org.basex.query.xquery.expr
Class Pred

java.lang.Object
  org.basex.query.ExprInfo
      org.basex.query.xquery.expr.Expr
          org.basex.query.xquery.expr.Arr
              org.basex.query.xquery.expr.Pred

Direct Known Subclasses:

PredIter

public class Pred
extends Arr

Predicate expression.

Author:

Workgroup DBIS, University of Konstanz 2005-08, ISC License, Christian Gruen

Nested Class Summary

Nested classes/interfaces inherited from class org.basex.query.xquery.expr.Expr

Expr.Return, Expr.Using

Field Summary

Fields inherited from class org.basex.query.xquery.expr.Arr

expr

Constructor Summary

Pred(Expr r, Expr[] e)
Constructor.

Method Summary

Expr	comp(XQContext ctx) Optimizes and compiles the expression.
java.lang.String	info() Returns a string description of the expression.
Iter	iter(XQContext ctx) Evaluates the expression and returns an iterator on the resulting items.
void	plan(Serializer ser) Recursively sends the abstract syntax of this expression to the specified serializer.
java.lang.String	toString()
boolean	uses(Expr.Using u) Indicates if an expression uses the specified type.

Methods inherited from class org.basex.query.xquery.expr.Arr

returned

Methods inherited from class org.basex.query.xquery.expr.Expr

e, i

Methods inherited from class org.basex.query.ExprInfo

color, name

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

Pred

public Pred(Expr r,
            Expr[] e)

Constructor.

Parameters:

r - expression

e - predicates

Method Detail

comp

public final Expr comp(XQContext ctx)
                throws XQException

Description copied from class: Expr

Optimizes and compiles the expression.

Overrides:

comp in class Arr

Parameters:

ctx - query context

Returns:

optimized Expression

Throws:

XQException - evaluation exception

iter

public Iter iter(XQContext ctx)
          throws XQException

Description copied from class: Expr

Evaluates the expression and returns an iterator on the resulting items.

Specified by:

iter in class Expr

Parameters:

ctx - query context

Returns:

resulting item

Throws:

XQException - evaluation exception

uses

public final boolean uses(Expr.Using u)

Description copied from class: Expr

Indicates if an expression uses the specified type. Called by the compiler to check if expressions can be reformulated. true is returned by default.

Overrides:

uses in class Arr

Parameters:

u - using flag

Returns:

result of check

toString

public final java.lang.String toString()

Specified by:

toString in class ExprInfo

info

public final java.lang.String info()

Description copied from class: ExprInfo

Returns a string description of the expression. Contrary to the ExprInfo.toString() method, the current expressions aren't included in the output.

Overrides:

info in class ExprInfo

Returns:

result of check

plan

public final void plan(Serializer ser)
                throws java.io.IOException

Description copied from class: ExprInfo

Recursively sends the abstract syntax of this expression to the specified serializer.

Overrides:

plan in class Arr

Parameters:

ser - serializer

Throws:

java.io.IOException - exception