net.sf.saxon.expr

Class ItemChecker

public final class ItemChecker extends UnaryExpression

A ItemChecker implements the item type checking of "treat as": that is, it returns the supplied sequence, checking that all its items are of the correct type

Constructor Summary
	ItemChecker(Expression sequence, ItemType itemType, RoleLocator role) Constructor

Method Summary
protected String	displayOperator(NamePool pool) Give a string representation of the operator for use in diagnostics
boolean	equals(Object other) Is this expression the same as another expression?
Item	evaluateItem(XPathContext context) Evaluate as an Item.
int	getImplementationMethod() An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
ItemType	getItemType(TypeHierarchy th) Determine the data type of the items returned by the expression
ItemType	getRequiredType() Get the required type
SequenceIterator	iterate(XPathContext context) Iterate over the sequence of values
void	process(XPathContext context) Process the instruction, without returning any tail calls
Expression	simplify(StaticContext env) Simplify an expression
Expression	typeCheck(StaticContext env, ItemType contextItemType) Type-check the expression

Constructor Detail

ItemChecker

public ItemChecker(Expression sequence, ItemType itemType, RoleLocator role)

Constructor

Method Detail

displayOperator

protected String displayOperator(NamePool pool)

Give a string representation of the operator for use in diagnostics

Returns: the operator, as a string

equals

public boolean equals(Object other)

Is this expression the same as another expression?

evaluateItem

public Item evaluateItem(XPathContext context)

Evaluate as an Item.

An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is provided. This implementation provides both iterate() and process() methods natively.