node package manager
It’s your turn. Help us improve JavaScript. Take the 2017 JavaScript Ecosystem Survey »



What is this?

sweet expressions for EDN. Lets just jump into an example:

    :name "cordelia" 
    :age 6
  :tofu 4
  :margaret 3
    :favorite-toys :ball1 :ball2 :ball3 
    :friends [:margaret] 
    :color {:hair [:black :tan] :eyes #myApp/eyeColor :brown}

{:cats {
   :cordelia {
       :name "cordelia"
       :age 6}
   :tofu 4
   :margaret 3}
 :dogs {
   :schnitzel {
     :favorite-toys [:ball1 :ball2 :ball3]
     :friends [:margaret]
     :color {:hair [:black :tan] :eyes #myApp/eyeColor :brown}}}}

Hopefully from the above it is apparent that we are implicitly in a Map as (for me at least) this is my most common use-case for EDN.

If we find a single item after a key we assume it represents itself.

If we find more than 1 we assume it is a vector (this means if we want a vector of one item as the value we need to explicitly do [item]).

If we explicitly want a list we need to express that, the same goes for sets.

All other normal edn values and parsing apply.

If we want an "inline map" it needs to be explicit e.g. {:key val}

If you want an ordered map you can accomplish this by starting in a vector (this is useful for a DSL for instance)

[define x
    y z
 define z
    x y]
[{define [x {y z}]} 
 {define [z {x y}]}]