org.eclipse.viatra.query.runtime.matchers.planning.helpers

Class TypeHelper

java.lang.Object

org.eclipse.viatra.query.runtime.matchers.planning.helpers.TypeHelper

public class TypeHelper
extends java.lang.Object

Constructor Summary

Constructors

Constructor and Description
TypeHelper()

Method Summary

Modifier and Type	Method and Description
static java.util.Set<TypeJudgement>	getDirectJudgements(java.util.Set<PConstraint> constraints, IQueryMetaContext context) Gets direct judgements reported by constraints.
static java.util.Map<PVariable,java.util.Set<TypeJudgement>>	inferUnaryTypes(java.util.Set<PConstraint> constraints, IQueryMetaContext context) Infers unary type information for variables, based on the given constraints.
static java.util.Map<PVariable,java.util.Set<IInputKey>>	inferUnaryTypesFor(java.lang.Iterable<PVariable> variables, java.util.Map<PVariable,java.util.Set<TypeJudgement>> typeMap) Collects the type constraints for the specified collection of variables.
static java.util.Map<PVariable,java.util.Set<IInputKey>>	inferUnaryTypesFor(java.lang.Iterable<PVariable> variables, java.util.Set<PConstraint> constraints, IQueryMetaContext context) Collects the type constraints for the specified collection of variables.
static java.util.Set<TypeJudgement>	subsumeTypes(java.util.Set<TypeJudgement> subsumableTypes, java.util.Set<TypeJudgement> subsumingTypes, IQueryMetaContext context) Calculates a remainder set of types from a larger set, that are not subsumed by a given set of subsuming types.
static java.util.Set<TypeJudgement>	typeClosure(java.util.Set<TypeJudgement> typesToClose, IQueryMetaContext context) Calculates the closure of a set of type judgements, with respect to supertyping.
static java.util.Set<TypeJudgement>	typeClosure(java.util.Set<TypeJudgement> preclosedBaseSet, java.util.Set<TypeJudgement> delta, IQueryMetaContext context) Calculates the closure of a set of type judgements (with respect to supertyping), where the closure has been calculated before for a given base set, but not for a separate delta set.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

TypeHelper

public TypeHelper()

Method Detail

inferUnaryTypesFor

public static java.util.Map<PVariable,java.util.Set<IInputKey>> inferUnaryTypesFor(java.lang.Iterable<PVariable> variables,
                                                                                   java.util.Set<PConstraint> constraints,
                                                                                   IQueryMetaContext context)

Collects the type constraints for the specified collection of variables. The type constraints consist of the constraints directly enforced on the variable itself, plus all of those that the given variable is unified with through equalities.

Parameters:

variables - the variables in question

constraints - the constraints in the pattern body

context - the query meta context

Returns:

the mapping from variable to set of type constraints

Since:

1.6

inferUnaryTypesFor

public static java.util.Map<PVariable,java.util.Set<IInputKey>> inferUnaryTypesFor(java.lang.Iterable<PVariable> variables,
                                                                                   java.util.Map<PVariable,java.util.Set<TypeJudgement>> typeMap)

Collects the type constraints for the specified collection of variables. The type constraints consist of the constraints directly enforced on the variable itself, plus all of those that the given variable is unified with through equalities. The method accepts a type map which is the result of the basic type inference from the TypeHelper.inferUnaryTypes method. The purpose of this method is that the type map can be reused across several calls to this method.

Parameters:

variables - the variables in question

typeMap - the type map of inference results

Returns:

the mapping from variable to set of type constraints

Since:

1.6

inferUnaryTypes

public static java.util.Map<PVariable,java.util.Set<TypeJudgement>> inferUnaryTypes(java.util.Set<PConstraint> constraints,
                                                                                    IQueryMetaContext context)

Infers unary type information for variables, based on the given constraints. Subsumptions are not taken into account.

Parameters:

constraints - the set of constraints to extract type info from

getDirectJudgements

public static java.util.Set<TypeJudgement> getDirectJudgements(java.util.Set<PConstraint> constraints,
                                                               IQueryMetaContext context)

Gets direct judgements reported by constraints. No closure is applied yet.

typeClosure

public static java.util.Set<TypeJudgement> typeClosure(java.util.Set<TypeJudgement> typesToClose,
                                                       IQueryMetaContext context)

Calculates the closure of a set of type judgements, with respect to supertyping.

Returns:

the set of all type judgements in typesToClose and all their direct and indirect supertypes

typeClosure

public static java.util.Set<TypeJudgement> typeClosure(java.util.Set<TypeJudgement> preclosedBaseSet,
                                                       java.util.Set<TypeJudgement> delta,
                                                       IQueryMetaContext context)

Calculates the closure of a set of type judgements (with respect to supertyping), where the closure has been calculated before for a given base set, but not for a separate delta set.

Precondition: the set (typesToClose MINUS delta) is already closed w.r.t. supertyping.

Returns:

the set of all type judgements in typesToClose and all their direct and indirect supertypes

Since:

1.6

subsumeTypes

public static java.util.Set<TypeJudgement> subsumeTypes(java.util.Set<TypeJudgement> subsumableTypes,
                                                        java.util.Set<TypeJudgement> subsumingTypes,
                                                        IQueryMetaContext context)

Calculates a remainder set of types from a larger set, that are not subsumed by a given set of subsuming types.

Parameters:

subsumableTypes - a set of types from which some may be implied by the subsuming types

subsumingTypes - a set of types that may imply some of the subsuming types

Returns:

the collection of types in subsumableTypes that are NOT identical to or supertypes of any type in subsumingTypes.