The concept of isomorphisms is useful, but is orthogonal to the concept of domains. The way the package interweaves these two ideas makes the code hard to modify. I'd propose removing all references to isomorphisms from DomainSets.jl and moving them to another package, say ArrayIsomorphisms.jl. (Isomorphisms.jl seems to broad.)
The concept of isomorphisms is useful, but is orthogonal to the concept of domains. The way the package interweaves these two ideas makes the code hard to modify. I'd propose removing all references to isomorphisms from DomainSets.jl and moving them to another package, say ArrayIsomorphisms.jl. (Isomorphisms.jl seems to broad.)