Here is yet another package: FixedSizeDictionaries.jl <https://github.com/SimonDanisch/FixedSizeDictionaries.jl>
>From the README: *Library which implements a FixedSize variant of Dictionaries. These can be stack allocated and have O(1) indexing performance without boundcheck. It implements most parts of the Base.Dict interface. * *This package is useful, when you want anonymous composite types. You should be a bit careful with generating a lot of FixedSizeDict's, since it will compile a unique set of functions for every field of a Dict.* I'll be using it to speed up various places where I'm currently using a dictionary but where the number of keys is set at compile time. Also, Shashi <https://github.com/shashi> and I contemplated to implement <goog_285611601>Extensible Records <http://elm-lang.org/docs/records>, which seems like a good fit to represent all kind of graphics/geometry types. FixedSizeDictionaries could be an integral part of this! Best, Simon PS: I do feel like it's time for a package announcement list...