| java.lang.Object
 net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.UnaryExpression
net.sf.saxon.expr.SingletonAtomizer
| SingletonAtomizer | | final public class SingletonAtomizer extends UnaryExpression (Code) | | A SingletonAtomizer combines the functions of an Atomizer and a CardinalityChecker: it is used to
atomize a sequence of nodes, checking that the result of the atomization contains zero or one atomic
values. Note that the input may be a sequence of nodes or atomic values, even though the result must
contain at most one atomic value.
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| SingletonAtomizer | | public SingletonAtomizer(Expression sequence, RoleLocator role, boolean allowEmpty)(Code) | | Constructor
Parameters:
sequence - the sequence to be atomized
Parameters:
allowEmpty - true if the result sequence is allowed to be empty. |
| computeCardinality | | public int computeCardinality()(Code) | | Determine the static cardinality of the expression
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| displayOperator | | protected String displayOperator(NamePool pool)(Code) | | Give a string representation of the operator for use in diagnostics
the operator, as a string |
| evaluateItem | | public Item evaluateItem(XPathContext context) throws XPathException(Code) | | Evaluate as an Item. This should only be called if the Atomizer has cardinality zero-or-one,
which will only be the case if the underlying expression has cardinality zero-or-one.
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| getItemType | | public ItemType getItemType(TypeHierarchy th)(Code) | | Determine the data type of the items returned by the expression, if possible
a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER. For this class, theresult is always an atomic type, but it might be more specific.
Parameters:
th - |
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