MacroDeclarationsCompositor

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

All Implemented Interfaces:

MacroDeclarations
```
public class MacroDeclarationsCompositor
extends java.lang.Object
implements MacroDeclarations
```
A helper class that allows to combine several macro declarations together.
It can be though of as layering several scopes over one another.
It will delegate the hasMacro(String) and getMacro(String) methods to other macro declarations.
Each macro declaration combined is checked in sequential order.
No checks for conflicts are done. Thus shadowing is possible.

Version:

$Revision: 1000 $

Author:

Benjamin Weber ( benweber at student dot ethz dot ch )

Constructor Summary

Constructors
Constructor Description

MacroDeclarationsCompositor(MacroDeclarations... declarations)
Constructs a MacroDeclarationsCompositor containing the provided declarations

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Macro`	`getMacro(java.lang.String name)`	Tries to fetch a macro from one of the combined declarations.
`boolean`	`hasMacro(java.lang.String name)`	Whether the macro is contained in one of the combined declarations.

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

- Constructor Detail
  - MacroDeclarationsCompositor
```
public MacroDeclarationsCompositor(MacroDeclarations... declarations)
```
    Constructs a MacroDeclarationsCompositor containing the provided declarations
    The order of the declarations will determine the order of checking the declarations for macros.
    
    Parameters:
    
    declarations - the declarations being combined
- Method Detail
  - hasMacro
```
public boolean hasMacro(java.lang.String name)
```
    Whether the macro is contained in one of the combined declarations.
    
    Specified by:
    
    hasMacro in interface MacroDeclarations
    
    Parameters:
    
    name - name of the macro
    
    Returns:
    
    whether the macro is contained in one of the combined declarations
  - getMacro
```
public Macro getMacro(java.lang.String name)
```
    Tries to fetch a macro from one of the combined declarations.
    The same invariant of MacroDeclarations applies here too.
    
    Specified by:
    
    getMacro in interface MacroDeclarations
    
    Parameters:
    
    name - the name of the macro to be fetched
    
    Returns:
    
    a macro