Module Js.Dict

Provide utilities for JS dictionary object

type 'a t

Dictionary type (ie an '{ }' JS object). However it is restricted to hold a single type; therefore values must have the same type.

This Dictionary type is mostly used with the Js_json.t type.

type key = string

Key type

val get : 'a t -> key -> 'a option

get dict key returns None if the key is not found in the dictionary, Some value otherwise

val unsafeGet : 'a t -> key -> 'a

unsafeGet dict key return the value if the key exists, otherwise an undefined value is returned. Must be used only when the existence of a key is certain. (i.e. when having called keys function previously.

Array.iter (fun key -> Js.log (Js_dict.unsafeGet dic key)) (Js_dict.keys dict)
val set : 'a t -> key -> 'a -> unit

set dict key value sets the key/value in dict

val keys : 'a t -> string array

keys dict returns all the keys in the dictionary dict

val empty : unit -> 'a t

empty () returns an empty dictionary

module Js := Js__.Js_internal
val unsafeDeleteKey : (string t -> string -> unit) Js.Fn.arity2

Experimental internal function

val entries : 'a t -> (key * 'a) array

entries dict returns the key value pairs in dict (ES2017)

val values : 'a t -> 'a array

values dict returns the values in dict (ES2017)

val fromList : (key * 'a) list -> 'a t

fromList entries creates a new dictionary containing each (key, value) pair in entries

val fromArray : (key * 'a) array -> 'a t

fromArray entries creates a new dictionary containing each (key, value) pair in entries

val map : f:('a -> 'b) Js.Fn.arity1 -> 'a t -> 'b t

map f dict maps dict to a new dictionary with the same keys, using f to map each value