Package org.apache.tinkerpop.gremlin.process.traversal.step.map

Class DeclarativeMatchStep<S>

java.lang.Object

org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep<S,Map<String,Object>>

org.apache.tinkerpop.gremlin.process.traversal.step.map.DeclarativeMatchStep<S>

All Implemented Interfaces:

Serializable, Cloneable, Iterator<Traverser.Admin<Map<String,Object>>>, Step<S,Map<String,Object>>, Configuring, Parameterizing

Direct Known Subclasses:

GqlMatchStep

public class DeclarativeMatchStep<S>
extends AbstractStep<S,Map<String,Object>>
implements Configuring

A placeholder step that represents a declarative pattern-matching query. This step is not directly executable; a graph provider must register an execution strategy that replaces it with a concrete implementation.

The query language is intentionally unset (null) by default. Graph providers accept or reject the query language they receive: a null value means the user did not specify a language and the provider should use its native query language; a non-null value is an explicit hint that the provider may accept or reject. Use the .with("queryLanguage", value) modulator to specify a language explicitly.

Since:

4.0.0

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected Parameters	parameters

Fields inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

id, labels, nextEnd, nextStep, previousStep, starts, traversal, traverserStepIdAndLabelsSetByChild

Constructor Summary

Constructors

Constructor	Description
DeclarativeMatchStep(Traversal.Admin traversal, String matchQuery, Map<String,Object> params)	Constructs a DeclarativeMatchStep as a mid-traversal step with the given query and optional parameters.
DeclarativeMatchStep(Traversal.Admin traversal, String matchQuery, Map<String,Object> params, String queryLanguage, boolean isStart)	Constructs a DeclarativeMatchStep with the given query, optional parameters, query language, and start-step flag.

Method Summary

Modifier and Type	Method	Description
void	configure(Object... keyValues)	Accepts configuration via the with() step modulator.
String	getMatchQuery()	Returns the declarative query string passed to this step.
Parameters	getParameters()	Gets the parameters on the step.
Map<String,Object>	getParams()	Returns the query parameters, or null if none were provided.
String	getQueryLanguage()	Returns the query language identifier in use for this step.
Set<TraverserRequirement>	getRequirements()	Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly.
boolean	isStart()	Returns true if this step is the first step in the traversal (spawned from a GraphTraversalSource).
protected Traverser.Admin<Map<String,Object>>	processNextStart()	Always throws UnsupportedOperationException.
String	toString()

Methods inherited from class org.apache.tinkerpop.gremlin.process.traversal.step.util.AbstractStep

addLabel, addStart, addStarts, clearLabels, clone, equals, getId, getLabels, getNextStep, getPreviousStep, getStarts, getTraversal, hashCode, hasNext, hasStarts, isTraverserStepIdAndLabelsSetByChild, next, prepareTraversalForNextStep, removeLabel, reset, setId, setNextStep, setPreviousStep, setTraversal

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface java.util.Iterator

forEachRemaining, remove

Methods inherited from interface org.apache.tinkerpop.gremlin.process.traversal.Step

equals

Field Details

parameters

protected Parameters parameters

Constructor Details

DeclarativeMatchStep

public DeclarativeMatchStep(Traversal.Admin traversal,
 String matchQuery,
 Map<String,Object> params)

Constructs a DeclarativeMatchStep as a mid-traversal step with the given query and optional parameters. The query language is left unset (null); graph providers treat null as "use your native language."

Parameters:

traversal - the parent traversal

matchQuery - the declarative query string

params - optional query parameters (may be null)

DeclarativeMatchStep

public DeclarativeMatchStep(Traversal.Admin traversal,
 String matchQuery,
 Map<String,Object> params,
 String queryLanguage,
 boolean isStart)

Constructs a DeclarativeMatchStep with the given query, optional parameters, query language, and start-step flag.

Parameters:

traversal - the parent traversal

matchQuery - the declarative query string

params - optional query parameters (may be null)

queryLanguage - the query language identifier, or null if not specified

isStart - true when this step is the first step in the traversal (spawned from a GraphTraversalSource); the step will self-seed rather than pulling from upstream starts

Method Details

processNextStart

protected Traverser.Admin<Map<String,Object>> processNextStart()

Always throws UnsupportedOperationException. A provider strategy must replace this step before the traversal is executed.

Specified by:

processNextStart in class AbstractStep<S,Map<String,Object>>

configure

public void configure(Object... keyValues)

Accepts configuration via the with() step modulator. Recognises the WithOptions.queryLanguage key to override the query language; all other key/value pairs are stored in the step's Parameters.

Specified by:

configure in interface Configuring

getParameters

public Parameters getParameters()

Description copied from interface: Parameterizing

Gets the parameters on the step.

Specified by:

getParameters in interface Parameterizing

getRequirements

public Set<TraverserRequirement> getRequirements()

Description copied from interface: Step

Provide the necessary TraverserRequirement that must be met by the traverser in order for the step to function properly. The provided default implements returns an empty set.

Specified by:

getRequirements in interface Step<S,Map<String,Object>>

Returns:

the set of requirements

getMatchQuery

public String getMatchQuery()

Returns the declarative query string passed to this step.

getParams

public Map<String,Object> getParams()

Returns the query parameters, or null if none were provided.

getQueryLanguage

public String getQueryLanguage()

Returns the query language identifier in use for this step.

isStart

public boolean isStart()

Returns true if this step is the first step in the traversal (spawned from a GraphTraversalSource).

toString

public String toString()

Overrides:

toString in class AbstractStep<S,Map<String,Object>>