weka.core.expressionlanguage.common

Class 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 and Description
MacroDeclarationsCompositor(MacroDeclarations... declarations) Constructs a MacroDeclarationsCompositor containing the provided declarations

Method Summary

Modifier and Type	Method and 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