Extended fork

[exander77]

Hello, I made a fork of this library to write a supertinycron tool:
[email protected]:exander77/supertinycron.git

I extended the library for expressions described here:
https://www.javadoc.io/doc/org.quartz-scheduler/quartz/latest/org/quartz/CronExpression.html
https://github.com/gorhill/cronexpr

Would you be willing to take a very large pull request?

[staticlibs]

Hi, unfortunately I don't use ccronexpr myself anymore and cannot maintain it properly. Would it be convenient if I archive this repo and add a link to your repo on top of the README (instead of accepting the PR)?

[exander77]

@staticlibs I wrote supertinycron based on your work, and it is working great so far.

I think I fixed all the issues and implemented Quartz syntax as was requested here.

I also fixed building using Gihtub actions in my repo, and it should be working. You can review here: https://github.com/exander77/supertinycron/actions

So my repository should behave as your original one compiling under -std=c89, -std=c++11 in gcc and clang, static and non-static. I don't use it on embedded hardware, so I can't really test that, but I don't think I interfered with any of the code that handles that. I added year functionality that consumes an additional 29 bytes for year bit field and I may introduce some compile macro to disable for the embedded hardware purposes.

If it is ok with you, you can do as you suggest.

Btw, great work on this, I tried to follow the ideas of the original next/prev event calculation, but I merged most of the prev end next code, so it is more reliable as I primarily test next. I also implemented tonne of additional tests for new features as well as incorporated tests from this issue tracker.

I also find a bug recently, that I intend to fix as well:

60 * * * * * *
* 60 * * * * *

I wanted to find leap seconds for testing purposes, but neither glibc, nor musl handles this and ccronexpr segfaults due to not finding any matching in bitfield.

[staticlibs]

Archiving the repo now, thanks for keeping this project alive!