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java.lang.Objectnet.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.ContextItemExpression
This class represents the expression "(dot)", which always returns the context item. This may be a AtomicValue or a Node.
| Field Summary |
| Fields inherited from class net.sf.saxon.expr.ComputedExpression |
locationId, staticProperties |
| Fields inherited from interface net.sf.saxon.expr.Expression |
EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD |
| Constructor Summary | |
ContextItemExpression()
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|
| Method Summary | |
int |
computeCardinality()
Get the static cardinality |
int |
computeSpecialProperties()
Determine the special properties of this expression |
ContextItemExpression |
copy()
Create a clone copy of this expression |
void |
display(int level,
java.io.PrintStream out,
Configuration config)
Diagnostic print of expression structure |
boolean |
equals(java.lang.Object other)
Is this expression the same as another expression? |
Item |
evaluateItem(XPathContext context)
Evaluate the expression |
protected java.lang.String |
getErrorCodeForUndefinedContext()
|
int |
getIntrinsicDependencies()
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. |
ItemType |
getItemType(TypeHierarchy th)
Determine the item type |
int |
hashCode()
get HashCode for comparing two expressions |
SequenceIterator |
iterate(XPathContext context)
Iterate over the value of the expression |
Expression |
optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
Perform optimisation of an expression and its subexpressions. |
Expression |
typeCheck(StaticContext env,
ItemType contextItemType)
Type-check the expression. |
| Methods inherited from class java.lang.Object |
clone, finalize, getClass, notify, notifyAll, toString, wait, wait, wait |
| Constructor Detail |
public ContextItemExpression()
| Method Detail |
public ContextItemExpression copy()
protected java.lang.String getErrorCodeForUndefinedContext()
public Expression typeCheck(StaticContext env,
ItemType contextItemType)
throws XPathException
env - the static context of the expressioncontextItemType - 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
Type.ITEM_TYPE
XPathException
public Expression optimize(Optimizer opt,
StaticContext env,
ItemType contextItemType)
throws XPathException
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.
opt - the optimizer in use. This provides access to supporting functions; it also allows
different optimization strategies to be used in different circumstances.env - the static context of the expressioncontextItemType - 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
Type.ITEM_TYPE
StaticError - if an error is discovered during this phase
(typically a type error)
XPathExceptionpublic ItemType getItemType(TypeHierarchy th)
th -
public int computeCardinality()
computeCardinality in class ComputedExpressionpublic int computeSpecialProperties()
computeSpecialProperties in class ComputedExpressionStaticProperty.NON_CREATIVEpublic boolean equals(java.lang.Object other)
public int hashCode()
public int getIntrinsicDependencies()
ComputedExpression
getIntrinsicDependencies in class ComputedExpression
public SequenceIterator iterate(XPathContext context)
throws XPathException
iterate in interface Expressioniterate in class ComputedExpressioncontext - supplies the context for evaluation
XPathException - if any dynamic error occurs evaluating the
expression
public Item evaluateItem(XPathContext context)
throws XPathException
evaluateItem in interface ExpressionevaluateItem in class ComputedExpressioncontext - The context in which the expression is to be evaluated
XPathException - if any dynamic error occurs evaluating the
expression
public void display(int level,
java.io.PrintStream out,
Configuration config)
level - indentation level for this expressionout - Output destinationconfig -
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