edn (parse tree) -> Elixir

[jfacorro]

Data Structures Mapping: edn <-> Elixir

Edn	Elixir
nil	:nil = nil
true	:true = true
false	:false = false
string	String
character	ExEdn.Character
symbol	ExEdn.Symbol
keyword	Atom
integer	Integer
float	Float
list	List
vector	Array
map	Map
set	HashSet
#inst	Timex.DateTime
#uuid	ExEdn.UUID

Further Considerations

Character

There is no way of distinguishing a common integer from the representation of a character in a String or in Char lists. This forces the creation of a new representation for this type so it can be correctly translated to from and to edn.

Arbitrary Precision Integer and Float

The Erlang VM (EVM) only provides arbitrary precision integer so all integers will have this and the N modifier will be ignored when present.

On the other hand native arbitrary precision floating point numbers are not provided by the EVM so all values of type float will be represented according to what the EVM supports.

Keyword and Symbol Representation

The decision to translate keywords as atoms on the EVM comes form the common use these two data type are given. It might get awkward really quickly using a new ExEdn.Symbol struct as the representation for edn's symbols so this might change.

vector

There is no constant lookup or nearly constant indexed data structure like edn's vector other than the :array data structure implemented in one of Erlang's standard library modules. Until there is a better implementation for this ExEdn will use the Array, an Elixir wrapper library for Erlang's array.