**** BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
License Version 2.0 (the "License"); you may not use this file
except in compliance with the License. You may obtain a copy of
the License at http://www.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2009-2011 Yoko Harada 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
 **** END LICENSE BLOCK *****
/**
 * **** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * License Version 2.0 (the "License"); you may not use this file
 * except in compliance with the License. You may obtain a copy of
 * the License at http://www.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2009-2011 Yoko Harada <yokolet@gmail.com>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 * **** END LICENSE BLOCK *****
 */
package org.jruby.embed.variable;

import org.jruby.embed.internal.BiVariableMap;
import org.jruby.RubyObject;

An implementation of BiVariable for a transient local variable. This type of
a local variable is available during only one evaluation. After the evaluation,
the variable vanishes.
Author:
Yoko Harada /**
 * An implementation of BiVariable for a transient local variable. This type of
 * a local variable is available during only one evaluation. After the evaluation,
 * the variable vanishes.
 *
 * @author Yoko Harada <yokolet@gmail.com>
 */
public class TransientLocalVariable extends AbstractVariable {

    private static final String VALID_NAME = "([a-z]|_)([a-zA-Z]|_|\\d)*";

    
Returns an instance of this class. This factory method is used when a transient local variable is put in BiVariableMap. 
Params:
runtime – Ruby runtime
name – a variable name
javaObject – Java object that should be assigned to.
Returns:
the instance of TransientLocalVariable/**
     * Returns an instance of this class. This factory method is used when a
     * transient local variable is put in {@link BiVariableMap}.
     *
     * @param runtime Ruby runtime
     * @param name a variable name
     * @param javaObject Java object that should be assigned to.
     * @return the instance of TransientLocalVariable
     */
    public static BiVariable getInstance(RubyObject receiver, String name, Object... javaObject) {
        if (name.matches(VALID_NAME)) {
            return new TransientLocalVariable(receiver, name, javaObject);
        }
        return null;
    }

    private TransientLocalVariable(RubyObject receiver, String name, Object... javaObjects) {
        super(receiver, name, false);
        updateByJavaObject(receiver.getRuntime(), javaObjects);
    }

    
Returns enum type of this variable defined in BiVariable. 
Returns:
this enum type, BiVariable.Type.LocalVariable./**
     * Returns enum type of this variable defined in {@link BiVariable}.
     *
     * @return this enum type, BiVariable.Type.LocalVariable.
     */
    @Override
    public Type getType() {
        return Type.LocalVariable;
    }

    
Returns true if the given name is a decent Ruby local variable. Unless
returns false.
Params:
name – is a name to be checked.
Returns:
true if the given name is of a Ruby local variable./**
     * Returns true if the given name is a decent Ruby local variable. Unless
     * returns false.
     *
     * @param name is a name to be checked.
     * @return true if the given name is of a Ruby local variable.
     */
    public static boolean isValidName(Object name) {
        return isValidName(VALID_NAME, name);
    }

    
Doesn't do anything since a transient local variable should not be retrieved
from Ruby.
Params:
runtime – Ruby runtime
receiver – receiver object returned when a script is evaluated.
vars – map to save retrieved local variables./**
     * Doesn't do anything since a transient local variable should not be retrieved
     * from Ruby.
     *
     * @param runtime Ruby runtime
     * @param receiver receiver object returned when a script is evaluated.
     * @param vars map to save retrieved local variables.
     */
    public static void retrieve(RubyObject receiver, BiVariableMap vars) {
        // Does nothing. This type of variavles never survive over evaluations.
    }

    
Injects a local variable value to a parsed Ruby script. This method is
invoked during EvalUnit#run() is executed.
/**
     * Injects a local variable value to a parsed Ruby script. This method is
     * invoked during EvalUnit#run() is executed.
     */
    @Override
    public void inject() {
        //done in BiVariableMap.inject()
    }

    
Attempts to remove this variable from top self or receiver.
/**
     * Attempts to remove this variable from top self or receiver.
     *
     */
    @Override
    public void remove() {
        // local variables won't survice over the eval on runime.
        // no need to remove lvar from runtime
        /*
        ThreadContext context = receiver.getRuntime().getCurrentContext();
        try {
            DynamicScope currentScope = context.getCurrentScope();
            ManyVarsDynamicScope scope = (ManyVarsDynamicScope) context.getCurrentScope();
            scope = new ManyVarsDynamicScope(StaticScope.newEvalScope(currentScope.getStaticScope()), currentScope);
        } catch (ArrayIndexOutOfBoundsException e) {
            //no context is left.
            //no operation is needed.
        }*/
    }
}