org.basex.query.xpath.internal
Class InternalExpr
java.lang.Object
org.basex.query.ExprInfo
org.basex.query.xpath.expr.Expr
org.basex.query.xpath.internal.InternalExpr
- Direct Known Subclasses:
- AllOf, IndexAccess, IndexMatch, OneOf, Range, RangeAccess
public abstract class InternalExpr
- extends Expr
Abstract class for internal (optimized) XPath expressions.
- Author:
- Workgroup DBIS, University of Konstanz 2005-08, ISC License, Christian Gruen
Method Summary |
Expr |
comp(XPContext ctx)
Optimizes the expression. |
boolean |
usesPos()
Checks whether this Expression (or its children) make use of the position
parameter. |
boolean |
usesSize()
Checks whether this Expression (or its children) make use of the setsize
parameter. |
Methods inherited from class java.lang.Object |
equals, getClass, hashCode, notify, notifyAll, wait, wait, wait |
InternalExpr
public InternalExpr()
comp
public final Expr comp(XPContext ctx)
- Description copied from class:
Expr
- Optimizes the expression.
- Specified by:
comp
in class Expr
- Parameters:
ctx
- expression context
- Returns:
- optimized Expression
usesSize
public final boolean usesSize()
- Description copied from class:
Expr
- Checks whether this Expression (or its children) make use of the setsize
parameter. If not this allows early predicate evaluation.
- Specified by:
usesSize
in class Expr
- Returns:
- whether setsize is used
usesPos
public final boolean usesPos()
- Description copied from class:
Expr
- Checks whether this Expression (or its children) make use of the position
parameter. If not this allows some nice optimizations.
- Specified by:
usesPos
in class Expr
- Returns:
- whether position is used