net.sf.saxon.expr
public class RangeExpression extends BinaryExpression
From Saxon 7.8, the sequence must be ascending; if the end-point is less than the start-point, an empty sequence is returned. This is to allow expressions of the form "for $i in 1 to count($seq) return ...."
Constructor Summary | |
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RangeExpression(Expression start, int op, Expression end)
Construct a RangeExpression |
Method Summary | |
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int | computeCardinality()
Determine the static cardinality |
Expression | copy()
Copy an expression. |
ItemType | getItemType(TypeHierarchy th)
Get the data type of the items returned |
SequenceIterator | iterate(XPathContext context)
Return an iteration over the sequence |
Expression | optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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Expression | typeCheck(ExpressionVisitor visitor, ItemType contextItemType)
Type-check the expression |
Parameters: start expression that computes the start of the range op represents the operator "to", needed only because this class is a subclass of BinaryExpression which needs an operator end expression that computes the end of the range
Returns: the copy of the original expression
Parameters: th the type hierarchy cache
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: visitor an expression visitor 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: XPathException if an error is discovered during this phase (typically a type error)