uniqueBy

KIT · function · Runtime value

Stable deduplication preserves the original values; the host chooses equivalence.

The first occurrence of each key wins and the input order is kept, so callers can rely on deduplication never reordering their list.

Import

TypeScript

import { uniqueBy } from '@jangts/agent-core/kits/normalization';

JavaScript

import { uniqueBy } from '@jangts/agent-core/kits/normalization';

Other public entry points:@jangts/agent-core/types, @jangts/agent-core/kits/normalization, @jangts/agent-core/kits.

Definition

Type parameters

Type parameter	Constraint	Default type
Value	—	—
Key	—	—

Call

uniqueBy<Value, Key>(values: readonly Value[], key: (value: Value) => Key, initial?: Iterable<Key>): Value[]

Stable deduplication preserves the original values; the host chooses equivalence.

The first occurrence of each key wins and the input order is kept, so callers can rely on deduplication never reordering their list.

Type parameter	Constraint	Default type
Value	—	—
Key	—	—

Parameter	Type	Passing	Description
values	readonly Value[]	Required	—
key	(value: Value) => Key	Required	—
initial	Iterable<Key>	Optional	—

Returns: Value[].

Examples

• Normalization: ordered value transformation: Collect cleaning, replacement, and stop conditions into one transformation list that actually drives execution.

Start by cleaning one query

Beginner · Node.js

TypeScript

import { Normalization } from '@jangts/agent-core/kits/normalization';
const query = Normalization.defineNormalization<string>([
  { id: 'trim', normalize: value => value.trim() },
]);
console.log(query.normalize('  Agent Core  ', undefined));

JavaScript

import { Normalization } from '@jangts/agent-core/kits/normalization';
const query = Normalization.defineNormalization([
    { id: 'trim', normalize: value => value.trim() },
]);
console.log(query.normalize('  Agent Core  ', undefined));

Continue by adding steps and a stop condition

Configuration · Node.js

TypeScript

import { Normalization } from '@jangts/agent-core/kits/normalization';
const query = Normalization.defineNormalization<string>([
  { id: 'trim', normalize: value => value.trim() },
  { id: 'collapse-space', normalize: value => value.replace(/\s+/g, ' ') },
  { id: 'lowercase', when: value => value !== '*', normalize: value => value.toLowerCase() },
], { isComplete: value => value === '*' });
const values = [' Agent  Core ', 'agent core', '*'].map(value => query.normalize(value, undefined));
console.log(Normalization.uniqueBy(values, value => value));

JavaScript

import { Normalization } from '@jangts/agent-core/kits/normalization';
const query = Normalization.defineNormalization([
    { id: 'trim', normalize: value => value.trim() },
    { id: 'collapse-space', normalize: value => value.replace(/\s+/g, ' ') },
    { id: 'lowercase', when: value => value !== '*', normalize: value => value.toLowerCase() },
], { isComplete: value => value === '*' });
const values = [' Agent  Core ', 'agent core', '*'].map(value => query.normalize(value, undefined));
console.log(Normalization.uniqueBy(values, value => value));

Related policy source

• Step execution, synchronous constraints, and stop order