Among other things, this release contains work on pattern matching.

Release notes - https://github.com/ngs-lang/ngs/releases/tag/v0.2.11

More about pattern matching design in NGS - https://github.com/ngs-lang/ngs/wiki/UPM-Design

I would appreciate your thoughts about the pattern matching. I’m having hard time to “get it right”. I’ve looked at many other implementations (listed at the “UPM-Design” link above) and all of them feel “not 100%”. Unfortunately, right now, I am failing to come up with my own design that would feel “100%”. Biggest next obstacle is syntax (smaller) and semantics (bigger) of capturing values.

Problems:

• NGS does not have a reference type and I’m not fond introducing one just for patterns to be able to return values.
• A syntax (example @a) for creating a function which would set a variable (F(val) a=val) would introduce additional problem - to which scope to add the a variable. According to language rules, it would be set inside the F..., which is not useful at all. Maybe in this case it should be “one above F”?
• Capturing all the values and returning them is a bit verbose, “direct” mention of a variable name is more expressive.
• Does ability to pass a pattern as value contradicts the ability to capture directly into variables?

I’ve probably missed some information, feel free to ask.