org.exist.xquery
Class FunctionCall

java.lang.Object
  org.exist.xquery.AbstractExpression
      org.exist.xquery.PathExpr
          org.exist.xquery.Function
              org.exist.xquery.FunctionCall

All Implemented Interfaces:

CompiledXQuery, Expression, CompiledExpression

public class FunctionCall
extends Function

Represents a call to a user-defined function UserDefinedFunction. FunctionCall wraps around a user-defined function. It makes sure that all function parameters are checked against the signature of the function.

Author:

wolf

Field Summary

Fields inherited from class org.exist.xquery.Function

BUILTIN_FUNCTION_NS

Fields inherited from interface org.exist.xquery.Expression

DOT_TEST, EXPRESSION_ID_INVALID, IGNORE_CONTEXT, IN_PREDICATE, IN_UPDATE, IN_WHERE_CLAUSE, NEED_INDEX_INFO, NO_CONTEXT_ID, SINGLE_STEP_EXECUTION

Constructor Summary

FunctionCall(XQueryContext context, QName name, List arguments)

FunctionCall(XQueryContext context, UserDefinedFunction functionDef)

Method Summary

void	accept(ExpressionVisitor visitor) Start traversing the expression tree using the specified ExpressionVisitor.
void	analyze(AnalyzeContextInfo contextInfo) Statically analyze the expression and its subexpressions.
Sequence	eval(Sequence contextSequence, Item contextItem) Evaluates all arguments, then forwards them to the user-defined function.
Sequence	evalFunction(Sequence contextSequence, Item contextItem, Sequence[] seq)
int	getArgumentCount() Get the number of arguments passed to this function.
QName	getQName()
void	resetState() Called to inform an expression that it should reset to its initial state.
void	resolveForwardReference(UserDefinedFunction functionDef) Called by XQueryContext to resolve a call to a function that has not yet been declared.

Methods inherited from class org.exist.xquery.Function

createFunction, dump, getArgument, getArguments, getASTNode, getCardinality, getDependencies, getName, getParent, getSignature, isCalledAs, returnsType, setArguments, setASTNode, setParent, setPrimaryAxis, toString

Methods inherited from class org.exist.xquery.PathExpr

add, add, addPath, addPredicate, dump, getContext, getDocumentSet, getExpression, getLastExpression, getLength, getLiteralValue, getSource, isValid, replaceExpression, replaceLastExpression, reset, setContext, setSource

Methods inherited from class org.exist.xquery.AbstractExpression

eval, getContextDocSet, getContextId, getExpressionId, setContextDocSet

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.exist.xquery.CompiledXQuery

eval

Constructor Detail

FunctionCall

public FunctionCall(XQueryContext context,
                    QName name,
                    List arguments)

FunctionCall

public FunctionCall(XQueryContext context,
                    UserDefinedFunction functionDef)

Method Detail

analyze

public void analyze(AnalyzeContextInfo contextInfo)
             throws XPathException

Description copied from interface: Expression

Statically analyze the expression and its subexpressions. During the static analysis phase, the query engine can detect unknown variables and some type errors.

Specified by:

analyze in interface Expression

Overrides:

analyze in class Function

Throws:

XPathException

resolveForwardReference

public void resolveForwardReference(UserDefinedFunction functionDef)
                             throws XPathException

Called by XQueryContext to resolve a call to a function that has not yet been declared. XQueryContext remembers all calls to undeclared functions and tries to resolve them after parsing has completed.

Parameters:

functionDef -

Throws:

XPathException

getArgumentCount

public int getArgumentCount()

Description copied from class: Function

Get the number of arguments passed to this function.

Overrides:

getArgumentCount in class Function

Returns:

number of arguments

getQName

public QName getQName()

eval

public Sequence eval(Sequence contextSequence,
                     Item contextItem)
              throws XPathException

Evaluates all arguments, then forwards them to the user-defined function. The return value of the user-defined function will be checked against the provided function signature.

Specified by:

eval in interface Expression

Specified by:

eval in class Function

Parameters:

contextSequence - the current context sequence.

contextItem - a single item, taken from context. This defines the item, the expression should work on.

Throws:

XPathException

See Also:

Expression.eval(Sequence, Item)

evalFunction

public Sequence evalFunction(Sequence contextSequence,
                             Item contextItem,
                             Sequence[] seq)
                      throws XPathException

Parameters:

contextSequence -

contextItem -

seq -

Throws:

XPathException

resetState

public void resetState()

Description copied from interface: Expression

Called to inform an expression that it should reset to its initial state. All cached data in the expression object should be dropped. For example, the document() function calls this method whenever the input document set has changed.

Specified by:

resetState in interface Expression

Overrides:

resetState in class PathExpr

accept

public void accept(ExpressionVisitor visitor)

Description copied from interface: Expression

Start traversing the expression tree using the specified ExpressionVisitor.

Specified by:

accept in interface Expression

Overrides:

accept in class Function