feat: Integrate PR #857 dictionary intelligence and sub-activity refactor

Pull in the full feature update from PR #857 while preserving fork
advantages (HTML parsing, custom drawHints, PageForward/PageBack,
cache management, stardictCmp, /.dictionary/ paths).

- Add morphological stemming (getStemVariants), Levenshtein edit
  distance, and fuzzy matching (findSimilar) to Dictionary
- Create DictionarySuggestionsActivity for "Did you mean?" flow
- Add onDone callback to DictionaryDefinitionActivity for direct
  exit-to-reader via "Done" button
- Refactor DictionaryWordSelectActivity to ActivityWithSubactivity
  with cascading lookup (exact → stems → suggestions → not found),
  en-dash/em-dash splitting, and cross-page hyphenation
- Refactor LookedUpWordsActivity with reverse-chronological order,
  inline cascading lookup, UITheme-aware rendering, and sub-activities
- Simplify EpubReaderActivity LOOKUP/LOOKED_UP_WORDS handlers

Co-authored-by: Cursor <cursoragent@cursor.com>

src/activities/reader/DictionaryDefinitionActivity.cpp

@@ -450,8 +450,16 @@ void DictionaryDefinitionActivity::loop() {
     updateRequired = true;
   }
 
-  if (mappedInput.wasReleased(MappedInputManager::Button::Back) ||
+  if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
-      mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
+    if (onDone) {
+      onDone();
+    } else {
+      onBack();
+    }
+    return;
+  }
+
+  if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
     onBack();
     return;
   }
@@ -491,8 +499,8 @@ void DictionaryDefinitionActivity::renderScreen() {
                       renderer.getScreenHeight() - 50, pageInfo.c_str());
   }
 
-  // Button hints (bottom face buttons — hide Confirm stub like Home Screen)
+  // Button hints (bottom face buttons)
-  const auto labels = mappedInput.mapLabels("\xC2\xAB Back", "", "\xC2\xAB Page", "Page \xC2\xBB");
+  const auto labels = mappedInput.mapLabels("\xC2\xAB Back", onDone ? "Done" : "", "\xC2\xAB Page", "Page \xC2\xBB");
   GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
 
   // Side button hints (drawn in portrait coordinates for correct placement)

src/activities/reader/DictionaryDefinitionActivity.h

@@ -14,13 +14,15 @@ class DictionaryDefinitionActivity final : public Activity {
  public:
   explicit DictionaryDefinitionActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
                                         const std::string& headword, const std::string& definition, int readerFontId,
-                                        uint8_t orientation, const std::function<void()>& onBack)
+                                        uint8_t orientation, const std::function<void()>& onBack,
+                                        const std::function<void()>& onDone = nullptr)
       : Activity("DictionaryDefinition", renderer, mappedInput),
         headword(headword),
         definition(definition),
         readerFontId(readerFontId),
         orientation(orientation),
-        onBack(onBack) {}
+        onBack(onBack),
+        onDone(onDone) {}
 
   void onEnter() override;
   void onExit() override;
@@ -53,6 +55,7 @@ class DictionaryDefinitionActivity final : public Activity {
   int readerFontId;
   uint8_t orientation;
   const std::function<void()> onBack;
+  const std::function<void()> onDone;
 
   std::vector<std::vector<Segment>> wrappedLines;
   int currentPage = 0;

src/activities/reader/DictionarySuggestionsActivity.cpp

@@ -0,0 +1,141 @@
+#include "DictionarySuggestionsActivity.h"
+
+#include <GfxRenderer.h>
+
+#include "DictionaryDefinitionActivity.h"
+#include "MappedInputManager.h"
+#include "components/UITheme.h"
+#include "fontIds.h"
+#include "util/Dictionary.h"
+
+void DictionarySuggestionsActivity::taskTrampoline(void* param) {
+  auto* self = static_cast<DictionarySuggestionsActivity*>(param);
+  self->displayTaskLoop();
+}
+
+void DictionarySuggestionsActivity::displayTaskLoop() {
+  while (true) {
+    if (updateRequired && !subActivity) {
+      updateRequired = false;
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      renderScreen();
+      xSemaphoreGive(renderingMutex);
+    }
+    vTaskDelay(10 / portTICK_PERIOD_MS);
+  }
+}
+
+void DictionarySuggestionsActivity::onEnter() {
+  ActivityWithSubactivity::onEnter();
+  renderingMutex = xSemaphoreCreateMutex();
+  updateRequired = true;
+  xTaskCreate(&DictionarySuggestionsActivity::taskTrampoline, "DictSugTask", 4096, this, 1, &displayTaskHandle);
+}
+
+void DictionarySuggestionsActivity::onExit() {
+  ActivityWithSubactivity::onExit();
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+  if (displayTaskHandle) {
+    vTaskDelete(displayTaskHandle);
+    displayTaskHandle = nullptr;
+  }
+  vSemaphoreDelete(renderingMutex);
+  renderingMutex = nullptr;
+}
+
+void DictionarySuggestionsActivity::loop() {
+  if (subActivity) {
+    subActivity->loop();
+    if (pendingBackFromDef) {
+      pendingBackFromDef = false;
+      exitActivity();
+      updateRequired = true;
+    }
+    if (pendingExitToReader) {
+      pendingExitToReader = false;
+      exitActivity();
+      onDone();
+    }
+    return;
+  }
+
+  if (suggestions.empty()) {
+    if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
+      onBack();
+    }
+    return;
+  }
+
+  buttonNavigator.onNext([this] {
+    selectedIndex = ButtonNavigator::nextIndex(selectedIndex, static_cast<int>(suggestions.size()));
+    updateRequired = true;
+  });
+
+  buttonNavigator.onPrevious([this] {
+    selectedIndex = ButtonNavigator::previousIndex(selectedIndex, static_cast<int>(suggestions.size()));
+    updateRequired = true;
+  });
+
+  if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
+    const std::string& selected = suggestions[selectedIndex];
+    std::string definition = Dictionary::lookup(selected);
+
+    if (definition.empty()) {
+      GUI.drawPopup(renderer, "Not found");
+      renderer.displayBuffer(HalDisplay::FAST_REFRESH);
+      vTaskDelay(1000 / portTICK_PERIOD_MS);
+      updateRequired = true;
+      return;
+    }
+
+    enterNewActivity(new DictionaryDefinitionActivity(
+        renderer, mappedInput, selected, definition, readerFontId, orientation,
+        [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+    return;
+  }
+
+  if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
+    onBack();
+    return;
+  }
+}
+
+void DictionarySuggestionsActivity::renderScreen() {
+  renderer.clearScreen();
+
+  const auto orient = renderer.getOrientation();
+  const auto metrics = UITheme::getInstance().getMetrics();
+  const bool isLandscapeCw = orient == GfxRenderer::Orientation::LandscapeClockwise;
+  const bool isLandscapeCcw = orient == GfxRenderer::Orientation::LandscapeCounterClockwise;
+  const bool isInverted = orient == GfxRenderer::Orientation::PortraitInverted;
+  const int hintGutterWidth = (isLandscapeCw || isLandscapeCcw) ? metrics.sideButtonHintsWidth : 0;
+  const int hintGutterHeight = isInverted ? (metrics.buttonHintsHeight + metrics.verticalSpacing) : 0;
+  const int contentX = isLandscapeCw ? hintGutterWidth : 0;
+  const int leftPadding = contentX + metrics.contentSidePadding;
+  const int pageWidth = renderer.getScreenWidth();
+  const int pageHeight = renderer.getScreenHeight();
+
+  // Header
+  GUI.drawHeader(
+      renderer,
+      Rect{contentX, hintGutterHeight + metrics.topPadding, pageWidth - hintGutterWidth, metrics.headerHeight},
+      "Did you mean?");
+
+  // Subtitle: the original word (manual, below header)
+  const int subtitleY = hintGutterHeight + metrics.topPadding + metrics.headerHeight + 5;
+  std::string subtitle = "\"" + originalWord + "\" not found";
+  renderer.drawText(SMALL_FONT_ID, leftPadding, subtitleY, subtitle.c_str());
+
+  // Suggestion list
+  const int listTop = subtitleY + 25;
+  const int listHeight = pageHeight - listTop - metrics.buttonHintsHeight - metrics.verticalSpacing;
+  GUI.drawList(
+      renderer, Rect{contentX, listTop, pageWidth - hintGutterWidth, listHeight}, suggestions.size(), selectedIndex,
+      [this](int index) { return suggestions[index]; }, nullptr, nullptr, nullptr);
+
+  // Button hints
+  const auto labels = mappedInput.mapLabels("\xC2\xAB Back", "Select", "Up", "Down");
+  GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
+  renderer.displayBuffer(HalDisplay::FAST_REFRESH);
+}

