Package org.apache.xpath.operations
Class Operation
java.lang.Object
org.apache.xpath.Expression
org.apache.xpath.operations.Operation
- All Implemented Interfaces:
Serializable
,SourceLocator
,ExpressionNode
,ExpressionOwner
,XPathVisitable
- Direct Known Subclasses:
And
,Div
,Equals
,Gt
,Gte
,Lt
,Lte
,Minus
,Mod
,Mult
,NotEquals
,Or
,Plus
,Quo
The baseclass for a binary operation.
- See Also:
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionvoid
callVisitors
(ExpressionOwner owner, XPathVisitor visitor) This will traverse the heararchy, calling the visitor for each member.boolean
Tell if this expression or it's subexpressions can traverse outside the current subtree.boolean
deepEquals
(Expression expr) Compare this object with another object and see if they are equal, include the sub heararchy.execute
(XPathContext xctxt) Execute a binary operation by calling execute on each of the operands, and then calling the operate method on the derived class.void
fixupVariables
(Vector vars, int globalsSize) This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.Get the raw Expression object that this class wraps.Apply the operation to two operands, and return the result.void
setExpression
(Expression exp) Set the raw expression object for this object.void
setLeftRight
(Expression l, Expression r) Set the left and right operand expressions for this operation.Methods inherited from class org.apache.xpath.Expression
asIterator, asIteratorRaw, asNode, assertion, bool, error, execute, execute, execute, executeCharsToContentHandler, exprAddChild, exprGetChild, exprGetNumChildren, exprGetParent, exprSetParent, getColumnNumber, getExpressionOwner, getLineNumber, getPublicId, getSystemId, isNodesetExpr, isStableNumber, num, warn, xstr
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Constructor Details
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Operation
public Operation()
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Method Details
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fixupVariables
This function is used to fixup variables from QNames to stack frame indexes at stylesheet build time.- Specified by:
fixupVariables
in classExpression
- Parameters:
vars
- List of QNames that correspond to variables. This list should be searched backwards for the first qualified name that corresponds to the variable reference qname. The position of the QName in the vector from the start of the vector will be its position in the stack frame (but variables above the globalsTop value will need to be offset to the current stack frame).
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canTraverseOutsideSubtree
public boolean canTraverseOutsideSubtree()Tell if this expression or it's subexpressions can traverse outside the current subtree.- Overrides:
canTraverseOutsideSubtree
in classExpression
- Returns:
- true if traversal outside the context node's subtree can occur.
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setLeftRight
Set the left and right operand expressions for this operation.- Parameters:
l
- The left expression operand.r
- The right expression operand.
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execute
Execute a binary operation by calling execute on each of the operands, and then calling the operate method on the derived class.- Specified by:
execute
in classExpression
- Parameters:
xctxt
- The runtime execution context.- Returns:
- The XObject result of the operation.
- Throws:
TransformerException
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operate
Apply the operation to two operands, and return the result.- Parameters:
left
- non-null reference to the evaluated left operand.right
- non-null reference to the evaluated right operand.- Returns:
- non-null reference to the XObject that represents the result of the operation.
- Throws:
TransformerException
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getLeftOperand
- Returns:
- the left operand of binary operation, as an Expression.
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getRightOperand
- Returns:
- the right operand of binary operation, as an Expression.
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callVisitors
Description copied from interface:XPathVisitable
This will traverse the heararchy, calling the visitor for each member. If the called visitor method returns false, the subtree should not be called.- Specified by:
callVisitors
in interfaceXPathVisitable
- Parameters:
owner
- The owner of the visitor, where that path may be rewritten if needed.visitor
- The visitor whose appropriate method will be called.- See Also:
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getExpression
Description copied from interface:ExpressionOwner
Get the raw Expression object that this class wraps.- Specified by:
getExpression
in interfaceExpressionOwner
- Returns:
- the raw Expression object, which should not normally be null.
- See Also:
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setExpression
Description copied from interface:ExpressionOwner
Set the raw expression object for this object.- Specified by:
setExpression
in interfaceExpressionOwner
- Parameters:
exp
- the raw Expression object, which should not normally be null.- See Also:
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deepEquals
Description copied from class:Expression
Compare this object with another object and see if they are equal, include the sub heararchy.- Specified by:
deepEquals
in classExpression
- Parameters:
expr
- Another expression object.- Returns:
- true if this objects class and the expr object's class are the same, and the data contained within both objects are considered equal.
- See Also:
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