Correction algorithm to check for missing single characters.

Searches for alternative words by trying wild-card characters at different
character positions.

dictionary/jni/com_android_inputmethod_latin_BinaryDictionary.cpp

@@ -42,7 +42,7 @@ static jmethodID sAddWordMethod;
 //
 // helper function to throw an exception
 //
-static void throwException(JNIEnv *env, const char* ex, const char* fmt, int data) 
+static void throwException(JNIEnv *env, const char* ex, const char* fmt, int data)
 {
     if (jclass cls = env->FindClass(ex)) {
         char msg[1000];
@@ -66,7 +66,7 @@ static jint latinime_BinaryDictionary_open
 
     Asset *dictAsset = am->openNonAsset(resourcePath, Asset::ACCESS_BUFFER);
     if (dictAsset == NULL) {
-        LOGE("DICT: Couldn't get asset %s\n", resourcePath); 
+        LOGE("DICT: Couldn't get asset %s\n", resourcePath);
         env->ReleaseStringUTFChars(resourceString, resourcePath);
         return 0;
     }
@@ -79,15 +79,15 @@ static jint latinime_BinaryDictionary_open
     }
     Dictionary *dictionary = new Dictionary(dict, typedLetterMultiplier, fullWordMultiplier);
     dictionary->setAsset(dictAsset);
-    
+
     env->ReleaseStringUTFChars(resourceString, resourcePath);
-    return (jint) dictionary;  
+    return (jint) dictionary;
 }
 
 static int latinime_BinaryDictionary_getSuggestions(
-        JNIEnv *env, jobject object, jint dict, jintArray inputArray, jint arraySize, 
+        JNIEnv *env, jobject object, jint dict, jintArray inputArray, jint arraySize,
-        jcharArray outputArray, jintArray frequencyArray, jint maxWordLength, jint maxWords, 
+        jcharArray outputArray, jintArray frequencyArray, jint maxWordLength, jint maxWords,
-        jint maxAlternatives)
+        jint maxAlternatives, jint skipPos)
 {
     Dictionary *dictionary = (Dictionary*) dict;
     if (dictionary == NULL)
@@ -96,9 +96,9 @@ static int latinime_BinaryDictionary_getSuggestions(
     int *frequencies = env->GetIntArrayElements(frequencyArray, NULL);
     int *inputCodes = env->GetIntArrayElements(inputArray, NULL);
     jchar *outputChars = env->GetCharArrayElements(outputArray, NULL);
-    
+
     int count = dictionary->getSuggestions(inputCodes, arraySize, (unsigned short*) outputChars, frequencies,
-            maxWordLength, maxWords, maxAlternatives);
+            maxWordLength, maxWords, maxAlternatives, skipPos);
     
     env->ReleaseIntArrayElements(frequencyArray, frequencies, 0);
     env->ReleaseIntArrayElements(inputArray, inputCodes, JNI_ABORT);
@@ -112,16 +112,16 @@ static jboolean latinime_BinaryDictionary_isValidWord
 {
     Dictionary *dictionary = (Dictionary*) dict;
     if (dictionary == NULL) return (jboolean) false;
-    
+
     jchar *word = env->GetCharArrayElements(wordArray, NULL);
     jboolean result = dictionary->isValidWord((unsigned short*) word, wordLength);
     env->ReleaseCharArrayElements(wordArray, word, JNI_ABORT);
-    
+
     return result;
 }
 
 static void latinime_BinaryDictionary_close
-        (JNIEnv *env, jobject object, jint dict) 
+        (JNIEnv *env, jobject object, jint dict)
 {
     Dictionary *dictionary = (Dictionary*) dict;
     ((Asset*) dictionary->getAsset())->close();
@@ -131,10 +131,10 @@ static void latinime_BinaryDictionary_close
 // ----------------------------------------------------------------------------
 
 static JNINativeMethod gMethods[] = {
-    {"openNative",           "(Landroid/content/res/AssetManager;Ljava/lang/String;II)I", 
+    {"openNative",           "(Landroid/content/res/AssetManager;Ljava/lang/String;II)I",
                                           (void*)latinime_BinaryDictionary_open},
     {"closeNative",          "(I)V",            (void*)latinime_BinaryDictionary_close},
-    {"getSuggestionsNative", "(I[II[C[IIII)I",  (void*)latinime_BinaryDictionary_getSuggestions},
+    {"getSuggestionsNative", "(I[II[C[IIIII)I",  (void*)latinime_BinaryDictionary_getSuggestions},
     {"isValidWordNative",    "(I[CI)Z",         (void*)latinime_BinaryDictionary_isValidWord}
 };
 
@@ -153,7 +153,7 @@ static int registerNativeMethods(JNIEnv* env, const char* className,
         fprintf(stderr, "RegisterNatives failed for '%s'\n", className);
         return JNI_FALSE;
     }
-  
+
     return JNI_TRUE;
 }
 
