VariableDeclarationsCompositor

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

All Implemented Interfaces:

java.io.Serializable, VariableDeclarations
```
public class VariableDeclarationsCompositor
extends java.lang.Object
implements VariableDeclarations
```
A helper class that allows to combine several variable declarations together.
It can be thought of as layering several scopes over one another.
It will delegate the hasVariable(String) and getVariable(String) methods to other variable declarations.
Each variable 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 )

See Also:

Serialized Form

Constructor Summary

Constructors
Constructor	Description
`VariableDeclarationsCompositor(VariableDeclarations... declarations)`	Constructs a `VariableDeclarationsCompositor` containing the provided declarations

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`Node`	`getVariable(java.lang.String name)`	Tries to fetch a variable from one of the combined declarations.
`boolean`	`hasVariable(java.lang.String name)`	Whether the variable 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
  - VariableDeclarationsCompositor
```
public VariableDeclarationsCompositor(VariableDeclarations... declarations)
```
    Constructs a VariableDeclarationsCompositor containing the provided declarations
    The order of the declarations will determine the order of checking the declarations for variables.
    
    Parameters:
    
    declarations - the declarations being combined
- Method Detail
  - hasVariable
```
public boolean hasVariable(java.lang.String name)
```
    Whether the variable is contained in one of the combined declarations.
    
    Specified by:
    
    hasVariable in interface VariableDeclarations
    
    Parameters:
    
    name - name of the variable
    
    Returns:
    
    whether the variable is contained in one of the combined declarations
  - getVariable
```
public Node getVariable(java.lang.String name)
```
    Tries to fetch a variable from one of the combined declarations.
    The same invariant of VariableDeclarations applies here too.
    
    Specified by:
    
    getVariable in interface VariableDeclarations
    
    Parameters:
    
    name - the name of the variable to be fetched
    
    Returns:
    
    an AST (abstract syntax tree) node representing the variable