concepts that don't map to the domain ... there are ... a couple of levels down ... concepts that have no obvious connection to the domain
There always are. I took it to mean that dirty code has concepts that don't map properly to the domain, i.e.:
1) Objects that claim to map to the domain, but do so badly, or do so partly but fail at this in obvious and subtle ways.
2) Leaky abstractions
A huge problem with dirty code is that it is permanently owned by the author
Or worse, nobody will go near it. Coders move on or forget the hack that they did in the crunch, so the author may be absent or disavow it. As commented elsewhere, he meant to say "Dirty code inhibits the formation of a good, collective ownership culture"
There always are. I took it to mean that dirty code has concepts that don't map properly to the domain, i.e.:
1) Objects that claim to map to the domain, but do so badly, or do so partly but fail at this in obvious and subtle ways.
2) Leaky abstractions
A huge problem with dirty code is that it is permanently owned by the author
Or worse, nobody will go near it. Coders move on or forget the hack that they did in the crunch, so the author may be absent or disavow it. As commented elsewhere, he meant to say "Dirty code inhibits the formation of a good, collective ownership culture"