HunspellSharp

This is a C# port of Hunspell library.

Features

• Targets .NET Framework (4.0 the lowest), .NET 6+ and .NET Standard 2.0.
• Uses only safe managed code.
• Querying methods (Spell, Suggest, etc) are thread-safe.

Usage

Preliminary

If your application targets .NET or .NET Standard and intended to work with dictionaries encoded as anything other than ISO-8859-1 or UTF-8, install System.Text.Encoding.CodePages package and make additional encodings available by calling Encoding.RegisterProvider(CodePagesEncodingProvider.Instance) before loading Hunspell files.

Constructors

With file paths:

var hunspell = new Hunspell("en.aff", "en.dic");

Like the original Hunspell, it attempts to open hzipped files (.hz) if plain files are not found. An optional hzip key can be added:

var hunspell = new Hunspell("en.aff", "en.dic", key);

The key argument is a byte array. Use Encoding.GetBytes of the appropriate encoding to get a byte array from the string.

With streams:

var hunspell = new Hunspell(affStream, dicStream);

In case the stream is compressed with hzip, wrap it in HzipStream. HzipStream contructor also accepts an optional hzip key.

Disposing

A Hunspell instance uses some disposable resources and is thus itself disposable, so be sure to add a using statement or explicitly call hunspell.Dispose() when it is no longer needed.

Spelling

bool result = hunspell.Spell("sample");

There are also methods that provide additional information and the root word:

result = hunspell.Spell("sample", out var info);
result = hunspell.Spell("sample", out var info, out var root);

Suggestions

Generate suggestions for a misspelled word:

List<string> suggestions = hunspell.Suggest("sapmle");

Simplified XML API input is supported. See the Hunspell manual for a description.

Suggest words by applying the suffix rules to the root word:

List<string> suggestions = hunspell.SuffixSuggest("sample");

Morphology

Get morphlogical description:

List<string> description = hunspell.Analyze("examples");

Generate words using morphlogical description:

List<string> results = hunspell.Generate("sample", description);

or by example:

List<string> results = hunspell.Generate("sample", "examples");

Get stem(s):

List<string> stems = hunspell.Stem("samples");

Using the previous result of morphological analysis:

List<string> stems = hunspell.Stem("samples", description);

Dictionary manipulation

Note

These methods are not thread-safe and must be run exclusively.

Append additional dictionary from a file path or a stream:

hunspell.AddDic("some.dic");
hunspell.AddDic(dicStream);

As in the contructors, optional hzip key or HzipStream can be used:

hunspell.AddDic("some.dic", key);
hunspell.AddDic(new HzipStream(hzDicStream, key));

Add a word to the run-time dictionary:

hunspell.Add("word");

With flags and morphological description:

hunspell.AddWithFlags("word", flags, description);

With affixes using an example word:

hunspell.AddWithAffix("word", "example");

Remove a word from the run-time dictionary:

hunspell.Remove("word");

Various dictionary properties and methods

Dictionary encoding:

Encoding encoding = hunspell.DicEncoding;

Dictionary language number; the enum values correspond to the numbers in the original Hunspell:

LANG langnum = hunspell.LangNum;

Affix and dictionary file version:

string version = hunspell.Version;

Additional word characters defined in the affix file:

char[] wordchars = hunspell.Wordchars;

Input conversion according to the ICONV table specified in the affix file:

string output = hunspell.InputConv("input");

Error handling

HunspellSharp throws exceptions of the type HunspellException on severe affix/dictionary format errors. In you want the behavior of the original Hunspell, which always just issues warnings but continues execution, set the static StrictFormat property to false:

Hunspell.StrictFormat = false;

Warning handling

By default, HunspellSharp sends warning messages to System.Diagnostics.Debug. To change this, create a class implementing the IHunspellWarningHandler interface and pass the reference to its instance to the static SetWarningHandler method:

class CustomWarningHandler : IHunspellWarningHandler
{
  public bool HandleWarning(string message)
  {
    Console.WriteLine(message);
    return true;
  }
}

...

Hunspell.SetWarningHandler(new CustomWarningHandler());

Technical notes

HunspellSharp relies on System.Globalization features when converting characters to lower- or uppercase. If a language is specified in the affix file, the corresponding CultureInfo is used. If not, the culture is either guessed from the encoding, or the invariant culture is used by default. In the latter case, some results may differ from the original Hunspell that uses built-in case conversion tables. For example, the invariant culture does not convert capital 'İ' to lowercase 'i', so Turkish words containing 'İ' will not be recognized as forms of lowercase dictionary words if the language is not specified in the affix file and the dictionary encoding is not ISO-8859-9. To avoid this, explicitly specify the correct dictionary language.

HunspellSharp parses affix files in one pass, so options that affect further parsing (SET, FLAG) must precede options that depend on them. This differs from the original Hunspell, which makes two passes, picking up some options in the first pass, and then parsing the rest in the second.

When a dictionary is added with the AddDic method, HunspellSharp merges its entries with existing ones, and then makes lookups in a single runtime dictionary, whereas the original Hunspell stores additional dictionaries as separate structures, quiering them sequentially.

N-gram suggestions may sometimes differ from the original ones, since their choice depends on the order of words in internal hash tables, the sorting algorithm and other factors that do not match those in the original Hunspell.

This port is rather straightforward. The non-public source code intentionally does not follow normal C# conventions, in order to maintain similarity to the C++ source code where possible, making it easier to compare this port to the original.