feat(nlp): add translation task (Opus-MT, EuroLLM, Hy-MT2)

.cspell-wordlist.txt

@@ -448,3 +448,4 @@ Premul
 eurollm
 doclayout
 netp
+Uyghur

apps/nlp/app/_layout.tsx

@@ -48,6 +48,13 @@ export default function Layout() {
           title: 'Privacy Filter',
         }}
       />
+      <Drawer.Screen
+        name="translation/index"
+        options={{
+          drawerLabel: 'Translation',
+          title: 'Translation',
+        }}
+      />
       <Drawer.Screen
         name="llm/index"
         options={{

apps/nlp/app/index.tsx

@@ -23,6 +23,9 @@ export default function Home() {
         <TouchableOpacity style={styles.button} onPress={() => router.navigate('privacy-filter/')}>
           <Text style={styles.buttonText}>Privacy Filter</Text>
         </TouchableOpacity>
+        <TouchableOpacity style={styles.button} onPress={() => router.navigate('translation/')}>
+          <Text style={styles.buttonText}>Translation</Text>
+        </TouchableOpacity>
         <TouchableOpacity style={styles.button} onPress={() => router.navigate('llm/')}>
           <Text style={styles.buttonText}>LLM</Text>
         </TouchableOpacity>

apps/nlp/app/translation/index.tsx

@@ -0,0 +1,308 @@
+import React, { useState } from 'react';
+import {
+  View,
+  Text,
+  TextInput,
+  ScrollView,
+  StyleSheet,
+  TouchableOpacity,
+  KeyboardAvoidingView,
+  Platform,
+} from 'react-native';
+import {
+  useTranslator,
+  models,
+  type TranslationLanguages,
+  type TranslatorModel,
+} from 'react-native-executorch';
+import ScreenWrapper from '../../components/ScreenWrapper';
+import { ModelStatus } from '../../components/ModelStatus';
+import { Button } from '../../components/Button';
+import { theme } from '../../theme';
+
+/* cspell:disable */
+const SAMPLES: Record<string, string> = {
+  en: 'The weather is beautiful today. Shall we go for a walk in the park?\nI will bring something to drink.',
+  de: 'Das Wetter ist heute wunderschön. Sollen wir im Park spazieren gehen?\nIch bringe etwas zu trinken mit.',
+  es: 'Hoy hace un tiempo precioso. ¿Vamos a dar un paseo por el parque?\nYo llevaré algo de beber.',
+  fr: 'Il fait très beau aujourd’hui. On va se promener dans le parc ?\nJ’apporterai quelque chose à boire.',
+  pl: 'Dzisiaj jest piękna pogoda. Może pójdziemy na spacer do parku?\nPrzyniosę coś do picia.',
+  zh: '今天天气真好。我们去公园散步好吗？\n我会带点喝的。',
+  ja: '今日はとても良い天気です。公園に散歩に行きませんか？\n飲み物を持っていきます。',
+};
+/* cspell:enable */
+
+type Pair = { label: string; languages: TranslationLanguages };
+const pair = (sourceLanguage: string, targetLanguage: string): Pair => ({
+  label: `${sourceLanguage.toUpperCase()} → ${targetLanguage.toUpperCase()}`,
+  languages: { sourceLanguage, targetLanguage },
+});
+
+// Opus-MT ships one model per pair; EuroLLM and Hy-MT2 translate every pair with one.
+const OPUS_MT: { pair: Pair; model: TranslatorModel }[] = [
+  { pair: pair('en', 'de'), model: models.translation.OPUS_MT_EN_DE.DEFAULT },
+  { pair: pair('de', 'en'), model: models.translation.OPUS_MT_DE_EN.DEFAULT },
+  { pair: pair('en', 'es'), model: models.translation.OPUS_MT_EN_ES.DEFAULT },
+  { pair: pair('es', 'en'), model: models.translation.OPUS_MT_ES_EN.DEFAULT },
+  { pair: pair('en', 'fr'), model: models.translation.OPUS_MT_EN_FR.DEFAULT },
+  { pair: pair('fr', 'en'), model: models.translation.OPUS_MT_FR_EN.DEFAULT },
+];
+const EUROLLM_PAIRS = [...OPUS_MT.map((m) => m.pair), pair('en', 'pl'), pair('pl', 'en')];
+const HY_MT2_PAIRS = [
+  ...EUROLLM_PAIRS,
+  pair('en', 'zh'),
+  pair('zh', 'en'),
+  pair('en', 'ja'),
+  pair('ja', 'en'),
+];
+
+const FAMILIES = [
+  {
+    label: 'Opus-MT',
+    description:
+      'One small model per language pair. Translates a sentence at a time and streams the result as it is decoded.',
+    pairs: OPUS_MT.map((m) => m.pair),
