net.sf.saxon.functions
Class SystemFunction

java.lang.Object
  net.sf.saxon.expr.ComputedExpression
      net.sf.saxon.expr.FunctionCall
          net.sf.saxon.functions.SystemFunction

All Implemented Interfaces:

Container, Expression, InstructionInfoProvider, java.io.Serializable, javax.xml.transform.SourceLocator

Direct Known Subclasses:

Adjust, Aggregate, Available, BaseURI, BooleanFn, CodepointEqual, CollatingFunction, Collection, CompileTimeFunction, Component, Concat, Current, CurrentDateTime, CurrentGroup, DateTimeConstructor, Doc, Document, DynamicFunctionCall, Error, EscapeURI, Evaluate, Existence, Find, ForceCase, ForEachGroupFunction, FormatDate, FormatNumber2, Id, Idref, InScopePrefixes, Insert, KeyFn, Lang, Last, Matches, NamePart, NamespaceForPrefix, Nilled, NormalizeSpace, NormalizeUnicode, NumberFn, Parse, Position, QNameFn, RegexGroup, Remove, Replace, ResolveQName, ResolveURI, Root, Rounding, Serialize, StringFn, StringJoin, StringLength, Subsequence, Substring, SystemProperty, Tokenize, Trace, Translate, TreatFn, Try, Unicode, UnparsedEntity, UnparsedText

public abstract class SystemFunction

extends FunctionCall

Abstract superclass for system-defined and user-defined functions

See Also:

Serialized Form

Field Summary

protected int

operation

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

argument

Fields inherited from class net.sf.saxon.expr.ComputedExpression

locationId, staticProperties

Fields inherited from interface net.sf.saxon.expr.Expression

EVALUATE_METHOD, ITERATE_METHOD, PROCESS_METHOD

Constructor Summary

SystemFunction()

Method Summary

protected void	addContextDocumentArgument(int pos, java.lang.String augmentedName) Add an implicit argument referring to the context document.
void	checkArguments(StaticContext env) Method called during static type checking
int	computeCardinality() Determine the cardinality of the function.
int	computeSpecialProperties() Determine the special properties of this expression.
void	display(int level, NamePool pool, java.io.PrintStream out) Diagnostic print of expression structure
protected StandardFunction.Entry	getDetails() Get the details
java.lang.String	getErrorCodeForTypeErrors() Return the error code to be used for type errors
ItemType	getItemType(TypeHierarchy th) Determine the item type of the value returned by the function
protected SequenceType	getRequiredType(int arg) Get the required type of the nth argument
static void	main(java.lang.String[] args) The main() method of this class is not intended to be called, it merely tells the code inspection tools in IDEA that the constructors of each function class are actual entry points
static FunctionCall	makeSystemFunction(java.lang.String name, int arity, NamePool pool) Make a system function (one in the standard function namespace).
void	setDetails(StandardFunction.Entry entry) Set the details of this type of function
protected void	useContextItemAsDefault() Set "." as the default value for the first and only argument.

Methods inherited from class net.sf.saxon.expr.FunctionCall

checkArgumentCount, getDisplayName, getFunctionNameCode, getNumberOfArguments, iterateSubExpressions, optimize, preEvaluate, promote, setArguments, setFunctionNameCode, simplify, simplifyArguments, typeCheck

Methods inherited from class net.sf.saxon.expr.ComputedExpression

adoptChildExpression, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, getCardinality, getColumnNumber, getConstructType, getDependencies, getExecutable, getHostLanguage, getImplementationMethod, getInstructionInfo, getIntrinsicDependencies, getLineNumber, getLocationId, getLocationProvider, getParentExpression, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, hasBadParentPointer, iterate, markTailFunctionCalls, process, resetStaticProperties, setLocationId, setParentExpression, suppressValidation, typeError, typeError

Methods inherited from class java.lang.Object

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

Field Detail

operation

protected int operation

Constructor Detail

SystemFunction

public SystemFunction()

Method Detail

makeSystemFunction

public static FunctionCall makeSystemFunction(java.lang.String name,
                                              int arity,
                                              NamePool pool)

Make a system function (one in the standard function namespace).

Parameters:

name - The local name of the function. It may also be a lexical QName for a recognized built-in function, e.g. saxon:evaluate, in which case the prefix is hard-coded.

Returns:

a FunctionCall that implements this function, if it exists, or null if the function is unknown.

setDetails

public void setDetails(StandardFunction.Entry entry)

Set the details of this type of function

getDetails

protected StandardFunction.Entry getDetails()

Get the details

checkArguments

public void checkArguments(StaticContext env)
                    throws XPathException

Method called during static type checking

Specified by:

checkArguments in class FunctionCall

Throws:

XPathException

getErrorCodeForTypeErrors

public java.lang.String getErrorCodeForTypeErrors()

Return the error code to be used for type errors

getRequiredType

protected SequenceType getRequiredType(int arg)

Get the required type of the nth argument

getItemType

public ItemType getItemType(TypeHierarchy th)

Determine the item type of the value returned by the function

Parameters:

th -

Returns:

a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known at compile time)

computeCardinality

public int computeCardinality()

Determine the cardinality of the function.

Specified by:

computeCardinality in class ComputedExpression

computeSpecialProperties

public int computeSpecialProperties()

Determine the special properties of this expression. The general rule is that a system function call is non-creative if its return type is atomic, or if all its arguments are non-creative. This is overridden for the generate-id() function, which is considered creative if its operand is creative (because the result depends on the identity of the operand)

Overrides:

computeSpecialProperties in class ComputedExpression

useContextItemAsDefault

protected final void useContextItemAsDefault()

Set "." as the default value for the first and only argument. Called from subclasses.

addContextDocumentArgument

protected final void addContextDocumentArgument(int pos,
                                                java.lang.String augmentedName)
                                         throws StaticError

Add an implicit argument referring to the context document. Called by functions such as id() and key() that take the context document as an implicit argument

Throws:

StaticError

display

public void display(int level,
                    NamePool pool,
                    java.io.PrintStream out)

Diagnostic print of expression structure

Specified by:

display in interface Expression

Overrides:

display in class FunctionCall

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

The main() method of this class is not intended to be called, it merely tells the code inspection tools in IDEA that the constructors of each function class are actual entry points

Throws:

java.lang.Exception