Map works like a hashtable but preserving the key insertion order.

To install Map, run:

$ luarocks install map

local Map = require('Map')
local bill = Map()

bill.set('name', 'Bill Gates')
bill.set('age', 65)

bill.has('name') -- true
bill.has('company') -- false

bill.get('name') -- 'Bill Gates'
bill.get('age') -- 65
bill.get('company') -- nil

bill.each(function(key, value)
  print(key .. ' = ' .. value)
end)
-- name = Bill Gates
-- age = 65

• Map.items:table
  Table holds key-values pairs.

• Map.keys:table
  List of inserted keys.

• Map.values:table
  List of inserted values.

• Map.size:number
  Current Map length.

• Map.set(key:any, value:any):void
  Sets a key to a value.

• Map.get(key:any):any
  Returns the value associated to the key.

• Map.has(key:any):boolean
  Returns the value associated to the key.

• Map.delete(key:any):boolean
  Removes item by key and returns true in case of success and false if the item doesn't exist in the Map.

• Map.each(callback:function):void
  Calls function once for each item present in the Map object preserving insertion order.

MIT