[SOLR-9429] Spellcheck Token Filter

• Type: New Feature
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Component/s: Schema and Analysis
• Assignee: Unassigned
• Reporter: Alessandro Benedetti
• Created: 23/Aug/16 08:51
• Updated: 08/Jun/19 15:38

Description

This issue is about the design and implementation of a new token filter called : SpellcheckTokenFilter

This new token filter takes in input the token stream and return collated tokens, based on a Dictionary.
The aim of the token filter is to fix mispelled word and index the correct token.

e.g.
Given dictionary d1 :
gaming
gamer

Given text t1 for the field f1 :
gamign is a strong industry

The token filter will return in output :
gaming is a strong industry

A first possible design is to mimic the approach used in the spellchecker.
Building an FST for the dictionary, then building the levenstein FST for each token and doing the intersection .

Possible application could be for OCR generated text and other use cases when misspelled words are common and we want to clean them up at indexing time.
This can possibly be used in a complex analyser adding a stemmer afterward.

This is draft idea coming from a blog comment of Shyamsunder.
Feedback and additional ideas are welcome!