Data structure that maps entries to numeric ids
npm install numeric-id-mapData structure that maps entries to numeric ids
```
npm install numeric-id-map

` js
var map = require('numeric-id-map')
var ids = map()
// map an entry to a numeric id
var id = ids.add({hello: 'world'})
// remove an id and get the data back
// the id will be reused for another entry
var entry = map.remove(id)
`
#### var ids = map()
Create a new instance
#### id = ids.add(entry)
Map an entry to a numberic id.
#### entry = ids.remove(id)
Remove an id and return the previously mapped entry.
After removing the id might be reused in the future.
#### entry = ids.get(id)`
Lookup a mapped entry by it's id without removing it
MIT