Add spellcheck and word suggestion to the prediction service

third_party/android_prediction/suggest/core/dicnode/dic_node_utils.cpp

Index: third_party/android_prediction/suggest/core/dicnode/dic_node_utils.cpp
diff --git a/third_party/android_prediction/suggest/core/dicnode/dic_node_utils.cpp b/third_party/android_prediction/suggest/core/dicnode/dic_node_utils.cpp
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index 0000000000000000000000000000000000000000..d8d2674493f5eef7549f9b2f8243c197c2e0b377
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+++ b/third_party/android_prediction/suggest/core/dicnode/dic_node_utils.cpp
@@ -0,0 +1,97 @@
+/*
+ * 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.
+ */
+
+#include "third_party/android_prediction/suggest/core/dicnode/dic_node_utils.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/dictionary/multi_bigram_map.h"
+#include "third_party/android_prediction/suggest/core/policy/dictionary_structure_with_buffer_policy.h"
+
+namespace latinime {
+
+///////////////////////////////
+// Node initialization utils //
+///////////////////////////////
+
+/* static */ void DicNodeUtils::initAsRoot(
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        const int *const prevWordsPtNodePos, DicNode *const newRootDicNode) {
+    newRootDicNode->initAsRoot(dictionaryStructurePolicy->getRootPosition(), prevWordsPtNodePos);
+}
+
+/*static */ void DicNodeUtils::initAsRootWithPreviousWord(
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        const DicNode *const prevWordLastDicNode, DicNode *const newRootDicNode) {
+    newRootDicNode->initAsRootWithPreviousWord(
+            prevWordLastDicNode, dictionaryStructurePolicy->getRootPosition());
+}
+
+/* static */ void DicNodeUtils::initByCopy(const DicNode *const srcDicNode,
+        DicNode *const destDicNode) {
+    destDicNode->initByCopy(srcDicNode);
+}
+
+///////////////////////////////////
+// Traverse node expansion utils //
+///////////////////////////////////
+/* static */ void DicNodeUtils::getAllChildDicNodes(const DicNode *dicNode,
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        DicNodeVector *const childDicNodes) {
+    if (dicNode->isTotalInputSizeExceedingLimit()) {
+        return;
+    }
+    if (!dicNode->isLeavingNode()) {
+        childDicNodes->pushPassingChild(dicNode);
+    } else {
+        dictionaryStructurePolicy->createAndGetAllChildDicNodes(dicNode, childDicNodes);
+    }
+}
+
+///////////////////
+// Scoring utils //
+///////////////////
+/**
+ * Computes the combined bigram / unigram cost for the given dicNode.
+ */
+/* static */ float DicNodeUtils::getBigramNodeImprobability(
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        const DicNode *const dicNode, MultiBigramMap *const multiBigramMap) {
+    if (dicNode->hasMultipleWords() && !dicNode->isValidMultipleWordSuggestion()) {
+        return static_cast<float>(MAX_VALUE_FOR_WEIGHTING);
+    }
+    const int probability = getBigramNodeProbability(dictionaryStructurePolicy, dicNode,
+            multiBigramMap);
+    // TODO: This equation to calculate the improbability looks unreasonable.  Investigate this.
+    const float cost = static_cast<float>(MAX_PROBABILITY - probability)
+            / static_cast<float>(MAX_PROBABILITY);
+    return cost;
+}
+
+/* static */ int DicNodeUtils::getBigramNodeProbability(
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        const DicNode *const dicNode, MultiBigramMap *const multiBigramMap) {
+    const int unigramProbability = dicNode->getProbability();
+    if (multiBigramMap) {
+        const int *const prevWordsPtNodePos = dicNode->getPrevWordsTerminalPtNodePos();
+        return multiBigramMap->getBigramProbability(dictionaryStructurePolicy,
+                prevWordsPtNodePos, dicNode->getPtNodePos(), unigramProbability);
+    }
+    return dictionaryStructurePolicy->getProbability(unigramProbability,
+            NOT_A_PROBABILITY);
+}
+
+} // namespace latinime