src/activities/reader/DictionarySuggestionsActivity.h

@@ -0,0 +1,53 @@
+#pragma once
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <functional>
+#include <string>
+#include <vector>
+
+#include "../ActivityWithSubactivity.h"
+#include "util/ButtonNavigator.h"
+
+class DictionarySuggestionsActivity final : public ActivityWithSubactivity {
+ public:
+  explicit DictionarySuggestionsActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
+                                         const std::string& originalWord, const std::vector<std::string>& suggestions,
+                                         int readerFontId, uint8_t orientation, const std::string& cachePath,
+                                         const std::function<void()>& onBack, const std::function<void()>& onDone)
+      : ActivityWithSubactivity("DictionarySuggestions", renderer, mappedInput),
+        originalWord(originalWord),
+        suggestions(suggestions),
+        readerFontId(readerFontId),
+        orientation(orientation),
+        cachePath(cachePath),
+        onBack(onBack),
+        onDone(onDone) {}
+
+  void onEnter() override;
+  void onExit() override;
+  void loop() override;
+
+ private:
+  std::string originalWord;
+  std::vector<std::string> suggestions;
+  int readerFontId;
+  uint8_t orientation;
+  std::string cachePath;
+  const std::function<void()> onBack;
+  const std::function<void()> onDone;
+
+  int selectedIndex = 0;
+  bool updateRequired = false;
+  bool pendingBackFromDef = false;
+  bool pendingExitToReader = false;
+  ButtonNavigator buttonNavigator;
+
+  TaskHandle_t displayTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+
+  void renderScreen();
+  static void taskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+};

src/activities/reader/DictionaryWordSelectActivity.cpp

@@ -6,6 +6,8 @@
 #include <climits>
 
 #include "CrossPointSettings.h"
+#include "DictionaryDefinitionActivity.h"
+#include "DictionarySuggestionsActivity.h"
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -19,7 +21,7 @@ void DictionaryWordSelectActivity::taskTrampoline(void* param) {
 
 void DictionaryWordSelectActivity::displayTaskLoop() {
   while (true) {
-    if (updateRequired) {
+    if (updateRequired && !subActivity) {
       updateRequired = false;
       xSemaphoreTake(renderingMutex, portMAX_DELAY);
       renderScreen();
@@ -30,7 +32,7 @@ void DictionaryWordSelectActivity::displayTaskLoop() {
 }
 
 void DictionaryWordSelectActivity::onEnter() {
-  Activity::onEnter();
+  ActivityWithSubactivity::onEnter();
   renderingMutex = xSemaphoreCreateMutex();
   extractWords();
   mergeHyphenatedWords();
@@ -43,7 +45,7 @@ void DictionaryWordSelectActivity::onEnter() {
 }
 
