com.facebook.buck.query

Class RdepsFunction<T extends QueryTarget>

java.lang.Object

com.facebook.buck.query.RdepsFunction<T>

All Implemented Interfaces:

QueryEnvironment.QueryFunction<T,T>

public class RdepsFunction<T extends QueryTarget>
extends Object
implements QueryEnvironment.QueryFunction<T,T>

A 'rdeps(u, x, [, depth])' expression, which finds the reverse dependencies of the given argument set 'x' within the transitive closure of the set 'u'. The optional parameter 'depth' specifies the depth of the search. If the argument is absent, the search is unbounded.

expr ::= RDEPS '(' expr ',' expr ')'

       | RDEPS '(' expr ',' expr ',' WORD ')'

Constructor Summary

Constructors

Constructor and Description
RdepsFunction()

Method Summary

Modifier and Type	Method and Description
Set<T>	eval(QueryEvaluator<T> evaluator, QueryEnvironment<T> env, com.google.common.collect.ImmutableList<QueryEnvironment.Argument<T>> args) Evaluates to the reverse dependencies of the argument 'x' in the transitive closure of the set 'u'.
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

RdepsFunction

public RdepsFunction()

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<T extends QueryTarget,T extends QueryTarget>

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<T extends QueryTarget,T extends QueryTarget>

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<T extends QueryTarget,T extends QueryTarget>

eval

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

Evaluates to the reverse dependencies of the argument 'x' in the transitive closure of the set 'u'. Breadth first search from the set 'x' until there are no more unvisited nodes in the reverse transitive closure or the maximum depth (if supplied) is reached.

Specified by:

eval in interface QueryEnvironment.QueryFunction<T extends QueryTarget,T extends QueryTarget>

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