+    modelFor: (i: number) => OPUS_MT[i]!.model,
+  },
+  {
+    label: 'EuroLLM',
+    description:
+      'One 1.7 GB model for 35 languages, so switching the pair does not reload it. Translates a line at a time.',
+    pairs: EUROLLM_PAIRS,
+    modelFor: () => models.translation.EUROLLM_1_7B.DEFAULT as TranslatorModel,
+  },
+  {
+    label: 'Hy-MT2',
+    description:
+      'One 1.2 GB model for 38 languages and dialects, strongest on Chinese. Translates a line at a time.',
+    pairs: HY_MT2_PAIRS,
+    modelFor: () => models.translation.HY_MT2_1_8B.DEFAULT as TranslatorModel,
+  },
+];
+
+function TranslationContent() {
+  const [family, setFamily] = useState(0);
+  const [selected, setSelected] = useState(0);
+  const { pairs, modelFor, description } = FAMILIES[family]!;
+  const active = pairs[selected]!;
+  const { isReady, downloadProgress, error, translate, translateStop } = useTranslator(
+    modelFor(selected)
+  );
+
+  const [text, setText] = useState(SAMPLES[active.languages.sourceLanguage] ?? '');
+  const [output, setOutput] = useState('');
+  const [busy, setBusy] = useState(false);
+  const [runError, setRunError] = useState<string | null>(null);
+  const [elapsedMs, setElapsedMs] = useState<number | null>(null);
+
+  const select = (nextFamily: number, nextPair: number) => {
+    if (nextFamily === family && nextPair === selected) return;
+    translateStop?.();
+    setFamily(nextFamily);
+    setSelected(nextPair);
+    const source = FAMILIES[nextFamily]!.pairs[nextPair]!.languages.sourceLanguage;
+    setText(SAMPLES[source] ?? '');
+    setOutput('');
+    setRunError(null);
+    setElapsedMs(null);
+  };
+
+  const run = async () => {
+    if (!translate || !text.trim()) return;
+    setBusy(true);
+    setRunError(null);
+    setOutput('');
+    setElapsedMs(null);
+    try {
+      const startedAt = Date.now();
+      const result = await translate(text, active.languages, (piece) =>
+        setOutput((prev) => prev + piece)
+      );
+      setElapsedMs(Date.now() - startedAt);
+      setOutput(result);
+    } catch (e: any) {
+      const msg = e?.message ?? String(e);
+      if (!/disposed/i.test(msg)) setRunError(msg);
+    } finally {
+      setBusy(false);
+    }
+  };
+
+  const chips = (labels: string[], current: number, onPress: (i: number) => void) => (
+    <ScrollView
+      horizontal
+      showsHorizontalScrollIndicator={false}
+      contentContainerStyle={styles.chipRow}
+    >
+      {labels.map((label, i) => (
+        <TouchableOpacity
+          key={label}
+          style={[styles.chip, i === current && styles.chipActive]}
+          onPress={() => onPress(i)}
+        >
+          <Text style={[styles.chipText, i === current && styles.chipTextActive]}>{label}</Text>
+        </TouchableOpacity>
+      ))}
+    </ScrollView>
+  );
+
+  return (
+    <KeyboardAvoidingView
+      style={styles.flex}
+      behavior={Platform.OS === 'ios' ? 'padding' : undefined}
+    >
+      <ScrollView style={styles.container} contentContainerStyle={styles.content}>
+        <View style={styles.card}>
+          <Text style={styles.cardTitle}>Translation</Text>
+          <Text style={styles.cardDescription}>{description}</Text>
+
+          <Text style={styles.fieldLabel}>Model</Text>
+          {chips(
+            FAMILIES.map((f) => f.label),
+            family,
+            (i) => select(i, 0)
+          )}
+
+          <Text style={styles.fieldLabel}>Language pair</Text>
+          {chips(
+            pairs.map((p) => p.label),
+            selected,
+            (i) => select(family, i)
+          )}
+
+          <ModelStatus
+            isReady={isReady}
+            downloadProgress={downloadProgress}
+            error={error ? error.message : null}
+            modelTypeLabel="model"
