Add spellcheck and word suggestion to the prediction service

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

Index: third_party/prediction/suggest/policyimpl/typing/typing_weighting.h
diff --git a/third_party/prediction/suggest/policyimpl/typing/typing_weighting.h b/third_party/prediction/suggest/policyimpl/typing/typing_weighting.h
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+/*
+ * Copyright (C) 2012 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_WEIGHTING_H
+#define LATINIME_TYPING_WEIGHTING_H
+
+#include "third_party/prediction/defines.h"
+#include "third_party/prediction/suggest/core/dicnode/dic_node_utils.h"
+#include "third_party/prediction/suggest/core/dictionary/error_type_utils.h"
+#include "third_party/prediction/suggest/core/layout/touch_position_correction_utils.h"
+#include "third_party/prediction/suggest/core/policy/weighting.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 DicNode;
+struct DicNode_InputStateG;
+class MultiBigramMap;
+
+class TypingWeighting : public Weighting {
+ public:
+  static const TypingWeighting* getInstance() { return &sInstance; }
+
+ protected:
+  float getTerminalSpatialCost(const DicTraverseSession* const traverseSession,
+                               const DicNode* const dicNode) const {
+    float cost = 0.0f;
+    if (dicNode->hasMultipleWords()) {
+      cost += ScoringParams::HAS_MULTI_WORD_TERMINAL_COST;
+    }
+    if (dicNode->getProximityCorrectionCount() > 0) {
+      cost += ScoringParams::HAS_PROXIMITY_TERMINAL_COST;
+    }
+    if (dicNode->getEditCorrectionCount() > 0) {
+      cost += ScoringParams::HAS_EDIT_CORRECTION_TERMINAL_COST;
+    }
+    return cost;
+  }
+
+  float getOmissionCost(const DicNode* const parentDicNode,
+                        const DicNode* const dicNode) const {
+    const bool isZeroCostOmission = parentDicNode->isZeroCostOmission();
+    const bool isIntentionalOmission =
+        parentDicNode->canBeIntentionalOmission();
+    const bool sameCodePoint = dicNode->isSameNodeCodePoint(parentDicNode);
+    // If the traversal omitted the first letter then the dicNode should now be
+    // on the second.
+    const bool isFirstLetterOmission = dicNode->getNodeCodePointCount() == 2;
+    float cost = 0.0f;
+    if (isZeroCostOmission) {
+      cost = 0.0f;
+    } else if (isIntentionalOmission) {
+      cost = ScoringParams::INTENTIONAL_OMISSION_COST;
+    } else if (isFirstLetterOmission) {
+      cost = ScoringParams::OMISSION_COST_FIRST_CHAR;
+    } else {
+      cost = sameCodePoint ? ScoringParams::OMISSION_COST_SAME_CHAR
+                           : ScoringParams::OMISSION_COST;
+    }
+    return cost;
+  }
+
+  float getMatchedCost(const DicTraverseSession* const traverseSession,
+                       const DicNode* const dicNode,
+                       DicNode_InputStateG* inputStateG) const {
+    const int pointIndex = dicNode->getInputIndex(0);
+    const float normalizedSquaredLength =
+        traverseSession->getProximityInfoState(0)->getPointToKeyLength(
+            pointIndex,
+            CharUtils::toBaseLowerCase(dicNode->getNodeCodePoint()));
+    const float normalizedDistance =
+        TouchPositionCorrectionUtils::getSweetSpotFactor(
+            traverseSession->isTouchPositionCorrectionEnabled(),
+            normalizedSquaredLength);
+    const float weightedDistance =
+        ScoringParams::DISTANCE_WEIGHT_LENGTH * normalizedDistance;
+
+    const bool isFirstChar = pointIndex == 0;
+    const bool isProximity = isProximityDicNode(traverseSession, dicNode);
+    float cost = isProximity
+                     ? (isFirstChar ? ScoringParams::FIRST_CHAR_PROXIMITY_COST
+                                    : ScoringParams::PROXIMITY_COST)
+                     : 0.0f;
+    if (isProximity && dicNode->getProximityCorrectionCount() == 0) {
+      cost += ScoringParams::FIRST_PROXIMITY_COST;
+    }
+    if (dicNode->getNodeCodePointCount() == 2) {
+      // At the second character of the current word, we check if the first char
+      // is uppercase
+      // and the word is a second or later word of a multiple word suggestion.
+      // We demote it
+      // if so.
