Add spellcheck and word suggestion to the prediction service

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

Index: third_party/android_prediction/suggest/policyimpl/typing/typing_traversal.h
diff --git a/third_party/android_prediction/suggest/policyimpl/typing/typing_traversal.h b/third_party/android_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/android_prediction/defines.h"
+#include "third_party/android_prediction/suggest/core/dicnode/dic_node.h"
+#include "third_party/android_prediction/suggest/core/dicnode/dic_node_vector.h"
+#include "third_party/android_prediction/suggest/core/layout/proximity_info_state.h"
+#include "third_party/android_prediction/suggest/core/layout/proximity_info_utils.h"
+#include "third_party/android_prediction/suggest/core/policy/traversal.h"
+#include "third_party/android_prediction/suggest/core/session/dic_traverse_session.h"
+#include "third_party/android_prediction/suggest/policyimpl/typing/scoring_params.h"
+#include "third_party/android_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