[463225] Create new IInterpreter instances for expression validation

The expression validation uses a specific singleton instead of
CompoundInterpreter.INSTANCE to provide the guarante the IInterpreter
instance configuration regarding metamodels/scope/imported classes is
correctly set for each expression.

The expected result is that for every call to analyze/validateExpression
the IInterpreter instance has been configured *from the outside* based
on the IInterpreterContext. When a new context requires a configuration
update, the IInterpreter is reconfigured.

Why still a singleton ? to pass a MultiLanguagesValidator instance
around on all those calls would require major API breaks in many places
(DialectService, SiriusInterpreterContextFactory and
IInterpretedExpressionTargetSwitch among others)

Bug: 463225
Change-Id: I2595abdead85dbb2b77a5d7fd1f287a20857479d
Signed-off-by: Cedric Brun <cedric.brun@obeo.fr>

11 files changed, 291 insertions, 46 deletions

diff --git a/plugins/org.eclipse.sirius.common.acceleo.aql/src/org/eclipse/sirius/common/acceleo/aql/business/internal/AQLSiriusInterpreter.java b/plugins/org.eclipse.sirius.common.acceleo.aql/src/org/eclipse/sirius/common/acceleo/aql/business/internal/AQLSiriusInterpreter.java
index 78baef0c6d..b9e9171884 100644
--- a/plugins/org.eclipse.sirius.common.acceleo.aql/src/org/eclipse/sirius/common/acceleo/aql/business/internal/AQLSiriusInterpreter.java
+++ b/plugins/org.eclipse.sirius.common.acceleo.aql/src/org/eclipse/sirius/common/acceleo/aql/business/internal/AQLSiriusInterpreter.java
@@ -44,7 +44,6 @@ import org.eclipse.acceleo.query.validation.type.EClassifierType;
 import org.eclipse.acceleo.query.validation.type.IType;
 import org.eclipse.core.runtime.IStatus;
 import org.eclipse.core.runtime.Status;
-import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EPackage;
 import org.eclipse.emf.ecore.EPackage.Registry;
@@ -222,33 +221,11 @@ public class AQLSiriusInterpreter extends AcceleoAbstractInterpreter {
     @Override
     public ValidationResult analyzeExpression(IInterpreterContext context, String fullExpression) {
 
-        /*
-         * use the VSM resource to declare dependent project/bundles.
-         */
-        EObject vsmElement = context.getElement();
-        if (vsmElement.eResource() != null && vsmElement.eResource().getURI() != null && vsmElement.eResource().getURI().segmentCount() >= 2) {
-            URI vsmURI = vsmElement.eResource().getURI();
-            String bundleOrProjectName = vsmURI.segment(1);
-            if (vsmURI.isPlatformResource()) {
-                javaExtensions.updateScope(Sets.<String> newHashSet(), Sets.newHashSet(bundleOrProjectName));
-            } else if (vsmURI.isPlatformPlugin()) {
-                javaExtensions.updateScope(Sets.newHashSet(bundleOrProjectName), Sets.<String> newHashSet());
-            }
-        }
-
         String trimmedExpression = new ExpressionTrimmer(fullExpression).getExpression();
-
         ValidationResult result = new ValidationResult();
-        for (EPackage pak : context.getAvailableEPackages()) {
-            if (pak != null) {
-                queryEnvironment.registerEPackage(pak);
-            }
-        }
+
         Map<String, Set<IType>> variableTypes = TypesUtil.createAQLVariableTypesFromInterpreterContext(context, queryEnvironment);
 
-        for (String dependency : context.getDependencies()) {
-            addImport(dependency);
-        }
         QueryValidationEngine validator = new QueryValidationEngine(this.queryEnvironment);
         try {
             IValidationResult validationResult = validator.validate(trimmedExpression, variableTypes);
diff --git a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/CompoundInterpreter.java b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/CompoundInterpreter.java
index ba77ce8d6d..ef362596d9 100644
--- a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/CompoundInterpreter.java
+++ b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/CompoundInterpreter.java
@@ -18,6 +18,7 @@ import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Map;
+import java.util.Map.Entry;
 import java.util.Set;
 
 import org.eclipse.core.runtime.CoreException;
@@ -97,6 +98,8 @@ public final class CompoundInterpreter implements IInterpreter, IProposalProvide
      */
     private boolean extensionsLoaded;
 
