Ported as conceptual article from .NET dev blog: Regex enhancements with .NET 7

[IEvangelist]

Summary

Ported an existing .NET dev blog from @stephentoub into the .NET docs, as a new conceptual article introducing Regex enhancements for .NET 7:

• Rephrased wording from passive to active.
• Replaced phrases such as "I" or "we", with "you" where appropriate.
• Fixed markdown warnings and applied markdown linter fixes where possible.
• Renamed the image files and ran them through image compression and resizing.
• Added to TOC with the corresponding title.

Fixes #30289

Preview

• .NET regular expression source generators

[stephentoub]

Thanks, @IEvangelist. Though FWIW I find this out-of-place. It's one thing to have conceptual docs about GeneratedRegex, but this post was about things that are new in .NET 7; it's not limited to just the source generator, there's a lot of implementation detail in here, and there's a lot more to regex than just what's discussed in this post, since it's written about the delta from .NET 6 to .NET 7.

[IEvangelist]

Thanks, @IEvangelist. Though FWIW I find this out-of-place. It's one thing to have conceptual docs about GeneratedRegex, but this post was about things that are new in .NET 7; it's not limited to just the source generator, there's a lot of implementation detail in here, and there's a lot more to regex than just what's discussed in this post, since it's written about the delta from .NET 6 to .NET 7.

Thanks, @stephentoub. This is still a draft, with lots of plans for stripping it down - I haven't gotten that far yet. There is a ton of great info in this post, and I want the conceptual parts to remain after I shake away the implementation details. The current title was an initial thought, but this is all in flux right now, but will most likely be hyperfocused on the source generation bits. Give me a bit to work on this more, and I'll tag you for review when it's ready. Is that fair?

[stephentoub]

Yup :-)

[CamSoper]

LGTM, let's

I love your fun string examples.

[stephentoub]

There's no benefit to caching this into a static field. The source generator does that itself. If you look at the generated code for this, you'll see the generated AbcOrDefGeneratedRegex method is essentially just AbcOrDefGeneratedRegex() => s_cachedField;.

[IEvangelist]

I thought the purpose of this section was to show exactly what the analyzer with the applied fix will do, I can adjust this. The analyzer's applied fix though doesn't behave this way, instead, it will re-write your code like the resulting code above.

[stephentoub]

The analyzer isn't mentioned in this section. The description of this code sample states: "You can now rewrite the previous code as follows:"

[IEvangelist]

Thanks for the feedback @stephentoub, I've addressed it in #31758.

[stephentoub]

Much of this section is about implementation detail. Is it all relevant to the docs?