net.sf.saxon.functions
Class Doc
java.lang.Object
net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.FunctionCall
net.sf.saxon.functions.SystemFunction
net.sf.saxon.functions.Doc
- All Implemented Interfaces:
- Expression, Serializable
- public class Doc
- extends SystemFunction
Implement the fn:doc() function - a simplified form of the Document function
- See Also:
- Serialized Form
Constructor Summary |
Doc()
|
Methods inherited from class net.sf.saxon.expr.ComputedExpression |
computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, getCardinality, getDependencies, getIntrinsicDependencies, getLineNumber, getSpecialProperties, iterate, markTailFunctionCalls, setLineNumber, typeError |
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
Doc
public Doc()
checkArguments
public void checkArguments(StaticContext env)
throws XPathException
- Description copied from class:
SystemFunction
- Method called during static type checking
- Overrides:
checkArguments
in class SystemFunction
- Throws:
XPathException
preEvaluate
public Expression preEvaluate(StaticContext env)
- preEvaluate: this method suppresses compile-time evaluation by doing nothing
- Overrides:
preEvaluate
in class FunctionCall
evaluateItem
public Item evaluateItem(XPathContext context)
throws XPathException
- Description copied from class:
ComputedExpression
- Evaluate an expression as a single item. This always returns either a single Item or
null (denoting the empty sequence). No conversion is done. This method should not be
used unless the static type of the expression is a subtype of "item" or "item?": that is,
it should not be called if the expression may return a sequence. There is no guarantee that
this condition will be detected.
- Specified by:
evaluateItem
in interface Expression
- Overrides:
evaluateItem
in class ComputedExpression
- Parameters:
context
- The context in which the expression is to be evaluated
- Returns:
- the node or atomic value that results from evaluating the
expression; or null to indicate that the result is an empty
sequence
- Throws:
XPathException
- if any dynamic error occurs evaluating the
expression