Add spellcheck and word suggestion to the prediction service

third_party/prediction/suggest/policyimpl/typing/typing_traversal.h

Index: third_party/prediction/suggest/policyimpl/typing/typing_traversal.h
diff --git a/third_party/prediction/suggest/policyimpl/typing/typing_traversal.h b/third_party/prediction/suggest/policyimpl/typing/typing_traversal.h
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+/*
+ * Copyright (C) 2013 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#ifndef LATINIME_TYPING_TRAVERSAL_H
+#define LATINIME_TYPING_TRAVERSAL_H
+
+#include <cstdint>
+
+#include "third_party/prediction/defines.h"
+#include "third_party/prediction/suggest/core/dicnode/dic_node.h"
+#include "third_party/prediction/suggest/core/dicnode/dic_node_vector.h"
+#include "third_party/prediction/suggest/core/layout/proximity_info_state.h"
+#include "third_party/prediction/suggest/core/layout/proximity_info_utils.h"
+#include "third_party/prediction/suggest/core/policy/traversal.h"
+#include "third_party/prediction/suggest/core/session/dic_traverse_session.h"
+#include "third_party/prediction/suggest/policyimpl/typing/scoring_params.h"
+#include "third_party/prediction/utils/char_utils.h"
+
+namespace latinime {
+class TypingTraversal : public Traversal {
+ public:
+  static const TypingTraversal* getInstance() { return &sInstance; }
+
+  AK_FORCE_INLINE int getMaxPointerCount() const { return MAX_POINTER_COUNT; }
+
+  AK_FORCE_INLINE bool allowsErrorCorrections(
+      const DicNode* const dicNode) const {
+    return dicNode->getNormalizedSpatialDistance() <
+           ScoringParams::NORMALIZED_SPATIAL_DISTANCE_THRESHOLD_FOR_EDIT;
+  }
+
+  AK_FORCE_INLINE bool isOmission(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode,
+      const DicNode* const childDicNode,
+      const bool allowsErrorCorrections) const {
+    if (!CORRECT_OMISSION) {
+      return false;
+    }
+    // Note: Always consider intentional omissions (like apostrophes) since they
+    // are common.
+    const bool canConsiderOmission =
+        allowsErrorCorrections || childDicNode->canBeIntentionalOmission();
+    if (!canConsiderOmission) {
+      return false;
+    }
+    const int inputSize = traverseSession->getInputSize();
+    // TODO: Don't refer to isCompletion?
+    if (dicNode->isCompletion(inputSize)) {
+      return false;
+    }
+    if (dicNode->canBeIntentionalOmission()) {
+      return true;
+    }
+    const int point0Index = dicNode->getInputIndex(0);
+    const int currentBaseLowerCodePoint =
+        CharUtils::toBaseLowerCase(childDicNode->getNodeCodePoint());
+    const int typedBaseLowerCodePoint =
+        CharUtils::toBaseLowerCase(traverseSession->getProximityInfoState(0)
+                                       ->getPrimaryCodePointAt(point0Index));
+    return (currentBaseLowerCodePoint != typedBaseLowerCodePoint);
+  }
+
+  AK_FORCE_INLINE bool isSpaceSubstitutionTerminal(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode) const {
+    if (!CORRECT_NEW_WORD_SPACE_SUBSTITUTION) {
+      return false;
+    }
+    if (!canDoLookAheadCorrection(traverseSession, dicNode)) {
+      return false;
+    }
+    const int point0Index = dicNode->getInputIndex(0);
+    return dicNode->isTerminalDicNode() &&
+           traverseSession->getProximityInfoState(0)
+               ->hasSpaceProximity(point0Index);
+  }
+
+  AK_FORCE_INLINE bool isSpaceOmissionTerminal(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode) const {
+    if (!CORRECT_NEW_WORD_SPACE_OMISSION) {
+      return false;
+    }
+    const int inputSize = traverseSession->getInputSize();
+    // TODO: Don't refer to isCompletion?
