Use an immutable http://docs.julialang.org/en/release-0.2/manual/types/#immutable-composite- types with an inner constructor: http://docs.julialang.org/en/release-0.2/manual/constructors/#inner- constructor-methods
You may find the example http://docs.julialang.org/en/release-0.2/manual/constructors/#case-study- rational helpful. Best, --Tim
