Add spellcheck and word suggestion to the prediction service

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

+/*
+ * 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/prediction/suggest/core/dictionary/dictionary_utils.h"
+
+#include "third_party/prediction/suggest/core/dicnode/dic_node.h"
+#include "third_party/prediction/suggest/core/dicnode/dic_node_priority_queue.h"
+#include "third_party/prediction/suggest/core/dicnode/dic_node_vector.h"
+#include "third_party/prediction/suggest/core/dictionary/dictionary.h"
+#include "third_party/prediction/suggest/core/dictionary/digraph_utils.h"
+#include "third_party/prediction/suggest/core/session/prev_words_info.h"
+#include "third_party/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