/// <summary>
/// Instantiates the current synset. If idSynset is non-null, related synsets references are set to those from
/// idSynset; otherwise, related synsets are created as shells.
/// </summary>
/// <param name="definition">Definition line of synset from data file</param>
/// <param name="idSynset">Lookup for related synsets. If null, all related synsets will be created as shells.</param>
internal void Instantiate(string definition, Dictionary <string, SynSet> idSynset)
{
// don't re-instantiate
if (Instantiated)
{
throw new Exception("Synset has already been instantiated");
}
/* get lexicographer file name...the enumeration lines up precisely with the wordnet spec (see the lexnames file) except that
* it starts with None, so we need to add 1 to the definition line's value to get the correct file name */
int lexicographerFileNumber = int.Parse(GetField(definition, 1)) + 1;
if (lexicographerFileNumber <= 0)
{
throw new Exception("Invalid lexicographer file name number. Should be >= 1.");
}
LexicographerFileName = (LexicographerFileName)lexicographerFileNumber;
// get number of words in the synset and the start character of the word list
int numWords = int.Parse(GetField(definition, 3, out int wordStart), NumberStyles.HexNumber);
wordStart = definition.IndexOf(' ', wordStart) + 1;
// get words in synset
Words = new List <string>(numWords);
for (int i = 0; i < numWords; ++i)
{
int wordEnd = definition.IndexOf(' ', wordStart + 1) - 1;
int wordLen = wordEnd - wordStart + 1;
string word = definition.Substring(wordStart, wordLen);
if (word.Contains(' '))
{
throw new Exception("Unexpected space in word: " + word);
}
Words.Add(word);
// skip lex_id field
wordStart = definition.IndexOf(' ', wordEnd + 2) + 1;
}
// get gloss
Gloss = definition.Substring(definition.IndexOf('|') + 1).Trim();
if (Gloss.Contains('|'))
{
throw new Exception("Unexpected pipe in gloss");
}
// get number and start of relations
int relationCountField = 3 + Words.Count * 2 + 1;
int numRelations = int.Parse(GetField(definition, relationCountField, out int relationFieldStart));
relationFieldStart = definition.IndexOf(' ', relationFieldStart) + 1;
// grab each related synset
relationSynSets = new Dictionary <SynSetRelation, List <SynSet> >();
lexicalRelations =
new Dictionary <SynSetRelation, Dictionary <SynSet, Dictionary <int, List <int> > > >();
for (int relationNum = 0; relationNum < numRelations; ++relationNum)
{
string relationSymbol = null;
int relatedSynSetOffset = -1;
WordType relatedSynSetPOS = WordType.Unknown;
int sourceWordIndex = -1;
int targetWordIndex = -1;
// each relation has four columns
for (int relationField = 0; relationField <= 3; ++relationField)
{
int fieldEnd = definition.IndexOf(' ', relationFieldStart + 1) - 1;
int fieldLen = fieldEnd - relationFieldStart + 1;
string fieldValue = definition.Substring(relationFieldStart, fieldLen);
// relation symbol
if (relationField == 0)
{
relationSymbol = fieldValue;
}
// related synset offset
else if (relationField == 1)
{
relatedSynSetOffset = int.Parse(fieldValue);
}
// related synset POS
else if (relationField == 2)
{
relatedSynSetPOS = GetPOS(fieldValue);
}
// source/target word for lexical relation
else if (relationField == 3)
{
sourceWordIndex = int.Parse(fieldValue.Substring(0, 2), NumberStyles.HexNumber);
targetWordIndex = int.Parse(fieldValue.Substring(2), NumberStyles.HexNumber);
}
else
{
throw new Exception();
}
relationFieldStart = definition.IndexOf(' ', relationFieldStart + 1) + 1;
}
// get related synset...create shell if we don't have a lookup
SynSet relatedSynSet;
if (idSynset == null)
{
relatedSynSet = new SynSet(relatedSynSetPOS, relatedSynSetOffset);
}
// look up related synset directly
else
{
relatedSynSet = idSynset[relatedSynSetPOS + ":" + relatedSynSetOffset];
}
// get relation
SynSetRelation relation = WordNetEngine.GetSynSetRelation(POS, relationSymbol);
// add semantic relation if we have neither a source nor a target word index
if (sourceWordIndex == 0 &&
targetWordIndex == 0)
{
var list = relationSynSets.GetItemCreate(relation);
list.Add(relatedSynSet);
}
// add lexical relation
else
{
var itemRelation = lexicalRelations.GetItemCreate(relation);
var itemRelatedSynSet = itemRelation.GetItemCreate(relatedSynSet);
