VariableDeclarations (weka-dev 3.9.7 API)

All Superinterfaces:

Serializable

All Known Implementing Classes:

InstancesHelper, NoVariables, SimpleVariableDeclarations, StatsHelper, VariableDeclarationsCompositor
```
public interface VariableDeclarations
extends Serializable
```
Interface to expose variables to a program.
It is deliberately kept very simple to give as little constraints as possible to implementations.
There is an implied invariant here:
hasVariable(String) == true -> getVariable(String) != null
hasVariable(String) should be pure i.e. have no side effects.
Whereas getVariable(String) may have side effects.
(This is useful for creating variables on the fly in getVariable(String))

Version:

$Revision: 1000 $

Author:

Benjamin Weber ( benweber at student dot ethz dot ch )

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`Node`	`getVariable(String name)`	Tries to fetch a variable
`boolean`	`hasVariable(String name)`	Whether the variable is declared

- Method Detail
  - hasVariable
```
boolean hasVariable(String name)
```
    Whether the variable is declared
    
    Parameters:
    
    name - name of the variable being queried
    
    Returns:
    
    whether the variable is declared
  - getVariable
```
Node getVariable(String name)
```
    Tries to fetch a variable
    Before a variable is fetched it should be checked whether it is declared through hasVariable(String).
    
    Parameters:
    
    name - name of the variable to be fetched
    
    Returns:
    
    an AST (abstract syntax tree) node representing the variable