 void DictionaryWordSelectActivity::onExit() {
-  Activity::onExit();
+  ActivityWithSubactivity::onExit();
   xSemaphoreTake(renderingMutex, portMAX_DELAY);
   if (displayTaskHandle) {
     vTaskDelete(displayTaskHandle);
@@ -82,9 +84,55 @@ void DictionaryWordSelectActivity::extractWords() {
     while (wordIt != wordList.end() && xIt != xPosList.end()) {
       int16_t screenX = line->xPos + static_cast<int16_t>(*xIt) + marginLeft;
       int16_t screenY = line->yPos + marginTop;
-      int16_t wordWidth = renderer.getTextWidth(fontId, wordIt->c_str());
+      const std::string& wordText = *wordIt;
+
+      // Split on en-dash (U+2013: E2 80 93) and em-dash (U+2014: E2 80 94)
+      std::vector<size_t> splitStarts;
+      size_t partStart = 0;
+      for (size_t i = 0; i < wordText.size();) {
+        if (i + 2 < wordText.size() && static_cast<uint8_t>(wordText[i]) == 0xE2 &&
+            static_cast<uint8_t>(wordText[i + 1]) == 0x80 &&
+            (static_cast<uint8_t>(wordText[i + 2]) == 0x93 || static_cast<uint8_t>(wordText[i + 2]) == 0x94)) {
+          if (i > partStart) splitStarts.push_back(partStart);
+          i += 3;
+          partStart = i;
+        } else {
+          i++;
+        }
+      }
+      if (partStart < wordText.size()) splitStarts.push_back(partStart);
+
+      if (splitStarts.size() <= 1 && partStart == 0) {
+        // No dashes found -- add as a single word
+        int16_t wordWidth = renderer.getTextWidth(fontId, wordText.c_str());
+        words.push_back({wordText, screenX, screenY, wordWidth, 0});
+      } else {
+        // Add each part as a separate selectable word
+        for (size_t si = 0; si < splitStarts.size(); si++) {
+          size_t start = splitStarts[si];
+          size_t end = (si + 1 < splitStarts.size()) ? splitStarts[si + 1] : wordText.size();
+          // Find actual end by trimming any trailing dash bytes
+          size_t textEnd = end;
+          while (textEnd > start && textEnd <= wordText.size()) {
+            if (textEnd >= 3 && static_cast<uint8_t>(wordText[textEnd - 3]) == 0xE2 &&
+                static_cast<uint8_t>(wordText[textEnd - 2]) == 0x80 &&
+                (static_cast<uint8_t>(wordText[textEnd - 1]) == 0x93 ||
+                 static_cast<uint8_t>(wordText[textEnd - 1]) == 0x94)) {
+              textEnd -= 3;
+            } else {
+              break;
+            }
+          }
+          std::string part = wordText.substr(start, textEnd - start);
+          if (part.empty()) continue;
+
+          std::string prefix = wordText.substr(0, start);
+          int16_t offsetX = prefix.empty() ? 0 : renderer.getTextWidth(fontId, prefix.c_str());
+          int16_t partWidth = renderer.getTextWidth(fontId, part.c_str());
+          words.push_back({part, static_cast<int16_t>(screenX + offsetX), screenY, partWidth, 0});
+        }
+      }
 
-      words.push_back({*wordIt, screenX, screenY, wordWidth, 0});
       ++wordIt;
       ++xIt;
     }
@@ -146,11 +194,53 @@ void DictionaryWordSelectActivity::mergeHyphenatedWords() {
     words[nextWordIdx].continuationIndex = nextWordIdx;  // self-ref so highlight logic finds the second part
   }
 
+  // Cross-page hyphenation: last word on page + first word of next page
+  if (!nextPageFirstWord.empty() && !rows.empty()) {
+    int lastWordIdx = rows.back().wordIndices.back();
+    const std::string& lastWord = words[lastWordIdx].text;
+    if (!lastWord.empty()) {
+      bool endsWithHyphen = false;
+      if (lastWord.back() == '-') {
+        endsWithHyphen = true;
+      } else if (lastWord.size() >= 2 && static_cast<uint8_t>(lastWord[lastWord.size() - 2]) == 0xC2 &&
+                 static_cast<uint8_t>(lastWord[lastWord.size() - 1]) == 0xAD) {
+        endsWithHyphen = true;
+      }
+      if (endsWithHyphen) {
+        std::string firstPart = lastWord;
+        if (firstPart.back() == '-') {
+          firstPart.pop_back();
+        } else if (firstPart.size() >= 2 && static_cast<uint8_t>(firstPart[firstPart.size() - 2]) == 0xC2 &&
+                   static_cast<uint8_t>(firstPart[firstPart.size() - 1]) == 0xAD) {
+          firstPart.erase(firstPart.size() - 2);
+        }
+        std::string merged = firstPart + nextPageFirstWord;
+        words[lastWordIdx].lookupText = merged;
+      }
+    }
+  }
+
   // Remove empty rows that may result from merging (e.g., a row whose only word was a continuation)
   rows.erase(std::remove_if(rows.begin(), rows.end(), [](const Row& r) { return r.wordIndices.empty(); }), rows.end());
 }
 
 void DictionaryWordSelectActivity::loop() {
+  // Delegate to subactivity (definition/suggestions screen) if active
+  if (subActivity) {
+    subActivity->loop();
+    if (pendingBackFromDef) {
+      pendingBackFromDef = false;
+      exitActivity();
+      updateRequired = true;
+    }
+    if (pendingExitToReader) {
+      pendingExitToReader = false;
+      exitActivity();
+      onBack();
+    }
+    return;
+  }
+
   if (words.empty()) {
     if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
       onBack();
@@ -297,7 +387,36 @@ void DictionaryWordSelectActivity::loop() {
       return;
     }
 
-    if (definition.empty()) {
+    LookupHistory::addWord(cachePath, cleaned);
+
+    if (!definition.empty()) {
+      enterNewActivity(new DictionaryDefinitionActivity(
+          renderer, mappedInput, cleaned, definition, fontId, orientation,
+          [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+      return;
+    }
+
+    // Try stem variants (e.g., "jumped" -> "jump")
+    auto stems = Dictionary::getStemVariants(cleaned);
+    for (const auto& stem : stems) {
+      std::string stemDef = Dictionary::lookup(stem);
+      if (!stemDef.empty()) {
+        enterNewActivity(new DictionaryDefinitionActivity(
+            renderer, mappedInput, stem, stemDef, fontId, orientation,
+            [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+        return;
+      }
+    }
+
+    // Find similar words for suggestions
+    auto similar = Dictionary::findSimilar(cleaned, 6);
+    if (!similar.empty()) {
+      enterNewActivity(new DictionarySuggestionsActivity(
+          renderer, mappedInput, cleaned, similar, fontId, orientation, cachePath,
+          [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+      return;
+    }
+
     GUI.drawPopup(renderer, "Not found");
     renderer.displayBuffer(HalDisplay::FAST_REFRESH);
     vTaskDelay(1500 / portTICK_PERIOD_MS);
@@ -305,11 +424,6 @@ void DictionaryWordSelectActivity::loop() {
     return;
   }
 
