All Known Implementing Classes:

CacheFunDef.CacheFunResolver, MultiResolver, ParameterFunDef.ParameterResolver, ParameterFunDef.ParamRefResolver, ReflectiveMultiResolver, UdfResolver
```
public interface Resolver
```
A Resolver converts a function name, invocation type, and set of arguments into a FunDef.

Since:

3 March, 2002

Author:

jhyde

Nested Class Summary

Nested Classes
Modifier and Type Interface Description

static interface Resolver.Conversion
Description of an implicit conversion that occurred while resolving an operator call.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`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, List<Resolver.Conversion> conversions)`	Given a particular set of arguments the function is applied to, returns the correct overloaded form of the function.

- Method Detail
  - getName
```
String getName()
```
    Returns the name of the function or operator.
  - getDescription
```
String getDescription()
```
    Returns the description of the function or operator.
  - getSyntax
```
Syntax getSyntax()
```
    Returns the syntax with which the function or operator was invoked.
  - resolve
```
FunDef resolve(Exp[] args,
               Validator validator,
               List<Resolver.Conversion> conversions)
```
    Given a particular set of arguments the function is applied to, returns the correct overloaded form of the function.
    The method adds an item to conversions 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.
    
    Parameters:
    
    args - Expressions which this function call is applied to.
    
    validator - Validator
    
    conversions - List of implicit conversions performed (out)
    
    Returns:
    
    The function definition which matches these arguments, or null if no function definition that this resolver knows about matches.
  - requiresExpression
```
boolean requiresExpression(int k)
```
    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.
  - getReservedWords
```
String[] getReservedWords()
```
    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.
    
    Returns:
    
    An array of the names of the symbolic constants
  - getSignature
```
String getSignature()
```
    Returns a string describing the syntax of this function, for example
    StrToSet()
  - getFunDef
```
FunDef getFunDef()
```
    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.

Interface Resolver

Nested Class Summary

Method Summary

Method Detail

getName

getDescription

getSyntax

resolve

requiresExpression

getReservedWords

getSignature

getFunDef