net.sf.saxon.functions

Class DynamicErrorInfo

java.lang.Object

net.sf.saxon.lib.ExtensionFunctionDefinition

net.sf.saxon.functions.DynamicErrorInfo

public class DynamicErrorInfo
extends ExtensionFunctionDefinition

This class implements the extension function saxon:dynamic-error-info(), which underpins the variables accessible within saxon:catch such as $err:code etc. This function is not documented for direct use by applications, though there is no reason it would not work; instead, calls to this function are generated to represent the conventional variables $err:code, $err:description, etc. The function has a single argument, which is the local name of the corresponding variable name, as a string.

Constructor Summary

Constructors

Constructor and Description
DynamicErrorInfo()

Method Summary

Methods

Modifier and Type	Method and Description
boolean	dependsOnFocus() Ask whether the result of the function depends on the focus
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
boolean	hasSideEffects() Ask whether the function has side-effects.
ExtensionFunctionCall	makeCallExpression() Create a call on this function.

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

trustResultType

Methods inherited from class java.lang.Object

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

Constructor Detail

DynamicErrorInfo

public DynamicErrorInfo()

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.

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

dependsOnFocus

public boolean dependsOnFocus()

Ask whether the result of the function depends on the focus

Overrides:

dependsOnFocus in class ExtensionFunctionDefinition

Returns:

true if the result of the function depends on the context item, position, or size. The default implementation returns false. This must be set to true if the function makes use of any of these values from the dynamic context.

hasSideEffects

public boolean hasSideEffects()

Ask whether the function has side-effects. If the function does have side-effects, the optimizer will be less aggressive in moving or removing calls to the function. However, calls on functions with side-effects can never be guaranteed.

Overrides:

hasSideEffects in class ExtensionFunctionDefinition

Returns:

true if the function has side-effects (including creation of new nodes, if the identity of those nodes is significant). The default implementation returns false.

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