+    private Map<Object, Object> properties;
+
     /**
      * The default constructor.
      */
@@ -106,6 +109,7 @@ public final class CompoundInterpreter implements IInterpreter, IProposalProvide
         this.dependencies = new LinkedList<String>();
         this.listeners = new ArrayList<IVariableStatusListener>();
         this.interpreterIdentifiers = Maps.newHashMap();
+        this.properties = Maps.newHashMap();
     }
 
     /**
@@ -282,6 +286,10 @@ public final class CompoundInterpreter implements IInterpreter, IProposalProvide
             result = this.providers.get(provider);
             if (result == null) {
                 result = provider.createInterpreter();
+                for (Entry<Object, Object> entry : this.properties.entrySet()) {
+                    result.setProperty(entry.getKey(), entry.getValue());
+                }
+                result.activateMetamodels(additionalMetamodels);
                 this.variableManager.setVariables(result);
                 for (final String dependency : this.dependencies) {
                     result.addImport(dependency);
@@ -426,6 +434,7 @@ public final class CompoundInterpreter implements IInterpreter, IProposalProvide
      *      java.lang.Object)
      */
     public void setProperty(final Object key, final Object value) {
+        this.properties.put(key, value);
         for (final IInterpreter interpreter : this.providers.values()) {
             if (interpreter != null) {
                 interpreter.setProperty(key, value);
@@ -461,6 +470,8 @@ public final class CompoundInterpreter implements IInterpreter, IProposalProvide
         this.variableManager.clearVariables();
         this.dependencies.clear();
         this.providers.clear();
+        this.properties.clear();
+        this.additionalMetamodels.clear();
         this.extensionsLoaded = false;
         this.modelAccessor = null;
     }
diff --git a/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/IInterpreterContextUtils.java b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/IInterpreterContextUtils.java
new file mode 100644
index 0000000000..6882452634
--- /dev/null
+++ b/plugins/org.eclipse.sirius.common/src/org/eclipse/sirius/common/tools/api/interpreter/IInterpreterContextUtils.java
@@ -0,0 +1,132 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Obeo.
+ * 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:
+ *    Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.common.tools.api.interpreter;
+
+import java.util.Collection;
+import java.util.Set;
+
+import org.eclipse.emf.common.util.URI;
+import org.eclipse.emf.ecore.EObject;
+import org.eclipse.emf.ecore.EPackage;
+import org.eclipse.emf.ecore.resource.Resource;
+import org.eclipse.sirius.common.tools.api.util.StringUtil;
+import org.eclipse.sirius.ecore.extender.business.api.accessor.EcoreMetamodelDescriptor;
+import org.eclipse.sirius.ecore.extender.business.api.accessor.MetamodelDescriptor;
+
+import com.google.common.collect.Sets;
+
+/**
+ * Utility methods for working with IInterpreterContexts.
+ * 
+ * @author <a href="mailto:cedric.brun@obeo.fr">Cedric Brun</a>
+ *
+ */
+public final class IInterpreterContextUtils {
+
+    private IInterpreterContextUtils() {
+
+    }
+
+    /**
+     * Configure the given {@link IInterpreter} instance with the metamodels,
+     * dependencies and scope settings provided by the
+     * {@link IInterpreterContext}.
+     * 
+     * @param interpreter
+     *            the interpreter to configure.
+     * @param context
+     *            the context holding the settings.
+     */
+    public static void configureInterpreter(IInterpreter interpreter, IInterpreterContext context) {
+        Set<String> projectsOrBundleInScope = collectProjectsOrPlugins(context);
+        interpreter.setProperty(IInterpreter.FILES, projectsOrBundleInScope);
+
+        Collection<MetamodelDescriptor> availableMetamodels = Sets.newLinkedHashSet();
+        for (EPackage pak : context.getAvailableEPackages()) {
+            if (pak != null && pak.eResource() != null) {
+                availableMetamodels.add(new EcoreMetamodelDescriptor(pak));
+            }
+        }
+        interpreter.activateMetamodels(availableMetamodels);
+
+        interpreter.clearImports();
+        for (String dependency : context.getDependencies()) {
+            interpreter.addImport(dependency);
+        }
+
+    }
+
+    static Set<String> collectProjectsOrPlugins(IInterpreterContext context) {
+        /*
+         * use the VSM resource to declare dependent project/bundles.
+         */
+        EObject vsmElement = context.getElement();
+        Set<String> projectsOrBundleInScope = Sets.newLinkedHashSet();
+        if (vsmElement != null && vsmElement.eResource() != null) {
+            collectProjectName(vsmElement.eResource(), projectsOrBundleInScope);
+            if (vsmElement.eResource().getResourceSet() != null) {