+      const bool isSecondOrLaterWordFirstCharUppercase =
+          dicNode->hasMultipleWords() && dicNode->isFirstCharUppercase();
+      if (isSecondOrLaterWordFirstCharUppercase) {
+        cost += ScoringParams::COST_SECOND_OR_LATER_WORD_FIRST_CHAR_UPPERCASE;
+      }
+    }
+    return weightedDistance + cost;
+  }
+
+  bool isProximityDicNode(const DicTraverseSession* const traverseSession,
+                          const DicNode* const dicNode) const {
+    const int pointIndex = dicNode->getInputIndex(0);
+    const int primaryCodePoint =
+        CharUtils::toBaseLowerCase(traverseSession->getProximityInfoState(0)
+                                       ->getPrimaryCodePointAt(pointIndex));
+    const int dicNodeChar =
+        CharUtils::toBaseLowerCase(dicNode->getNodeCodePoint());
+    return primaryCodePoint != dicNodeChar;
+  }
+
+  float getTranspositionCost(const DicTraverseSession* const traverseSession,
+                             const DicNode* const parentDicNode,
+                             const DicNode* const dicNode) const {
+    const int16_t parentPointIndex = parentDicNode->getInputIndex(0);
+    const int prevCodePoint = parentDicNode->getNodeCodePoint();
+    const float distance1 =
+        traverseSession->getProximityInfoState(0)->getPointToKeyLength(
+            parentPointIndex + 1, CharUtils::toBaseLowerCase(prevCodePoint));
+    const int codePoint = dicNode->getNodeCodePoint();
+    const float distance2 =
+        traverseSession->getProximityInfoState(0)->getPointToKeyLength(
+            parentPointIndex, CharUtils::toBaseLowerCase(codePoint));
+    const float distance = distance1 + distance2;
+    const float weightedLengthDistance =
+        distance * ScoringParams::DISTANCE_WEIGHT_LENGTH;
+    return ScoringParams::TRANSPOSITION_COST + weightedLengthDistance;
+  }
+
+  float getInsertionCost(const DicTraverseSession* const traverseSession,
+                         const DicNode* const parentDicNode,
+                         const DicNode* const dicNode) const {
+    const int16_t insertedPointIndex = parentDicNode->getInputIndex(0);
+    const int prevCodePoint = traverseSession->getProximityInfoState(0)
+                                  ->getPrimaryCodePointAt(insertedPointIndex);
+    const int currentCodePoint = dicNode->getNodeCodePoint();
+    const bool sameCodePoint = prevCodePoint == currentCodePoint;
+    const bool existsAdjacentProximityChars =
+        traverseSession->getProximityInfoState(0)
+            ->existsAdjacentProximityChars(insertedPointIndex);
+    const float dist =
+        traverseSession->getProximityInfoState(0)->getPointToKeyLength(
+            insertedPointIndex + 1,
+            CharUtils::toBaseLowerCase(dicNode->getNodeCodePoint()));
+    const float weightedDistance = dist * ScoringParams::DISTANCE_WEIGHT_LENGTH;
+    const bool singleChar = dicNode->getNodeCodePointCount() == 1;
+    float cost = (singleChar ? ScoringParams::INSERTION_COST_FIRST_CHAR : 0.0f);
+    if (sameCodePoint) {
+      cost += ScoringParams::INSERTION_COST_SAME_CHAR;
+    } else if (existsAdjacentProximityChars) {
+      cost += ScoringParams::INSERTION_COST_PROXIMITY_CHAR;
+    } else {
+      cost += ScoringParams::INSERTION_COST;
+    }
+    return cost + weightedDistance;
+  }
+
+  float getNewWordSpatialCost(const DicTraverseSession* const traverseSession,
+                              const DicNode* const dicNode,
+                              DicNode_InputStateG* inputStateG) const {
+    return ScoringParams::COST_NEW_WORD *
+           traverseSession->getMultiWordCostMultiplier();
+  }
+
+  float getNewWordBigramLanguageCost(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode,
+      MultiBigramMap* const multiBigramMap) const {
+    return DicNodeUtils::getBigramNodeImprobability(
+               traverseSession->getDictionaryStructurePolicy(), dicNode,
+               multiBigramMap) *
+           ScoringParams::DISTANCE_WEIGHT_LANGUAGE;
+  }
+
+  float getCompletionCost(const DicTraverseSession* const traverseSession,
+                          const DicNode* const dicNode) const {
+    // The auto completion starts when the input index is same as the input size
+    const bool firstCompletion =
+        dicNode->getInputIndex(0) == traverseSession->getInputSize();
+    // TODO: Change the cost for the first completion for the gesture?
+    const float cost = firstCompletion ? ScoringParams::COST_FIRST_COMPLETION
+                                       : ScoringParams::COST_COMPLETION;
+    return cost;
+  }
+
+  float getTerminalLanguageCost(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode,
+      const float dicNodeLanguageImprobability) const {
+    return dicNodeLanguageImprobability *
+           ScoringParams::DISTANCE_WEIGHT_LANGUAGE;
+  }
+
+  float getTerminalInsertionCost(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode) const {
+    const int inputIndex = dicNode->getInputIndex(0);
+    const int inputSize = traverseSession->getInputSize();
+    ASSERT(inputIndex < inputSize);
+    // TODO: Implement more efficient logic
+    return ScoringParams::TERMINAL_INSERTION_COST * (inputSize - inputIndex);
+  }
+
+  AK_FORCE_INLINE bool needsToNormalizeCompoundDistance() const {
+    return false;
+  }
+
+  AK_FORCE_INLINE float getAdditionalProximityCost() const {
+    return ScoringParams::ADDITIONAL_PROXIMITY_COST;
+  }
+
+  AK_FORCE_INLINE float getSubstitutionCost() const {
+    return ScoringParams::SUBSTITUTION_COST;
+  }
+
+  AK_FORCE_INLINE float getSpaceSubstitutionCost(
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const dicNode) const {
+    const float cost =
+        ScoringParams::SPACE_SUBSTITUTION_COST + ScoringParams::COST_NEW_WORD;
+    return cost * traverseSession->getMultiWordCostMultiplier();
+  }
+
+  ErrorTypeUtils::ErrorType getErrorType(
+      const CorrectionType correctionType,
+      const DicTraverseSession* const traverseSession,
+      const DicNode* const parentDicNode,
+      const DicNode* const dicNode) const;
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(TypingWeighting);
+  static const TypingWeighting sInstance;
+
+  TypingWeighting() {}
+  ~TypingWeighting() {}
+};
+}  // namespace latinime
+#endif  // LATINIME_TYPING_WEIGHTING_H