Extended spell checker with phrase support and adaptive user session analysis. [LUCENE-626]

Extensive javadocs available in patch, but I also try to keep it compiled here: http://ginandtonique.org/\~kalle/javadocs/didyoumean/org/apache/lucene/search/didyoumean/package-summary.html#package_description

A semi-retarded reinforcement learning thingy backed by algorithmic second level suggestion schemes that learns from and adapts to user behavior as queries change, suggestions are accepted or declined, etc.

Except for detecting spelling errors it considers context, composition/decomposition and a few other things.

heroes of light and magik -> heroes of might and magic
vinci da code -> da vinci code
java docs -> javadocs
blacksabbath -> black sabbath

Depends on #1628

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Migrated from [LUCENE-626](https://issues.apache.org/jira/browse/LUCENE-626) by Karl Wettin, 4 votes, updated Jun 11 2010
Attachments: [LUCENE-626_20071023.txt](https://apache.github.io/lucene-jira-archive/attachments/LUCENE-626/LUCENE-626_20071023.txt)

Start with the attached LUCENE-626_20071023.txt patch and the linked javadocs for the didyoumean package. Review dependency #1628 and the existing proposal before defining scope. Done would require agreed support for phrase suggestions, contextual composition or decomposition, and adaptation to accepted or declined suggestions.

Written by the indexing model from the issue text.