sql framework experiment

example.ceylon

shared object serversTable extends Table<String|Boolean,[String, Boolean]>("servers") {

    Column<String> name => Column<String>("name");
    Column<Boolean> online => Column<Boolean>("online");

    shared actual [Column<String>, Column<Boolean>] columns => [name, online];
}

Table.ceylon

shared abstract class Table<Col, Columns>(name)
        given Columns satisfies Col[] {

    shared String name;

    shared formal Column<Col>[] columns;

    shared class Column<out Value>(name, default = null)
            given Value satisfies Col {

        shared String name;

        shared Value? default;
    }
}