public void EditDistance_SingleInsertionAtStartAndMiddle_2()
{
int editDistance = ApproximateMatcher.EditDistance("abo", "habho", 2, false);
Assert.AreEqual(2, editDistance);
}
public void EditDistance_SingleInsertionAtStartAndMiddle_1Max_EditDistanceLargerThanMax()
{
int editDistance = ApproximateMatcher.EditDistance("abo", "habho", 1, false);
Assert.AreEqual(ApproximateMatcher.EditDistanceLargerThanMax, editDistance);
}
public void EditDistance_SingleInsertionAtEnd_1()
{
int editDistance = ApproximateMatcher.EditDistance("abo", "aboh", 1, false);
Assert.AreEqual(1, editDistance);
}
public void EditDistance_Same_0()
{
int editDistance = ApproximateMatcher.EditDistance("abo", "abo", 0, false);
Assert.AreEqual(0, editDistance);
}
public int Compare(LanguageInfo x, LanguageInfo y)
{
if (x.LanguageTag == y.LanguageTag)
{
return(0);
}
if (!x.Names[0].Equals(y.Names[0], StringComparison.InvariantCultureIgnoreCase))
{
// Favor ones where some language matches to solve BL-1141
if (x.Names[0].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(-1);
}
if (y.Names[0].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(1);
}
if (x.Names.Count > 1 && x.Names[1].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(-1);
}
if (y.Names.Count > 1 && y.Names[1].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(1);
}
}
if (x.LanguageTag.Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(-1);
}
if (y.LanguageTag.Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(1);
}
if (IetfLanguageTag.GetLanguagePart(x.LanguageTag).Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(-1);
}
if (IetfLanguageTag.GetLanguagePart(y.LanguageTag).Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
{
return(1);
}
// Use the "editing distance" relative to the search string to sort by the primary name.
// (But we don't really care once the editing distance gets very large.)
// See https://silbloom.myjetbrains.com/youtrack/issue/BL-5847 for motivation.
// Timing tests indicate that 1) calculating these distances doesn't slow down the sorting noticeably
// and 2) caching these distances in a dictionary also doesn't speed up the sorting noticeably.
var xDistance = ApproximateMatcher.EditDistance(_lowerSearch, x.Names[0].ToLowerInvariant(), 25, false);
var yDistance = ApproximateMatcher.EditDistance(_lowerSearch, y.Names[0].ToLowerInvariant(), 25, false);
var distanceDiff = xDistance - yDistance;
if (distanceDiff != 0)
{
return(distanceDiff);
}
// If the editing distances for the primary names are the same, sort by the primary name.
int res = string.Compare(x.Names[0], y.Names[0], StringComparison.InvariantCultureIgnoreCase);
if (res != 0)
{
return(res);
}
return(string.Compare(x.LanguageTag, y.LanguageTag, StringComparison.InvariantCultureIgnoreCase));
}
/// <summary>
/// Sorting the languages for display is tricky: we want the most relevant languages at the
/// top of the list, so we can't simply sort alphabetically by language name or by language tag,
/// but need to take both items into account together with the current search string. Ordering
/// by relevance is clearly impossible since we'd have to read the user's mind and apply that
/// knowledge to the data. But the heuristics we use here may be better than nothing...
/// </summary>
public int Compare(LanguageInfo x, LanguageInfo y)
{
if (x.LanguageTag == y.LanguageTag)
return 0;
// Favor ones where some language name matches the search string to solve BL-1141
// We restrict this to the top 2 names of each language, and to cases where the
// corresponding names of the two languages are different. (If both language names
// match the search string, there's no good reason to favor one over the other!)
if (!x.Names[0].Equals(y.Names[0], StringComparison.InvariantCultureIgnoreCase))
{
if (x.Names[0].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
return -1;
if (y.Names[0].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
return 1;
}
else if (x.Names.Count == 1 || y.Names.Count == 1 || !x.Names[1].Equals(y.Names[1], StringComparison.InvariantCultureIgnoreCase))
{
// If we get here, x.Names[0] == y.Names[0]. If both equal the search string, then neither x.Names[1]
// nor y.Names[1] should equal the search string since the code adding to Names checks for redundancy.
