BooleanSearchParser

, _(*1)

The aim of this class is to take a Boolean Search and to convert it into something that can be used in a MySQL Fulltext Search., _(*2)

The idea came about after recently working a lot with Boolean Search systems, and after reading this StackOverflow question, nothing really exists out there for MySQL., _(*3)

Big thanks goes to PHP SQL Parser for having such a lovely Tokeniser and related methods, which made this easier., _(*4)

Goals

To provide a good-enough conversion
To not try and correct mistakes with brackets and quotes etc.

Notes

Use

$parser = new \DuncanOgle\BooleanSearchParser\Parser();

echo $parser->parse("ict OR (technology AND bob)");
// ict (+technology +bob)

Regarding order

Order and brackets are important, more often than not OR logic takes priority, _(*5)

sales OR finance AND manager will become sales finance +manager and not sales +finance +manager, _(*6)

Todo

[x] Handle the * character
[x] Turn into a package that can be pulled in via composer
[x] Move tests over to PHP Unit
[ ] Add custom priority settings (currently its OR>AND>NOT)
[ ] Add optional word stemmer like the one used here

Simple Examples

Input	Output
`ict`	`+ict`
`ict it`	`+ict +it`
`ict OR it`	`ict it`
`NOT ict`	`-ict`
`it NOT ict`	`+it -ict`
`web AND (ict OR it)`	`+web +(ict it)`
`ict OR (it AND web)`	`ict (+it +web)`
`ict NOT (ict AND it AND web)`	`+ict -(+ict +it +web)`
`php OR (NOT web NOT embedded ict OR it)`	`php (-web -embedded ict it)`
`(web OR embedded) (ict OR it)`	`+(web embedded) +(ict it)`
`develop AND (web OR (ict AND php))`	`+develop +(web (+ict +php))`
`"ict`	`null`
`"ict OR it"`	`+"ict OR it"`

Complex Examples

|Input|Output| |-----|------| "business development" or "it sales" and (danish or dutch or italian or denmark or holland or netherlands or italy) | "business development" "it sales" +(danish dutch italian denmark holland netherlands italy) (procurement or buying or purchasing) and (marine or sea) and (engineering or engineer) | +(procurement buying purchasing) +(marine sea) +(engineering engineer), _(*7)