com.saxonica.functions.hof

Class DynamicFunctionCallDefinition

java.lang.Object

net.sf.saxon.lib.ExtensionFunctionDefinition

com.saxonica.functions.hof.DynamicFunctionCallDefinition

public class DynamicFunctionCallDefinition
extends ExtensionFunctionDefinition

This class implements the extension function saxon:call(), which calls a FunctionItem The first argument is the FunctionItem object, the remaining arguments are the parameters to be supplied in the call.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	DynamicFunctionCallDefinition.DynamicFunctionCall

Constructor Summary

Constructors

Constructor and Description
DynamicFunctionCallDefinition()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	dependsOnFocus() Ask whether the result of the function depends on the focus, or on other variable parts of the context.
SequenceType[]	getArgumentTypes() Get the required types for the arguments of this function, counting from zero
StructuredQName	getFunctionQName() Get the function name, as a QName
int	getMaximumNumberOfArguments() Get the maximum number of arguments allowed by the function
int	getMinimumNumberOfArguments() Get the minimum number of arguments required by the function
SequenceType	getResultType(SequenceType[] suppliedArgumentTypes) Get the type of the result of the function
ExtensionFunctionCall	makeCallExpression() Create a call on this function.

Methods inherited from class net.sf.saxon.lib.ExtensionFunctionDefinition

hasSideEffects, trustResultType

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

DynamicFunctionCallDefinition

public DynamicFunctionCallDefinition()

Method Detail

getFunctionQName

public StructuredQName getFunctionQName()

Get the function name, as a QName

Specified by:

getFunctionQName in class ExtensionFunctionDefinition

Returns:

the QName of the function

getMinimumNumberOfArguments

public int getMinimumNumberOfArguments()

Get the minimum number of arguments required by the function

Overrides:

getMinimumNumberOfArguments in class ExtensionFunctionDefinition

Returns:

the minimum number of arguments that must be supplied in a call to this function

getMaximumNumberOfArguments

public int getMaximumNumberOfArguments()

Get the maximum number of arguments allowed by the function

Overrides:

getMaximumNumberOfArguments in class ExtensionFunctionDefinition

Returns:

the maximum number of arguments that may be supplied in a call to this function

getArgumentTypes

public SequenceType[] getArgumentTypes()

Get the required types for the arguments of this function, counting from zero

Specified by:

getArgumentTypes in class ExtensionFunctionDefinition

Returns:

the required types of the argument, as defined by the function signature. Normally this should be an array of size getMaximumNumberOfArguments(); however for functions that allow a variable number of arguments, the array can be smaller than this, with the last entry in the array providing the required type for all the remaining arguments.

dependsOnFocus

public boolean dependsOnFocus()

Ask whether the result of the function depends on the focus, or on other variable parts of the context.

Overrides:

dependsOnFocus in class ExtensionFunctionDefinition

Returns:

true if the result of the function depends on the context item, position, or size. Despite the method name, the method should also return true if the function depends on other parts of the context that vary from one part of the query/stylesheet to another, for example the XPath default namespace.

The default implementation returns false.

The method must return true if the function makes use of any of these values from the dynamic context. Returning true inhibits certain optimizations, such as moving the function call out of the body of an xsl:for-each loop, or extracting it into a global variable.

getResultType

public SequenceType getResultType(SequenceType[] suppliedArgumentTypes)

Get the type of the result of the function

Specified by:

getResultType in class ExtensionFunctionDefinition

Parameters:

suppliedArgumentTypes - the static types of the arguments to the function. This is provided so that a more precise result type can be returned in the common case where the type of the result depends on the type of the first argument. The value will be null if the function call has no arguments.

Returns:

the return type of the function, as defined by its function signature

makeCallExpression

public ExtensionFunctionCall makeCallExpression()

Create a call on this function. This method is called by the compiler when it identifies a function call that calls this function.

Specified by:

makeCallExpression in class ExtensionFunctionDefinition

Returns:

an expression representing a call of this extension function