diff --git a/native/jni/src/suggest/core/dictionary/dictionary.cpp b/native/jni/src/suggest/core/dictionary/dictionary.cpp
index bf917d6..92f5c17 100644
--- a/native/jni/src/suggest/core/dictionary/dictionary.cpp
+++ b/native/jni/src/suggest/core/dictionary/dictionary.cpp
@@ -59,32 +59,40 @@
     }
 }
 
+Dictionary::NgramListenerForPrediction::NgramListenerForPrediction(
+        const PrevWordsInfo *const prevWordsInfo, SuggestionResults *const suggestionResults,
+        const DictionaryStructureWithBufferPolicy *const dictStructurePolicy)
+    : mPrevWordsInfo(prevWordsInfo), mSuggestionResults(suggestionResults),
+      mDictStructurePolicy(dictStructurePolicy) {}
+
+void Dictionary::NgramListenerForPrediction::onVisitEntry(const int ngramProbability,
+        const int targetPtNodePos) {
+    if (targetPtNodePos == NOT_A_DICT_POS) {
+        return;
+    }
+    if (mPrevWordsInfo->isNthPrevWordBeginningOfSentence(1 /* n */)
+            && ngramProbability == NOT_A_PROBABILITY) {
+        return;
+    }
+    int targetWordCodePoints[MAX_WORD_LENGTH];
+    int unigramProbability = 0;
+    const int codePointCount = mDictStructurePolicy->
+            getCodePointsAndProbabilityAndReturnCodePointCount(targetPtNodePos,
+                    MAX_WORD_LENGTH, targetWordCodePoints, &unigramProbability);
+    if (codePointCount <= 0) {
+        return;
+    }
+    const int probability = mDictStructurePolicy->getProbability(
+            unigramProbability, ngramProbability);
+    mSuggestionResults->addPrediction(targetWordCodePoints, codePointCount, probability);
+}
+
 void Dictionary::getPredictions(const PrevWordsInfo *const prevWordsInfo,
         SuggestionResults *const outSuggestionResults) const {
     TimeKeeper::setCurrentTime();
-    int unigramProbability = 0;
-    int bigramCodePoints[MAX_WORD_LENGTH];
-    BinaryDictionaryBigramsIterator bigramsIt = prevWordsInfo->getBigramsIteratorForPrediction(
+    NgramListenerForPrediction listener(prevWordsInfo, outSuggestionResults,
             mDictionaryStructureWithBufferPolicy.get());
-    while (bigramsIt.hasNext()) {
-        bigramsIt.next();
-        if (bigramsIt.getBigramPos() == NOT_A_DICT_POS) {
-            continue;
-        }
-        if (prevWordsInfo->isNthPrevWordBeginningOfSentence(1 /* n */)
-                && bigramsIt.getProbability() == NOT_A_PROBABILITY) {
-            continue;
-        }
-        const int codePointCount = mDictionaryStructureWithBufferPolicy->
-                getCodePointsAndProbabilityAndReturnCodePointCount(bigramsIt.getBigramPos(),
-                        MAX_WORD_LENGTH, bigramCodePoints, &unigramProbability);
-        if (codePointCount <= 0) {
-            continue;
-        }
-        const int probability = mDictionaryStructureWithBufferPolicy->getProbability(
-                unigramProbability, bigramsIt.getProbability());
-        outSuggestionResults->addPrediction(bigramCodePoints, codePointCount, probability);
-    }
+    mDictionaryStructureWithBufferPolicy->iterateNgramEntries(prevWordsInfo, &listener);
 }
 
 int Dictionary::getProbability(const int *word, int length) const {
diff --git a/native/jni/src/suggest/core/dictionary/dictionary.h b/native/jni/src/suggest/core/dictionary/dictionary.h
index 3b41088..732d3b1 100644
--- a/native/jni/src/suggest/core/dictionary/dictionary.h
+++ b/native/jni/src/suggest/core/dictionary/dictionary.h
@@ -21,6 +21,7 @@
 
 #include "defines.h"
 #include "jni.h"
+#include "suggest/core/dictionary/ngram_listener.h"
 #include "suggest/core/dictionary/property/word_property.h"
 #include "suggest/core/policy/dictionary_header_structure_policy.h"
 #include "suggest/core/policy/dictionary_structure_with_buffer_policy.h"
@@ -114,6 +115,21 @@
 
     typedef std::unique_ptr<SuggestInterface> SuggestInterfacePtr;
 
