selectVariant
KIT · function · Runtime value
Pick one variant, avoiding an immediate repeat when alternatives exist.
When every candidate equals previous, the full list is used again, so a single-value set still yields a result instead of failing.
Import
ts
import { selectVariant } from '@jangts/agent-core/kits/presentation';js
import { selectVariant } from '@jangts/agent-core/kits/presentation';Other public entry points:@jangts/agent-core/types, @jangts/agent-core/kits/presentation, @jangts/agent-core/kits.
Definition
Type parameters
| Type parameter | Constraint | Default type |
|---|---|---|
Value | — | — |
Call
ts
selectVariant<Value>(values: readonly Value[], options: { previous?: Value; randomIndex(limit: number): number; }): Value | undefinedPick one variant, avoiding an immediate repeat when alternatives exist.
When every candidate equals previous, the full list is used again, so a single-value set still yields a result instead of failing.
| Type parameter | Constraint | Default type |
|---|---|---|
Value | — | — |
| Parameter | Type | Passing | Description |
|---|---|---|---|
values | readonly Value[] | Required | — |
options | { previous?: Value; randomIndex(limit: number): number; } | Required | — |
Fields of options
| Field | Type | Required | Description |
|---|---|---|---|
previous | Value | undefined | Optional | See the type definition and usage context. |
randomIndex | (limit: number) => number | Required | See the type definition and usage context. |
Returns: Value \| undefined.
Awaited value: Awaited<Value> \| undefined.
Examples
- Templates, semantic slots, and expression selection: The program owns templates and preference order, inserted values are replaced only once, and the App supplies the random source for variants.
First compose an explanation with a program template
Beginner · Node.js
ts
import { Presentation } from '@jangts/agent-core/kits/presentation';
const template = Presentation.defineTextTemplate('你好，{{name}}。{{body}}');
console.log(template.render({ name: '开发者', body: '普通对象也能实现接口。' }));js
import { Presentation } from '@jangts/agent-core/kits/presentation';
const template = Presentation.defineTextTemplate('你好，{{name}}。{{body}}');
console.log(template.render({ name: '开发者', body: '普通对象也能实现接口。' }));Add semantic key validation and a non-repeating variant to the same template
Configuration · Node.js
ts
import { Presentation } from '@jangts/agent-core/kits/presentation';
const slots = Presentation.defineSemanticSlots({ namespace: 'tone', keys: ['brief', 'detailed'], maxOccurrences: 1 });
console.log(slots.isValid('{{tone:brief}}'));
const greeting = Presentation.selectVariant(['你好', '欢迎'], { previous: '你好', randomIndex: () => 0 });
const tone = Presentation.resolvePreference([{ value: 'brief', priority: 1, order: 0 }, { value: 'detailed', priority: 2, order: 1 }]);
const template = Presentation.defineTextTemplate('{{greeting}}，{{body}}');
console.log(template.render({ greeting: greeting ?? '你好', body: tone === 'detailed' ? '下面逐步说明接口。' : '普通对象即可。' }));js
import { Presentation } from '@jangts/agent-core/kits/presentation';
const slots = Presentation.defineSemanticSlots({ namespace: 'tone', keys: ['brief', 'detailed'], maxOccurrences: 1 });
console.log(slots.isValid('{{tone:brief}}'));
const greeting = Presentation.selectVariant(['你好', '欢迎'], { previous: '你好', randomIndex: () => 0 });
const tone = Presentation.resolvePreference([{ value: 'brief', priority: 1, order: 0 }, { value: 'detailed', priority: 2, order: 1 }]);
const template = Presentation.defineTextTemplate('{{greeting}}，{{body}}');
console.log(template.render({ greeting: greeting ?? '你好', body: tone === 'detailed' ? '下面逐步说明接口。' : '普通对象即可。' }));