feat: add support v flag

[ota-meshi]

Overview

This PR adds support for v flag.

Add new AST nodes

• ExpressionCharacterClass
  If the character class has intersection or subtraction it will be wrapped in this node. E.g. [a--b], [a&&b],[^a--b], [^a&&b]
• ClassIntersection
  It is an intersection node. E.g. a&&b
• ClassSubtraction
  It is a subtraction node. E.g. a--b
• ClassStringDisjunction
  It is \p{...} node. E.g. \q{a|b}
• StringAlternative
  It is Alternative like node in ClassStringDisjunction.

Change AST nodes

• CharacterClass
  • Add unicodeSets flag. true if the regex has the v flag. It had this because negation (^) behaves differently at runtime.
• CharacterSet (with kind: "property")
  • Add strings flag. true if it \p{} with property of string (e.g. Basic_Emoji). It has no negation.

Change API

• The fourth argument of parser.parsePattern and validator.validatePattern has been changed from a boolean uFlag to an object with flags.
  This is because the object format is easier to use than specifying multiple flags in argument order. For backward compatibility, the old boolean value work as well.

---

close #80

[RunDevelopment]

Thank you @ota-meshi! I'll review this soon.

---

There is one thing I noticed by looking at the AST format: Alternative. I think that it's very confusing that Alternative is now either a DisjunctionAlternative or a StringAlternative. The 2 types of alternatives seem very different to me, so I think that combining them under Alternative doesn't make much sense.

I also think that the new Alternative just isn't a useful type. In the entire AST definition, the Alterantive type is used 2 times, while DisjunctionAlternative is used 20 times and StringAlternative used 2 times. DisjunctionAlternative and StringAlternative aren't used together much.

So I think it would make sense to more clearly separate the new StringAlternative. I would keep the old Alternative definition and make a new type for StringAlternative.

[ota-meshi]

Good point. I think your idea makes sense. I will change the AST.

[ota-meshi]

I refactored this PR. Previously, a string indicating the kind was returned from some consume functions and processed. However, this was inconsistent so I refactored the consume function to return a boolean.

8d46d14

[ota-meshi]

I refactored this PR. Changed MayContainStrings to handle using result. This follows a review comment in PR in Acorn.

ffcaed5

[ota-meshi]

@eslint-community/core-team @RunDevelopment
Could you please check this PR if you are interested?
If no one responds, I'll merge and release this PR after next week.

[aladdin-add]

Not very familiar with this repo, but the test cases look good! :)

[ota-meshi]

Thank you for checking out this PR. I will merge this PR.

[github-actions]

🎉 This PR is included in version 4.6.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

Your semantic-release bot 📦🚀

[ota-meshi]

Hi @RunDevelopment!
I invited you to the team. I would be happy if you accept it.

[RunDevelopment]

Joined. Thanks @ota-meshi!