deepmap

Maps with multiple keys per value

Supports the following Map methods:

• clear
• delete
• has
• get
• set

All other Map methods & properties, including well-known symbols and coercion logic, are not catered for at present.

Signature for all methods is the same as for Map, except that in place of a key, it instead accepts an array of keys.

map[ method ]( key, value? )

...DeepMaps instead provide:

map[ method ]( [ ...keys ], value? )

Ergo:

const sums = new DeepMap()
 
sums.set( [ 1, 2 ], 3 )
 
sums.has( 1 )           // false
 
sums.has( [ 1 ] )       // false
 
sums.has( [ 1, 2 ] )    // true
 
sums.get( [ 1, 2 ] )    // 3
 
sums.delete( [ 1, 2 ] ) // true
 
sums.has( [ 1, 2 ] )    // false