Hi. Good idea.

I think changing the property type in this way is not quite backwards compatible, even if __str__ is provided. Maybe something like

class GameNode:

    comments: List[Comment]

    @property
    def comment(self) -> str: ...

    @comment.setter
    def comment(self, value: str) -> None: ...

could work?

Or maybe it's also just time to consider 2.x at some point.

I tried to make GameNodeComment backwards compatible in terms of assignment and writing to a PGN file. The breaking change comes from getting comments from a node (with some allowances for comparing a single comment to a single string), since I didn't want users to accidentally miss comments. What would GameNode.comment return, just the first comment?

Saving this until 2.x would make things much easier. A new class wouldn't even be needed.

class GameNode:
    comments: list[str]

If you want to save this PR until 2.x, this would be an easy change.

In 1.x, GameNode.comment would have to be the concatenation of all comments, to match the current behavior.

That should do it. GameNode.comments returns the GameNodeComment (a list[str] essentially), and GameNode.comment returns a single str formed from joining the strings with spaces.

Do you want to save this functionality for v2.0? I can make a new PR (not backwards compatible) that would be much simpler than this one--basically replacing all comment: str members of GameNode and ChildNode with comments: list[str] and changing the PGN comment functions.

Let's do 2.x. So it would contain "small" breaking changes and clean-ups, and more ambitious plans and far-reaching changes would be pushed back to 3.x.

Updated changes:

1. Rename GameNode comment field from comment to comments and starting_comment to starting_comments.
2. Adapt methods that process comments (e.g., eval() and set_eval()).
3. Adapt PGN reading and writing to handle moves/games with multiple comments.

The change from comment to comments is the breaking change. Assigning to node.comment no longer has any effect. I figured that using a plural name emphasizes that the field should be a list. Plus, assigning a string comment instead of a list of strings will cause problems with comment processing methods (Item 2, above).