var itemSourceWordIndex = itemRelatedSynSet.GetItemCreate(sourceWordIndex);
if (!itemSourceWordIndex.Contains(targetWordIndex))
{
itemSourceWordIndex.Add(targetWordIndex);
}
}
}
Instantiated = true;
}
private void Load()
{
if (!Directory.Exists(WordNetDirectory))
{
throw new DirectoryNotFoundException("Non-existent WordNet directory: " + WordNetDirectory);
}
// get data and index paths
string[] dataPaths =
{
Path.Combine(WordNetDirectory, "data.adj"),
Path.Combine(WordNetDirectory, "data.adv"),
Path.Combine(WordNetDirectory, "data.noun"),
Path.Combine(WordNetDirectory, "data.verb")
};
string[] indexPaths = new[]
{
Path.Combine(WordNetDirectory, "index.adj"),
Path.Combine(WordNetDirectory, "index.adv"),
Path.Combine(WordNetDirectory, "index.noun"),
Path.Combine(WordNetDirectory, "index.verb")
};
// make sure all files exist
foreach (string path in dataPaths.Union(indexPaths))
{
if (!File.Exists(path))
{
throw new FileNotFoundException("Failed to find WordNet file: " + path);
}
}
string sortFlagPath = Path.Combine(WordNetDirectory, ".sorted_for_dot_net");
if (!File.Exists(sortFlagPath))
{
/* make sure the index files are sorted according to the current sort order. the index files in the
* wordnet distribution are sorted in the order needed for (presumably) the java api, which uses
* a different sort order than the .net runtime. thus, unless we resort the lines in the index
* files, we won't be able to do a proper binary search over the data. */
foreach (string indexPath in indexPaths)
{
// create temporary file for sorted lines
string tempPath = Path.GetTempFileName();
using (StreamWriter tempFile = new StreamWriter(tempPath))
{
// get number of words (lines) in file
int numWords = 0;
using (TextReader indexFile = new StreamReader(indexPath))
{
string line;
while ((line = indexFile.ReadLine()) != null)
{
if (!line.StartsWith(" "))
{
++numWords;
}
}
}
// get lines in file, sorted by first column (i.e., the word)
Dictionary <string, string> wordLine = new Dictionary <string, string>(numWords, StringComparer.OrdinalIgnoreCase);
using (StreamReader indexFile = new StreamReader(indexPath))
{
string line;
while ((line = indexFile.ReadLine()) != null)
{
// write header lines to temp file immediately
if (line.StartsWith(" "))
{
tempFile.WriteLine(line);
}
else
{
// trim useless blank spaces from line and map line to first column
line = line.Trim();
wordLine.Add(line.Substring(0, line.IndexOf(' ')), line);
}
}
}
// get sorted words
List <string> sortedWords = new List <string>(wordLine.Count);
sortedWords.AddRange(wordLine.Keys);
sortedWords.Sort();
// write lines sorted by word
foreach (string word in sortedWords)
{
tempFile.WriteLine(wordLine[word]);
}
tempFile.Close();
}
// replace original index file with properly sorted one
File.Delete(indexPath);
File.Move(tempPath, indexPath);
}
// create flag file, indicating that we've sorted the data
using (StreamWriter sortFlagFile = new StreamWriter(sortFlagPath))
{
sortFlagFile.WriteLine(
"This file serves no purpose other than to indicate that the WordNet distribution data in the current directory has been sorted for use by the .NET API.");
sortFlagFile.Close();
}
}
// pass 1: get total number of synsets
int totalSynsets = 0;
foreach (string dataPath in dataPaths)
{
// scan synset data file for lines that don't start with a space...these are synset definition lines
using (StreamReader dataFile = new StreamReader(dataPath))
{
string line;
while ((line = dataFile.ReadLine()) != null)
{
int firstSpace = line.IndexOf(' ');
if (firstSpace > 0)
{
++totalSynsets;
}
}
}
}
// pass 2: create synset shells (pos and offset only)
idSynset = new Dictionary <string, SynSet>(totalSynsets, StringComparer.OrdinalIgnoreCase);
foreach (string dataPath in dataPaths)
{
WordType pos = GetFilePOS(dataPath);
// scan synset data file
using (StreamReader dataFile = new StreamReader(dataPath))
{
string line;
while ((line = dataFile.ReadLine()) != null)
{
int firstSpace = line.IndexOf(' ');
if (firstSpace > 0)
{
// get offset and create synset shell
int offset = int.Parse(line.Substring(0, firstSpace));
SynSet synset = new SynSet(pos, offset);
idSynset.Add(synset.ID, synset);
}
}
}
}
// pass 3: instantiate synsets (hooks up relations, set glosses, etc.)
