com.facebook.buck.query

Interface QueryEnvironment.QueryFunction<OUTPUT_TYPE extends QueryTarget,ENV_NODE_TYPE>

Type Parameters:

ENV_NODE_TYPE - determines the type of the QueryEnvironment in which this function is expected to operate.

OUTPUT_TYPE - return type of this function.

All Known Implementing Classes:

AllPathsFunction, AttrFilterFunction, AttrRegexFilterFunction, BuildFileFunction, ClasspathFunction, DepsFunction, DepsFunction.FirstOrderDepsFunction, DepsFunction.LookupFunction, FilterFunction, InputsFunction, KindFunction, LabelsFunction, OwnerFunction, RdepsFunction, TestsOfFunction

Enclosing interface:

QueryEnvironment<NODE_TYPE>

public static interface QueryEnvironment.QueryFunction<OUTPUT_TYPE extends QueryTarget,ENV_NODE_TYPE>

A user-defined query function.

Method Summary

Modifier and Type	Method and Description
Set<OUTPUT_TYPE>	eval(QueryEvaluator<ENV_NODE_TYPE> evaluator, QueryEnvironment<ENV_NODE_TYPE> env, com.google.common.collect.ImmutableList<QueryEnvironment.Argument<ENV_NODE_TYPE>> 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.

Method Detail

getName

String getName()

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

getMandatoryArguments

int getMandatoryArguments()

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 getArgumentTypes().

getArgumentTypes

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

The types of the arguments of the function.

eval

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

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

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 getArgumentTypes() and 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