CirrusSearch\Parser\AST\ParsedBooleanNode Class Reference

A boolean expression. More...

Inheritance diagram for CirrusSearch\Parser\AST\ParsedBooleanNode:

Collaboration diagram for CirrusSearch\Parser\AST\ParsedBooleanNode:

Public Member Functions
	__construct ( $startOffset, $endOffset, array $children)
	toArray ()
	getClauses ()
	accept (Visitor $visitor)
Public Member Functions inherited from CirrusSearch\Parser\AST\ParsedNode
	__construct ( $startOffset, $endOffset)
	getStartOffset ()
	getEndOffset ()

Additional Inherited Members
Protected Member Functions inherited from CirrusSearch\Parser\AST\ParsedNode
	baseParams ()

Detailed Description

A boolean expression.

This "boolean expression" is suited for matching document in search. It's not really describing a binary tree as one would use to a compute a boolean algebra. It is a flat list of clauses where the clauses are not connected to each others but rather describe how individual clause must occur in a given document:

• MUST
• MUST_NOT
• SHOULD

There is a direct relationship between boolean algebra and this representation:

• A AND B: [ MUST:A, MUST:B ]
• A OR B: [ SHOULD:A, SHOULD:B ]
• A AND NOT B: [ MUST:A, MUST_NOT: B ]

But it supports describing something that is impossible to describe in a boolean algebra:

• [ MUST:A, SHOULD:B ]: here the boolean algebra is not suited since SHOULD:B is pointless but for search it can be considered as a "scoring hint", i.e. give me all docs matching A but it's "better" to have docs matching B as well. When filtering the search backend can silently ignore the SHOULD:B but when scoring it will be taken into account.

In the end this representation makes it possible to support a syntax like: word1 +word2 -word3: [ SHOULD:word1, MUST:word2, MUST_NOT:word3 ] which would not be possible with a binary expression tree

Constructor & Destructor Documentation

__construct()

CirrusSearch\Parser\AST\ParsedBooleanNode::__construct	(		$startOffset,
			$endOffset,
		array	$children )

Parameters

int	$startOffset
int	$endOffset
BooleanClause[]	$children

Member Function Documentation

accept()

CirrusSearch\Parser\AST\ParsedBooleanNode::accept

(

Visitor

$visitor

)

Parameters

Visitor

$visitor

Implements CirrusSearch\Parser\AST\Visitor\Visitable.

getClauses()

CirrusSearch\Parser\AST\ParsedBooleanNode::getClauses

(

)

Returns

BooleanClause[]

toArray()

CirrusSearch\Parser\AST\ParsedBooleanNode::toArray

(

)

Returns

array

Reimplemented from CirrusSearch\Parser\AST\ParsedNode.

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The documentation for this class was generated from the following file:

• includes/Parser/AST/ParsedBooleanNode.php