foreach (string dataPath in dataPaths)
{
WordType pos = GetFilePOS(dataPath);
// scan synset data file
using (StreamReader dataFile = new StreamReader(dataPath))
{
string line;
while ((line = dataFile.ReadLine()) != null)
{
int firstSpace = line.IndexOf(' ');
if (firstSpace > 0)
{
// instantiate synset defined on current line, using the instantiated synsets for all references
idSynset[pos + ":" + int.Parse(line.Substring(0, firstSpace))].Instantiate(line, idSynset);
}
}
}
}
// organize synsets by pos and words...also set most common synset for word-pos pairs that have multiple synsets
posWordSynSets = new Dictionary <WordType, Dictionary <string, List <SynSet> > >();
foreach (string indexPath in indexPaths)
{
WordType pos = GetFilePOS(indexPath);
posWordSynSets.GetItemCreate(pos);
// scan word index file, skipping header lines
using (StreamReader indexFile = new StreamReader(indexPath))
{
string line;
while ((line = indexFile.ReadLine()) != null)
{
int firstSpace = line.IndexOf(' ');
if (firstSpace > 0)
{
// grab word and synset shells, along with the most common synset
string word = line.Substring(0, firstSpace);
List <SynSet> synsets = GetSynSetShells(line, pos, out SynSet mostCommonSynSet);
// set flag on most common synset if it's ambiguous
if (synsets.Count > 1)
{
idSynset[mostCommonSynSet.ID].SetAsMostCommonSynsetFor(word);
}
// use reference to the synsets that we instantiated in our three-pass routine above
posWordSynSets[pos].Add(word, new List <SynSet>(synsets.Count));
foreach (SynSet synset in synsets)
{
posWordSynSets[pos][word].Add(idSynset[synset.ID]);
}
}
}
}
}
}
/// <summary>
/// Gets the shortest path from the current synset to another, following the given synset relations.
/// </summary>
/// <param name="destination">Destination synset</param>
/// <param name="relations">Relations to follow, or null for all relations.</param>
/// <returns>Synset path, or null if none exists.</returns>
public List <SynSet> GetShortestPathTo(SynSet destination, IEnumerable <SynSetRelation> relations)
{
if (relations == null)
{
relations = Enum.GetValues(typeof(SynSetRelation)) as SynSetRelation[];
}
// make sure the backpointer on the current synset is null - can't predict what other functions might do
SearchBackPointer = null;
// avoid cycles
List <SynSet> synsetsEncountered = new List <SynSet>();
synsetsEncountered.Add(this);
// start search queue
Queue <SynSet> searchQueue = new Queue <SynSet>();
searchQueue.Enqueue(this);
// run search
List <SynSet> path = null;
while (searchQueue.Count > 0 &&
path == null)
{
SynSet currSynSet = searchQueue.Dequeue();
// see if we've finished the search
if (currSynSet == destination)
{
// gather synsets along path
path = new List <SynSet>();
while (currSynSet != null)
{
path.Add(currSynSet);
currSynSet = currSynSet.SearchBackPointer;
}
// reverse for the correct order
path.Reverse();
}
// expand the search one level
else
{
foreach (SynSet synset in currSynSet.GetRelatedSynSets(relations, false))
{
if (!synsetsEncountered.Contains(synset))
{
synset.SearchBackPointer = currSynSet;
searchQueue.Enqueue(synset);
synsetsEncountered.Add(synset);
}
}
}
}
// null-out all search backpointers
foreach (SynSet synset in synsetsEncountered)
{
synset.SearchBackPointer = null;
}
return(path);
}
/// <summary>
/// Gets synset shells from a word index line. A synset shell is an instance of SynSet with only the POS and Offset
/// members initialized. These members are enough to look up the full synset within the corresponding data file. This
/// method is static to prevent inadvertent references to a current WordNetEngine, which should be passed via the
/// corresponding parameter.
/// </summary>
/// <param name="wordIndexLine">Word index line from which to get synset shells</param>
/// <param name="pos">POS of the given index line</param>
/// <param name="mostCommonSynSet">Returns the most common synset for the word</param>
/// <returns>Synset shells for the given index line</returns>
private static List <SynSet> GetSynSetShells(string wordIndexLine, WordType pos, out SynSet mostCommonSynSet)
{
List <SynSet> synsets = new List <SynSet>();
mostCommonSynSet = null;
// get number of synsets
string[] parts = wordIndexLine.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries);
int numSynSets = int.Parse(parts[2]);
// grab each synset shell, from last to first
int firstOffsetIndex = parts.Length - numSynSets;
for (int i = parts.Length - 1; i >= firstOffsetIndex; --i)
{
// create synset
int offset = int.Parse(parts[i]);
// add synset to collection
SynSet synset = new SynSet(pos, offset);
synsets.Add(synset);
// if this is the last synset offset to get (since we grabbed them in reverse order), record it as the most common synset
if (i == firstOffsetIndex)
{
mostCommonSynSet = synset;
}
}
if (mostCommonSynSet == null)
{
throw new Exception("Failed to get most common synset");
}
return(synsets);
}
