mondrian.olap.fun
Class UdfResolver

java.lang.Object
  mondrian.olap.fun.UdfResolver

All Implemented Interfaces:

Resolver

public class UdfResolver
extends Object
implements Resolver

Resolver for user-defined functions.

Since:

2.0

Author:

jhyde

Constructor Summary

UdfResolver(UserDefinedFunction udf)

Method Summary

String	getDescription() Returns the description of the function or operator.
FunDef	getFunDef() Returns a representative example of the function which this Resolver can produce, for purposes of describing the function set.
String	getName() Returns the name of the function or operator.
String[]	getReservedWords() Returns an array of symbolic constants which can appear as arguments to this function.
String	getSignature() Returns a string describing the syntax of this function, for example
Syntax	getSyntax() Returns the syntax with which the function or operator was invoked.
boolean	requiresExpression(int k) Returns whether a particular argument must be a scalar expression.
FunDef	resolve(Exp[] args, Validator validator, int[] conversionCount) Given a particular set of arguments the function is applied to, returns the correct overloaded form of the function.

Methods inherited from class java.lang.Object

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

Constructor Detail

UdfResolver

public UdfResolver(UserDefinedFunction udf)

Method Detail

getName

public String getName()

Description copied from interface: Resolver

Returns the name of the function or operator.

Specified by:

getName in interface Resolver

getDescription

public String getDescription()

Description copied from interface: Resolver

Returns the description of the function or operator.

Specified by:

getDescription in interface Resolver

getSignature

public String getSignature()

Description copied from interface: Resolver

Returns a string describing the syntax of this function, for example

StrToSet()

Specified by:

getSignature in interface Resolver

getSyntax

public Syntax getSyntax()

Description copied from interface: Resolver

Returns the syntax with which the function or operator was invoked.

Specified by:

getSyntax in interface Resolver

getFunDef

public FunDef getFunDef()

Description copied from interface: Resolver

Returns a representative example of the function which this Resolver can produce, for purposes of describing the function set. May return null if there is no representative function, or if the Resolver has a way to describe itself in more detail.

Specified by:

getFunDef in interface Resolver

resolve

public FunDef resolve(Exp[] args,
                      Validator validator,
                      int[] conversionCount)

Description copied from interface: Resolver

Given a particular set of arguments the function is applied to, returns the correct overloaded form of the function.

The method must increment conversionCount argument every time it performs an implicit type-conversion. If there are several candidate functions with the same signature, the validator will choose the one which used the fewest implicit conversions.

Specified by:

resolve in interface Resolver

Parameters:

args - Expressions which this function call is applied to.

validator - Validator

conversionCount - This argument must be an int array with a single element; in effect, it is an in/out parameter. It The method increments the count every time it performs a conversion.

Returns:

The function definition which matches these arguments, or null if no function definition that this resolver knows about matches.

requiresExpression

public boolean requiresExpression(int k)

Description copied from interface: Resolver

Returns whether a particular argument must be a scalar expression. Returns false if any of the variants of this resolver allows a set as its kth argument; true otherwise.

Specified by:

requiresExpression in interface Resolver

getReservedWords

public String[] getReservedWords()

Description copied from interface: Resolver

Returns an array of symbolic constants which can appear as arguments to this function.

For example, the DrilldownMember may take the symbol RECURSIVE as an argument. Most functions do not define any symbolic constants.

Specified by:

getReservedWords in interface Resolver

Returns:

An array of the names of the symbolic constants