-    LookupHistory::addWord(cachePath, cleaned);
-    onLookup(cleaned, definition);
-    return;
-  }
-
   if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
     onBack();
     return;

src/activities/reader/DictionaryWordSelectActivity.h

@@ -9,16 +9,16 @@
 #include <string>
 #include <vector>
 
-#include "../Activity.h"
+#include "../ActivityWithSubactivity.h"
 
-class DictionaryWordSelectActivity final : public Activity {
+class DictionaryWordSelectActivity final : public ActivityWithSubactivity {
  public:
   explicit DictionaryWordSelectActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
                                         std::unique_ptr<Page> page, int fontId, int marginLeft, int marginTop,
                                         const std::string& cachePath, uint8_t orientation,
                                         const std::function<void()>& onBack,
-                                        const std::function<void(const std::string&, const std::string&)>& onLookup)
+                                        const std::string& nextPageFirstWord = "")
-      : Activity("DictionaryWordSelect", renderer, mappedInput),
+      : ActivityWithSubactivity("DictionaryWordSelect", renderer, mappedInput),
         page(std::move(page)),
         fontId(fontId),
         marginLeft(marginLeft),
@@ -26,7 +26,7 @@ class DictionaryWordSelectActivity final : public Activity {
         cachePath(cachePath),
         orientation(orientation),
         onBack(onBack),
-        onLookup(onLookup) {}
+        nextPageFirstWord(nextPageFirstWord) {}
 
   void onEnter() override;
   void onExit() override;
@@ -58,13 +58,15 @@ class DictionaryWordSelectActivity final : public Activity {
   std::string cachePath;
   uint8_t orientation;
   const std::function<void()> onBack;
-  const std::function<void(const std::string&, const std::string&)> onLookup;
+  std::string nextPageFirstWord;
 
   std::vector<WordInfo> words;
   std::vector<Row> rows;
   int currentRow = 0;
   int currentWordInRow = 0;
   bool updateRequired = false;
+  bool pendingBackFromDef = false;
+  bool pendingExitToReader = false;
 
   TaskHandle_t displayTaskHandle = nullptr;
   SemaphoreHandle_t renderingMutex = nullptr;

src/activities/reader/EpubReaderActivity.cpp

@@ -19,7 +19,6 @@
 #include "fontIds.h"
 #include "util/BookmarkStore.h"
 #include "util/Dictionary.h"
-#include "util/LookupHistory.h"
 
 namespace {
 // pagesPerRefresh now comes from SETTINGS.getRefreshFrequency()
@@ -665,24 +664,27 @@ void EpubReaderActivity::onReaderMenuConfirm(EpubReaderMenuActivity::MenuAction
       const std::string bookCachePath = epub->getCachePath();
       const uint8_t currentOrientation = SETTINGS.orientation;
 
+      // Get first word of next page for cross-page hyphenation
+      std::string nextPageFirstWord;
+      if (section && section->currentPage < section->pageCount - 1) {
+        int savedPage = section->currentPage;
+        section->currentPage = savedPage + 1;
+        auto nextPage = section->loadPageFromSectionFile();
+        section->currentPage = savedPage;
+        if (nextPage && !nextPage->elements.empty()) {
+          const auto* firstLine = static_cast<const PageLine*>(nextPage->elements[0].get());
+          if (firstLine->getBlock() && !firstLine->getBlock()->getWords().empty()) {
+            nextPageFirstWord = firstLine->getBlock()->getWords().front();
+          }
+        }
+      }
+
       exitActivity();
 
       if (pageForLookup) {
         enterNewActivity(new DictionaryWordSelectActivity(
             renderer, mappedInput, std::move(pageForLookup), readerFontId, orientedMarginLeft, orientedMarginTop,
-            bookCachePath, currentOrientation,
+            bookCachePath, currentOrientation, [this]() { pendingSubactivityExit = true; }, nextPageFirstWord));
-            [this]() {
-              // On back from word select
-              pendingSubactivityExit = true;
-            },
-            [this, bookCachePath, readerFontId, currentOrientation](const std::string& headword,
-                                                                    const std::string& definition) {
-              // On successful lookup - show definition
-              exitActivity();
-              enterNewActivity(new DictionaryDefinitionActivity(renderer, mappedInput, headword, definition,
-                                                                readerFontId, currentOrientation,
-                                                                [this]() { pendingSubactivityExit = true; }));
-            }));
       }
 
       xSemaphoreGive(renderingMutex);
@@ -690,36 +692,11 @@ void EpubReaderActivity::onReaderMenuConfirm(EpubReaderMenuActivity::MenuAction
     }
     case EpubReaderMenuActivity::MenuAction::LOOKED_UP_WORDS: {
       xSemaphoreTake(renderingMutex, portMAX_DELAY);
-      const std::string bookCachePath = epub->getCachePath();
-      const int readerFontId = SETTINGS.getReaderFontId();
-      const uint8_t currentOrientation = SETTINGS.orientation;
 
       exitActivity();
       enterNewActivity(new LookedUpWordsActivity(
-          renderer, mappedInput, bookCachePath,
+          renderer, mappedInput, epub->getCachePath(), SETTINGS.getReaderFontId(), SETTINGS.orientation,
-          [this]() {
+          [this]() { pendingSubactivityExit = true; }, [this]() { pendingSubactivityExit = true; }));
-            // On back from looked up words
-            pendingSubactivityExit = true;
-          },
-          [this, bookCachePath, readerFontId, currentOrientation](const std::string& headword) {
-            // Look up the word and show definition with progress bar
-            Rect popupLayout = GUI.drawPopup(renderer, "Looking up...");
-
-            std::string definition = Dictionary::lookup(
-                headword, [this, &popupLayout](int percent) { GUI.fillPopupProgress(renderer, popupLayout, percent); });
-
-            if (definition.empty()) {
-              GUI.drawPopup(renderer, "Not found");
-              renderer.displayBuffer(HalDisplay::FAST_REFRESH);
-              vTaskDelay(1500 / portTICK_PERIOD_MS);
-              return;
-            }
-
-            exitActivity();
-            enterNewActivity(new DictionaryDefinitionActivity(renderer, mappedInput, headword, definition, readerFontId,
-                                                              currentOrientation,
-                                                              [this]() { pendingSubactivityExit = true; }));
-          }));
       xSemaphoreGive(renderingMutex);
       break;
     }

