diff --git a/native/src/correction.cpp b/native/src/correction.cpp
index 31493ee7d..0c566802c 100644
--- a/native/src/correction.cpp
+++ b/native/src/correction.cpp
@@ -27,6 +27,87 @@
namespace latinime {
+/////////////////////////////
+// edit distance funcitons //
+/////////////////////////////
+
+#if 0 /* no longer used */
+inline static int editDistance(
+ int* editDistanceTable, const unsigned short* input,
+ const int inputLength, const unsigned short* output, const int outputLength) {
+ // dp[li][lo] dp[a][b] = dp[ a * lo + b]
+ int* dp = editDistanceTable;
+ const int li = inputLength + 1;
+ const int lo = outputLength + 1;
+ for (int i = 0; i < li; ++i) {
+ dp[lo * i] = i;
+ }
+ for (int i = 0; i < lo; ++i) {
+ dp[i] = i;
+ }
+
+ for (int i = 0; i < li - 1; ++i) {
+ for (int j = 0; j < lo - 1; ++j) {
+ const uint32_t ci = Dictionary::toBaseLowerCase(input[i]);
+ const uint32_t co = Dictionary::toBaseLowerCase(output[j]);
+ const uint16_t cost = (ci == co) ? 0 : 1;
+ dp[(i + 1) * lo + (j + 1)] = min(dp[i * lo + (j + 1)] + 1,
+ min(dp[(i + 1) * lo + j] + 1, dp[i * lo + j] + cost));
+ if (i > 0 && j > 0 && ci == Dictionary::toBaseLowerCase(output[j - 1])
+ && co == Dictionary::toBaseLowerCase(input[i - 1])) {
+ dp[(i + 1) * lo + (j + 1)] = min(
+ dp[(i + 1) * lo + (j + 1)], dp[(i - 1) * lo + (j - 1)] + cost);
+ }
+ }
+ }
+
+ if (DEBUG_EDIT_DISTANCE) {
+ LOGI("IN = %d, OUT = %d", inputLength, outputLength);
+ for (int i = 0; i < li; ++i) {
+ for (int j = 0; j < lo; ++j) {
+ LOGI("EDIT[%d][%d], %d", i, j, dp[i * lo + j]);
+ }
+ }
+ }
+ return dp[li * lo - 1];
+}
+#endif
+
+inline static void initEditDistance(int *editDistanceTable) {
+ for (int i = 0; i <= MAX_WORD_LENGTH_INTERNAL; ++i) {
+ editDistanceTable[i] = i;
+ }
+}
+
+inline static void calcEditDistanceOneStep(int *editDistanceTable, const unsigned short *input,
+ const int inputLength, const unsigned short *output, const int outputLength) {
+ // Let dp[i][j] be editDistanceTable[i * (inputLength + 1) + j].
+ // Assuming that dp[0][0] ... dp[outputLength - 1][inputLength] are already calculated,
+ // and calculate dp[ouputLength][0] ... dp[outputLength][inputLength].
+ int *const current = editDistanceTable + outputLength * (inputLength + 1);
+ const int *const prev = editDistanceTable + (outputLength - 1) * (inputLength + 1);
+ const int *const prevprev =
+ outputLength >= 2 ? editDistanceTable + (outputLength - 2) * (inputLength + 1) : NULL;
+ current[0] = outputLength;
+ const uint32_t co = Dictionary::toBaseLowerCase(output[outputLength - 1]);
+ const uint32_t prevCO =
+ outputLength >= 2 ? Dictionary::toBaseLowerCase(output[outputLength - 2]) : 0;
+ for (int i = 1; i <= inputLength; ++i) {
+ const uint32_t ci = Dictionary::toBaseLowerCase(input[i - 1]);
+ const uint16_t cost = (ci == co) ? 0 : 1;
+ current[i] = min(current[i - 1] + 1, min(prev[i] + 1, prev[i - 1] + cost));
+ if (i >= 2 && prevprev && ci == prevCO
+ && co == Dictionary::toBaseLowerCase(input[i - 2])) {
+ current[i] = min(current[i], prevprev[i - 2] + 1);
+ }
+ }
+}
+
+inline static int getCurrentEditDistance(
+ int *editDistanceTable, const int inputLength, const int outputLength) {
+ return editDistanceTable[(inputLength + 1) * (outputLength + 1) - 1];
+}
+
//////////////////////
// inline functions //
//////////////////////
@@ -43,6 +124,7 @@ inline bool Correction::isQuote(const unsigned short c) {
Correction::Correction(const int typedLetterMultiplier, const int fullWordMultiplier)
: TYPED_LETTER_MULTIPLIER(typedLetterMultiplier), FULL_WORD_MULTIPLIER(fullWordMultiplier) {
+ initEditDistance(mEditDistanceTable);
}
void Correction::initCorrection(const ProximityInfo *pi, const int inputLength,
@@ -197,13 +279,21 @@ void Correction::startToTraverseAllNodes() {
}
bool Correction::needsToPrune() const {
+ // TODO: use edit distance here
return mOutputIndex - 1 >= mMaxDepth || mProximityCount > mMaxEditDistance;
}
+void Correction::addCharToCurrentWord(const int32_t c) {
+ mWord[mOutputIndex] = c;
+ const unsigned short *primaryInputWord = mProximityInfo->getPrimaryInputWord();
+ calcEditDistanceOneStep(mEditDistanceTable, primaryInputWord, mInputLength,
+ mWord, mOutputIndex + 1);
+}
+
// TODO: inline?