+                for (Resource other : vsmElement.eResource().getResourceSet().getResources()) {
+                    if (other != vsmElement.eResource()) {
+                        collectProjectName(other, projectsOrBundleInScope);
+                    }
+                }
+            }
+        }
+        return projectsOrBundleInScope;
+    }
+
+    private static void collectProjectName(Resource eResource, Set<String> projectsOrBundleInScope) {
+        if (eResource.getURI() != null && eResource.getURI().segmentCount() >= 2) {
+            URI vsmURI = eResource.getURI();
+            String bundleOrProjectName = vsmURI.segment(1);
+            if (!StringUtil.isEmpty(bundleOrProjectName)) {
+                projectsOrBundleInScope.add(bundleOrProjectName);
+            }
+
+        }
+    }
+
+    /**
+     * Utility method to compare two contexts in order to detect if it is
+     * necessary to re-configure an {@link IInterpreter}.
+     * 
+     * Only the information related to the search scope of an IInterpreter are
+     * compared : the available metamodels, the imported classes, the available
+     * EPackages.
+     * 
+     * @param a
+     *            a context.
+     * @param b
+     *            another context.
+     * @return true if both context have the same scope definition, false
+     *         otherwise.
+     */
+    public static boolean haveSameScopeDefinition(IInterpreterContext a, IInterpreterContext b) {
+        Set<String> aDependencies = Sets.newLinkedHashSet(a.getDependencies());
+        Set<String> bDependencies = Sets.newLinkedHashSet(b.getDependencies());
+        Set<String> aNSURI = collectNSUris(a);
+        Set<String> bNSURI = collectNSUris(b);
+        Set<String> aProjects = collectProjectsOrPlugins(a);
+        Set<String> bProjects = collectProjectsOrPlugins(b);
+        return aDependencies.equals(bDependencies) && aNSURI.equals(bNSURI) && aProjects.equals(bProjects);
+    }
+
+    private static Set<String> collectNSUris(IInterpreterContext a) {
+        Set<String> aNSURI = Sets.newLinkedHashSet();
+        for (EPackage pak : a.getAvailableEPackages()) {
+            String nsURI = pak.getNsURI();
+            if (!StringUtil.isEmpty(nsURI)) {
+                aNSURI.add(nsURI);
+            }
+        }
+        return aNSURI;
+    }
+}
diff --git a/plugins/org.eclipse.sirius.doc/doc/Release Notes.html b/plugins/org.eclipse.sirius.doc/doc/Release Notes.html
index d40dd1e496..ba486a23c7 100644
--- a/plugins/org.eclipse.sirius.doc/doc/Release Notes.html
+++ b/plugins/org.eclipse.sirius.doc/doc/Release Notes.html
@@ -273,6 +273,14 @@
 			<li>The class 
 				<code>org.eclipse.sirius.common.tools.api.interpreter.VariableType</code> has been introduced to represent the possible types a variable can have in a Viewpoint specification model.
 			</li>
+			<li>The utility class 
+				<code>org.eclipse.sirius.common.tools.api.interpreter.IInterpreterContextUtils</code> has been introduced to factorize code related to managing 
+				<code>IInterpreterContext</code> instances.
+			</li>
+			<li>The class 
+				<code>org.eclipse.sirius.business.api.dialect.description.MultiLanguagesValidator</code> has been introduced to provide a safe and more efficient way to switch to the proper 
+				<code>IInterpreter</code> instance when validating expressions.
+			</li>
 		</ul>
 		<h4 id="Changesinorg.eclipse.sirius.common.ui">Changes in 
 			<code>org.eclipse.sirius.common.ui</code>
diff --git a/plugins/org.eclipse.sirius.doc/doc/Release Notes.textile b/plugins/org.eclipse.sirius.doc/doc/Release Notes.textile
index 82c5f8aa62..592f0dcbaa 100644
--- a/plugins/org.eclipse.sirius.doc/doc/Release Notes.textile
+++ b/plugins/org.eclipse.sirius.doc/doc/Release Notes.textile
@@ -76,6 +76,8 @@ h4. Changes in @org.eclipse.sirius.common@
 * The class @org.eclipse.sirius.common.tools.api.interpreter.TypeName@ has been introduced to represent in the codebase any type which was previously represented as a plain String.
 * A new interface @org.eclipse.sirius.common.tools.api.interpreter.TypedValidation@ has been introduced for @IInterpreter@ implementations able to provide richer information when validating an expression. This information is captured through a @org.eclipse.sirius.common.tools.api.interpreter.ValidationResult@ instance.
 * The class @org.eclipse.sirius.common.tools.api.interpreter.VariableType@ has been introduced to represent the possible types a variable can have in a Viewpoint specification model.
+* The utility class @org.eclipse.sirius.common.tools.api.interpreter.IInterpreterContextUtils@ has been introduced to factorize code related to managing @IInterpreterContext@ instances.
+* The class @org.eclipse.sirius.business.api.dialect.description.MultiLanguagesValidator@ has been introduced to provide a safe and more efficient way to switch to the proper @IInterpreter@ instance when validating expressions.
 
