/*
 * Copyright (c) 2005, 2007 IBM Corporation and others.
 * All rights reserved.   This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *   IBM - initial API and implementation
 *
 * $Id: Expression.java,v 1.10 2007/10/23 15:54:21 jbruck Exp $
 */
package org.eclipse.uml2.uml;

import org.eclipse.emf.common.util.EList;

import org.eclipse.emf.ecore.EClass;

/**
 * <!-- begin-user-doc -->
 * A representation of the model object '<em><b>Expression</b></em>'.
 * <!-- end-user-doc -->
 *
 * <!-- begin-model-doc -->
 * An expression is a structured tree of symbols that denotes a (possibly empty) set of values when evaluated in a context.
 * An expression represents a node in an expression tree, which may be non-terminal or terminal. It defines a symbol, and has a possibly empty sequence of operands which are value specifications.
 * <!-- end-model-doc -->
 *
 * <p>
 * The following features are supported:
 * <ul>
 *   <li>{@link org.eclipse.uml2.uml.Expression#getSymbol <em>Symbol</em>}</li>
 *   <li>{@link org.eclipse.uml2.uml.Expression#getOperands <em>Operand</em>}</li>
 * </ul>
 * </p>
 *
 * @see org.eclipse.uml2.uml.UMLPackage#getExpression()
 * @model
 * @generated
 */
public interface Expression
		extends ValueSpecification {

	/**
	 * Returns the value of the '<em><b>Symbol</b></em>' attribute.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * <!-- begin-model-doc -->
	 * The symbol associated with the node in the expression tree.
	 * <!-- end-model-doc -->
	 * @return the value of the '<em>Symbol</em>' attribute.
	 * @see #isSetSymbol()
	 * @see #unsetSymbol()
	 * @see #setSymbol(String)
	 * @see org.eclipse.uml2.uml.UMLPackage#getExpression_Symbol()
	 * @model unsettable="true" dataType="org.eclipse.uml2.uml.String" ordered="false"
	 * @generated
	 */
	String getSymbol();

	/**
	 * Sets the value of the '{@link org.eclipse.uml2.uml.Expression#getSymbol <em>Symbol</em>}' attribute.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @param value the new value of the '<em>Symbol</em>' attribute.
	 * @see #isSetSymbol()
	 * @see #unsetSymbol()
	 * @see #getSymbol()
	 * @generated
	 */
	void setSymbol(String value);

	/**
	 * Unsets the value of the '{@link org.eclipse.uml2.uml.Expression#getSymbol <em>Symbol</em>}' attribute.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @see #isSetSymbol()
	 * @see #getSymbol()
	 * @see #setSymbol(String)
	 * @generated
	 */
	void unsetSymbol();

	/**
	 * Returns whether the value of the '{@link org.eclipse.uml2.uml.Expression#getSymbol <em>Symbol</em>}' attribute is set.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @return whether the value of the '<em>Symbol</em>' attribute is set.
	 * @see #unsetSymbol()
	 * @see #getSymbol()
	 * @see #setSymbol(String)
	 * @generated
	 */
	boolean isSetSymbol();

	/**
	 * Returns the value of the '<em><b>Operand</b></em>' containment reference list.
	 * The list contents are of type {@link org.eclipse.uml2.uml.ValueSpecification}.
	 * <p>
	 * This feature subsets the following features:
	 * <ul>
	 *   <li>'{@link org.eclipse.uml2.uml.Element#getOwnedElements() <em>Owned Element</em>}'</li>
	 * </ul>
	 * </p>
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * <!-- begin-model-doc -->
	 * Specifies a sequence of operands.
	 * <!-- end-model-doc -->
	 * @return the value of the '<em>Operand</em>' containment reference list.
	 * @see org.eclipse.uml2.uml.UMLPackage#getExpression_Operand()
	 * @model containment="true" resolveProxies="true"
	 * @generated
	 */
	EList<ValueSpecification> getOperands();

	/**
	 * Creates a new {@link org.eclipse.uml2.uml.ValueSpecification}, with the specified '<em><b>Name</b></em>', and '<em><b>Type</b></em>', and appends it to the '<em><b>Operand</b></em>' containment reference list.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @param name The '<em><b>Name</b></em>' for the new {@link org.eclipse.uml2.uml.ValueSpecification}, or <code>null</code>.
	 * @param type The '<em><b>Type</b></em>' for the new {@link org.eclipse.uml2.uml.ValueSpecification}, or <code>null</code>.
	 * @param eClass The Ecore class of the {@link org.eclipse.uml2.uml.ValueSpecification} to create.
	 * @return The new {@link org.eclipse.uml2.uml.ValueSpecification}.
	 * @see #getOperands()
	 * @generated
	 */
	ValueSpecification createOperand(String name, Type type, EClass eClass);

	/**
	 * Retrieves the first {@link org.eclipse.uml2.uml.ValueSpecification} with the specified '<em><b>Name</b></em>', and '<em><b>Type</b></em>' from the '<em><b>Operand</b></em>' containment reference list.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @param name The '<em><b>Name</b></em>' of the {@link org.eclipse.uml2.uml.ValueSpecification} to retrieve, or <code>null</code>.
	 * @param type The '<em><b>Type</b></em>' of the {@link org.eclipse.uml2.uml.ValueSpecification} to retrieve, or <code>null</code>.
	 * @return The first {@link org.eclipse.uml2.uml.ValueSpecification} with the specified '<em><b>Name</b></em>', and '<em><b>Type</b></em>', or <code>null</code>.
	 * @see #getOperands()
	 * @generated
	 */
	ValueSpecification getOperand(String name, Type type);

	/**
	 * Retrieves the first {@link org.eclipse.uml2.uml.ValueSpecification} with the specified '<em><b>Name</b></em>', and '<em><b>Type</b></em>' from the '<em><b>Operand</b></em>' containment reference list.
	 * <!-- begin-user-doc -->
	 * <!-- end-user-doc -->
	 * @param name The '<em><b>Name</b></em>' of the {@link org.eclipse.uml2.uml.ValueSpecification} to retrieve, or <code>null</code>.
	 * @param type The '<em><b>Type</b></em>' of the {@link org.eclipse.uml2.uml.ValueSpecification} to retrieve, or <code>null</code>.
	 * @param ignoreCase Whether to ignore case in {@link java.lang.String} comparisons.
	 * @param eClass The Ecore class of the {@link org.eclipse.uml2.uml.ValueSpecification} to retrieve, or <code>null</code>.
	 * @param createOnDemand Whether to create a {@link org.eclipse.uml2.uml.ValueSpecification} on demand if not found.
	 * @return The first {@link org.eclipse.uml2.uml.ValueSpecification} with the specified '<em><b>Name</b></em>', and '<em><b>Type</b></em>', or <code>null</code>.
	 * @see #getOperands()
	 * @generated
	 */
	ValueSpecification getOperand(String name, Type type, boolean ignoreCase,
			EClass eClass, boolean createOnDemand);

} // Expression