feat: align pattern matching with Java 21 spec

[jtkiesel]

What changed with this PR:

Aligns pattern matching parsing with the Java 21 spec, and attempts to improve the formatting of switch pattern matching. Record patterns are now supported, and the preview-style guards (&&) have been replaced with the official-style guards (when).

NOTE: This means that the &&-style guards will no longer be supported by the parser/printer. Because that style was only present as a preview feature (and has been removed as of Java 21 in favor of the official style), perhaps that is okay. I will defer to the project owners. If they decide we must continue supporting the pattern matching preview-style guards, I can attempt to modify this PR to support both simultaneously. My initial thought is that it would be incredibly easy to support both -- I should be able to simply allow a Guard to contain either a When or an AndAnd, instead of only a When.

Example

Input

class Example {

  void example() {
    return switch (r) {
      case null, default -> 0;
      case MyRecord(A a) -> 0;
      case MyRecord(A a, B b) -> 0;
      case MyRecord(MyRecord(A a), B b) -> 0;
      case MyRecord(MyLongRecordTypeName(LongTypeName longVariableName, LongTypeName longVariableName), MyLongRecordTypeName(LongTypeName longVariableName, LongTypeName longVariableName)) -> 0;
      case MyRecord(LongTypeName longVariableName, LongTypeName longVariableName) -> 0;
      case MyRecord(LongTypeName longVariableName, LongTypeName longVariableName) when this.longVariableName > longVariableName && this.longVariableName > longVariableName -> 0;
      case MyRecord(LongTypeName longVariableName, LongTypeName longVariableName) when this.longVariableName > longVariableName && this.longVariableName > longVariableName -> longMethodName(longVariableName, longVariableName, longVariableName, longVariableName);
    };
  }
}

Output

class Example {

  void example() {
    return switch (r) {
      case null, default -> 0;
      case MyRecord(A a) -> 0;
      case MyRecord(A a, B b) -> 0;
      case MyRecord(MyRecord(A a), B b) -> 0;
      case MyRecord(
        MyLongRecordTypeName(
          LongTypeName longVariableName,
          LongTypeName longVariableName
        ),
        MyLongRecordTypeName(
          LongTypeName longVariableName,
          LongTypeName longVariableName
        )
      ) -> 0;
      case MyRecord(
        LongTypeName longVariableName,
        LongTypeName longVariableName
      ) -> 0;
      case MyRecord(
        LongTypeName longVariableName,
        LongTypeName longVariableName
      ) when (
        this.longVariableName > longVariableName &&
        this.longVariableName > longVariableName
      ) -> 0;
      case MyRecord(
        LongTypeName longVariableName,
        LongTypeName longVariableName
      ) when (
        this.longVariableName > longVariableName &&
        this.longVariableName > longVariableName
      ) -> longMethodName(
        longVariableName,
        longVariableName,
        longVariableName,
        longVariableName
      );
    };
  }
}

Simultaneously fixes an instanceof pattern matching printer bug.

Example

Input

class Example {

  public boolean test(final Object obj) {
    return (
      obj instanceof
      final Integer x &&
      (x == 5 || x == 6 || x == 7 || x == 8 || x == 9 || x == 10 || x == 11)
    );
  }
}

Output

class Example {

  public boolean test(final Object obj) {
    return (
      obj instanceof final Integer x &&
      (x == 5 || x == 6 || x == 7 || x == 8 || x == 9 || x == 10 || x == 11)
    );
  }
}

Relative issues or prs:

Closes #605
Closes #610
Obsoletes #606

[jtkiesel]

Fixed a printer indentation bug with (and added a test for) nested record patterns.

[clementdessoude]

I think we could switch the two options: as there is recursion in the pattern/recordPattern definition, I would suggest backtracking on the typePattern instead

[jtkiesel]

Good point! Done.

[clementdessoude]

Thanks @jtkiesel !