net.sf.saxon.functions
public class Minimax extends CollatingFunction
Field Summary | |
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static int | MAX |
static int | MIN |
Method Summary | |
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void | checkArguments(ExpressionVisitor visitor)
Static analysis: prevent sorting of the argument |
int | computeCardinality()
Determine the cardinality of the function. |
Item | evaluateItem(XPathContext context)
Evaluate the function |
ItemType | getItemType(TypeHierarchy th)
Determine the item type of the value returned by the function
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boolean | isIgnoreNaN()
Test whether NaN values are to be ignored |
static AtomicValue | minimax(SequenceIterator iter, int operation, AtomicComparer atomicComparer, boolean ignoreNaN, XPathContext context)
Static method to evaluate the minimum or maximum of a sequence |
Expression | optimize(ExpressionVisitor visitor, ItemType contextItemType)
Perform optimisation of an expression and its subexpressions.
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void | setIgnoreNaN(boolean ignore)
Indicate whether NaN values should be ignored. |
Parameters: th the type hierarchy cache
Returns: the statically inferred type of the expression
Returns: true if NaN values are to be ignored. This is the case for internally-generated min() and max() functions used to support general comparisons
Parameters: iter Iterator over the input sequence operation either MIN or MAX atomicComparer an AtomicComparer used to compare values ignoreNaN true if NaN values are to be ignored context dynamic evaluation context
Returns: the min or max value in the sequence, according to the rules of the fn:min() or fn:max() functions
Throws: XPathException typically if non-comparable values are found in the sequence
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)
Parameters: ignore true if NaN values are to be ignored when computing the min or max.