public static WordCharMap CreateCharIndexMap(WordList wordList, bool reverse = false)
{
ImmutableDictionary <WordChar, ImmutableHashSet <string> > map = wordList.Values
.Select(s =>
{
return(
value: s,
chars: ((reverse) ? s.Reverse() : s).Select((ch, i) => (ch, i)));
})
.SelectMany(f => f.chars.Select(g =>
{
return(
f.value,
g.ch,
g.i,
key: new WordChar(g.ch, g.i));
}))
.GroupBy(f => f.key)
.ToImmutableDictionary(
f => f.Key,
f => f.Select(f => f.value).ToImmutableHashSet(wordList.Comparer));
return(new WordCharMap(wordList, map));
}
private WordCharMap(WordList list, ImmutableDictionary <WordChar, ImmutableHashSet <string> > map)
{
List = list;
Map = map;
}
public static void Save(
string path,
WordList wordList)
{
Save(path, wordList.Values, wordList.Comparer);
}