enh(csharp) add keywords record and init (C# 9.0)

[Youssef1313]

No description provided.

[joshgoebel]

Please show examples of how both of these are used... sometimes it's not just as simple as adding them to the keywords list. If record is more of a "class" like in Java then it likely needs far more complex rules.

[Youssef1313]

using System;
public record MyRecord
{
    public string SomeMember { get; set; }
}

Not sure if it requires some complex rules or not.

https://sharplab.io/#v2:EYLgZgpghgLgrgJwgZwLRIMYHsEBNkA0uIA1AD4ACATAIwCwAUBQMwAEmOurAsgJ4BKEbHkYBvRq0msW0mgAZWAZSwBbCNwgrgEBK1GsA5hBgBuVsmNmAvoytA==

[joshgoebel]

Yes, it's more like a class. See lines 148 or 159. We'd expect that MyRecord was highlighted as a title as well, which requires a custom rule.

init looks like more a normal boring keyword, at least from https://csharp.christiannagel.com/2020/04/21/c-9-positional-or-nominal-creation/ this.

[joshgoebel]

So we'd need a new rule for record, plus a simple expects test to prove that the rule works as expected.

[Youssef1313]

I'm not familiar with making custom rules. :(
May I keep this PR for init only and open an issue to track adding record, or you'd like to close it all together and open an issue to track both keywords?

[joshgoebel]

May I keep this PR for init only and open an issue to track adding record

This please. Thought you should consider giving it a try, it's not hard. I'm happy to help.

It'd look pretty much like (probably):

      {
        beginKeywords: 'record', end: /[{;=]/,
        illegal: /[^\s:]/,
        contains: [
          TITLE_MODE,
          // are generics allowed?
          hljs.C_LINE_COMMENT_MODE,
          hljs.C_BLOCK_COMMENT_MODE
        ]
      },

And then adding a test case to test/markup/csharp/. Let me know how I could encourage youto make a PR. :-)

[joshgoebel]

Either way this would need a mention in CHANGES.md. :-)

[Youssef1313]

That doesn't seem hard.

It looks like generics are allowed based on what I'm getting in sharplab.
I've updated csharp.js and will add the test and update CHANGES.md soon.

@joshgoebel Thanks for helping!

[joshgoebel]

@Youssef1313 Thanks so much for your contribution! Wasn't so hard, was it?