dest('images/png-64'));

  return es.merge(png32, png64);

The following code would be equivalent to the code above, but as you can see you need to read the files twice (with a small performance impact, and conceptually it feels like repeating the same operation twice):

var png32 = gulp.src('images/svg/*.svg')
  .pipe(rsvg({
    width: 32,
    height: 32
  }))
  .pipe(gulp.dest('images/png-32'));

var png64 = gulp.src('images/svg/*.svg')
  .pipe(rsvg({
    width: 64,
    height: 64
  }))
  .pipe(gulp.dest('images/png-64'));

return es.merge(png32, png64);

I understand that the example in the README is not exactly the best, it's mainly meant for explaining the API with a simple use case. Might have to find a better one I guess.

[colelawrence]

This example is very helpful, especially being able to see the before and after.

[gregjacobs]

Hey, just wanted to thank you for this plugin @mariocasciaro. I was looking for a while to figure out how to avoid re-reading files from disk to perform multiple operations on them, and this was exactly what I needed.

You have a great description of why to use this plugin in this thread too. Even just a short summary of it in the readme would be great. Maybe adding a "Why" section with something like "Avoid re-reading source files or writing intermediary files to disk in order to perform multiple operations on them." would be helpful to others?