src/activities/reader/EpubReaderActivity.h

@@ -5,7 +5,6 @@
 #include <freertos/semphr.h>
 #include <freertos/task.h>
 
-#include "DictionaryDefinitionActivity.h"
 #include "DictionaryWordSelectActivity.h"
 #include "EpubReaderMenuActivity.h"
 #include "LookedUpWordsActivity.h"

src/activities/reader/LookedUpWordsActivity.cpp

@@ -4,9 +4,12 @@
 
 #include <algorithm>
 
+#include "DictionaryDefinitionActivity.h"
+#include "DictionarySuggestionsActivity.h"
 #include "MappedInputManager.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
+#include "util/Dictionary.h"
 #include "util/LookupHistory.h"
 
 void LookedUpWordsActivity::taskTrampoline(void* param) {
@@ -30,6 +33,7 @@ void LookedUpWordsActivity::onEnter() {
   ActivityWithSubactivity::onEnter();
   renderingMutex = xSemaphoreCreateMutex();
   words = LookupHistory::load(cachePath);
+  std::reverse(words.begin(), words.end());
   updateRequired = true;
   xTaskCreate(&LookedUpWordsActivity::taskTrampoline, "LookedUpTask", 4096, this, 1, &displayTaskHandle);
 }
@@ -48,6 +52,16 @@ void LookedUpWordsActivity::onExit() {
 void LookedUpWordsActivity::loop() {
   if (subActivity) {
     subActivity->loop();
+    if (pendingBackFromDef) {
+      pendingBackFromDef = false;
+      exitActivity();
+      updateRequired = true;
+    }
+    if (pendingExitToReader) {
+      pendingExitToReader = false;
+      exitActivity();
+      onDone();
+    }
     return;
   }
 
@@ -94,18 +108,68 @@ void LookedUpWordsActivity::loop() {
     return;
   }
 
-  buttonNavigator.onNext([this] {
+  const int totalItems = static_cast<int>(words.size());
-    selectedIndex = ButtonNavigator::nextIndex(selectedIndex, static_cast<int>(words.size()));
+  const int pageItems = getPageItems();
+
+  buttonNavigator.onNextRelease([this, totalItems] {
+    selectedIndex = ButtonNavigator::nextIndex(selectedIndex, totalItems);
     updateRequired = true;
   });
 
-  buttonNavigator.onPrevious([this] {
+  buttonNavigator.onPreviousRelease([this, totalItems] {
-    selectedIndex = ButtonNavigator::previousIndex(selectedIndex, static_cast<int>(words.size()));
+    selectedIndex = ButtonNavigator::previousIndex(selectedIndex, totalItems);
+    updateRequired = true;
+  });
+
+  buttonNavigator.onNextContinuous([this, totalItems, pageItems] {
+    selectedIndex = ButtonNavigator::nextPageIndex(selectedIndex, totalItems, pageItems);
+    updateRequired = true;
+  });
+
+  buttonNavigator.onPreviousContinuous([this, totalItems, pageItems] {
+    selectedIndex = ButtonNavigator::previousPageIndex(selectedIndex, totalItems, pageItems);
     updateRequired = true;
   });
 
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
-    onSelectWord(words[selectedIndex]);
+    const std::string& headword = words[selectedIndex];
+
+    Rect popupLayout = GUI.drawPopup(renderer, "Looking up...");
+    std::string definition = Dictionary::lookup(
+        headword, [this, &popupLayout](int percent) { GUI.fillPopupProgress(renderer, popupLayout, percent); });
+
+    if (!definition.empty()) {
+      enterNewActivity(new DictionaryDefinitionActivity(
+          renderer, mappedInput, headword, definition, readerFontId, orientation,
+          [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+      return;
+    }
+
+    // Try stem variants
+    auto stems = Dictionary::getStemVariants(headword);
+    for (const auto& stem : stems) {
+      std::string stemDef = Dictionary::lookup(stem);
+      if (!stemDef.empty()) {
+        enterNewActivity(new DictionaryDefinitionActivity(
+            renderer, mappedInput, stem, stemDef, readerFontId, orientation,
+            [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+        return;
+      }
+    }
+
+    // Show similar word suggestions
+    auto similar = Dictionary::findSimilar(headword, 6);
+    if (!similar.empty()) {
+      enterNewActivity(new DictionarySuggestionsActivity(
+          renderer, mappedInput, headword, similar, readerFontId, orientation, cachePath,
+          [this]() { pendingBackFromDef = true; }, [this]() { pendingExitToReader = true; }));
+      return;
+    }
+
+    GUI.drawPopup(renderer, "Not found");
+    renderer.displayBuffer(HalDisplay::FAST_REFRESH);
+    vTaskDelay(1500 / portTICK_PERIOD_MS);
+    updateRequired = true;
     return;
   }
 
@@ -115,39 +179,46 @@ void LookedUpWordsActivity::loop() {
   }
 }
 
+int LookedUpWordsActivity::getPageItems() const {
+  const auto orient = renderer.getOrientation();
+  const auto metrics = UITheme::getInstance().getMetrics();
+  const bool isInverted = orient == GfxRenderer::Orientation::PortraitInverted;
+  const int hintGutterHeight = isInverted ? (metrics.buttonHintsHeight + metrics.verticalSpacing) : 0;
+  const int contentTop = hintGutterHeight + metrics.topPadding + metrics.headerHeight + metrics.verticalSpacing;
+  const int contentHeight =
+      renderer.getScreenHeight() - contentTop - metrics.buttonHintsHeight - metrics.verticalSpacing;
+  return std::max(1, contentHeight / metrics.listRowHeight);
+}
+
 void LookedUpWordsActivity::renderScreen() {
   renderer.clearScreen();
 
