Pools

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Transformation ​

Methods for transforming, grouping, and organizing pool data.

deduplicate() ​

Removes duplicate entries based on uniqueBy.

typescript
pool.deduplicate(uniqueBy: keyof T | ((item: T) => any)): this

Parameters:

  • uniqueBy - Field name or function to determine uniqueness

Returns: This pool for chaining

Example:

typescript
// Remove duplicates by ID
pool.deduplicate('id');

// Remove duplicates by email
pool.deduplicate(user => user.email);

partition() ​

Partitions the pool into two pools based on predicate.

typescript
pool.partition(predicate: (entry: PoolEntry<T>) => boolean): [Pool<T>, Pool<T>]

Parameters:

  • predicate - Function to determine partition

Returns: Tuple of two pools [matching, notMatching]

Example:

typescript
const [premium, free] = users.partition(({ data }) => data.premium === true);

console.log(`Premium: ${premium.size}, Free: ${free.size}`);

groupBy() ​

Groups entries by a field or function.

typescript
pool.groupBy(groupBy: keyof T | ((item: T) => any)): Map<any, Pool<T>>

Parameters:

  • groupBy - Field name or function to group by

Returns: Map of group keys to pools

Example:

typescript
const byCountry = users.groupBy('country');
byCountry.forEach((pool, country) => {
  console.log(`${country}: ${pool.size} users`);
});

// By function
const byAgeGroup = users.groupBy(user =>
  user.age < 18 ? 'minor' : user.age < 65 ? 'adult' : 'senior'
);

clone() ​

Clones the pool (deep copy of entries).

typescript
pool.clone(): Pool<T>

Returns: A new pool with the same entries

Example:

typescript
const backup = pool.clone();

sample() ​

Returns a random sample of entries.

typescript
pool.sample(count: number): Pool<T>

Parameters:

  • count - Number of entries to sample

Returns: A new pool with sampled entries

Example:

typescript
const randomThree = pool.sample(3);

shuffle() ​

Shuffles the pool in place.

typescript
pool.shuffle(): this

Returns: This pool for chaining

Example:

typescript
pool.shuffle();
const first = pool.all[0]; // Random entry