import { HashMap } from '@esfx/collections-hashmap' ; import { Equaler } from '@esfx/equatable' ; import { Hierarchical , HierarchyProvider , HierarchyIterable } from '@esfx/iter-hierarchy' ; internal export function createGroupings < T , K , V > ( source , keySelector , elementSelector , keyEqualer ? ) { const map = new HashMap < K , V [ ] > ( keyEqualer ) ; for ( const item of source ) { const key = keySelector ( item ) ; const element = elementSelector ( item ) ; const grouping = map . get ( key ) ; if ( grouping === undefined ) { map . set ( key , [ element ] ) ; } else { grouping . push ( element ) ; } } return map ; } internal export function flowHierarchy < TNode , T extends TNode , TIter extends Iterable < T > > ( to , fromLeft , fromRight ? ) ; internal export function flowHierarchy < TNode , T extends TNode , TIter extends Iterable < T > > ( to , fromLeft , fromRight ) ; internal export function flowHierarchy < T , TIter extends Iterable < T > > ( to , fromLeft , fromRight ? ) ; export function flowHierarchy < T , TIter extends Iterable < T > > ( to , fromLeft , fromRight ? ) { const leftProvider = HierarchyIterable . hasInstance ( fromLeft ) ? fromLeft [ Hierarchical . hierarchy ] ( ) : undefined ; const rightProvider = HierarchyIterable . hasInstance ( fromRight ) ? fromRight [ Hierarchical . hierarchy ] ( ) : undefined ; const provider = HierarchyProvider . combine ( leftProvider , rightProvider ) ; if ( provider ) { Object . defineProperty ( to , Hierarchical . hierarchy , { enumerable : false , configurable : true , writable : true , value : ( ) => provider } ) ; } return to ; }