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## net.sf.saxon.functions
Class IntegratedFunctionCall

    java.lang.Object
      net.sf.saxon.expr.Expression
          net.sf.saxon.expr.FunctionCall
              net.sf.saxon.functions.IntegratedFunctionCall

All Implemented Interfaces:
  Serializable, SourceLocator, LocationProvider, SaxonLocator, CallableExpression, InstructionInfo, Locator

    public class IntegratedFunctionCall

extends FunctionCall
implements CallableExpression

Expression representing a call to a user-written extension function implemented as a subtype of `ExtensionFunctionCall`

See Also:
  Serialized Form

Field Summary

Fields inherited from class net.sf.saxon.expr.FunctionCall
`argument`

Fields inherited from class net.sf.saxon.expr.Expression
`EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD`

Constructor Summary
`IntegratedFunctionCall(ExtensionFunctionCall function)`

Method Summary
`SequenceIterator<? extends Item>` | `call(SequenceIterator<? extends Item>[] arguments, XPathContext context)` Evaluate the expression
`void` | `checkArguments(ExpressionVisitor visitor)` Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read.
`protected int` | `computeCardinality()` Compute the static cardinality of this expression
`protected int` | `computeSpecialProperties()` Compute the special properties of this expression.
`Expression` | `copy()` Copy an expression.
`boolean` | `effectiveBooleanValue(XPathContext context)` Get the effective boolean value of the expression.
`ExtensionFunctionCall` | `getFunction()` Get the ExtensionFunctionCall object supplied by the application
`int` | `getIntrinsicDependencies()` Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.
`ItemType` | `getItemType(TypeHierarchy th)` Determine the data type of the expression, if possible.
`SequenceIterator` | `iterate(XPathContext context)` Return an Iterator to iterate over the values of a sequence.
`Expression` | `preEvaluate(ExpressionVisitor visitor)` Pre-evaluate a function at compile time.
`void` | `setContainer(Container container)` Mark an expression as being in a given Container.
`Expression` | `typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType)` Type-check the expression.

Methods inherited from class net.sf.saxon.expr.FunctionCall
`addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, getExpressionName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString`

Methods inherited from class net.sf.saxon.expr.Expression
`addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getImplementationMethod, getIntegerBounds, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError`

Methods inherited from class java.lang.Object
`clone, finalize, getClass, notify, notifyAll, wait, wait, wait`

Methods inherited from interface net.sf.saxon.expr.CallableExpression
`getArguments`

Constructor Detail

### IntegratedFunctionCall

    public IntegratedFunctionCall(ExtensionFunctionCall function)

Method Detail

### getFunction

    public ExtensionFunctionCall getFunction()

  Get the ExtensionFunctionCall object supplied by the application

  Returns:
    the ExtensionFunctionCall object

### setContainer

    public void setContainer(Container container)

  Mark an expression as being in a given Container. This link is used primarily for diagnostics: the container links to the location map held in the executable.

  This affects the expression and all its subexpressions. Any subexpressions that are not in the same container are marked with the new container, and this proceeds recursively. However, any subexpression that is already in the correct container is not modified.

  Overrides:
    `setContainer` in class `Expression`
  Parameters:
    `container` - The container of this expression.

### checkArguments

    public void checkArguments(ExpressionVisitor visitor)
                        throws XPathException

  Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read. This implementation of the method checks the arguments of the supplied function call against the argument types declared as part of the extension function definition, and generates code to do the conversion if necessary.

  Specified by:
    `checkArguments` in class `FunctionCall`
  Parameters:
    `visitor` - the expression visitor
  Throws:
    `XPathException` - if the arguments are statically determined to be incompatible with the declared argument types of the function.

### typeCheck

    public Expression typeCheck(ExpressionVisitor visitor,
                                ExpressionVisitor.ContextItemType contextItemType)
                         throws XPathException

  Type-check the expression.

  Overrides:
    `typeCheck` in class `FunctionCall`
  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 `Type.ITEM_TYPE`
  Returns:
    the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
  Throws:
    `XPathException` - if an error is discovered during this phase (typically a type error)

### preEvaluate

    public Expression preEvaluate(ExpressionVisitor visitor)
                           throws XPathException

  Pre-evaluate a function at compile time. Functions that do not allow pre-evaluation, or that need access to context information, can override this method.

  Overrides:
    `preEvaluate` in class `FunctionCall`
  Parameters:
    `visitor` - an expression visitor
  Returns:
    the result of the early evaluation, or the original expression, or potentially a simplified expression
  Throws:
    `XPathException` - if evaluation fails

### getItemType

    public ItemType getItemType(TypeHierarchy th)

  Determine the data type of the expression, if possible. All expression return sequences, in general; this method determines the type of the items within the sequence, assuming that (a) this is known in advance, and (b) it is the same for all items in the sequence.

  This method should always return a result, though it may be the best approximation that is available at the time.

  Specified by:
    `getItemType` in class `Expression`
  Parameters:
    `th` - the type hierarchy cache
  Returns:
    a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known at compile time)

### computeCardinality

    protected int computeCardinality()

  Compute the static cardinality of this expression

  Specified by:
    `computeCardinality` in class `Expression`
  Returns:
    the computed cardinality, as one of the values `StaticProperty.ALLOWS_ZERO_OR_ONE`, `StaticProperty.EXACTLY_ONE`, `StaticProperty.ALLOWS_ONE_OR_MORE`, `StaticProperty.ALLOWS_ZERO_OR_MORE`

### getIntrinsicDependencies

    public int getIntrinsicDependencies()

  Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".

  Overrides:
    `getIntrinsicDependencies` in class `Expression`
  Returns:
    a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty

### computeSpecialProperties

    protected int computeSpecialProperties()

  Compute the special properties of this expression. These properties are denoted by a bit-significant integer, possible values are in class `StaticProperty`. The "special" properties are properties other than cardinality and dependencies, and most of them relate to properties of node sequences, for example whether the nodes are in document order.

  Overrides:
    `computeSpecialProperties` in class `Expression`
  Returns:
    the special properties, as a bit-significant integer

### copy

    public Expression copy()

  Copy an expression. This makes a deep copy.

  Specified by:
    `copy` in class `Expression`
  Returns:
    the copy of the original expression

### iterate

    public SequenceIterator iterate(XPathContext context)
                             throws XPathException

  Return an Iterator to iterate over the values of a sequence. The value of every expression can be regarded as a sequence, so this method is supported for all expressions. This default implementation handles iteration for expressions that return singleton values: for non-singleton expressions, the subclass must provide its own implementation.

  Overrides:
    `iterate` in class `Expression`
  Parameters:
    `context` - supplies the context for evaluation
  Returns:
    a SequenceIterator that can be used to iterate over the result of the expression
  Throws:
    `XPathException` - if any dynamic error occurs evaluating the expression

### effectiveBooleanValue

    public boolean effectiveBooleanValue(XPathContext context)
                                  throws XPathException

  Get the effective boolean value of the expression. This returns false if the value is the empty sequence, a zero-length string, a number equal to zero, or the boolean false. Otherwise it returns true.

  Overrides:
    `effectiveBooleanValue` in class `Expression`
  Parameters:
    `context` - The context in which the expression is to be evaluated
  Returns:
    the effective boolean value
  Throws:
    `XPathException` - if any dynamic error occurs evaluating the expression

### call

    public SequenceIterator<? extends Item> call(SequenceIterator<? extends Item>[] arguments,
                                                 XPathContext context)
                                          throws XPathException

  Description copied from interface: `CallableExpression`
  Evaluate the expression

  Specified by:
    `call` in interface `CallableExpression`
  Parameters:
    `arguments` - the values of the arguments, supplied as SequenceIterators
    `context` - the dynamic evaluation context
  Returns:
    the result of the evaluation, in the form of a SequenceIterator
  Throws:
    `XPathException` - if a dynamic error occurs during the evaluation of the expression

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Copyright (c) 2004-2011 Saxonica Limited. All rights reserved.