tagcoll::TagexprContext Class Reference

Context for evaluating expressions of derived tags. More...

#include <expression.h>

List of all members.

Public Member Functions
	TagexprContext (const std::set< std::string > &tags, const std::map< std::string, Expression > &derivedTags)
	Create a context for recursive tagset evaluation.
bool	eval (const std::string &tag) const
	Evaluates the input tags on the contents to see if they contain the given tag, or if they match its associated tag expression if tag is a derived tag.
Protected Attributes
const std::set< std::string > &	tags
const std::map< std::string, Expression > &	derivedTags
std::set< std::string >	seen

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Detailed Description

Context for evaluating expressions of derived tags.

A derived tag is a tag which is automatically inferred when a tag expression is matched on a tagset.

TagexprContext allows the inference engine to distinguish between a normal tag or a derived tag.

This class is mainly used to support DerivedTags and has probably little applications elsewhere.

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Constructor & Destructor Documentation

tagcoll::TagexprContext::TagexprContext	(	const std::set< std::string > &	tags,
		const std::map< std::string, Expression > &	derivedTags
	)			[inline]

Create a context for recursive tagset evaluation.

Evaluation happens using a derivation table, which can list a tag as an alias for another tag expression. Whenever a tag is matched for equality with a derived tag, the match is performed with the derived tag expression instead.

Parameters:

	tags	The tags to evaluate
	derivedTags	The table of derived tags to use in the evaluation

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Member Function Documentation

bool tagcoll::TagexprContext::eval

(

const std::string &

tag

)

const

Evaluates the input tags on the contents to see if they contain the given tag, or if they match its associated tag expression if tag is a derived tag.

References derivedTags, and seen.

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Member Data Documentation

const std::map<std::string, Expression>& tagcoll::TagexprContext::derivedTags [protected]

Referenced by eval().

std::set<std::string> tagcoll::TagexprContext::seen [mutable, protected]

Referenced by eval().

const std::set<std::string>& tagcoll::TagexprContext::tags [protected]

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

• expression.h
• expression.cc