 h4. Changes in @org.eclipse.sirius.common.ui@
 
diff --git a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/interpreter/acceleo/mtl/IInterpreterValidationExpressionTest.java b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/interpreter/acceleo/mtl/IInterpreterValidationExpressionTest.java
index 1c2f611c69..026d0fb3dd 100644
--- a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/interpreter/acceleo/mtl/IInterpreterValidationExpressionTest.java
+++ b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/common/interpreter/acceleo/mtl/IInterpreterValidationExpressionTest.java
@@ -120,7 +120,7 @@ public class IInterpreterValidationExpressionTest extends SiriusDiagramTestCase
         odesignEditor = page.openEditor(new FileEditorInput(odesignFile), "org.eclipse.sirius.editor.editorPlugin.SiriusEditorID");
 
         ResourceSet rs = new ResourceSetImpl();
-        Resource r = rs.getResource(URI.createURI(odesignFile.getLocationURI().toString()), true);
+        Resource r = rs.getResource(URI.createPlatformResourceURI(odesignFile.getFullPath().toOSString(), true), true);
         // A CrossReferenceAdapter is needed for validation to work. In the
         // standard VSM editor, one is installed on the constructor (see
         // org.eclipse.sirius.editor.tools.internal.presentation.CustomSiriusEditor.CustomSiriusEditor()).
diff --git a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/diagram/vsm/VSMValidationTest.java b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/diagram/vsm/VSMValidationTest.java
index d2dbadbadd..12ded3a2f8 100644
--- a/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/diagram/vsm/VSMValidationTest.java
+++ b/plugins/org.eclipse.sirius.tests.junit/src/org/eclipse/sirius/tests/unit/diagram/vsm/VSMValidationTest.java
@@ -26,6 +26,10 @@ import org.eclipse.sirius.tests.support.api.EclipseTestsSupportHelper;
 import org.eclipse.sirius.tests.support.api.SiriusDiagramTestCase;
 import org.eclipse.sirius.viewpoint.description.Group;
 