+    class NgramListenerForPrediction : public NgramListener {
+     public:
+        NgramListenerForPrediction(const PrevWordsInfo *const prevWordsInfo,
+                SuggestionResults *const suggestionResults,
+                const DictionaryStructureWithBufferPolicy *const dictStructurePolicy);
+        virtual void onVisitEntry(const int ngramProbability, const int targetPtNodePos);
+
+     private:
+        DISALLOW_IMPLICIT_CONSTRUCTORS(NgramListenerForPrediction);
+
+        const PrevWordsInfo *const mPrevWordsInfo;
+        SuggestionResults *const mSuggestionResults;
+        const DictionaryStructureWithBufferPolicy *const mDictStructurePolicy;
+    };
+
     static const int HEADER_ATTRIBUTE_BUFFER_SIZE;
 
     const DictionaryStructureWithBufferPolicy::StructurePolicyPtr
diff --git a/native/jni/src/suggest/core/dictionary/ngram_listener.h b/native/jni/src/suggest/core/dictionary/ngram_listener.h
new file mode 100644
index 0000000..88b88ba
--- /dev/null
+++ b/native/jni/src/suggest/core/dictionary/ngram_listener.h
@@ -0,0 +1,40 @@
+/*
+ * 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.
+ */
+
+#ifndef LATINIME_NGRAM_LISTENER_H
+#define LATINIME_NGRAM_LISTENER_H
+
+#include "defines.h"
+
+namespace latinime {
+
+/**
+ * Interface to iterate ngram entries.
+ */
+class NgramListener {
+ public:
+    virtual void onVisitEntry(const int ngramProbability, const int targetPtNodePos) = 0;
+    virtual ~NgramListener() {};
+
+ protected:
+    NgramListener() {}
+
+ private:
+    DISALLOW_COPY_AND_ASSIGN(NgramListener);
+
+};
+} // namespace latinime
+#endif /* LATINIME_NGRAM_LISTENER_H */
diff --git a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
index 7ad20e7..81e38f7 100644
--- a/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
+++ b/native/jni/src/suggest/core/policy/dictionary_structure_with_buffer_policy.h
@@ -30,6 +30,7 @@
 class DictionaryBigramsStructurePolicy;
 class DictionaryHeaderStructurePolicy;
 class DictionaryShortcutsStructurePolicy;
+class NgramListener;
 class PrevWordsInfo;
 class UnigramProperty;
 
@@ -61,6 +62,9 @@
     virtual int getProbabilityOfPtNode(const PrevWordsInfo *const prevWordsInfo,
             const int nodePos) const = 0;
 
+    virtual void iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+            NgramListener *const listener) const = 0;
+
     virtual int getShortcutPositionOfPtNode(const int nodePos) const = 0;
 
     virtual BinaryDictionaryBigramsIterator getBigramsIteratorOfPtNode(const int nodePos) const = 0;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp
index 3277410..4b834a0 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.cpp
@@ -28,6 +28,7 @@
 
 #include "suggest/core/dicnode/dic_node.h"
 #include "suggest/core/dicnode/dic_node_vector.h"
+#include "suggest/core/dictionary/ngram_listener.h"
 #include "suggest/core/dictionary/property/bigram_property.h"
 #include "suggest/core/dictionary/property/unigram_property.h"
 #include "suggest/core/dictionary/property/word_property.h"
@@ -155,6 +156,16 @@
     return getProbability(ptNodeParams.getProbability(), NOT_A_PROBABILITY);
 }
 
+void Ver4PatriciaTriePolicy::iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+        NgramListener *const listener) const {
+    BinaryDictionaryBigramsIterator bigramsIt = prevWordsInfo->getBigramsIteratorForPrediction(
+            this /* dictStructurePolicy */);
+    while (bigramsIt.hasNext()) {
+        bigramsIt.next();
+        listener->onVisitEntry(bigramsIt.getProbability(), bigramsIt.getBigramPos());
+    }
+}
+
 int Ver4PatriciaTriePolicy::getShortcutPositionOfPtNode(const int ptNodePos) const {
     if (ptNodePos == NOT_A_DICT_POS) {
         return NOT_A_DICT_POS;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.h
index c80a73a..e61c060 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/backward/v402/ver4_patricia_trie_policy.h
@@ -93,6 +93,9 @@
     int getProbabilityOfPtNode(const PrevWordsInfo *const prevWordsInfo,
             const int ptNodePos) const;
 
