76 lines
2.8 KiB
TypeScript
76 lines
2.8 KiB
TypeScript
 
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// Public translation-engine abstraction. One implementation today
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// (`chromeEngine` — the Chromium on-device Translator/LanguageDetector API);
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// a Bergamot-WASM engine can implement the same interface later with no
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// call-site changes. Privacy invariant: an engine MUST run on-device only —
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// message text may never leave the machine. There is intentionally no network
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// engine.
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export type TranslateAvailability = 'unavailable' | 'downloadable' | 'downloading' | 'available';
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export interface TranslationEngine {
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/** Is this engine usable in the current browser right now? */
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isSupported(): boolean;
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/** Detect the source language of `text` — a normalized base code (e.g. "de") or undefined. */
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detect(text: string): Promise<string | undefined>;
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/** Can this source→target pair be translated (and is the model downloaded)? */
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availability(source: string, target: string): Promise<TranslateAvailability>;
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/**
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* Translate `text` from `source` to `target`. May trigger a one-time on-device
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* model download (reported via `onDownloadProgress`, 0..1). Must be invoked
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* from a user gesture the first time a pair's model needs downloading.
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*/
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translate(
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text: string,
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source: string,
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target: string,
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onDownloadProgress?: (progress: number) => void,
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): Promise<string>;
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}
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// ── Ambient types for the Chromium on-device APIs ──────────────────────────────
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// Experimental globals not present in TS's lib.dom; declared minimally here.
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// See https://developer.chrome.com/docs/ai/translator-api and the MDN
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// Translator_and_Language_Detector_APIs page.
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interface CreateMonitor {
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addEventListener(type: 'downloadprogress', listener: (event: { loaded: number }) => void): void;
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}
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export interface ChromeTranslatorInstance {
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translate(input: string): Promise<string>;
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destroy?(): void;
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}
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export interface ChromeTranslatorFactory {
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availability(opts: {
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sourceLanguage: string;
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targetLanguage: string;
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}): Promise<TranslateAvailability>;
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create(opts: {
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sourceLanguage: string;
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targetLanguage: string;
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monitor?: (m: CreateMonitor) => void;
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}): Promise<ChromeTranslatorInstance>;
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}
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export interface ChromeDetectorResult {
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detectedLanguage: string;
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confidence: number;
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}
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export interface ChromeLanguageDetectorInstance {
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detect(input: string): Promise<ChromeDetectorResult[]>;
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destroy?(): void;
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}
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export interface ChromeLanguageDetectorFactory {
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create(opts?: { monitor?: (m: CreateMonitor) => void }): Promise<ChromeLanguageDetectorInstance>;
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}
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declare global {
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// eslint-disable-next-line vars-on-top
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var Translator: ChromeTranslatorFactory | undefined;
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// eslint-disable-next-line vars-on-top
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var LanguageDetector: ChromeLanguageDetectorFactory | undefined;
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}
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