-  constexpr int sidePadding = 20;
+  const auto orient = renderer.getOrientation();
-  constexpr int titleY = 15;
+  const auto metrics = UITheme::getInstance().getMetrics();
-  constexpr int startY = 60;
+  const bool isLandscapeCw = orient == GfxRenderer::Orientation::LandscapeClockwise;
-  constexpr int lineHeight = 30;
+  const bool isLandscapeCcw = orient == GfxRenderer::Orientation::LandscapeCounterClockwise;
+  const bool isInverted = orient == GfxRenderer::Orientation::PortraitInverted;
+  const int hintGutterWidth = (isLandscapeCw || isLandscapeCcw) ? metrics.sideButtonHintsWidth : 0;
+  const int hintGutterHeight = isInverted ? (metrics.buttonHintsHeight + metrics.verticalSpacing) : 0;
+  const int contentX = isLandscapeCw ? hintGutterWidth : 0;
+  const int pageWidth = renderer.getScreenWidth();
+  const int pageHeight = renderer.getScreenHeight();
 
-  // Title
+  // Header
-  const int titleX =
+  GUI.drawHeader(
-      (renderer.getScreenWidth() - renderer.getTextWidth(UI_12_FONT_ID, "Lookup History", EpdFontFamily::BOLD)) / 2;
+      renderer,
-  renderer.drawText(UI_12_FONT_ID, titleX, titleY, "Lookup History", true, EpdFontFamily::BOLD);
+      Rect{contentX, hintGutterHeight + metrics.topPadding, pageWidth - hintGutterWidth, metrics.headerHeight},
+      "Lookup History");
+
+  const int contentTop = hintGutterHeight + metrics.topPadding + metrics.headerHeight + metrics.verticalSpacing;
+  const int contentHeight = pageHeight - contentTop - metrics.buttonHintsHeight - metrics.verticalSpacing;
 
   if (words.empty()) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 300, "No words looked up yet");
+    renderer.drawCenteredText(UI_10_FONT_ID, contentTop + 20, "No words looked up yet");
   } else {
-    const int screenHeight = renderer.getScreenHeight();
+    GUI.drawList(
-    const int pageItems = std::max(1, (screenHeight - startY - 40) / lineHeight);
+        renderer, Rect{contentX, contentTop, pageWidth - hintGutterWidth, contentHeight}, words.size(), selectedIndex,
-    const int pageStart = selectedIndex / pageItems * pageItems;
+        [this](int index) { return words[index]; }, nullptr, nullptr, nullptr);
-
-    for (int i = 0; i < pageItems; i++) {
-      int idx = pageStart + i;
-      if (idx >= static_cast<int>(words.size())) break;
-
-      const int displayY = startY + i * lineHeight;
-      const bool isSelected = (idx == selectedIndex);
-
-      if (isSelected) {
-        renderer.fillRect(0, displayY - 2, renderer.getScreenWidth() - 1, lineHeight);
-      }
-
-      renderer.drawText(UI_10_FONT_ID, sidePadding, displayY, words[idx].c_str(), !isSelected);
-    }
   }
 
   if (deleteConfirmMode && pendingDeleteIndex < static_cast<int>(words.size())) {
@@ -161,12 +232,12 @@ void LookedUpWordsActivity::renderScreen() {
     std::string msg = "Delete '" + displayWord + "'?";
 
     constexpr int margin = 15;
-    constexpr int popupY = 200;
+    const int popupY = 200 + hintGutterHeight;
     const int textWidth = renderer.getTextWidth(UI_12_FONT_ID, msg.c_str(), EpdFontFamily::BOLD);
     const int textHeight = renderer.getLineHeight(UI_12_FONT_ID);
     const int w = textWidth + margin * 2;
     const int h = textHeight + margin * 2;
-    const int x = (renderer.getScreenWidth() - w) / 2;
+    const int x = contentX + (renderer.getScreenWidth() - hintGutterWidth - w) / 2;
 
     renderer.fillRect(x - 2, popupY - 2, w + 4, h + 4, true);
     renderer.fillRect(x, popupY, w, h, false);
@@ -183,12 +254,14 @@ void LookedUpWordsActivity::renderScreen() {
     if (!words.empty()) {
       const char* deleteHint = "Hold select to delete";
       const int hintWidth = renderer.getTextWidth(SMALL_FONT_ID, deleteHint);
-      renderer.drawText(SMALL_FONT_ID, (renderer.getScreenWidth() - hintWidth) / 2, renderer.getScreenHeight() - 70,
+      const int hintX = contentX + (renderer.getScreenWidth() - hintGutterWidth - hintWidth) / 2;
+      renderer.drawText(SMALL_FONT_ID, hintX,
+                        renderer.getScreenHeight() - metrics.buttonHintsHeight - metrics.verticalSpacing * 2,
                         deleteHint);
     }
 
     // Normal button hints
-    const auto labels = mappedInput.mapLabels("\xC2\xAB Back", "Select", "^", "v");
+    const auto labels = mappedInput.mapLabels("\xC2\xAB Back", "Select", "Up", "Down");
     GUI.drawButtonHints(renderer, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
   }
 

src/activities/reader/LookedUpWordsActivity.h

@@ -13,12 +13,14 @@
 class LookedUpWordsActivity final : public ActivityWithSubactivity {
  public:
   explicit LookedUpWordsActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, const std::string& cachePath,
-                                 const std::function<void()>& onBack,
+                                 int readerFontId, uint8_t orientation, const std::function<void()>& onBack,
-                                 const std::function<void(const std::string&)>& onSelectWord)
+                                 const std::function<void()>& onDone)
       : ActivityWithSubactivity("LookedUpWords", renderer, mappedInput),
         cachePath(cachePath),
+        readerFontId(readerFontId),
+        orientation(orientation),
         onBack(onBack),
-        onSelectWord(onSelectWord) {}
+        onDone(onDone) {}
 
   void onEnter() override;
   void onExit() override;
@@ -26,12 +28,16 @@ class LookedUpWordsActivity final : public ActivityWithSubactivity {
 
  private:
   std::string cachePath;
+  int readerFontId;
+  uint8_t orientation;
   const std::function<void()> onBack;
-  const std::function<void(const std::string&)> onSelectWord;
+  const std::function<void()> onDone;
 
   std::vector<std::string> words;
   int selectedIndex = 0;
   bool updateRequired = false;
+  bool pendingBackFromDef = false;
+  bool pendingExitToReader = false;
   ButtonNavigator buttonNavigator;
 
