net.sf.saxon.expr
public final class InstanceOfExpression extends UnaryExpression implements MappingExpression
Field Summary | |
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int | targetCardinality |
ItemType | targetType |
Constructor Summary | |
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InstanceOfExpression(Expression source, SequenceType target)
Construct an "instance of" expression in the form "source instance of target" |
Method Summary | |
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int | computeCardinality()
Determine the cardinality |
Expression | copy()
Copy an expression. |
boolean | effectiveBooleanValue(XPathContext context)
Evaluate the expression as a boolean |
boolean | equals(Object other)
Is this expression the same as another expression? |
Item | evaluateItem(XPathContext context)
Evaluate the expression |
void | explain(ExpressionPresenter destination)
Diagnostic print of expression structure. |
ItemType | getItemType(TypeHierarchy th)
Determine the data type of the result of the InstanceOf expression |
SequenceIterator | getMappingIterator(SequenceIterator base, XPathContext context)
Return an iterator over the results of the expression, given an iterator over the principal
operand to the expression |
int | getRequiredCardinality()
Get the cardinality that we are testing for membership of |
ItemType | getRequiredItemType()
Get the item type that we are testing for membership of |
Expression | optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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Expression | typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Type-check the expression |
Parameters: source the expression whose type is to be tested target the type against which it is tested
Returns: the copy of the original expression
Parameters: th the type hierarchy cache
Parameters: base an interator over the input to the expression context dynamic evaluation context
Returns: an iterator over the results of the expression
Throws: XPathException
Returns: the required cardinality
Returns: the item type
This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
Parameters: visitor an expression visitor contextItemType the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set to ITEM_TYPE
Returns: the original expression, rewritten if appropriate to optimize execution
Throws: XPathException if an error is discovered during this phase (typically a type error)
Returns: the checked expression