Spelling suggestions

DidYouMeanSuggester returns alternative spellings for a term, ranked by document frequency divided by edit distance.

Quick path

using Rowles.LeanLucene.Search.Suggestions;

var suggestions = DidYouMeanSuggester.Suggest(
    searcher, field: "title", queryTerm: "lukcy",
    maxEdits: 2, topN: 5);

foreach (var s in suggestions)
    Console.WriteLine($"{s.Term} (distance={s.Distance}, df={s.DocFreq})");

The underlying SpellIndex is built once per searcher / field and cached for subsequent calls.

Reusing a SpellIndex

For repeated suggestions over the same field, build the index explicitly:

var spell = SpellIndex.Build(searcher, "title");
var s1 = DidYouMeanSuggester.Suggest(spell, "lukcy", maxEdits: 2, topN: 5);
var s2 = DidYouMeanSuggester.Suggest(spell, "frmo",  maxEdits: 2, topN: 5);

This avoids re-scanning the term dictionary.

Tuning

• maxEdits — Levenshtein cap (sensible values 1–2).
• topN — number of suggestions returned.

See also

• DidYouMeanSuggester
• SpellIndex