com.facebook.buck.query

Class LabelsFunction

java.lang.Object

com.facebook.buck.query.LabelsFunction

All Implemented Interfaces:

QueryEnvironment.QueryFunction<QueryTarget,QueryBuildTarget>

public class LabelsFunction
extends Object
implements QueryEnvironment.QueryFunction<QueryTarget,QueryBuildTarget>

A labels(label, argument) expression, which returns the targets in the attribute 'label' of the targets evaluated in the argument

expr ::= LABELS '(' WORD ',' expr ')'

Constructor Summary

Constructors

Constructor and Description
LabelsFunction()

Method Summary

Modifier and Type	Method and Description
Set<QueryTarget>	eval(QueryEvaluator<QueryBuildTarget> evaluator, QueryEnvironment<QueryBuildTarget> env, com.google.common.collect.ImmutableList<QueryEnvironment.Argument<QueryBuildTarget>> args) Called when a user-defined function is to be evaluated.
com.google.common.collect.ImmutableList<QueryEnvironment.ArgumentType>	getArgumentTypes() The types of the arguments of the function.
int	getMandatoryArguments() The number of arguments that are required.
String	getName() Name of the function as it appears in the query language.

Methods inherited from class java.lang.Object

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

Constructor Detail

LabelsFunction

public LabelsFunction()

Method Detail

getName

public String getName()

Description copied from interface: QueryEnvironment.QueryFunction

Name of the function as it appears in the query language.

Specified by:

getName in interface QueryEnvironment.QueryFunction<QueryTarget,QueryBuildTarget>

getMandatoryArguments

public int getMandatoryArguments()

Description copied from interface: QueryEnvironment.QueryFunction

The number of arguments that are required. The rest is optional.

This should be greater than or equal to zero and at smaller than or equal to the length of the list returned by QueryEnvironment.QueryFunction.getArgumentTypes().

Specified by:

getMandatoryArguments in interface QueryEnvironment.QueryFunction<QueryTarget,QueryBuildTarget>

getArgumentTypes

public com.google.common.collect.ImmutableList<QueryEnvironment.ArgumentType> getArgumentTypes()

Description copied from interface: QueryEnvironment.QueryFunction

The types of the arguments of the function.

Specified by:

getArgumentTypes in interface QueryEnvironment.QueryFunction<QueryTarget,QueryBuildTarget>

eval

public Set<QueryTarget> eval(QueryEvaluator<QueryBuildTarget> evaluator,
                             QueryEnvironment<QueryBuildTarget> env,
                             com.google.common.collect.ImmutableList<QueryEnvironment.Argument<QueryBuildTarget>> args)
                      throws QueryException

Description copied from interface: QueryEnvironment.QueryFunction

Called when a user-defined function is to be evaluated.

Specified by:

eval in interface QueryEnvironment.QueryFunction<QueryTarget,QueryBuildTarget>

Parameters:

evaluator - the evaluator for evaluating argument expressions.

env - the query environment this function is evaluated in.

args - the input arguments. These are type-checked against the specification returned by QueryEnvironment.QueryFunction.getArgumentTypes() and QueryEnvironment.QueryFunction.getMandatoryArguments()

Returns:

results of evaluating the query expression. The result type is mutable Set to enable actual implementation to avoid making unnecessary copies, but resulting set is not supposed to be mutated afterwards so implementation is ok to return ImmutableSet.

Throws:

QueryException