1-based ranges support

[georgthegreat]

Please explain your intent
Provide a better UX for pdfly cat.

Describe the solution you'd like
Use 1-based ranges, not 0-based.
Modern pdf viewer number pages from 1.

Additional context

Even pdfly cat --help shows that something is indeed wrong with the current approach:

 Page range expression examples:
     ...
     22    just the 23rd page.          :-1   all but the last page
     ...
     5:    from the sixth page onward.  -3:-1 third & second to last.

[georgthegreat]

Thinking of an even better approach one might consider: comma support, dash support and inclusive ranges.

So to cat pages 1 and 6 to 11 from a file one should type just that: pdfly cat -o out.pdf in.pdf 1,6-11. This is the range description used by PdfSam (the software I currently use to work with pdf files).

[Lucas-C]

Hi @georgthegreat

Thank you for reaching out with some interesting suggestions 👍

Use 1-based ranges, not 0-based.

This would be a backward-incomptible change, and I fear that it would bring quite some annoyance to our end-users when they upgrade pdfly...
Yet it's true that all PDF viewers I know index pages starting at 1, so making pdfly pages indices starting at 1 would probably be a usability improvement.
In fact, I just realized that I suggested the same idea in issue #23 two years ago 🙂

I'd be curious to know what do you think about this @MartinThoma, as you originally implemented the pages ranges? 🙂

Thinking of an even better approach one might consider: comma support, dash support and inclusive ranges.

I think we could support bot the "Python ranges" syntax, and the more common "comma & dashes" syntaxes.
That could probably make pdfly cat usage more intuitive.

---

Regarding those 2 suggestions, we should take care to make this page-indexing changes for ALL pdfly SUBCOMMANDS, of course.

@georgthegreat: would you like to contribute yourself some of those enhancements to pdfly?
This project is 100% volunteer-based, so the best way to introduce such new usability features is to implement them 🙂

[Lucas-C]

@allcontributors please add @georgthegreat for ideas

[allcontributors]

@Lucas-C

I've put up a pull request to add @georgthegreat! 🎉

[georgthegreat]

Maybe we should follow du cli interface and do something like pdfly cat --human-readable 1,5-8 .

As I am looking for pdfsam replacement, I will take a look on implementing this later on.

[Lucas-C]

As I am looking for pdfsam replacement, I will take a look on implementing this later on.

Thank you for volunteering! 👍

Maybe we should follow du cli interface and do something like pdfly cat --human-readable 1,5-8.

It's a good idea to take inspiration from existing standard tools 🙂
However du --human-readable is about making the output human-readable, it does not affect how it interprets CLI args.

[georgthegreat]

Let option naming to be the hardest thing to discuss inside the PR.