net.sf.saxon.expr
public final class ItemChecker extends UnaryExpression implements MappingExpression
Constructor Summary | |
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ItemChecker(Expression sequence, ItemType itemType, RoleLocator role)
Constructor |
Method Summary | |
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Expression | copy()
Copy an expression. |
boolean | equals(Object other)
Is this expression the same as another expression? |
Item | evaluateItem(XPathContext context)
Evaluate as an Item. |
void | explain(ExpressionPresenter out)
Diagnostic print of expression structure. |
int | getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
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ItemType | getItemType(TypeHierarchy th)
Determine the data type of the items returned by the expression |
SequenceIterator | getMappingIterator(SequenceIterator base, XPathContext context) |
ItemType | getRequiredType()
Get the required type |
RoleLocator | getRoleLocator()
Get the RoleLocator (used to construct error messages) |
SequenceIterator | iterate(XPathContext context)
Iterate over the sequence of values |
void | process(XPathContext context)
Process the instruction, without returning any tail calls
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Expression | simplify(ExpressionVisitor visitor)
Simplify an expression |
Expression | typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Type-check the expression |
Parameters: sequence the expression whose value we are checking itemType the required type of the items in the sequence role information used in constructing an error message
Returns: the copy of the original expression
Parameters: th the type hierarchy cache
Returns: the required type of the items in the sequence
Returns: the RoleLocator
Parameters: context The dynamic context, giving access to the current node, the current variables, etc.
Parameters: visitor an expression visitor