46 lines
1.0 KiB
Plaintext
46 lines
1.0 KiB
Plaintext
/**
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* This function takes one parameter and just returns it. Simply put,
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* this is like `<T>(x: T): T => x`.
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*
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* ## Examples
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*
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* This is useful in some cases when using things like `mergeMap`
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*
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* ```ts
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* import { interval, take, map, range, mergeMap, identity } from 'rxjs';
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*
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* const source$ = interval(1000).pipe(take(5));
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*
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* const result$ = source$.pipe(
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* map(i => range(i)),
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* mergeMap(identity) // same as mergeMap(x => x)
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* );
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*
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* result$.subscribe({
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* next: console.log
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* });
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* ```
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*
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* Or when you want to selectively apply an operator
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*
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* ```ts
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* import { interval, take, identity } from 'rxjs';
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*
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* const shouldLimit = () => Math.random() < 0.5;
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*
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* const source$ = interval(1000);
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*
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* const result$ = source$.pipe(shouldLimit() ? take(5) : identity);
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*
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* result$.subscribe({
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* next: console.log
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* });
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* ```
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*
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* @param x Any value that is returned by this function
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* @returns The value passed as the first parameter to this function
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*/
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export function identity<T>(x: T): T {
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return x;
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}
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