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innerjoin.ts
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innerjoin.ts
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import { IterableX } from './iterablex';
import { createGrouping } from './_grouping';
import { identity } from '../internal/identity';
export class JoinIterable<TOuter, TInner, TKey, TResult> extends IterableX<TResult> {
private _outer: Iterable<TOuter>;
private _inner: Iterable<TInner>;
private _outerSelector: (value: TOuter) => TKey;
private _innerSelector: (value: TInner) => TKey;
private _resultSelector: (outer: TOuter, inner: TInner) => TResult;
constructor(
outer: Iterable<TOuter>,
inner: Iterable<TInner>,
outerSelector: (value: TOuter) => TKey,
innerSelector: (value: TInner) => TKey,
resultSelector: (outer: TOuter, inner: TInner) => TResult
) {
super();
this._outer = outer;
this._inner = inner;
this._outerSelector = outerSelector;
this._innerSelector = innerSelector;
this._resultSelector = resultSelector;
}
*[Symbol.iterator]() {
const map = createGrouping(this._inner, this._innerSelector, identity);
for (let outerElement of this._outer) {
const outerKey = this._outerSelector(outerElement);
if (map.has(outerKey)) {
for (let innerElement of map.get(outerKey)!) {
yield this._resultSelector(outerElement, innerElement);
}
}
}
}
}
export function innerJoin<TOuter, TInner, TKey, TResult>(
outer: Iterable<TOuter>,
inner: Iterable<TInner>,
outerSelector: (value: TOuter) => TKey,
innerSelector: (value: TInner) => TKey,
resultSelector: (outer: TOuter, inner: TInner) => TResult
): IterableX<TResult> {
return new JoinIterable<TOuter, TInner, TKey, TResult>(
outer,
inner,
outerSelector,
innerSelector,
resultSelector
);
}