ContentProjectionOptions

KIT · interface · 类型合同

Candidate strategy for content projection.

导入

TypeScript

import type { ContentProjectionOptions } from '@jangts/agent-core/kits/projection';

JavaScript

/** @typedef {import('@jangts/agent-core/kits/projection').ContentProjectionOptions} ContentProjectionOptions */

其他公开入口：@jangts/agent-core/types、@jangts/agent-core/kits/projection、@jangts/agent-core/kits。

定义

interface ContentProjectionOptions

字段结构

字段	类型	必需	说明
counts	readonly number[]	必需	只读。Maximum array items to keep, tried in order before moving to the next length.
lengths	readonly number[]	必需	只读。Maximum characters per string, tried in order inside each count candidate.
render	(excerpt: unknown) => string	必需	只读。Renders a shortened value; must be synchronous.
fallback	(limit: number) => string	必需	只读。Builds fallback text for a limit, used when no candidate fits; must be synchronous.

成员目录

成员	用途
render	Renders a shortened value; must be synchronous.
fallback	Builds fallback text for a limit, used when no candidate fits; must be synchronous.

成员详情

render

Renders a shortened value; must be synchronous.

ContentProjectionOptions.render(excerpt: unknown): string

参数	类型	传递	说明
excerpt	unknown	必需	—

返回： string。

fallback

Builds fallback text for a limit, used when no candidate fits; must be synchronous.

ContentProjectionOptions.fallback(limit: number): string

参数	类型	传递	说明
limit	number	必需	—

返回： string。

使用示例

• Projection：按预算投影内容：先缩短文本，再减少条目；源数据、投影结果和预算由 App 显式区分。

为同一份查询结果准备紧凑 JSON

入门 · Node.js

TypeScript

import { Projection } from '@jangts/agent-core/kits/projection';
const projection = Projection.defineContentProjection({
  counts: [10, 3, 1], lengths: [200, 80, 20],
  render: value => JSON.stringify(value), fallback: () => '{}',
});
const result = projection.project({ value: { items: [{ title: '配置说明', body: '正文'.repeat(100) }] }, maxChars: 120 });
console.log(result.text, result.truncated);

JavaScript

import { Projection } from '@jangts/agent-core/kits/projection';
const projection = Projection.defineContentProjection({
    counts: [10, 3, 1], lengths: [200, 80, 20],
    render: value => JSON.stringify(value), fallback: () => '{}',
});
const result = projection.project({ value: { items: [{ title: '配置说明', body: '正文'.repeat(100) }] }, maxChars: 120 });
console.log(result.text, result.truncated);

相同数据先移除私有字段，再按预算投影

配置 · Node.js

TypeScript

import { Projection } from '@jangts/agent-core/kits/projection';
const tree = Projection.defineTreeProjection({
  maxDepth: 4,
  visitRecord(record) { delete record.privateNote; },
});
const source = { items: [{ title: '配置说明', body: '正文'.repeat(100), privateNote: '不向模型提供' }] };
// 调用者明确选择副本所有权；visitor 不会碰原记录。
const publicData = tree.visit(structuredClone(source), undefined);
const compact = Projection.defineContentProjection({ counts: [10, 3, 1], lengths: [200, 80, 20], render: JSON.stringify, fallback: () => '{}' });
console.log(compact.project({ value: publicData, maxChars: 120 }));

JavaScript

import { Projection } from '@jangts/agent-core/kits/projection';
const tree = Projection.defineTreeProjection({
    maxDepth: 4,
    visitRecord(record) { delete record.privateNote; },
});
const source = { items: [{ title: '配置说明', body: '正文'.repeat(100), privateNote: '不向模型提供' }] };
// 调用者明确选择副本所有权；visitor 不会碰原记录。
const publicData = tree.visit(structuredClone(source), undefined);
const compact = Projection.defineContentProjection({ counts: [10, 3, 1], lengths: [200, 80, 20], render: JSON.stringify, fallback: () => '{}' });
console.log(compact.project({ value: publicData, maxChars: 120 }));

相关策略源码

• 缩减顺序与树遍历