+    if (dicNode->isCompletion(inputSize)) {
+      return false;
+    }
+    if (!dicNode->isTerminalDicNode()) {
+      return false;
+    }
+    const int16_t pointIndex = dicNode->getInputIndex(0);
+    return pointIndex <= inputSize &&
+           !dicNode->isTotalInputSizeExceedingLimit() &&
+           !dicNode->shouldBeFilteredBySafetyNetForBigram();
+  }
+
+  AK_FORCE_INLINE bool shouldDepthLevelCache(
+      const DicTraverseSession* const traverseSession) const {
+    const int inputSize = traverseSession->getInputSize();
+    return traverseSession->isCacheBorderForTyping(inputSize);
+  }
+
+  AK_FORCE_INLINE bool shouldNodeLevelCache(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode) const {
+    return false;
+  }
+
+  AK_FORCE_INLINE bool canDoLookAheadCorrection(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode) const {
+    const int inputSize = traverseSession->getInputSize();
+    return dicNode->canDoLookAheadCorrection(inputSize);
+  }
+
+  AK_FORCE_INLINE ProximityType
+  getProximityType(const DicTraverseSession* const traverseSession,
+                   const DicNode* const dicNode,
+                   const DicNode* const childDicNode) const {
+    return traverseSession->getProximityInfoState(0)->getProximityType(
+        dicNode->getInputIndex(0), childDicNode->getNodeCodePoint(),
+        true /* checkProximityChars */);
+  }
+
+  AK_FORCE_INLINE bool needsToTraverseAllUserInput() const { return true; }
+
+  AK_FORCE_INLINE float getMaxSpatialDistance() const {
+    return ScoringParams::MAX_SPATIAL_DISTANCE;
+  }
+
+  AK_FORCE_INLINE int getDefaultExpandDicNodeSize() const {
+    return DicNodeVector::DEFAULT_NODES_SIZE_FOR_OPTIMIZATION;
+  }
+
+  AK_FORCE_INLINE int getMaxCacheSize(const int inputSize) const {
+    return (inputSize <= 1)
+               ? ScoringParams::MAX_CACHE_DIC_NODE_SIZE_FOR_SINGLE_POINT
+               : ScoringParams::MAX_CACHE_DIC_NODE_SIZE;
+  }
+
+  AK_FORCE_INLINE int getTerminalCacheSize() const { return MAX_RESULTS; }
+
+  AK_FORCE_INLINE bool isPossibleOmissionChildNode(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const parentDicNode,
+      const DicNode* const dicNode) const {
+    const ProximityType proximityType =
+        getProximityType(traverseSession, parentDicNode, dicNode);
+    if (!ProximityInfoUtils::isMatchOrProximityChar(proximityType)) {
+      return false;
+    }
+    return true;
+  }
+
+  AK_FORCE_INLINE bool isGoodToTraverseNextWord(
+      const DicNode* const dicNode) const {
+    const int probability = dicNode->getProbability();
+    if (probability < ScoringParams::THRESHOLD_NEXT_WORD_PROBABILITY) {
+      return false;
+    }
+    const bool shortCappedWord =
+        dicNode->getNodeCodePointCount() <
+            ScoringParams::THRESHOLD_SHORT_WORD_LENGTH &&
+        dicNode->isFirstCharUppercase();
+    return !shortCappedWord ||
+           probability >=
+               ScoringParams::THRESHOLD_NEXT_WORD_PROBABILITY_FOR_CAPPED;
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TypingTraversal);
+  static const bool CORRECT_OMISSION;
+  static const bool CORRECT_NEW_WORD_SPACE_SUBSTITUTION;
+  static const bool CORRECT_NEW_WORD_SPACE_OMISSION;
+  static const TypingTraversal sInstance;
+
+  TypingTraversal() {}
+  ~TypingTraversal() {}
+};
+}  // namespace latinime
+#endif  // LATINIME_TYPING_TRAVERSAL_H