Checking key edit distance of candidate words for gesture scoring. (a09f9709) · Commits · e / os / android_packages_inputmethods_LatinIME

native/jni/src/correction.cpp

+5 −42

Original line number	Original line	Diff line number	Diff line
	@@ -23,6 +23,8 @@
	#include "defines.h"		#include "defines.h"
	#include "proximity_info_state.h"		#include "proximity_info_state.h"
	#include "suggest_utils.h"		#include "suggest_utils.h"
			#include "suggest/policyimpl/utils/edit_distance.h"
			#include "suggest/policyimpl/utils/damerau_levenshtein_edit_distance_policy.h"

	namespace latinime {		namespace latinime {

	@@ -906,50 +908,11 @@ inline static bool isUpperCase(unsigned short c) {
	return totalFreq;		return totalFreq;
	}		}

	/* Damerau-Levenshtein distance */
	inline static int editDistanceInternal(int editDistanceTable, const int before,
	const int beforeLength, const int *after, const int afterLength) {
	// dp[li][lo] dp[a][b] = dp[ a * lo + b]
	int *dp = editDistanceTable;
	const int li = beforeLength + 1;
	const int lo = afterLength + 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 int ci = toBaseLowerCase(before[i]);
	const int co = toBaseLowerCase(after[j]);
	const int 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 == toBaseLowerCase(after[j - 1])
	&& co == toBaseLowerCase(before[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) {
	AKLOGI("IN = %d, OUT = %d", beforeLength, afterLength);
	for (int i = 0; i < li; ++i) {
	for (int j = 0; j < lo; ++j) {
	AKLOGI("EDIT[%d][%d], %d", i, j, dp[i * lo + j]);
	}
	}
	}
	return dp[li * lo - 1];
	}

	/* static / int Correction::RankingAlgorithm::editDistance(const int before,		/* static / int Correction::RankingAlgorithm::editDistance(const int before,
	const int beforeLength, const int *after, const int afterLength) {		const int beforeLength, const int *after, const int afterLength) {
	int table[(beforeLength + 1) * (afterLength + 1)];		const DamerauLevenshteinEditDistancePolicy daemaruLevenshtein(
	return editDistanceInternal(table, before, beforeLength, after, afterLength);		before, beforeLength, after, afterLength);
			return static_cast<int>(EditDistance::getEditDistance(&daemaruLevenshtein));
	}		}

native/jni/src/suggest/policyimpl/utils/damerau_levenshtein_edit_distance_policy.h

0 → 100644

+79 −0

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			/*
			* Copyright (C) 2013 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_DAEMARU_LEVENSHTEIN_EDIT_DISTANCE_POLICY_H
			#define LATINIME_DAEMARU_LEVENSHTEIN_EDIT_DISTANCE_POLICY_H

			#include "char_utils.h"
			#include "suggest/policyimpl/utils/edit_distance_policy.h"

			namespace latinime {

			class DamerauLevenshteinEditDistancePolicy : public EditDistancePolicy {
			public:
			DamerauLevenshteinEditDistancePolicy(const int *const string0, const int length0,
			const int *const string1, const int length1)
			: mString0(string0), mString0Length(length0), mString1(string1),
			mString1Length(length1) {}
			~DamerauLevenshteinEditDistancePolicy() {}

			AK_FORCE_INLINE float getSubstitutionCost(const int index0, const int index1) const {
			const int c0 = toBaseLowerCase(mString0[index0]);
			const int c1 = toBaseLowerCase(mString1[index1]);
			return (c0 == c1) ? 0.0f : 1.0f;
			}

			AK_FORCE_INLINE float getDeletionCost(const int index0, const int index1) const {
			return 1.0f;
			}

			AK_FORCE_INLINE float getInsertionCost(const int index0, const int index1) const {
			return 1.0f;
			}

			AK_FORCE_INLINE bool allowTransposition(const int index0, const int index1) const {
			const int c0 = toBaseLowerCase(mString0[index0]);
			const int c1 = toBaseLowerCase(mString1[index1]);
			if (index0 > 0 && index1 > 0 && c0 == toBaseLowerCase(mString1[index1 - 1])
			&& c1 == toBaseLowerCase(mString0[index0 - 1])) {
			return true;
			}
			return false;
			}