@@ -161,21 +161,21 @@ static int registerNatives(JNIEnv *env)
 {
     const char* const kClassPathName = "com/android/inputmethod/latin/BinaryDictionary";
     jclass clazz;
-    
+
     clazz = env->FindClass("java/io/FileDescriptor");
     if (clazz == NULL) {
         LOGE("Can't find %s", "java/io/FileDescriptor");
         return -1;
     }
     sDescriptorField = env->GetFieldID(clazz, "descriptor", "I");
-    
+
     clazz = env->FindClass("android/content/res/AssetManager");
     if (clazz == NULL) {
         LOGE("Can't find %s", "java/io/FileDescriptor");
         return -1;
     }
     sAssetManagerNativeField = env->GetFieldID(clazz, "mObject", "I");
-    
+
     return registerNativeMethods(env,
             kClassPathName, gMethods, sizeof(gMethods) / sizeof(gMethods[0]));
 }

dictionary/src/dictionary.cpp

@@ -49,11 +49,8 @@ Dictionary::~Dictionary()
 }
 
 int Dictionary::getSuggestions(int *codes, int codesSize, unsigned short *outWords, int *frequencies,
-        int maxWordLength, int maxWords, int maxAlternatives)
+        int maxWordLength, int maxWords, int maxAlternatives, int skipPos)
 {
-    memset(frequencies, 0, maxWords * sizeof(*frequencies));
-    memset(outWords, 0, maxWords * maxWordLength * sizeof(*outWords));
-
     mFrequencies = frequencies;
     mOutputChars = outWords;
     mInputCodes = codes;
@@ -62,6 +59,7 @@ int Dictionary::getSuggestions(int *codes, int codesSize, unsigned short *outWor
     mMaxWordLength = maxWordLength;
     mMaxWords = maxWords;
     mWords = 0;
+    mSkipPos = skipPos;
 
     getWordsRec(0, 0, mInputLength * 3, false, 1, 0);
 
@@ -209,9 +207,9 @@ Dictionary::getWordsRec(int pos, int depth, int maxDepth, bool completion, int s
                 getWordsRec(childrenAddress, depth + 1, maxDepth,
                             completion, snr, inputIndex);
             }
-        } else if (c == QUOTE && currentChars[0] != QUOTE) {
+        } else if (c == QUOTE && currentChars[0] != QUOTE || mSkipPos == depth) {
-            // Skip the ' and continue deeper
+            // Skip the ' or other letter and continue deeper
-            mWord[depth] = QUOTE;
+            mWord[depth] = c;
             if (childrenAddress != 0) {
                 getWordsRec(childrenAddress, depth + 1, maxDepth, false, snr, inputIndex);
             }
@@ -239,6 +237,7 @@ Dictionary::getWordsRec(int pos, int depth, int maxDepth, bool completion, int s
                     }
                 }
                 j++;
+                if (mSkipPos >= 0) break;
             }
         }
     }

dictionary/src/dictionary.h

@@ -32,7 +32,7 @@ class Dictionary {
 public:
     Dictionary(void *dict, int typedLetterMultipler, int fullWordMultiplier);
     int getSuggestions(int *codes, int codesSize, unsigned short *outWords, int *frequencies,
-        int maxWordLength, int maxWords, int maxAlternatives);
+        int maxWordLength, int maxWords, int maxAlternatives, int skipPos);
     bool isValidWord(unsigned short *word, int length);
     void setAsset(void *asset) { mAsset = asset; }
     void *getAsset() { return mAsset; }
@@ -66,6 +66,7 @@ private:
     int mInputLength;
     int mMaxAlternatives;
     unsigned short mWord[128];
+    int mSkipPos;
 
     int mFullWordMultiplier;
     int mTypedLetterMultiplier;

src/com/android/inputmethod/latin/BinaryDictionary.java

@@ -32,6 +32,7 @@ public class BinaryDictionary extends Dictionary {
     private static final int MAX_WORDS = 16;
 
     private static final int TYPED_LETTER_MULTIPLIER = 2;
+    private static final boolean ENABLE_MISSED_CHARACTERS = true;
 
     private int mNativeDict;
     private int[] mInputCodes = new int[MAX_WORD_LENGTH * MAX_ALTERNATIVES];
@@ -64,7 +65,7 @@ public class BinaryDictionary extends Dictionary {
     private native boolean isValidWordNative(int nativeData, char[] word, int wordLength);
     private native int getSuggestionsNative(int dict, int[] inputCodes, int codesSize, 
             char[] outputChars, int[] frequencies,
-            int maxWordLength, int maxWords, int maxAlternatives);
+            int maxWordLength, int maxWords, int maxAlternatives, int skipPos);
     private native void setParamsNative(int typedLetterMultiplier,
             int fullWordMultiplier);
 
@@ -88,9 +89,24 @@ public class BinaryDictionary extends Dictionary {
                     Math.min(alternatives.length, MAX_ALTERNATIVES));
         }
         Arrays.fill(mOutputChars, (char) 0);
+        Arrays.fill(mFrequencies, 0);
 
-        int count = getSuggestionsNative(mNativeDict, mInputCodes, codesSize, mOutputChars, mFrequencies,
+        int count = getSuggestionsNative(mNativeDict, mInputCodes, codesSize,
-                MAX_WORD_LENGTH, MAX_WORDS, MAX_ALTERNATIVES);
+                mOutputChars, mFrequencies,
+                MAX_WORD_LENGTH, MAX_WORDS, MAX_ALTERNATIVES, -1);
+
+        // If there aren't sufficient suggestions, search for words by allowing wild cards at
+        // the different character positions. This feature is not ready for prime-time as we need
+        // to figure out the best ranking for such words compared to proximity corrections and
+        // completions.
+        if (ENABLE_MISSED_CHARACTERS && count < 5) {
+            for (int skip = 0; skip < codesSize; skip++) {
+                count = getSuggestionsNative(mNativeDict, mInputCodes, codesSize,
+                        mOutputChars, mFrequencies,
+                        MAX_WORD_LENGTH, MAX_WORDS, MAX_ALTERNATIVES, skip);
+                if (count > 0) break;
+            }
+        }
 
         for (int j = 0; j < count; j++) {
             if (mFrequencies[j] < 1) break;
@@ -111,7 +127,7 @@ public class BinaryDictionary extends Dictionary {
         char[] chars = word.toString().toLowerCase().toCharArray();
         return isValidWordNative(mNativeDict, chars, chars.length);
     }
-    
+
     public synchronized void close() {
         if (mNativeDict != 0) {
             closeNative(mNativeDict);