com.facebook.buck.query

Class QueryExpression<NODE_TYPE>

java.lang.Object

com.facebook.buck.query.QueryExpression<NODE_TYPE>

Type Parameters:

NODE_TYPE - Type of the node in the QueryEnvironment this expression should be evaluated in the context of.

Direct Known Subclasses:

TargetLiteral

public abstract class QueryExpression<NODE_TYPE>
extends Object

Base class for expressions in the Buck query language.

All queries return a set of targets that match the query expression.

All queries must ensure that sufficient graph edges are created in the QueryEnvironment so that all nodes in the result are correctly ordered according to the type of query. For example, "deps" queries require that all the nodes in the transitive closure of its argument set are correctly ordered w.r.t. each other algebraic set operations such as intersect and union are inherently unordered.

Package overview

This package consists of two basic class hierarchies. The first, QueryExpression, is the set of different query expressions in the language, and the eval(com.facebook.buck.query.QueryEvaluator<NODE_TYPE>, com.facebook.buck.query.QueryEnvironment<NODE_TYPE>) method of each defines the semantics. The result of evaluating a query is set of Buck QueryTargets (a file or build target). The set may be interpreted as either a set or as nodes of a DAG, depending on the context.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	QueryExpression()

Method Summary

Modifier and Type	Method and Description
void	collectTargetPatterns(Collection<String> literals) Collects all target patterns that are referenced anywhere within this query expression and adds them to the given collection, which must be mutable.
Set<QueryTarget>	getTargets(QueryEnvironment<NODE_TYPE> env) Returns a set of all targets referenced from literals within this query expression.
static <NODE_TYPE> QueryExpression<NODE_TYPE>	parse(String query, QueryEnvironment<NODE_TYPE> env) Scan and parse the specified query expression.
abstract String	toString() Returns this query expression pretty-printed.
abstract void	traverse(com.facebook.buck.query.QueryExpression.Visitor<NODE_TYPE> visitor) Accepts and applies the given visitor.

Methods inherited from class java.lang.Object

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

Constructor Detail

QueryExpression

protected QueryExpression()

Method Detail

parse

public static <NODE_TYPE> QueryExpression<NODE_TYPE> parse(String query,
                                                           QueryEnvironment<NODE_TYPE> env)
                                                    throws QueryException

Scan and parse the specified query expression.

Throws:

QueryException

collectTargetPatterns

public void collectTargetPatterns(Collection<String> literals)

Collects all target patterns that are referenced anywhere within this query expression and adds them to the given collection, which must be mutable.

This is intended to accumulate patterns from multiple expressions for preloading at once.

traverse

public abstract void traverse(com.facebook.buck.query.QueryExpression.Visitor<NODE_TYPE> visitor)

Accepts and applies the given visitor.

getTargets

public Set<QueryTarget> getTargets(QueryEnvironment<NODE_TYPE> env)

Returns a set of all targets referenced from literals within this query expression.

toString

public abstract String toString()

Returns this query expression pretty-printed.

Overrides:

toString in class Object