| java.lang.Object
 net.sf.saxon.expr.ComputedExpression
net.sf.saxon.expr.PositionRange
| PositionRange | | final public class PositionRange extends ComputedExpression (Code) | | PositionRange: a boolean expression that tests whether the position() is
within a certain range. This expression can occur in any context but it is
optimized when it appears as a predicate (see FilterIterator)
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| PositionRange | | public PositionRange(int min, int max)(Code) | | Create a constant position range
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| computeCardinality | | public int computeCardinality()(Code) | | Determine the static cardinality
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| getIntrinsicDependencies | | public int getIntrinsicDependencies()(Code) | | Get the dependencies
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| hasFocusDependentRange | | public boolean hasFocusDependentRange()(Code) | | Test whether the range is focus-dependent. An example of a focus-dependent range is
(1 to position()). We could treat last() specially but we don't.
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| isFirstPositionOnly | | public boolean isFirstPositionOnly()(Code) | | Test if the first and last position are both constant 1
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| iterateSubExpressions | | public Iterator iterateSubExpressions()(Code) | | Get the immediate sub-expressions of this expression. Default implementation
returns a zero-length array, appropriate for an expression that has no
sub-expressions.
an iterator containing the sub-expressions of this expression |
| makeTailExpression | | public TailExpression makeTailExpression(Expression start)(Code) | | If this is an open-ended range with a constant start position, make a TailExpression.
Otherwise return null
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| matchesAtMostOneItem | | public boolean matchesAtMostOneItem()(Code) | | Test if the position range matches at most one item
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| optimize | | public Expression optimize(Optimizer opt, StaticContext env, ItemType contextItemType) throws XPathException(Code) | | Perform optimisation of an expression and its subexpressions.
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 allowsdifferent optimization strategies to be used in different circumstances.
Parameters:
env - the static context of the expression
Parameters:
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 tonet.sf.saxon.type.Type.ITEM_TYPE 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) |
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