three
Version:
JavaScript 3D library
60 lines (30 loc) • 816 B
JavaScript
export default class ChainMap {
constructor() {
this.weakMap = new WeakMap();
}
get( keys ) {
let map = this.weakMap;
for ( let i = 0; i < keys.length; i ++ ) {
map = map.get( keys[ i ] );
if ( map === undefined ) return undefined;
}
return map.get( keys[ keys.length - 1 ] );
}
set( keys, value ) {
let map = this.weakMap;
for ( let i = 0; i < keys.length; i ++ ) {
const key = keys[ i ];
if ( map.has( key ) === false ) map.set( key, new WeakMap() );
map = map.get( key );
}
return map.set( keys[ keys.length - 1 ], value );
}
delete( keys ) {
let map = this.weakMap;
for ( let i = 0; i < keys.length; i ++ ) {
map = map.get( keys[ i ] );
if ( map === undefined ) return false;
}
return map.delete( keys[ keys.length - 1 ] );
}
}