			AK_FORCE_INLINE float getTranspositionCost(const int index0, const int index1) const {
			return getSubstitutionCost(index0, index1);
			}

			AK_FORCE_INLINE int getString0Length() const {
			return mString0Length;
			}

			AK_FORCE_INLINE int getString1Length() const {
			return mString1Length;
			}

			private:
			DISALLOW_COPY_AND_ASSIGN (DamerauLevenshteinEditDistancePolicy);

			const int *const mString0;
			const int mString0Length;
			const int *const mString1;
			const int mString1Length;
			};
			} // namespace latinime

			#endif // LATINIME_DAEMARU_LEVENSHTEIN_EDIT_DISTANCE_POLICY_H

native/jni/src/suggest/policyimpl/utils/edit_distance.h

0 → 100644

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			/*
			* Copyright (C) 2013 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_EDIT_DISTANCE_H
			#define LATINIME_EDIT_DISTANCE_H

			#include "defines.h"
			#include "suggest/policyimpl/utils/edit_distance_policy.h"

			namespace latinime {

			class EditDistance {
			public:
			// CAVEAT: There may be performance penalty if you need the edit distance as an integer value.
			AK_FORCE_INLINE static float getEditDistance(const EditDistancePolicy *const policy) {
			const int beforeLength = policy->getString0Length();
			const int afterLength = policy->getString1Length();
			float dp[(beforeLength + 1) * (afterLength + 1)];
			for (int i = 0; i <= beforeLength; ++i) {
			dp[(afterLength + 1) * i] = i * policy->getInsertionCost(i - 1, -1);
			}
			for (int i = 0; i <= afterLength; ++i) {
			dp[i] = i * policy->getDeletionCost(-1, i - 1);
			}

			for (int i = 0; i < beforeLength; ++i) {
			for (int j = 0; j < afterLength; ++j) {
			dp[(afterLength + 1) * (i + 1) + (j + 1)] = min(
			dp[(afterLength + 1) * i + (j + 1)] + policy->getInsertionCost(i, j),
			min(dp[(afterLength + 1) * (i + 1) + j] + policy->getDeletionCost(i, j),
			dp[(afterLength + 1) * i + j]
			+ policy->getSubstitutionCost(i, j)));
			if (policy->allowTransposition(i, j)) {
			dp[(afterLength + 1) * (i + 1) + (j + 1)] = min(
			dp[(afterLength + 1) * (i + 1) + (j + 1)],
			dp[(afterLength + 1) * (i - 1) + (j - 1)]
			+ policy->getTranspositionCost(i, j));
			}
			}
			}
			if (DEBUG_EDIT_DISTANCE) {
			AKLOGI("IN = %d, OUT = %d", beforeLength, afterLength);
			for (int i = 0; i < beforeLength + 1; ++i) {
			for (int j = 0; j < afterLength + 1; ++j) {
			AKLOGI("EDIT[%d][%d], %f", i, j, dp[(afterLength + 1) * i + j]);
			}
			}
			}
			return dp[(beforeLength + 1) * (afterLength + 1) - 1];
			}

			private:
			DISALLOW_IMPLICIT_CONSTRUCTORS(EditDistance);
			};
			} // namespace latinime

			#endif // LATINIME_EDIT_DISTANCE_H

native/jni/src/suggest/policyimpl/utils/edit_distance_policy.h

0 → 100644

+43 −0

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			/*
			* Copyright (C) 2013 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_EDIT_DISTANCE_POLICY_H
			#define LATINIME_EDIT_DISTANCE_POLICY_H

			#include "defines.h"

			namespace latinime {

			class EditDistancePolicy {
			public:
			virtual float getSubstitutionCost(const int index0, const int index1) const = 0;
			virtual float getDeletionCost(const int index0, const int index1) const = 0;
			virtual float getInsertionCost(const int index0, const int index1) const = 0;
			virtual bool allowTransposition(const int index0, const int index1) const = 0;
			virtual float getTranspositionCost(const int index0, const int index1) const = 0;
			virtual int getString0Length() const = 0;
			virtual int getString1Length() const = 0;

			protected:
			EditDistancePolicy() {}
			virtual ~EditDistancePolicy() {}

			private:
			DISALLOW_COPY_AND_ASSIGN(EditDistancePolicy);
			};
			} // namespace latinime

			#endif // LATINIME_EDIT_DISTANCE_POLICY_H