Is there a need to make the class AbstractColumn internal?

[YokiToki]

Or maybe there is another way to create a custom column (e.g postgreSQL geography point)? I can create extension function of TableBuilder but can't access to ColumnBuilder and AbstractColumn from another package.

[KenjiOhtsuka]

I thought that a good library doesn't force users to think about the internal structure, so I made most classes internal.

You are saying https://www.postgresql.org/docs/9.4/datatype-geometric.html , right?

I have to add those types of columns...
Or, if you have code for those columns and give me the Pull Request, I can review and merge.

[KenjiOhtsuka]

But I know it is a debatable point, because it could be very flexible if users can customize.

[YokiToki]

Sorry, I mean https://postgis.net/workshops/postgis-intro/geography.html but I think it is not necessary to add those types to the library, it would be good to have them separate extension if we talk specifically about PostGIS.