Class Horde_Db_SearchParser

This class provides a parser which can construct an SQL WHERE clause from a Google-like search expression.

Copyright 2004-2012 Horde LLC (http://www.horde.org/)

The expression recognizes boolean "AND", "OR", and "NOT" (providing no operator between keywords implies "AND"), like so: cat and dog cat or dog cat and not dog

If no operator appears between keywords or quoted strings, "AND" is assumed. A comma can be used instead of "OR": cat dog cat, dog cat not dog

The parser recognizes parentheses, so complex expressions can be created: cat and not (dog or puppy)

Quoted strings are also recognized, and are taken as literal keywords: "cat and dog"

Parsing is designed to be as fuzzy as possible, so it shouldn't error unless people search for "AND", "OR", or "NOT" without quoting it or use unbalanced parentheses.