net.sf.saxon.expr
public final class ContextItemExpression extends ComputedExpression
Field Summary | |
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ItemType | itemType |
Constructor Summary | |
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ContextItemExpression() |
Method Summary | |
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int | computeCardinality()
Get the static cardinality |
int | computeSpecialProperties()
Determine the special properties of this expression |
void | display(int level, NamePool pool, PrintStream out)
Diagnostic print of expression structure |
boolean | equals(Object other)
Is this expression the same as another expression? |
Item | evaluateItem(XPathContext context)
Evaluate the expression |
int | getIntrinsicDependencies() |
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.
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Expression | typeCheck(StaticContext env, ItemType contextItemType)
Type-check the expression. |
Returns: NON_CREATIVE
Parameters: th
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.
Parameters: 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 expression contextItemType 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 ITEM_TYPE
Returns: the original expression, rewritten if appropriate to optimize execution
Throws: net.sf.saxon.trans.StaticError if an error is discovered during this phase (typically a type error)