Add match operator in ColumnExpression for FTS5.

[GetToSet]

Pull Request Checklist

• This pull request is submitted against the development branch.
• Inline documentation has been updated.
• README.md or another dedicated guide has been updated.
• Changes are tested.

I'm using GRDB.swift with FTS5 support in my own project and found that in FTS5 query interface, there is no match operator for column expressions, which is found in FTS3.

This PR add this operator expression and related tests, making it aligned with FTS3 query interface API.

[groue]

Thank you @GetToSet, FTS5 column filters were lacking 👍

[groue]

I removed the support for column.match(nil), since SQLite throws a syntax error for MATCH NULL.

I also updated the documentation.

[GetToSet]

I removed the support for column.match(nil), since SQLite throws a syntax error for MATCH NULL.

I also updated the documentation.

column.match(nil) also presents in FTS3 (FTS3+QueryInterface.swift), should it also be disabled?

[groue]

No, because FTS3 accepts NULL. A little harmless SQLite inconsistency ;-)

[GetToSet]

No, because FTS3 accepts NULL. An little harmless SQLite inconsistency ;-)

🤔 I've never dived such detailed into SQLite grammar, BTW, thanks for instant response for this PR.

[groue]

I just ran the tests, and saw that nil matching was throwing an error.

Since you are contributing many FTS5 enhancements to GRDB, please let me share a tip. When you open the GRDB workspace, you can run tests with FTS5 enabled by modifying GRDBDeploymentTarget.xcconfig:

// Add this line to GRDBDeploymentTarget.xcconfig
OTHER_SWIFT_FLAGS = $(inherited) -D SQLITE_ENABLE_FTS5

You can then select the GRDBOSX schema, and run FTS5 tests.

Do not commit this change! The raw project must remain FTS5-free so can users can embed it in their apps that target older operating systems.

[groue]

Shipped in v5.10.0