config-rules.hpp File Reference

Interface for accessing rule based configuration. More...

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Description

Interface for accessing rule based configuration.

By using the Query template, you can pose a query in prolog syntax and get some existing or newly created object fulfilling the requested predicates. The actual implementation will be hidden behind a instance (Singleton factory). As of 1/2008, it is planned to use an embedded YAP Prolog system at some point in the future, for now we use a mock implementation based on lookup in a hard-wired, preconfigured Map.

Fully implementing this facility would require the participating objects to register capabilities they want to provide, together with functors carrying out the necessary configuration steps. All details and consequences of this approach still have to be worked out...

relation to Query and QueryResolver

The ConfigRules resolver is just a special kind of QueryResolver, able to handle specific kinds of queries. Clients using the ConfigRules directly get a more easy to use point-and-shot style interface, allowing just to retrieve some suitable solution, instead of having to iterate through a result set.

Todo:

right now (12/2012) the above paragraph is a lie. ConfigQuery is way older than QueryResolver and will be retrofitted step by step. Not much of a problem, since the currently utilised mock implementation isn't able to deal with a real query anyway.

Note

this is rather a concept draft and left as such for now... don't take this code too literal!

Todo:

clarify the relation of config query and query-for-defaults ///////////////TICKET #705

as of 11/2016 the situation is basically the same: this is placeholder code and just implemented enough to keep us going without violating the architecture vision

See also

lumiera::Query

mobject::session::DefsManager

asset::StructFactory

config-resolver.hpp specialised setup for the Steam-Layer

fake-configrules.hpp currently used dummy-implementation

Definition in file config-rules.hpp.

#include "lib/p.hpp"
#include "lib/symbol.hpp"
#include "lib/meta/generator.hpp"
#include "common/query.hpp"
#include <string>

Namespaces
namespace	lumiera
	Lumiera public interface.
namespace	lumiera::error
namespace	lumiera::query

Macros
#define	SYMBOL   uint
	placeholder definition for later.

Classes
class	Resolver
class	Pred< SYM, SIG >
class	TypeHandler< TY >
	the "back side" interface towards the classes participating in the configuration system (the config system will be delivering instances of these classes for a given query). More...
class	QueryHandler< TY >
	the "front side" interface: the Steam-Layer code can use this QueryHandler to retrieve instances of the type TY fulfilling the given Query. More...
class	ConfigRules< TYPES >
	Generic query interface for retrieving objects matching some capability query. More...

Functions
	LUMIERA_ERROR_DECLARE (CAPABILITY_QUERY)
	unresolvable capability query.
void	setFakeBypass (lumiera::QueryKey const &q)
	backdoor for tests: the next config query with this query string will magically succeed with every candidate object provided.
bool	isFakeBypass (lumiera::QueryKey const &q)

Macro Definition Documentation

SYMBOL

#define SYMBOL   uint

placeholder definition for later.

Todo:

intention is to integrate with lib::Symbol

Definition at line 107 of file config-rules.hpp.

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Class Documentation

lumiera::query::Resolver

class lumiera::query::Resolver

Collaboration diagram for Resolver:

lumiera::query::Pred

class lumiera::query::Pred

Collaboration diagram for Pred< SYM, SIG >: