/*
 * JBoss, Home of Professional Open Source.
*
* See the LEGAL.txt file distributed with this work for information regarding copyright ownership and licensing.
*
* See the AUTHORS.txt file distributed with this work for a full listing of individual contributors.
*/
package org.teiid.designer.query.sql;

import org.teiid.designer.query.sql.lang.ILanguageObject;

/**
 *
 */
public interface ISQLStringVisitor<LO extends ILanguageObject> extends ILanguageVisitor {

    /**
     * Should the visitor fail to evaluate then this
     * text is returned
     */
    public static final String UNDEFINED = "<undefined>"; //$NON-NLS-1$
    
    /**
     * Find the string representation of the given object
     * 
     * @param languageObject
     * 
     * @return SQL string
     */
    String returnSQLString(LO languageObject);

    /**
     * Disables comments by adding an id from the given
     * Object to the comments tag set. If any tags exist
     * then comments are disabled. Thus, to re-enable
     * comments the same object should be passed
     * into {@link #enableComments(Object)}
     *
     */
    void disableComments(Object obj);

    /**
     * Only removes the exact id of the object
     * from the comment tag set. Only when
     * the set is empty will comments be
     * re-enabled.
     */
    void enableComments(Object obj);

    /**
     * @param token
     * @return id tokens properly escaped
     */
    String displayName(IToken token);
}