#include "steam/mobject/session/scope-query.hpp"

Description

template<class MO>
class steam::mobject::session::ScopeQuery< MO >

Query a scope to discover it's contents or location.

This is a special kind of query, wired up such as to enumerate the contents or parents of a scope, filtered by a subtype-check. For the actual resolution of the elements to discover, this query relies on an index like facility (usually Session's PlacementIndex), which is abstracted as a QueryResolver, but actually is expected to cooperate especially with this Query subclass to retrieve the scope to be enumerated and the definition of the actual filter predicate. Currently (11/09), there is a special, hard-wired Query-kind-ID Goal::DISCOVERY to distinguish this special kind of a Query.

Contrary to the usual handling of a generic query, a ScopeQuery object holds it's own discovery iterator and thus is completely self contained. The query is issued automatically on construction, thus the embedded iterator immediately points at the first result. Moreover, since any Lumiera Forward Iterator is bool checkable, a ScopeQuery not yielding any results will evaluate to false immediately after construction, allowing convenient inline checks. The query can be re-issued by the function operator, and the embedded result iterator can of course be copied to a bare iterator instance, e.g. for passing it on (ScopeQuery itself is intended to be used polymorphically and thus defined to be not assignable)

Definition at line 134 of file scope-query.hpp.

Public Types
using	iterator = _Parent::iterator

using	ContentFilter = _Parent::ContentFilter

Public Types inherited from DiscoveryQuery< MO >
using	iterator = _Query::iterator

using	ContentFilter = function< bool(PlacementMO const &)>

Public Types inherited from Query< RES >
typedef lib::IterAdapter< Cursor, PReso >	iterator

Public Types inherited from Goal
enum	Kind { EMPTY = 0 , GENERIC = 1 , DISCOVERY , PLACEMENT }

Public Member Functions
	ScopeQuery (PlacementMO const &scope, ScopeQueryKind direction)

PlacementMO::ID const &	searchScope () const

ScopeQueryKind	searchDirection () const

Public Member Functions inherited from DiscoveryQuery< MO >
ContentFilter	contentFilter () const

Public Member Functions inherited from Query< RES >
	Query ()

	Query (string querySpec)

	operator QueryKey () const
	automatic conversion from Query to QueryKey for indexing and ordering.

Builder	rebuild () const

string	extractID (Symbol predicate) const
	convenience shortcut to extract a desired name-ID.

bool	usesPredicate (Symbol predicate) const

iterator	operator() (QueryResolver const &resolver) const
	notational convenience shortcut, synonymous to Query<RES>::resolveBy()

iterator	resolveBy (QueryResolver const &resolver) const

Public Member Functions inherited from Goal
virtual	~Goal ()
	this is a marker baseclass

QueryID const &	getQID () const

Private Types
using	_Parent = DiscoveryQuery< MO >

using	_Query = Query< Placement< MO > >

Private Member Functions
ContentFilter	buildContentFilter () const
	the default implementation of the content filtering builds on the downcast-function available on each Placement instance.

lib::QueryText	buildSyntacticRepresentation () const
	supplement a syntactic representation (as generic query in predicate form).

Private Attributes
PlacementMO::ID	startPoint_

ScopeQueryKind	to_discover_

Additional Inherited Members
Static Public Member Functions inherited from Query< RES >
static Builder	build (Kind queryType=Goal::GENERIC)

Protected Member Functions inherited from DiscoveryQuery< MO >
	DiscoveryQuery ()

Protected Member Functions inherited from Query< RES >
lib::QueryText	getQueryDefinition () const
	access the complete syntactical representation of this query.

	Query (QueryID typeID, lib::QueryText const &genericQuerySpec)

	Query (QueryID typeID, string querySpec)

Protected Member Functions inherited from Goal
	Goal (QueryID qid)

Static Protected Member Functions inherited from Query< RES >
static QueryID	defineQueryTypeID (Kind queryType=Goal::GENERIC)

Protected Attributes inherited from Goal
QueryID	id_

Constructor & Destructor Documentation

◆ ScopeQuery()

template<class MO >

ScopeQuery	(	PlacementMO const &	scope,
		ScopeQueryKind	direction
	)

inline

Definition at line 149 of file scope-query.hpp.

Member Typedef Documentation

◆ _Parent

template<class MO >

using _Parent = DiscoveryQuery<MO>

private

Definition at line 137 of file scope-query.hpp.

◆ _Query

template<class MO >

using _Query = Query<Placement<MO> >

private

Definition at line 138 of file scope-query.hpp.

◆ iterator

template<class MO >

using iterator = _Parent::iterator

Definition at line 145 of file scope-query.hpp.

◆ ContentFilter

template<class MO >

using ContentFilter = _Parent::ContentFilter

Definition at line 146 of file scope-query.hpp.

Member Function Documentation

◆ searchScope()

template<class MO >

PlacementMO::ID const & searchScope ( ) const

inline

Definition at line 158 of file scope-query.hpp.

References ScopeQuery< MO >::startPoint_.

Referenced by ScopeQuery< MO >::buildSyntacticRepresentation(), and PlacementIndexQueryResolver::resolutionFunction().

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◆ searchDirection()

template<class MO >

ScopeQueryKind searchDirection ( ) const

inline

Definition at line 164 of file scope-query.hpp.

References ScopeQuery< MO >::to_discover_.

Referenced by ScopeQuery< MO >::buildSyntacticRepresentation(), and PlacementIndexQueryResolver::resolutionFunction().

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◆ buildContentFilter()

template<class MO >

ContentFilter buildContentFilter ( ) const

inlineprivatevirtual

the default implementation of the content filtering builds on the downcast-function available on each Placement instance.

By parametrising this function with our template parameter MO, we pick out only those elements of the scope being subclasses of MO

Implements DiscoveryQuery< MO >.

Reimplemented in SpecificContentsQuery< MO >.

Definition at line 179 of file scope-query.hpp.

◆ buildSyntacticRepresentation()

template<class MO >

lib::QueryText buildSyntacticRepresentation ( ) const

inlineprivatevirtual

supplement a syntactic representation (as generic query in predicate form).

Building this representation is done on demand for performance reasons; typically a ScopeQuery is issued immediately into a known sub scope of the Session/Model and resolved by the PlacementIndex

Todo:: we need a readable and sensible representation as generic query ///////////////////TICKET #901

Reimplemented from Query< RES >.

Definition at line 191 of file scope-query.hpp.

References Query< RES >::hash_value, ScopeQuery< MO >::searchDirection(), and ScopeQuery< MO >::searchScope().

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Member Data Documentation

◆ startPoint_

template<class MO >

PlacementMO::ID startPoint_

private

Definition at line 141 of file scope-query.hpp.

Referenced by ScopeQuery< MO >::searchScope().

◆ to_discover_

template<class MO >

ScopeQueryKind to_discover_

private

Definition at line 142 of file scope-query.hpp.

Referenced by ScopeQuery< MO >::searchDirection().

Inheritance diagram for ScopeQuery< MO >:

Collaboration diagram for ScopeQuery< MO >:

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

scope-query.hpp

Description

Public Types

Public Member Functions

Private Types

Private Member Functions

Private Attributes

Additional Inherited Members

Constructor & Destructor Documentation

◆ ScopeQuery()

Member Typedef Documentation

◆ _Parent

◆ _Query

◆ iterator

◆ ContentFilter

Member Function Documentation

◆ searchScope()

◆ searchDirection()

◆ buildContentFilter()

◆ buildSyntacticRepresentation()

Member Data Documentation

◆ startPoint_

◆ to_discover_