I work with a tool that provides diffing and merging for rich text (effectively a limited subset of HTML). It doesn’t have or need real-time collaborative functionality at all. I have read all the papers that I can find and understand, but I’m still not happy with our merging algorithm for rich text.
The issue is less about which fancy algorithm/data structure to use and more about even defining in human terms what would be expected in certain merge conflicts. Currently, we err on the side of raising a merge conflict rather than deciding to use one version for a certain change, but in practice most conflicts have a pretty obvious resolution when a human looks at the two conflicting versions.
> The issue is less about which fancy algorithm/data structure to use and more about even defining in human terms what would be expected in certain merge conflicts
Exactly. When it comes to rich text editing which can have semantic trees (e.g tables and tables within tables), merge conflicts are so tough to handle.
Consider this: one version deleting a column in a table, and the other version splitting the column and adding a new row - by this time it's sort of impossible to find a meaningful representation of the table without manual intervention.
The issue is less about which fancy algorithm/data structure to use and more about even defining in human terms what would be expected in certain merge conflicts. Currently, we err on the side of raising a merge conflict rather than deciding to use one version for a certain change, but in practice most conflicts have a pretty obvious resolution when a human looks at the two conflicting versions.