spell_checker

# SpellChecker

A small Elixir library for checking spelling in English, Spanish and French
against bundled dictionaries, with suggestions, autocorrect, custom
dictionaries, and whole-text checking.

## Installation

The package can be installed by adding `spell_checker` to your list of
dependencies in `mix.exs`:

```elixir
def deps do
  [
    {:spell_checker, "~> 0.3.0"}
  ]
end
```

Documentation can be found at <https://hexdocs.pm/spell_checker>.

## Usage

```elixir
SpellChecker.is_correct("hello")
# {:ok, true}

SpellChecker.is_correct?(["hello", "worlld", "Programming"])
# ["Programming", "hello"]

SpellChecker.is_correct!("worlld")
# ["world", "worldly", "worlds", "wold", "word"]

SpellChecker.correct("Helo")
# {:corrected, "Hello"}

SpellChecker.check_text("hello wrold")
# [{"wrold", ["wold", "world", "worlds", "would", "word"]}]

# Extend the dictionary with your own words (kept for the life of the node)
SpellChecker.add_words(["hexdocs", "genserver"])
SpellChecker.is_correct("GenServer")
# {:ok, true}

SpellChecker.clear_custom_words()

# Or swap a bundled dictionary out entirely, or add a new language
SpellChecker.load_dictionary!(["ẹ", "kú", "àárọ̀"], lang: :yo)
```

## Languages

English (`:en`), Spanish (`:es`) and French (`:fr`) are bundled. Every function
takes a `lang:` option, defaulting to `:en`:

```elixir
SpellChecker.is_correct("canción", lang: :es)
# {:ok, true}

SpellChecker.correct("Corazon", lang: :es)
# {:corrected, "Corazón"}

SpellChecker.check_text("Je suis allé à l’ecole", lang: :fr)
# [{"l’ecole", ["l'école", "l'écoles", "l'écoule", "l'écoulé", "l'éole"]}]

SpellChecker.languages()
# [:en, :es, :fr]
```

To change the default language for your whole app:

```elixir
# config/config.exs
config :spell_checker, default_lang: :fr
```

Missing or wrong accents ("ecole", "nino") are treated as the closest possible
mistake, so the accented word is suggested first. French elisions like
`l'école` and `qu'aujourd'hui` are checked as two words, and typographic
apostrophes (`’`) work the same as `'`.

Each language's dictionary is read from disk the first time it's used and
cached in memory (via `:persistent_term`) for the life of the running node,
so repeated lookups are cheap. Loading takes about 2 seconds and ~70 MB for
Spanish, ~50 MB for French, and ~4 MB for English; only the languages you use
are loaded. Custom words added with `add_words/2` are per language
(`add_words(words, lang: :es)`).

Suggestions only consider words that start with the same letter (ignoring
accents), which keeps them fast for the large Spanish and French dictionaries.

The Spanish and French word lists come from the LibreOffice Hunspell
dictionaries and keep their upstream licenses (MPL); see
[`priv/dictionaries/README.md`](https://github.com/Adeyeye93/SpellChecker/blob/main/priv/dictionaries/README.md).