   // Delete confirmation state
@@ -42,6 +48,7 @@ class LookedUpWordsActivity final : public ActivityWithSubactivity {
   TaskHandle_t displayTaskHandle = nullptr;
   SemaphoreHandle_t renderingMutex = nullptr;
 
+  int getPageItems() const;
   void renderScreen();
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();

src/util/Dictionary.cpp

@@ -326,3 +326,264 @@ std::string Dictionary::lookup(const std::string& word, const std::function<void
   if (onProgress) onProgress(100);
   return result;
 }
+
+std::vector<std::string> Dictionary::getStemVariants(const std::string& word) {
+  std::vector<std::string> variants;
+  size_t len = word.size();
+  if (len < 3) return variants;
+
+  auto endsWith = [&word, len](const char* suffix) {
+    size_t slen = strlen(suffix);
+    return len >= slen && word.compare(len - slen, slen, suffix) == 0;
+  };
+
+  auto add = [&variants](const std::string& s) {
+    if (s.size() >= 2) variants.push_back(s);
+  };
+
+  // Plurals (longer suffixes first to avoid partial matches)
+  if (endsWith("sses")) add(word.substr(0, len - 2));
+  if (endsWith("ses")) add(word.substr(0, len - 2) + "is");  // analyses -> analysis
+  if (endsWith("ies")) {
+    add(word.substr(0, len - 3) + "y");
+    add(word.substr(0, len - 2));  // dies -> die, ties -> tie
+  }
+  if (endsWith("ves")) {
+    add(word.substr(0, len - 3) + "f");   // wolves -> wolf
+    add(word.substr(0, len - 3) + "fe");  // knives -> knife
+    add(word.substr(0, len - 1));          // misgives -> misgive
+  }
+  if (endsWith("men")) add(word.substr(0, len - 3) + "man");  // firemen -> fireman
+  if (endsWith("es") && !endsWith("sses") && !endsWith("ies") && !endsWith("ves")) {
+    add(word.substr(0, len - 2));
+    add(word.substr(0, len - 1));
+  }
+  if (endsWith("s") && !endsWith("ss") && !endsWith("us") && !endsWith("es")) {
+    add(word.substr(0, len - 1));
+  }
+
+  // Past tense
+  if (endsWith("ied")) {
+    add(word.substr(0, len - 3) + "y");
+    add(word.substr(0, len - 1));
+  }
+  if (endsWith("ed") && !endsWith("ied")) {
+    add(word.substr(0, len - 2));
+    add(word.substr(0, len - 1));
+    if (len > 4 && word[len - 3] == word[len - 4]) {
+      add(word.substr(0, len - 3));
+    }
+  }
+
+  // Progressive
+  if (endsWith("ying")) {
+    add(word.substr(0, len - 4) + "ie");
+  }
+  if (endsWith("ing") && !endsWith("ying")) {
+    add(word.substr(0, len - 3));
+    add(word.substr(0, len - 3) + "e");
+    if (len > 5 && word[len - 4] == word[len - 5]) {
+      add(word.substr(0, len - 4));
+    }
+  }
+
+  // Adverb
+  if (endsWith("ically")) {
+    add(word.substr(0, len - 6) + "ic");  // historically -> historic
+    add(word.substr(0, len - 4));          // basically -> basic
+  }
+  if (endsWith("ally") && !endsWith("ically")) {
+    add(word.substr(0, len - 4) + "al");  // accidentally -> accidental
+    add(word.substr(0, len - 2));          // naturally -> natur... (fallback to -ly strip)
+  }
+  if (endsWith("ily") && !endsWith("ally")) {
+    add(word.substr(0, len - 3) + "y");
+  }
+  if (endsWith("ly") && !endsWith("ily") && !endsWith("ally")) {
+    add(word.substr(0, len - 2));
+  }
+
+  // Comparative / superlative
+  if (endsWith("ier")) {
+    add(word.substr(0, len - 3) + "y");
+  }
+  if (endsWith("er") && !endsWith("ier")) {
+    add(word.substr(0, len - 2));
+    add(word.substr(0, len - 1));
+    if (len > 4 && word[len - 3] == word[len - 4]) {
+      add(word.substr(0, len - 3));
+    }
+  }
+  if (endsWith("iest")) {
+    add(word.substr(0, len - 4) + "y");
+  }
+  if (endsWith("est") && !endsWith("iest")) {
+    add(word.substr(0, len - 3));
+    add(word.substr(0, len - 2));
+    if (len > 5 && word[len - 4] == word[len - 5]) {
+      add(word.substr(0, len - 4));
+    }
+  }
+
+  // Derivational suffixes
+  if (endsWith("ness")) add(word.substr(0, len - 4));
+  if (endsWith("ment")) add(word.substr(0, len - 4));
+  if (endsWith("ful")) add(word.substr(0, len - 3));
+  if (endsWith("less")) add(word.substr(0, len - 4));
+  if (endsWith("able")) {
+    add(word.substr(0, len - 4));
+    add(word.substr(0, len - 4) + "e");
+  }
+  if (endsWith("ible")) {
+    add(word.substr(0, len - 4));
+    add(word.substr(0, len - 4) + "e");
+  }
+  if (endsWith("ation")) {
+    add(word.substr(0, len - 5));           // information -> inform
+    add(word.substr(0, len - 5) + "e");     // exploration -> explore
+    add(word.substr(0, len - 5) + "ate");   // donation -> donate
+  }
+  if (endsWith("tion") && !endsWith("ation")) {
+    add(word.substr(0, len - 4) + "te");  // completion -> complete
+    add(word.substr(0, len - 3));          // action -> act
+    add(word.substr(0, len - 3) + "e");   // reduction -> reduce
+  }
+  if (endsWith("ion") && !endsWith("tion")) {
+    add(word.substr(0, len - 3));          // revision -> revis (-> revise via +e)
+    add(word.substr(0, len - 3) + "e");   // revision -> revise
+  }
+  if (endsWith("al") && !endsWith("ial")) {
+    add(word.substr(0, len - 2));
+    add(word.substr(0, len - 2) + "e");
+  }
+  if (endsWith("ial")) {
+    add(word.substr(0, len - 3));
+    add(word.substr(0, len - 3) + "e");
