https://github.com/alexcorvi/spelt
Fast & accurate spellchecker for node.js
https://github.com/alexcorvi/spelt
spell spellcheck spellchecker spelling
Last synced: about 1 month ago
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Fast & accurate spellchecker for node.js
- Host: GitHub
- URL: https://github.com/alexcorvi/spelt
- Owner: alexcorvi
- License: mit
- Created: 2017-04-04T16:55:49.000Z (over 8 years ago)
- Default Branch: master
- Last Pushed: 2017-04-05T22:26:59.000Z (over 8 years ago)
- Last Synced: 2024-11-23T03:26:35.247Z (11 months ago)
- Topics: spell, spellcheck, spellchecker, spelling
- Language: JavaScript
- Homepage: http://spelt-demo.surge.sh/
- Size: 991 KB
- Stars: 8
- Watchers: 2
- Forks: 3
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
- License: LICENSE.md
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README
# Spelt
JavaScript english spellchecker written in TypeScript.
Demo: [http://spelt-demo.surge.sh/](http://spelt-demo.surge.sh/)
## Installation
#### Install the spell checker via NPM
```
npm i --save spelt
```
#### Install one of the dictionaries
- British English dictionary
```
npm i --save spelt-gb-dict
```
- American English dictionary
```
npm i --save spelt-us-dict
```
- Canadian English dictionary
```
npm i --save spelt-ca-dict
```
- Australian English dictionary
```
npm i --save spelt-au-dict
```
## Usage
```typescript
// import the lib
import spelt from "spelt";
// import one of the dictionaries
import {dictionary} from "spelt-gb-dict";
// build dictionary
const check = spelt({
dictionary:dictionary,
// can be either "gb" or "us"
distanceThreshold:0.2
// when a correction found with this distance
// we'll stop looking for another
// this would improve performance
});
console.log(check("heve"));
```
The above code would output:
```javascript
{
// the raw input
raw:"heve",
// correct or not
correct:false
// corrections array sorted by string distance
[
{
// possible correction
correction:"have",
// distance from the input word
distance:0.4
},
// .... other possible corrections
]
}
```
## How it works
## String Distance
I've noticed that a lot of spellcheckers are using the __levenshtein distance (LD)__, I don't think it's the appropriate solution, since it doesn't take moving a two letters around in consideration.
For example:
1. the distance between `abcde` and `abcxx` is `2`.
2. the distance between `abcde` and `abced` is also `2`.
But on the first case we introduced two new letters, and removed two letters! while on the second case we just moved the `e` and `d` around without introducing or removing any letter.
So in short, I don't see the levenshtein distance as an appropriate solution for a spellchecker.
I've wrote my own string distance calculator and you can find it [here](https://github.com/FinNLP/strdistance).
## Performance
- __Spellchecking a book:__ Processing H.G Wells Novel _The Time Machine_ with (1000s of misspellings introduced took about 8 seconds), in a rate of __4K words/second__.
- __[Spellchecking Wikipedia list](http://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machines):__ Processing about 4 thousands words, all misspelt, took about 3.5 seconds with a rate of __2.3K word/second__.
This is not very impressive, but I'm working on it. However, it's far better than [Norvig's](http://norvig.com/spell-correct.html) spellchecker.
## Accuracy
Running on [wikipedia's list](http://en.wikipedia.org/wiki/Wikipedia:Lists_of_common_misspellings/For_machines), with a distance threshold of `0`, It was able to find the accurate correction in the first 5 suggestions on __85%__ of the cases.
## License
The MIT License