+          />
+        </View>
+
+        {runError && (
+          <View style={styles.errorContainer}>
+            <Text style={styles.errorText}>{runError}</Text>
+          </View>
+        )}
+
+        <View style={styles.card}>
+          <Text style={styles.sectionTitle}>Text to translate</Text>
+          <TextInput
+            style={styles.input}
+            value={text}
+            onChangeText={setText}
+            placeholder="Type or paste text…"
+            placeholderTextColor="#999"
+            multiline
+          />
+          <View style={styles.buttonRow}>
+            <Button
+              title="Translate"
+              onPress={run}
+              disabled={!isReady || !translate || !text.trim()}
+              loading={busy}
+            />
+            <Button
+              title="Stop"
+              variant="secondary"
+              onPress={() => translateStop?.()}
+              disabled={!busy}
+            />
+          </View>
+          {elapsedMs !== null && <Text style={styles.statsText}>Time: {elapsedMs} ms</Text>}
+        </View>
+
+        {output !== '' && (
+          <View style={styles.card}>
+            <Text style={styles.sectionTitle}>Translation</Text>
+            <Text style={styles.outputText}>{output}</Text>
+          </View>
+        )}
+      </ScrollView>
+    </KeyboardAvoidingView>
+  );
+}
+
+export default function TranslationScreen() {
+  return (
+    <ScreenWrapper>
+      <TranslationContent />
+    </ScreenWrapper>
+  );
+}
+
+const styles = StyleSheet.create({
+  flex: { flex: 1 },
+  container: { flex: 1, backgroundColor: theme.colors.background },
+  content: { padding: theme.spacing.large, paddingBottom: 40 },
+  card: {
+    backgroundColor: theme.colors.cardBackground,
+    borderRadius: theme.radius.large,
+    padding: 20,
+    marginBottom: 20,
+    borderWidth: 1,
+    borderColor: theme.colors.lightBorder,
+  },
+  cardTitle: {
+    fontSize: theme.typography.title.fontSize,
+    fontWeight: theme.typography.title.fontWeight,
+    color: theme.colors.strongPrimary,
+    marginBottom: 8,
+  },
+  cardDescription: {
+    fontSize: 14,
+    color: theme.colors.textMuted,
+    lineHeight: 20,
+    marginBottom: 16,
+  },
+  fieldLabel: {
+    fontSize: 12,
+    fontWeight: '600',
+    color: theme.colors.textPlaceholder,
+    textTransform: 'uppercase',
+    letterSpacing: 0.5,
+    marginBottom: 8,
+  },
+  chipRow: { gap: 8, paddingBottom: 4, marginBottom: 12 },
+  chip: {
+    paddingHorizontal: 14,
+    paddingVertical: 8,
+    borderRadius: 20,
+    backgroundColor: '#f1f3f5',
+    borderWidth: 1,
+    borderColor: theme.colors.lightBorder,
+  },
+  chipActive: {
+    backgroundColor: theme.colors.strongPrimary,
+    borderColor: theme.colors.strongPrimary,
+  },
+  chipText: { fontSize: 13, fontWeight: '600', color: theme.colors.textMuted },
+  chipTextActive: { color: '#fff' },
+  sectionTitle: { fontSize: 16, fontWeight: '700', color: '#212529', marginBottom: 12 },
+  input: {
+    backgroundColor: '#f1f3f5',
+    borderRadius: theme.radius.small,
+    padding: 12,
+    fontSize: 14,
+    color: '#212529',
+    marginBottom: 16,
+    minHeight: 140,
+    textAlignVertical: 'top',
+    borderWidth: 1,
+    borderColor: theme.colors.lightBorder,
+  },
+  buttonRow: { flexDirection: 'row', gap: theme.spacing.small },
+  statsText: {
+    fontSize: 13,
+    color: theme.colors.textPlaceholder,
+    marginTop: 12,
+    textAlign: 'center',
+  },
+  errorContainer: {
+    backgroundColor: theme.colors.errorBackground,
+    padding: 12,
+    borderRadius: theme.radius.small,
+    marginBottom: 20,
+  },
+  errorText: { color: theme.colors.errorText, fontSize: 14, textAlign: 'center' },
+  outputText: { fontSize: 15, lineHeight: 22, color: '#212529' },
+});