Add util method in ngramcontext for context array

Change-Id: I2e3e2ac7706be50ed2055b0c69b30e25a516a879
main
Jatin Matani 2015-03-03 13:08:06 -08:00
parent ddee491450
commit a568e0acb4
2 changed files with 65 additions and 0 deletions

View File

@ -146,6 +146,32 @@ public class NgramContext {
: TextUtils.join(CONTEXT_SEPARATOR, terms);
}
/**
* Extracts the previous words context.
*
* @return a String array with the previous words.
*/
public String[] extractPrevWordsContextArray() {
final ArrayList<String> prevTermList = new ArrayList<>();
for (int i = mPrevWordsInfo.length - 1; i >= 0; --i) {
if (mPrevWordsInfo[i] != null && mPrevWordsInfo[i].isValid()) {
final NgramContext.WordInfo wordInfo = mPrevWordsInfo[i];
if (wordInfo.mIsBeginningOfSentence) {
prevTermList.add(BEGINNING_OF_SENTENCE_TAG);
} else {
final String term = wordInfo.mWord.toString();
if (!term.isEmpty()) {
prevTermList.add(term);
}
}
}
}
final String[] contextStringArray = prevTermList.size() == 0 ?
new String[] { BEGINNING_OF_SENTENCE_TAG }
: prevTermList.toArray(new String[prevTermList.size()]);
return contextStringArray;
}
public boolean isValid() {
return mPrevWordsCount > 0 && mPrevWordsInfo[0].isValid();
}

View File

@ -64,4 +64,43 @@ public class NgramContextTests extends AndroidTestCase {
ngramContext_b_a.getNextNgramContext(new WordInfo("c"));
assertEquals("c", ngramContext_c_bos.getNthPrevWord(1));
}
public void testExtractPrevWordsContextTest() {
final NgramContext ngramContext_bos =
new NgramContext(WordInfo.BEGINNING_OF_SENTENCE_WORD_INFO);
assertEquals("<S>", ngramContext_bos.extractPrevWordsContext());
final NgramContext ngramContext_a = new NgramContext(new WordInfo("a"));
final NgramContext ngramContext_b_a =
ngramContext_a.getNextNgramContext(new WordInfo("b"));
assertEquals("b", ngramContext_b_a.getNthPrevWord(1));
assertEquals("a", ngramContext_b_a.getNthPrevWord(2));
assertEquals("a b", ngramContext_b_a.extractPrevWordsContext());
final NgramContext ngramContext_bos_b =
ngramContext_b_a.getNextNgramContext(WordInfo.BEGINNING_OF_SENTENCE_WORD_INFO);
assertTrue(ngramContext_bos_b.isBeginningOfSentenceContext());
assertEquals("b", ngramContext_bos_b.getNthPrevWord(2));
assertEquals("a b <S>", ngramContext_bos_b.extractPrevWordsContext());
}
public void testExtractPrevWordsContextArray() {
final NgramContext ngramContext_bos =
new NgramContext(WordInfo.BEGINNING_OF_SENTENCE_WORD_INFO);
assertEquals("<S>", ngramContext_bos.extractPrevWordsContext());
final NgramContext ngramContext_a = new NgramContext(new WordInfo("a"));
final NgramContext ngramContext_b_a =
ngramContext_a.getNextNgramContext(new WordInfo("b"));
assertEquals("b", ngramContext_b_a.getNthPrevWord(1));
assertEquals("a", ngramContext_b_a.getNthPrevWord(2));
assertEquals("a", ngramContext_b_a.extractPrevWordsContextArray()[0]);
assertEquals("b", ngramContext_b_a.extractPrevWordsContextArray()[1]);
final NgramContext ngramContext_bos_b =
ngramContext_b_a.getNextNgramContext(WordInfo.BEGINNING_OF_SENTENCE_WORD_INFO);
assertTrue(ngramContext_bos_b.isBeginningOfSentenceContext());
assertEquals("b", ngramContext_bos_b.getNthPrevWord(2));
assertEquals("a", ngramContext_bos_b.extractPrevWordsContextArray()[0]);
assertEquals("b", ngramContext_bos_b.extractPrevWordsContextArray()[1]);
assertEquals("<S>", ngramContext_bos_b.extractPrevWordsContextArray()[2]);
}
}