Add spellcheck and word suggestion to the prediction service

third_party/android_prediction/suggest/core/dictionary/dictionary_utils.cpp

Index: third_party/android_prediction/suggest/core/dictionary/dictionary_utils.cpp
diff --git a/third_party/android_prediction/suggest/core/dictionary/dictionary_utils.cpp b/third_party/android_prediction/suggest/core/dictionary/dictionary_utils.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..703997a1aeb4a582afe1f7d2fe4860ebd2915060
--- /dev/null
+++ b/third_party/android_prediction/suggest/core/dictionary/dictionary_utils.cpp
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2014, 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/dictionary/dictionary_utils.h"
+
+#include "third_party/android_prediction/suggest/core/dicnode/dic_node.h"
+#include "third_party/android_prediction/suggest/core/dicnode/dic_node_priority_queue.h"
+#include "third_party/android_prediction/suggest/core/dicnode/dic_node_vector.h"
+#include "third_party/android_prediction/suggest/core/dictionary/dictionary.h"
+#include "third_party/android_prediction/suggest/core/dictionary/digraph_utils.h"
+#include "third_party/android_prediction/suggest/core/session/prev_words_info.h"
+#include "third_party/android_prediction/suggest/core/policy/dictionary_structure_with_buffer_policy.h"
+
+namespace latinime {
+
+/* static */ int DictionaryUtils::getMaxProbabilityOfExactMatches(
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        const int *const codePoints, const int codePointCount) {
+    std::vector<DicNode> current;
+    std::vector<DicNode> next;
+
+    // No prev words information.
+    PrevWordsInfo emptyPrevWordsInfo;
+    int prevWordsPtNodePos[MAX_PREV_WORD_COUNT_FOR_N_GRAM];
+    emptyPrevWordsInfo.getPrevWordsTerminalPtNodePos(dictionaryStructurePolicy,
+            prevWordsPtNodePos, false /* tryLowerCaseSearch */);
+    current.emplace_back();
+    DicNodeUtils::initAsRoot(dictionaryStructurePolicy, prevWordsPtNodePos, &current.front());
+    for (int i = 0; i < codePointCount; ++i) {
+        // The base-lower input is used to ignore case errors and accent errors.
+        const int codePoint = CharUtils::toBaseLowerCase(codePoints[i]);
+        for (const DicNode &dicNode : current) {
+            if (dicNode.isInDigraph() && dicNode.getNodeCodePoint() == codePoint) {
+                next.emplace_back(dicNode);
+                next.back().advanceDigraphIndex();
+                continue;
+            }
+            processChildDicNodes(dictionaryStructurePolicy, codePoint, &dicNode, &next);
+        }
+        current.clear();
+        current.swap(next);
+    }
+
+    int maxProbability = NOT_A_PROBABILITY;
+    for (const DicNode &dicNode : current) {
+        if (!dicNode.isTerminalDicNode()) {
+            continue;
+        }
+        // dicNode can contain case errors, accent errors, intentional omissions or digraphs.
+        maxProbability = std::max(maxProbability, dicNode.getProbability());
+    }
+    return maxProbability;
+}
+
+/* static */ void DictionaryUtils::processChildDicNodes(
+        const DictionaryStructureWithBufferPolicy *const dictionaryStructurePolicy,
+        const int inputCodePoint, const DicNode *const parentDicNode,
+        std::vector<DicNode> *const outDicNodes) {
+    DicNodeVector childDicNodes;
+    DicNodeUtils::getAllChildDicNodes(parentDicNode, dictionaryStructurePolicy, &childDicNodes);
+    for (int childIndex = 0; childIndex < childDicNodes.getSizeAndLock(); ++childIndex) {
+        DicNode *const childDicNode = childDicNodes[childIndex];
+        const int codePoint = CharUtils::toBaseLowerCase(childDicNode->getNodeCodePoint());
+        if (inputCodePoint == codePoint) {
+            outDicNodes->emplace_back(*childDicNode);
+        }
+        if (childDicNode->canBeIntentionalOmission()) {
+            processChildDicNodes(dictionaryStructurePolicy, inputCodePoint, childDicNode,
+                    outDicNodes);
+        }
+        if (DigraphUtils::hasDigraphForCodePoint(
+                dictionaryStructurePolicy->getHeaderStructurePolicy(),
+                childDicNode->getNodeCodePoint())) {
+            childDicNode->advanceDigraphIndex();
+            if (childDicNode->getNodeCodePoint() == codePoint) {
+                childDicNode->advanceDigraphIndex();
+                outDicNodes->emplace_back(*childDicNode);
+            }
+        }
+    }
+}
+
+} // namespace latinime