Write out numbers

[Aras14HD]

DEPENDS ON #326 (Merged)

This adds the ability to write out numbers up to 9.9999999...*10^3000000.

It only writes out the most significant parts.

This is a breaking change in the library as the arguments for format change. To combat this in the future and make the signature less cluttered, I added a FormatOptions struct.

This is also only in english, as of this point. There would be a lot to add to locale, otherwise.

Resolves #150

[tolik518]

This is hilarious!
Could you write a test please how it behaves with other languages like russian and/or german?

From what I have seen so far the pr looks good, but now calculation_results.rs feels like it has more than I would expect from it, maybe move the logic for writing out to a dedicated file? What do you think?

Also I don't think I can remotely verify if

Factorial of one hundred seventy six thousand nine hundred two is seventy five quintriginoctingentrilloctogintillducentillillion five hundred fourty five quattuortriginoctingentrilloctogintillducentillillion seven hundred sixty six tretriginoctingentrilloctogintillducentillillion three hundred five duotriginoctingentrilloctogintillducentillillion fourty seven untriginoctingentrilloctogintillducentillillion one hundred fourty three triginoctingentrilloctogintillducentillillion

is correct, but I'll take it :D

[Aras14HD]

It would still write the number in english with everything around it localized. (if it's breaking anyway, I might add localization to it now)

Maybe a format for basic formatting functions like round truncate fromat_float get_factorial_level_string and write_out_number. With calculation_results just implementing methods of/traits for the types Calculation and CalculationResult.

And for the correctness, while I doubt anyone would unironically say centillillion, https://bignumbers.fandom.com/wiki/Millillion shows, that this is somewhat used/recognized. And for more normal numbers, it matches the Wikipedia list.

[Aras14HD]

I tried and concluded, that localizing that is infeasible, even german is quite some effort, and I have no idea how you would do something like french for example.

Instead, I would maybe add a warning for non en locales, so that people don't think it's a bug.

Also noticed: We could make locale way simpler, if we abandon the versioning and just have one struct with optional fields (default/missing field means None). That way we don't have all the boilerplate and repetition we have now.

Correction: localization basically means a fully new algorithm each time. So it is way lower on priority of localization

[tolik518]

Maybe a format for basic formatting functions like round truncate fromat_float get_factorial_level_string and write_out_number. With calculation_results just implementing methods of/traits for the types Calculation and CalculationResult.

Yeah I would welcome a clearer calculation -> result -> formatting pipeline. But this doesn't have to be done in the PR here

[tolik518]

Also please add a test in integration.rs for behavior with different languages. This would be a good documentation for what would happen in that case

[Aras14HD]

In addition to the fixes, asked additions, I added support for negative numbers and writing out the number of digits.

[tolik518]

Great! Thank you! I'll start the merge train!
(I'll merge slowly)