Package org.apache.jena.sparql.algebra.op

Class OpFilter

java.lang.Object

org.apache.jena.sparql.util.PrintSerializableBase

org.apache.jena.sparql.algebra.op.OpBase

org.apache.jena.sparql.algebra.op.Op1

org.apache.jena.sparql.algebra.op.OpFilter

All Implemented Interfaces:

org.apache.jena.atlas.io.Printable, Op, Named, PrintSerializable

public class OpFilter
extends Op1

Method Summary

Modifier and Type	Method	Description
Op	apply(Transform transform, Op subOp)
Op1	copy(Op subOp)
static OpFilter	ensureFilter(Op op)	Ensure that the algebra op is a filter.
boolean	equalTo(Op other, NodeIsomorphismMap labelMap)
static Op	filter(Expr expr, Op op)	Add expression - mutates an existing filter
static OpFilter	filterAlways(ExprList exprs, Op subOp)	Create a OpFilter with the expressions and subOp.
static Op	filterBy(ExprList exprs, Op op)	Combine an ExprList with an Op so that the expressions filter the Op.
static OpFilter	filterDirect(ExprList exprs, Op op)	Make a OpFilter - guaranteed to return an fresh OpFilter
static OpFilter	filterDirect(Expr expr, Op op)	Make a OpFilter - guaranteed to return an fresh OpFilter
ExprList	getExprs()
java.lang.String	getName()
int	hashCode()
static OpFilter	tidy(OpFilter base)	Compress multiple filters: (filter (filter (filter op)))) into one (filter op)
void	visit(OpVisitor opVisitor)

Methods inherited from class org.apache.jena.sparql.algebra.op.Op1

getSubOp

Methods inherited from class org.apache.jena.sparql.algebra.op.OpBase

equals, output, output

Methods inherited from class org.apache.jena.sparql.util.PrintSerializableBase

toString, toString

Methods inherited from class java.lang.Object

getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.apache.jena.sparql.util.PrintSerializable

toString

Method Detail

filter

public static Op filter(Expr expr,
                        Op op)

Add expression - mutates an existing filter

ensureFilter

public static OpFilter ensureFilter(Op op)

Ensure that the algebra op is a filter. If the input is a filter, just return that, else create a filter with no expressions and "this" as the subOp.

API Note:

This operation assumes the caller is going to add expressions. Filters without any expressions are discouraged. Consider collecting the expressions together first and using filterBy(org.apache.jena.sparql.expr.ExprList, org.apache.jena.sparql.algebra.Op).

filterBy

public static Op filterBy(ExprList exprs,
                          Op op)

Combine an ExprList with an Op so that the expressions filter the Op. If the exprs are empty, return the Op. If the op is already a OpFilter, merge the expressions into the filters existing expressions. Else create a new OpFilter with the expressions and subOp.

filterAlways

public static OpFilter filterAlways(ExprList exprs,
                                    Op subOp)

Create a OpFilter with the expressions and subOp. If subOp is a filter, combine expressions (de-layer).

filterDirect

public static OpFilter filterDirect(ExprList exprs,
                                    Op op)

Make a OpFilter - guaranteed to return an fresh OpFilter

filterDirect

public static OpFilter filterDirect(Expr expr,
                                    Op op)

Make a OpFilter - guaranteed to return an fresh OpFilter

tidy

public static OpFilter tidy(OpFilter base)

Compress multiple filters: (filter (filter (filter op)))) into one (filter op)

getExprs

public ExprList getExprs()

getName

public java.lang.String getName()

apply

public Op apply(Transform transform,
                Op subOp)

Specified by:

apply in class Op1

visit

public void visit(OpVisitor opVisitor)

copy

public Op1 copy(Op subOp)

Specified by:

copy in class Op1

hashCode

public int hashCode()

Specified by:

hashCode in class OpBase

equalTo

public boolean equalTo(Op other,
                       NodeIsomorphismMap labelMap)

Specified by:

equalTo in interface Op

Specified by:

equalTo in class OpBase