languagetool-org/languagetool · error · IllegalArgumentException

Dist to big: " + maxEditDistance

Error message

Dist to big: " + maxEditDistance

What it means

Parameter guard in SymSpell.lookup: the caller requested suggestions with a maximum edit distance larger than the edit distance the dictionary was built with (maxDictionaryEditDistance). Since the delete-based index only covers the built distance, a larger distance cannot be honored and the request is rejected.

Source

Thrown at languagetool-core/src/main/java/org/languagetool/rules/spelling/symspell/implementation/SymSpell.java:321

  public List<SuggestItem> lookup(String input, Verbosity verbosity) {
    return lookup(input, verbosity, maxDictionaryEditDistance);
  }

  /// <summary>Find suggested spellings for a given input word.</summary>
  /// <param name="input">The word being spell checked.</param>
  /// <param name="verbosity">The value controlling the quantity/closeness of the returned suggestions.</param>
  /// <param name="maxEditDistance">The maximum edit distance between input and suggested words.</param>
  /// <returns>A List of SymSpell.SuggestItem object representing suggested correct spellings for the input word,
  /// sorted by edit distance, and secondarily by count frequency.</returns>
  public List<SuggestItem> lookup(String input, Verbosity verbosity, int maxEditDistance) {
    //verbosity=Top: the suggestion with the highest term frequency of the suggestions of smallest edit distance found
    //verbosity=Closest: all suggestions of smallest edit distance found, the suggestions are ordered by term frequency
    //verbosity=All: all suggestions <= maxEditDistance, the suggestions are ordered by edit distance, then by term frequency (slower, no early termination)

    // maxEditDistance used in lookup can't be bigger than the maxDictionaryEditDistance
    // used to construct the underlying dictionary structure.
    if (maxEditDistance > maxDictionaryEditDistance) {
      throw new IllegalArgumentException("Dist to big: " + maxEditDistance);
    }

    List<SuggestItem> suggestions = new ArrayList<>();
    int inputLen = input.length();

    // early exit - word is too big to possibly match any words
    if (inputLen - maxEditDistance > maxLength) {
      return suggestions;
    }

    // deletes we've considered already
    HashSet<String> consideredDeletes = new HashSet<>();
    // suggestions we've considered already
    HashSet<String> consideredSuggestions = new HashSet<>();
    long suggestionCount;

    // quick look for exact match
    if (words.containsKey(input)) {

View on GitHub (pinned to 2e990059ce)

Solutions

1. Call lookup with an edit distance less than or equal to the dictionary's max edit distance
2. Rebuild the SymSpell dictionary with a larger initial edit distance if a bigger lookup distance is required

When it happens

Trigger: Thrown at languagetool-core/src/main/java/org/languagetool/rules/spelling/symspell/implementation/SymSpell.java:321 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of languagetool-org/languagetool@2e990059ce (2026-09-06). Data as JSON: /api/errors/e5819c98ee4603e9. Report an issue: GitHub.