// Also it's possible that neither x.Names[1] nor y.Names[1] exists at this point in the code, or that
// only one of them exists, or that both of them exist (in which case they are not equal).
if (x.Names.Count > 1 && x.Names[1].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
return -1;
if (y.Names.Count > 1 && y.Names[1].Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
return 1;
}
// Favor a language whose tag matches the search string exactly. (equal tags are handled above)
if (x.LanguageTag.Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
return -1;
if (y.LanguageTag.Equals(_searchString, StringComparison.InvariantCultureIgnoreCase))
return 1;
// written this way to avoid having to catch predictable exceptions as the user is typing
string xlanguage;
string ylanguage;
string script;
string region;
string variant;
var xtagParses = IetfLanguageTag.TryGetParts(x.LanguageTag, out xlanguage, out script, out region, out variant);
var ytagParses = IetfLanguageTag.TryGetParts(y.LanguageTag, out ylanguage, out script, out region, out variant);
var bothTagLanguagesMatchSearch = xtagParses && ytagParses && xlanguage == ylanguage &&
_searchString.Equals(xlanguage, StringComparison.InvariantCultureIgnoreCase);
if (!bothTagLanguagesMatchSearch)
{
// One of the tag language pieces may match the search string even though not both match. In that case,
// sort the matching language earlier in the list.
if (xtagParses && _searchString.Equals(xlanguage, StringComparison.InvariantCultureIgnoreCase))
return -1; // x.Tag's language part matches search string exactly, so sort it earlier in the list.
if (ytagParses && _searchString.Equals(ylanguage, StringComparison.InvariantCultureIgnoreCase))
return 1; // y.Tag's language part matches search string exactly, so sort it earlier in the list.
}
// If only one language has a name that is an exact match prefer that language
var xMatchingNameLoc = x.Names.IndexOf(l => _searchString.Equals(l, StringComparison.InvariantCultureIgnoreCase));
var yMatchingNameLoc = y.Names.IndexOf(l => _searchString.Equals(l, StringComparison.InvariantCultureIgnoreCase));
if (xMatchingNameLoc > 0 && yMatchingNameLoc < 0)
{
return -1;
}
if (yMatchingNameLoc > 0 && xMatchingNameLoc < 0)
{
return 1;
}
// Order the by country information for exact matches before dropping to editing distance
if (x.PrimaryCountry.ToLowerInvariant() == _lowerSearch || y.PrimaryCountry.ToLowerInvariant() == _lowerSearch)
{
if (x.PrimaryCountry.ToLowerInvariant() == _lowerSearch &&
y.PrimaryCountry.ToLowerInvariant() != _lowerSearch)
{
return -1;
}
if (y.PrimaryCountry.ToLowerInvariant() == _lowerSearch &&
x.PrimaryCountry.ToLowerInvariant() != _lowerSearch)
{
return 1;
}
// Both match the country exactly sort by language name
return string.Compare(x.Names[0], y.Names[0], StringComparison.InvariantCultureIgnoreCase);
}
// Editing distance to a language name is not useful when we've detected that the user appears to be
// typing a language tag in that both language tags match what the user has typed. (For example,
// it gives a strange and unwanted order to the variants of zh.) In such a case we just order the
// matching codes by length (already done) and then alphabetically by code, skipping the sort by
// editing distance to the language names.
if (!bothTagLanguagesMatchSearch)
{
// Use the "editing distance" relative to the search string to sort by the primary name.
// (But we don't really care once the editing distance gets very large.)
// See https://silbloom.myjetbrains.com/youtrack/issue/BL-5847 for motivation.
// Timing tests indicate that 1) calculating these distances doesn't slow down the sorting noticeably
// and 2) caching these distances in a dictionary also doesn't speed up the sorting noticeably.
var xDistance = ApproximateMatcher.EditDistance(_lowerSearch, x.Names[0].ToLowerInvariant(), 25, false);
var yDistance = ApproximateMatcher.EditDistance(_lowerSearch, y.Names[0].ToLowerInvariant(), 25, false);
var distanceDiff = xDistance - yDistance;
if (distanceDiff != 0)
return distanceDiff;
// If the editing distances for the primary names are the same, sort by the primary name.
