org.exist.xpath
Class Union
java.lang.Object
org.exist.xpath.PathExpr
org.exist.xpath.Union
- All Implemented Interfaces:
- Expression
- public class Union
- extends PathExpr
Methods inherited from class org.exist.xpath.PathExpr |
add, add, addDocument, addPath, addPredicate, getDocumentSet, getExpression, getLength, preselect, setDocumentSet, setFirstExpression |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
left
protected PathExpr left
right
protected PathExpr right
Union
public Union(BrokerPool pool,
PathExpr left,
PathExpr right)
returnsType
public int returnsType()
- Description copied from interface:
Expression
- The type of value, this expression returns.
Depending on the type of expression, this method should
return one of the constants defined in class Constants, e.g.
TYPE_NODELIST, TYPE_STRING, TYPE_NUM, TYPE_BOOL.
- Specified by:
returnsType
in interface Expression
- Overrides:
returnsType
in class PathExpr
preselect
public DocumentSet preselect(DocumentSet in_docs)
- check relevant documents. if right operand is a string literal
we check which documents contain it at all. in other cases
do nothing.
- Specified by:
preselect
in interface Expression
- Overrides:
preselect
in class PathExpr
eval
public Value eval(DocumentSet docs,
NodeSet context,
NodeProxy node)
- Description copied from interface:
Expression
- Evaluate the expression represented by this object.
Depending on the context in which this expression is executed,
either context, node or both of them may be set. An implementing
class should know how to handle this. Most classes only expect
context to contain a list of nodes which represents the current
context of this expression.
- Specified by:
eval
in interface Expression
- Overrides:
eval
in class PathExpr
pprint
public java.lang.String pprint()
- Description copied from interface:
Expression
- Return a readable representation of this expression.
This method is called whenever the xpath-query should be
displayed to the user.
- Specified by:
pprint
in interface Expression
- Overrides:
pprint
in class PathExpr
setInPredicate
public void setInPredicate(boolean inPredicate)
- Description copied from interface:
Expression
- This method is called to inform the expression object that
it is executed inside an XPath predicate.
- Specified by:
setInPredicate
in interface Expression
- Overrides:
setInPredicate
in class PathExpr
Copyright (C) Wolfgang Meier. All rights reserved.