public (bool foundTranslation, IReadOnlyCollection <Translation <TKey, TValue> > translationSteps) TryTranslation(
TValue fromValue,
TKey fromKey,
TKey toKey,
out TValue translated,
TranslatorSettings settings = null)
{
settings = settings ?? Settings ?? new TranslatorSettings();
var(foundTranslation, translationSteps) = Finder(translations, fromValue, fromKey, toKey, settings);
if (foundTranslation)
{
var keyEqualityComparer = EqualityComparer <TKey> .Default;
for (var i = 0; i < translationSteps.Count; i++)
{
for (var j = i + 1; j < translationSteps.Count; j++)
{
if (keyEqualityComparer.Equals(translationSteps[i].KeyA, translationSteps[j].KeyB))
{
translationSteps.RemoveRange(i, (j - i) + 1);
i--;
break;
}
}
}
translated = translationSteps.Aggregate(fromValue, (accumulator, translation) => translation.ValueB(accumulator));
return(true, translationSteps);
}
translated = default(TValue);
return(false, Enumerable.Empty <Translation <TKey, TValue> >().ToList());
}
private (bool foundTranslation, List <Translation <TKey, TValue> > translationSteps) Finder(
Dictionary <TKey, Dictionary <TKey, HashSet <Translation <TKey, TValue> > > > translations,
TValue fromValue,
TKey fromKey,
TKey toKey,
TranslatorSettings settings,
List <Translation <TKey, TValue> > translationSteps = null,
HashSet <KeyValuePair <TKey, TKey> > pathsTraveled = null)
{
translationSteps = translationSteps ?? new List <Translation <TKey, TValue> >();
pathsTraveled = pathsTraveled ?? new HashSet <KeyValuePair <TKey, TKey> >();
var keyEqualityComparer = EqualityComparer <TKey> .Default;
var valueEqualityComparer = EqualityComparer <TValue> .Default;
if (translations.TryGetValue(fromKey, out var fromSet))
{
if (fromSet.TryGetValue(toKey, out var toSet))
{
foreach (var item in toSet)
{
if (item is DirectTranslation <TKey, TValue> directTranslation
? valueEqualityComparer.Equals(directTranslation.DirectValueA, fromValue)
: keyEqualityComparer.Equals(item.KeyB, toKey))
{
translationSteps.Add(item);
return(true, translationSteps);
}
}
}
foreach (var item in fromSet
.SelectMany(x => x.Value)
.Where(x => x is DirectTranslation <TKey, TValue> directTranslation
? valueEqualityComparer.Equals(directTranslation.DirectValueA, fromValue)
: true))
{
if (pathsTraveled.Count >= settings.MaximumPathTraversal - 1)
{
break;
}
else
{
var pathKey = new KeyValuePair <TKey, TKey>(fromKey, item.KeyB);
if (!pathsTraveled.Contains(pathKey))
{
pathsTraveled.Add(pathKey);
var(finderFound, finderTranslationSteps) = Finder(
translations,
item is DirectTranslation <TKey, TValue> directTranslation
? directTranslation.DirectValueB
: fromValue,
item.KeyB,
toKey,
settings,
translationSteps,
pathsTraveled);
if (finderFound)
{
finderTranslationSteps.Insert(0, item);
return(finderFound, finderTranslationSteps);
}
}
}
}
}
return(false, Enumerable.Empty <Translation <TKey, TValue> >().ToList());
}
