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 |
ItemType | getItemType(TypeHierarchy th)
Get the data type of the items returned |
SequenceIterator | iterate(XPathContext context)
Return an iteration over the sequence |
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 |
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)