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/*******************************************************************************
* Copyright (c) 2005, 2007 committers of openArchitectureWare 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:
* committers of openArchitectureWare - initial API and implementation
*******************************************************************************/
package org.eclipse.internal.xtend.expression.ast;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.eclipse.xtend.expression.AnalysationIssue;
import org.eclipse.xtend.expression.ExecutionContext;
import org.eclipse.xtend.expression.ExpressionFacade;
import org.eclipse.xtend.typesystem.Type;
/**
* @author Sven Efftinge (http://www.efftinge.de)
* @author Arno Haase
* @author Bernd Kolb
*/
public class SwitchExpression extends Expression {
private Expression switchExpr = null;
private Expression defaultExpr = null;
private List<Case> cases = null;
public SwitchExpression(final Expression switchExpr, final List<Case> cases, final Expression defaultExpr) {
this.switchExpr = switchExpr;
this.cases = cases;
this.defaultExpr = defaultExpr;
}
@Override
protected Object evaluateInternal(final ExecutionContext ctx) {
Object switchVal = Boolean.TRUE;
if (switchExpr != null) {
switchVal = switchExpr.evaluate(ctx);
}
for (final Iterator<Case> iter = cases.iterator(); iter.hasNext();) {
final Case c = iter.next();
final Object caseCondVal = c.getCondition().evaluate(ctx);
if ((switchVal != null && equals(switchVal, caseCondVal, ctx)) || switchVal == caseCondVal)
return c.getThenPart().evaluate(ctx);
}
return defaultExpr.evaluate(ctx);
}
private boolean equals(Object switchVal, final Object caseCondVal, ExecutionContext ctx) {
Map<String, Object> props = new HashMap<String, Object>();
props.put("swtch", switchVal);
props.put("cse", caseCondVal);
return (Boolean) new ExpressionFacade(ctx).evaluate("swtch==cse", props);
}
@Override
public Type analyzeInternal(final ExecutionContext ctx, final Set<AnalysationIssue> issues) {
Type condType = ctx.getBooleanType();
if (switchExpr != null) {
condType = switchExpr.analyze(ctx, issues);
}
if (condType == null)
return null;
Type returnType = defaultExpr.analyze(ctx, issues);
if (returnType == null)
return null;
for (final Iterator<Case> iter = cases.iterator(); iter.hasNext();) {
final Case c = iter.next();
final Type caseCondType = c.getCondition().analyze(ctx, issues);
if (caseCondType != null) {
if (!condType.isAssignableFrom(caseCondType)) {
issues.add(new AnalysationIssue(AnalysationIssue.INCOMPATIBLE_TYPES, condType.getName()
+ " expected!", c.getCondition()));
}
}
final Type caseThenType = c.getThenPart().analyze(ctx, issues);
if (caseThenType != null) {
if (!returnType.isAssignableFrom(caseThenType)) {
if (caseThenType.isAssignableFrom(returnType)) {
returnType = caseThenType;
}
else {
returnType = ctx.getObjectType();
}
}
}
}
return returnType;
}
public List<Case> getCases() {
return cases;
}
public Expression getDefaultExpr() {
return defaultExpr;
}
public Expression getSwitchExpr() {
return switchExpr;
}
@Override
protected String toStringInternal() {
return "switch " + switchExpr.toStringInternal();
}
}
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