ItemTypeCheckingFunction

java.lang.Object
- net.sf.saxon.expr.ItemTypeCheckingFunction

All Implemented Interfaces:

ItemMappingFunction
```
public class ItemTypeCheckingFunction
extends java.lang.Object
implements ItemMappingFunction
```
A mapping function for use in conjunction with an ItemMappingIterator that checks that all the items in a sequence are instances of a given item type

Constructor Summary

Constructors
Constructor	Description
`ItemTypeCheckingFunction(ItemType requiredItemType, java.util.function.Supplier<RoleDiagnostic> roleSupplier, Location locator, Configuration config)`	Create the type-checking function

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type Method Description

Item mapItem(Item item)
Map one item to another item.
- Methods inherited from class java.lang.Object
  clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - ItemTypeCheckingFunction
```
public ItemTypeCheckingFunction(ItemType requiredItemType,
                                java.util.function.Supplier<RoleDiagnostic> roleSupplier,
                                Location locator,
                                Configuration config)
```
    Create the type-checking function
    
    Parameters:
    
    requiredItemType - the item type that all items in the sequence must conform to
    
    roleSupplier - information for error messages
    
    locator - the location of the expression for error messages
    
    config - the Saxon configuration
- Method Detail
  - mapItem
```
public Item mapItem(Item item)
             throws XPathException
```
    Description copied from interface: ItemMappingFunction
    
    Map one item to another item.
    
    Specified by:
    
    mapItem in interface ItemMappingFunction
    
    Parameters:
    
    item - The input item to be mapped.
    
    Returns:
    
    either the output item, or null.
    
    Throws:
    
    XPathException - if a dynamic error occurs