Correction::CorrectionType Correction::processSkipChar(
const int32_t c, const bool isTerminal, const bool inputIndexIncremented) {
- mWord[mOutputIndex] = c;
+ addCharToCurrentWord(c);
if (needsToTraverseAllNodes() && isTerminal) {
mTerminalInputIndex = mInputIndex - (inputIndexIncremented ? 1 : 0);
mTerminalOutputIndex = mOutputIndex;
@@ -412,7 +502,7 @@ Correction::CorrectionType Correction::processCharAndCalcState(
mProximityInfo->getNormalizedSquaredDistance(mInputIndex, proximityIndex);
}
- mWord[mOutputIndex] = c;
+ addCharToCurrentWord(c);
// 4. Last char excessive correction
mLastCharExceeded = mExcessiveCount == 0 && mSkippedCount == 0 && mTransposedCount == 0
@@ -526,47 +616,6 @@ inline static bool isUpperCase(unsigned short c) {
return false;
}
-/* static */
-inline static int editDistance(
- int* editDistanceTable, const unsigned short* input,
- const int inputLength, const unsigned short* output, const int outputLength) {
- // dp[li][lo] dp[a][b] = dp[ a * lo + b]
- int* dp = editDistanceTable;
- const int li = inputLength + 1;
- const int lo = outputLength + 1;
- for (int i = 0; i < li; ++i) {
- dp[lo * i] = i;
- }
- for (int i = 0; i < lo; ++i) {
- dp[i] = i;
- }
-
- for (int i = 0; i < li - 1; ++i) {
- for (int j = 0; j < lo - 1; ++j) {
- const uint32_t ci = Dictionary::toBaseLowerCase(input[i]);
- const uint32_t co = Dictionary::toBaseLowerCase(output[j]);
- const uint16_t cost = (ci == co) ? 0 : 1;
- dp[(i + 1) * lo + (j + 1)] = min(dp[i * lo + (j + 1)] + 1,
- min(dp[(i + 1) * lo + j] + 1, dp[i * lo + j] + cost));
- if (i > 0 && j > 0 && ci == Dictionary::toBaseLowerCase(output[j - 1])
- && co == Dictionary::toBaseLowerCase(input[i - 1])) {
- dp[(i + 1) * lo + (j + 1)] = min(
- dp[(i + 1) * lo + (j + 1)], dp[(i - 1) * lo + (j - 1)] + cost);
- }
- }
- }
-
- if (DEBUG_EDIT_DISTANCE) {
- LOGI("IN = %d, OUT = %d", inputLength, outputLength);
- for (int i = 0; i < li; ++i) {
- for (int j = 0; j < lo; ++j) {
- LOGI("EDIT[%d][%d], %d", i, j, dp[i * lo + j]);
- }
- }
- }
- return dp[li * lo - 1];
-}
-
//////////////////////
// RankingAlgorithm //
//////////////////////
@@ -612,9 +661,7 @@ int Correction::RankingAlgorithm::calculateFinalFreq(const int inputIndex, const
// TODO: Optimize this.
// TODO: Ignoring edit distance for transposed char, for now
if (transposedCount == 0 && (proximityMatchedCount > 0 || skipped || excessiveCount > 0)) {
- const unsigned short* primaryInputWord = proximityInfo->getPrimaryInputWord();
- ed = editDistance(editDistanceTable, primaryInputWord,
- inputLength, word, outputIndex + 1);
+ ed = getCurrentEditDistance(editDistanceTable, inputLength, outputIndex + 1);
const int matchWeight = powerIntCapped(typedLetterMultiplier,
max(inputLength, outputIndex + 1) - ed);
multiplyIntCapped(matchWeight, &finalFreq);
diff --git a/native/src/correction.h b/native/src/correction.h
index 437ef77f4..d4e99f0ce 100644
--- a/native/src/correction.h
+++ b/native/src/correction.h
@@ -102,6 +102,7 @@ private:
inline bool isQuote(const unsigned short c);
inline CorrectionType processSkipChar(
const int32_t c, const bool isTerminal, const bool inputIndexIncremented);
+ inline void addCharToCurrentWord(const int32_t c);
const int TYPED_LETTER_MULTIPLIER;
const int FULL_WORD_MULTIPLIER;