IfElseMacro

java.lang.Object
- weka.core.expressionlanguage.common.IfElseMacro

All Implemented Interfaces:

Macro, MacroDeclarations
```
public class IfElseMacro
extends java.lang.Object
implements MacroDeclarations, Macro
```
A macro declaration exposing the ifelse function.
The ifelse macro can be used as follows:
ifelse(condition, ifpart, elsepart)
Whith the following constraints:
- condition must be of boolean type
- ifpart and elsepart must be of the same type
- ifpart must be either of boolean, double or string type
Examples:
- ifelse(A < B, true, A = B)
- ifelse(A = B, 4.0^2, 1/5)
- ifelse(A > B, 'bigger', 'smaller')
Version:

$Revision: 1000 $

Author:

Benjamin Weber ( benweber at student dot ethz dot ch )

Constructor Summary

Constructors
Constructor Description

IfElseMacro()

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Node`	`evaluate(Node... params)`	Evaluates the ifelse macro
`Macro`	`getMacro(java.lang.String name)`	Tries to fetch the macro
`boolean`	`hasMacro(java.lang.String name)`	Whether the macro is declared

Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Constructor Detail
  - IfElseMacro
```
public IfElseMacro()
```
- Method Detail
  - hasMacro
```
public boolean hasMacro(java.lang.String name)
```
    Whether the macro is declared
    
    Specified by:
    
    hasMacro in interface MacroDeclarations
    
    Parameters:
    
    name - name of the macro
    
    Returns:
    
    whether the macro is declared
  - getMacro
```
public Macro getMacro(java.lang.String name)
```
    Tries to fetch the macro
    The same invariant of MacroDeclarations applies here too.
    
    Specified by:
    
    getMacro in interface MacroDeclarations
    
    Parameters:
    
    name - name of the macro
    
    Returns:
    
    a macro
  - evaluate
```
public Node evaluate(Node... params)
              throws SemanticException
```
    Evaluates the ifelse macro
    
    Specified by:
    
    evaluate in interface Macro
    
    Parameters:
    
    params - the parameters
    
    Returns:
    
    an AST (abstract syntax tree) node evaluating the ifelse function
    
    Throws:
    
    SemanticException