int res = string.Compare(x.Names[0], y.Names[0], StringComparison.InvariantCultureIgnoreCase);
if (res != 0)
return res;
}
// Alphabetize by Language tag if 3 characters or less or if there is a hyphen after the first 2 or 3 chars
if (_lowerSearch.Length <= 3 || _lowerSearch.IndexOf('-') == 3 || _lowerSearch.IndexOf('-') == 4)
{
return string.Compare(x.LanguageTag, y.LanguageTag, StringComparison.InvariantCultureIgnoreCase);
}
// Otherwise alphabetize by the language name
// (tags often have a completely different alphabetical order from the name e.g. 'auc' -> "Waoroni")
return string.Compare(x.Names[0], y.Names[0], StringComparison.InvariantCultureIgnoreCase);
}
/// <summary>
/// Get an list of languages that match the given string in some way (code, name, country)
/// </summary>
public IEnumerable<LanguageInfo> SuggestLanguages(string searchString)
{
if (searchString != null)
searchString = searchString.Trim();
if (string.IsNullOrEmpty(searchString))
yield break;
if (searchString == "*")
{
// there will be duplicate LanguageInfo entries for 2 and 3 letter codes and equivalent tags
var all_languages = new HashSet<LanguageInfo>(_codeToLanguageIndex.Select(l => l.Value));
foreach (LanguageInfo languageInfo in all_languages.OrderBy(l => l, new ResultComparer(searchString)))
yield return languageInfo;
}
// if the search string exactly matches a hard-coded way to say "sign", show all the sign languages
// there will be duplicate LanguageInfo entries for equivalent tags
else if (new []{"sign", "sign language","signes", "langage des signes", "señas","lenguaje de señas"}.Contains(searchString.ToLowerInvariant()))
{
var parallelSearch = new HashSet<LanguageInfo>(_codeToLanguageIndex.AsParallel().Select(li => li.Value).Where(l =>
l.Names.AsQueryable().Any(n => n.ToLowerInvariant().Contains("sign"))));
foreach (LanguageInfo languageInfo in parallelSearch)
{
yield return languageInfo;
}
}
else
{
IEnumerable<LanguageInfo> matchOnCode = from x in _codeToLanguageIndex where x.Key.StartsWith(searchString, StringComparison.InvariantCultureIgnoreCase) select x.Value;
List<LanguageInfo>[] matchOnName = (from x in _nameToLanguageIndex where x.Key.StartsWith(searchString, StringComparison.InvariantCultureIgnoreCase) select x.Value).ToArray();
// Apostrophes can cause trouble in lookup. Unicode TR-29 inexplicably says to use
// u2019 (RIGHT SINGLE QUOTATION MARK) for the English apostrophe when it also defines
// u02BC (MODIFIER LETTER APOSTROPHE) as a Letter character. Users are quite likely to
// type the ASCII apostrophe (u0027) which is defined as Punctuation. The current
// data appears to use u2019 in several language names, which means that users might
// end up thinking the language isn't in our database.
// See https://silbloom.myjetbrains.com/youtrack/issue/BL-6339.
if (!matchOnName.Any() && searchString.Contains('\''))
{
searchString = searchString.Replace('\'','\u2019');
matchOnName = (from x in _nameToLanguageIndex where x.Key.StartsWith(searchString, StringComparison.InvariantCultureIgnoreCase) select x.Value).ToArray();
}
List<LanguageInfo>[] matchOnCountry = (from x in _countryToLanguageIndex where x.Key.StartsWith(searchString, StringComparison.InvariantCultureIgnoreCase) select x.Value).ToArray();
if (!matchOnName.Any())
{
// look for approximate matches
const int kMaxEditDistance = 3;
var itemFormExtractor = new ApproximateMatcher.GetStringDelegate<KeyValuePair<string, List<LanguageInfo>>>(pair => pair.Key);
IList<KeyValuePair<string, List<LanguageInfo>>> matches = ApproximateMatcher.FindClosestForms(_nameToLanguageIndex, itemFormExtractor,
searchString,
ApproximateMatcherOptions.None,
kMaxEditDistance);
matchOnName = (from m in matches select m.Value).ToArray();
}
var combined = new HashSet<LanguageInfo>(matchOnCode);
foreach (List<LanguageInfo> l in matchOnName)
combined.UnionWith(l);
foreach (List<LanguageInfo> l in matchOnCountry)
combined.UnionWith(l);
var ordered = combined.OrderBy(l => l, new ResultComparer(searchString));
foreach (LanguageInfo languageInfo in ordered)
yield return languageInfo;
}
}