+  }
+  if (endsWith("ous")) {
+    add(word.substr(0, len - 3));          // dangerous -> danger
+    add(word.substr(0, len - 3) + "e");   // famous -> fame
+  }
+  if (endsWith("ive")) {
+    add(word.substr(0, len - 3));          // active -> act
+    add(word.substr(0, len - 3) + "e");   // creative -> create
+  }
+  if (endsWith("ize")) {
+    add(word.substr(0, len - 3));          // modernize -> modern
+    add(word.substr(0, len - 3) + "e");
+  }
+  if (endsWith("ise")) {
+    add(word.substr(0, len - 3));          // advertise -> advert
+    add(word.substr(0, len - 3) + "e");
+  }
+  if (endsWith("en")) {
+    add(word.substr(0, len - 2));          // darken -> dark
+    add(word.substr(0, len - 2) + "e");   // widen -> wide
+  }
+
+  // Prefix removal
+  if (len > 5 && word.compare(0, 2, "un") == 0) add(word.substr(2));
+  if (len > 6 && word.compare(0, 3, "dis") == 0) add(word.substr(3));
+  if (len > 6 && word.compare(0, 3, "mis") == 0) add(word.substr(3));
+  if (len > 6 && word.compare(0, 3, "pre") == 0) add(word.substr(3));
+  if (len > 7 && word.compare(0, 4, "over") == 0) add(word.substr(4));
+  if (len > 5 && word.compare(0, 2, "re") == 0) add(word.substr(2));
+
+  // Deduplicate while preserving insertion order (inflectional stems first, prefixes last)
+  std::vector<std::string> deduped;
+  for (const auto& v : variants) {
+    if (std::find(deduped.begin(), deduped.end(), v) != deduped.end()) continue;
+    // cppcheck-suppress useStlAlgorithm
+    deduped.push_back(v);
+  }
+  return deduped;
+}
+
+int Dictionary::editDistance(const std::string& a, const std::string& b, int maxDist) {
+  int m = static_cast<int>(a.size());
+  int n = static_cast<int>(b.size());
+  if (std::abs(m - n) > maxDist) return maxDist + 1;
+
+  std::vector<int> dp(n + 1);
+  for (int j = 0; j <= n; j++) dp[j] = j;
+
+  for (int i = 1; i <= m; i++) {
+    int prev = dp[0];
+    dp[0] = i;
+    int rowMin = dp[0];
+    for (int j = 1; j <= n; j++) {
+      int temp = dp[j];
+      if (a[i - 1] == b[j - 1]) {
+        dp[j] = prev;
+      } else {
+        dp[j] = 1 + std::min({prev, dp[j], dp[j - 1]});
+      }
+      prev = temp;
+      if (dp[j] < rowMin) rowMin = dp[j];
+    }
+    if (rowMin > maxDist) return maxDist + 1;
+  }
+  return dp[n];
+}
+
+std::vector<std::string> Dictionary::findSimilar(const std::string& word, int maxResults) {
+  if (!indexLoaded || sparseOffsets.empty()) return {};
+
+  FsFile idx;
+  if (!Storage.openFileForRead("DICT", IDX_PATH, idx)) return {};
+
+  // Binary search to find the segment containing or nearest to the word
+  int lo = 0, hi = static_cast<int>(sparseOffsets.size()) - 1;
+  while (lo < hi) {
+    int mid = lo + (hi - lo + 1) / 2;
+    idx.seekSet(sparseOffsets[mid]);
+    std::string key = readWord(idx);
+    if (stardictCmp(key.c_str(), word.c_str()) <= 0) {
+      lo = mid;
+    } else {
+      hi = mid - 1;
+    }
+  }
+
+  // Scan entries from the segment before through the segment after the target
+  int startSeg = std::max(0, lo - 1);
+  int endSeg = std::min(static_cast<int>(sparseOffsets.size()) - 1, lo + 1);
+  idx.seekSet(sparseOffsets[startSeg]);
+
+  int totalToScan = (endSeg - startSeg + 1) * SPARSE_INTERVAL;
+  int remaining = static_cast<int>(totalWords) - startSeg * SPARSE_INTERVAL;
+  if (totalToScan > remaining) totalToScan = remaining;
+
+  int maxDist = std::max(2, static_cast<int>(word.size()) / 3 + 1);
+
+  struct Candidate {
+    std::string text;
+    int distance;
+  };
+  std::vector<Candidate> candidates;
+
+  for (int i = 0; i < totalToScan; i++) {
+    std::string key = readWord(idx);
+    if (key.empty()) break;
+
+    uint8_t skip[8];
+    if (idx.read(skip, 8) != 8) break;
+
+    if (key == word) continue;
+    int dist = editDistance(key, word, maxDist);
+    if (dist <= maxDist) {
+      candidates.push_back({key, dist});
+    }
+  }
+
+  idx.close();
+
+  std::sort(candidates.begin(), candidates.end(),
+            [](const Candidate& a, const Candidate& b) { return a.distance < b.distance; });
+
+  std::vector<std::string> results;
+  for (size_t i = 0; i < candidates.size() && static_cast<int>(results.size()) < maxResults; i++) {
+    results.push_back(candidates[i].text);
+  }
+  return results;
+}

src/util/Dictionary.h

@@ -14,6 +14,8 @@ class Dictionary {
   static std::string lookup(const std::string& word, const std::function<void(int percent)>& onProgress = nullptr,
                             const std::function<bool()>& shouldCancel = nullptr);
   static std::string cleanWord(const std::string& word);
+  static std::vector<std::string> getStemVariants(const std::string& word);
+  static std::vector<std::string> findSimilar(const std::string& word, int maxResults = 6);
 
  private:
   static constexpr int SPARSE_INTERVAL = 512;
@@ -28,4 +30,5 @@ class Dictionary {
   static std::string searchIndex(const std::string& word, const std::function<bool()>& shouldCancel);
   static std::string readWord(FsFile& file);
   static std::string readDefinition(uint32_t offset, uint32_t size);
+  static int editDistance(const std::string& a, const std::string& b, int maxDist);
 };