+    void iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+            NgramListener *const listener) const;
+
     int getShortcutPositionOfPtNode(const int ptNodePos) const;
 
     BinaryDictionaryBigramsIterator getBigramsIteratorOfPtNode(const int ptNodePos) const;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.cpp
index b909e82..6f02ff3 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.cpp
@@ -21,6 +21,7 @@
 #include "suggest/core/dicnode/dic_node.h"
 #include "suggest/core/dicnode/dic_node_vector.h"
 #include "suggest/core/dictionary/binary_dictionary_bigrams_iterator.h"
+#include "suggest/core/dictionary/ngram_listener.h"
 #include "suggest/core/session/prev_words_info.h"
 #include "suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_helper.h"
 #include "suggest/policyimpl/dictionary/structure/pt_common/patricia_trie_reading_utils.h"
@@ -324,6 +325,16 @@
     return getProbability(ptNodeParams.getProbability(), NOT_A_PROBABILITY);
 }
 
+void PatriciaTriePolicy::iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+        NgramListener *const listener) const {
+    BinaryDictionaryBigramsIterator bigramsIt = prevWordsInfo->getBigramsIteratorForPrediction(
+            this /* dictStructurePolicy */);
+    while (bigramsIt.hasNext()) {
+        bigramsIt.next();
+        listener->onVisitEntry(bigramsIt.getProbability(), bigramsIt.getBigramPos());
+    }
+}
+
 int PatriciaTriePolicy::getShortcutPositionOfPtNode(const int ptNodePos) const {
     if (ptNodePos == NOT_A_DICT_POS) {
         return NOT_A_DICT_POS;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h
index 1dd5705..a3b2220 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v2/patricia_trie_policy.h
@@ -65,6 +65,9 @@
 
     int getProbabilityOfPtNode(const PrevWordsInfo *const prevWordsInfo, const int ptNodePos) const;
 
+    void iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+            NgramListener *const listener) const;
+
     int getShortcutPositionOfPtNode(const int ptNodePos) const;
 
     BinaryDictionaryBigramsIterator getBigramsIteratorOfPtNode(const int ptNodePos) const;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
index cada3d1..23bbbbd 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.cpp
@@ -20,6 +20,7 @@
 
 #include "suggest/core/dicnode/dic_node.h"
 #include "suggest/core/dicnode/dic_node_vector.h"
+#include "suggest/core/dictionary/ngram_listener.h"
 #include "suggest/core/dictionary/property/bigram_property.h"
 #include "suggest/core/dictionary/property/unigram_property.h"
 #include "suggest/core/dictionary/property/word_property.h"
@@ -145,6 +146,16 @@
     return getProbability(ptNodeParams.getProbability(), NOT_A_PROBABILITY);
 }
 
+void Ver4PatriciaTriePolicy::iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+        NgramListener *const listener) const {
+    BinaryDictionaryBigramsIterator bigramsIt = prevWordsInfo->getBigramsIteratorForPrediction(
+            this /* dictStructurePolicy */);
+    while (bigramsIt.hasNext()) {
+        bigramsIt.next();
+        listener->onVisitEntry(bigramsIt.getProbability(), bigramsIt.getBigramPos());
+    }
+}
+
 int Ver4PatriciaTriePolicy::getShortcutPositionOfPtNode(const int ptNodePos) const {
     if (ptNodePos == NOT_A_DICT_POS) {
         return NOT_A_DICT_POS;
diff --git a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
index b0f16cd..1838454 100644
--- a/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
+++ b/native/jni/src/suggest/policyimpl/dictionary/structure/v4/ver4_patricia_trie_policy.h
@@ -74,6 +74,9 @@
 
     int getProbabilityOfPtNode(const PrevWordsInfo *const prevWordsInfo, const int ptNodePos) const;
 
+    void iterateNgramEntries(const PrevWordsInfo *const prevWordsInfo,
+            NgramListener *const listener) const;
+
     int getShortcutPositionOfPtNode(const int ptNodePos) const;
 
     BinaryDictionaryBigramsIterator getBigramsIteratorOfPtNode(const int ptNodePos) const;