org.basex.query.xpath.func
Class Last
java.lang.Object
org.basex.query.ExprInfo
org.basex.query.xpath.expr.Expr
org.basex.query.xpath.func.Func
org.basex.query.xpath.func.Last
public final class Last
- extends Func
Constructor for last() function.
- Author:
- Workgroup DBIS, University of Konstanz 2005-08, ISC License, Tim Petrowsky
Fields inherited from class org.basex.query.xpath.func.Func |
desc |
Constructor Summary |
Last(Expr[] arg)
Function Constructor. |
Method Summary |
boolean |
checkArguments()
Checks validity/number of arguments. |
Dbl |
eval(XPContext ctx)
Evaluates the expression with the specified context set. |
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 |
Last
public Last(Expr[] arg)
- Function Constructor.
- Parameters:
arg
- expression array
eval
public Dbl eval(XPContext ctx)
throws QueryException
- Description copied from class:
Expr
- Evaluates the expression with the specified context set. Additionally
provides a context
- Specified by:
eval
in class Expr
- Parameters:
ctx
- query context
- Returns:
- resulting XPathValue
- Throws:
QueryException
- evaluation exception
checkArguments
public boolean checkArguments()
- Description copied from class:
Func
- Checks validity/number of arguments.
- Specified by:
checkArguments
in class Func
- Returns:
- result of comparison
usesSize
public 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.
- Overrides:
usesSize
in class Func
- Returns:
- whether setsize is used