+import com.google.common.base.Function;
+import com.google.common.base.Joiner;
+import com.google.common.collect.Iterables;
+
 /**
  * Test VSM validation. VP-2506, VP-2475, VP-3836
  * 
@@ -191,8 +195,17 @@ public class VSMValidationTest extends SiriusDiagramTestCase {
                 "^The image '  /org.eclipse.sirius.tests.junit/images/logo_o.png   ' does not exist.$", "^The image '/test/noimage.gif' does not exist.$",
                 "^The path 'icon' does not correspond to an image.$", "^The image 'icon' does not exist.$", "^The path '/org.eclipse.sirius.tests.junit/plugin.xml' does not correspond to an image.$",
                 "^The image 'C:\\\\images\\\\image.png' does not exist.$", "^The image '/org.eclipse.sirius.tests.junit/images/notexisting.png' does not exist.$",
-                "^The required feature 'decoratorPath' of 'org.eclipse.sirius.viewpoint.description.impl.SemanticBasedDecorationImpl@.*' must be set$", };
-        assertEquals("The diagnostic must contain " + expectedMessagesPatterns.length + " validation errors", expectedMessagesPatterns.length, children.size());
+                "^The required feature 'decoratorPath' of 'org.eclipse.sirius.viewpoint.description.impl.SemanticBasedDecorationImpl@.*' must be set$"};
+        
+        assertEquals(
+                "The diagnostic must contain " + expectedMessagesPatterns.length + " validation errors. Returned messages were :\n"
+                        + Joiner.on('\n').join(Iterables.transform(children, new Function<Diagnostic, String>() {
+
+                            @Override
+                            public String apply(Diagnostic input) {
+                                return input.getMessage();
+                            }
+                        })), expectedMessagesPatterns.length, children.size());
         for (int i = 0; i < expectedMessagesPatterns.length; i++) {
             assertTrue("Unexpected validation error at position " + i, children.get(i).getMessage().matches(expectedMessagesPatterns[i]));
         }
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/AbstractInterpretedExpressionQuery.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/AbstractInterpretedExpressionQuery.java
index d6fdcc4637..aa7a60fdad 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/AbstractInterpretedExpressionQuery.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/AbstractInterpretedExpressionQuery.java
@@ -23,11 +23,8 @@ import org.eclipse.emf.ecore.EPackage;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.emf.ecore.EcorePackage;
 import org.eclipse.sirius.business.api.query.EObjectQuery;
-import org.eclipse.sirius.common.tools.api.interpreter.CompoundInterpreter;
-import org.eclipse.sirius.common.tools.api.interpreter.IInterpreter;
 import org.eclipse.sirius.common.tools.api.interpreter.IInterpreterContext;
 import org.eclipse.sirius.common.tools.api.interpreter.TypeName;
-import org.eclipse.sirius.common.tools.api.interpreter.TypedValidation;
 import org.eclipse.sirius.common.tools.api.interpreter.ValidationResult;
 import org.eclipse.sirius.common.tools.api.interpreter.VariableType;
 import org.eclipse.sirius.common.tools.api.util.StringUtil;
@@ -364,15 +361,10 @@ public abstract class AbstractInterpretedExpressionQuery implements IInterpreted
             appendAllLocalVariableDefinitions(definitions, context);
             if (context instanceof ChangeContext && context != bottom) {
                 ChangeContext f = (ChangeContext) context;
-
-                IInterpreter interpreterForExpression = CompoundInterpreter.INSTANCE.getInterpreterForExpression(f.getBrowseExpression());
-
-                if (interpreterForExpression.supportsValidation() && interpreterForExpression instanceof TypedValidation) {
-                    IInterpreterContext iContext = SiriusInterpreterContextFactory.createInterpreterContext(f, ToolPackage.Literals.CHANGE_CONTEXT__BROWSE_EXPRESSION);
-                    ValidationResult res = ((TypedValidation) interpreterForExpression).analyzeExpression(iContext, f.getBrowseExpression());
-                    VariableType returnTypes = res.getReturnTypes();
-                    changeSelfType(definitions, returnTypes);
-                }
+                IInterpreterContext iContext = SiriusInterpreterContextFactory.createInterpreterContext(f, ToolPackage.Literals.CHANGE_CONTEXT__BROWSE_EXPRESSION);
+                ValidationResult res = MultiLanguagesValidator.getInstance().validateExpression(iContext, f.getBrowseExpression());
+                VariableType returnTypes = res.getReturnTypes();
+                changeSelfType(definitions, returnTypes);
 
             }
             if (context instanceof CreateInstance) {
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/MultiLanguagesValidator.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/MultiLanguagesValidator.java
new file mode 100644
index 0000000000..a1d8c4c5c8
--- /dev/null
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/business/api/dialect/description/MultiLanguagesValidator.java
@@ -0,0 +1,109 @@
+/*******************************************************************************
+ * Copyright (c) 2015 Obeo.
+ * 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:
+ *    Obeo - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.sirius.business.api.dialect.description;
+
+import org.eclipse.sirius.common.tools.api.interpreter.CompoundInterpreter;
+import org.eclipse.sirius.common.tools.api.interpreter.IInterpreter;
+import org.eclipse.sirius.common.tools.api.interpreter.IInterpreterContext;
+import org.eclipse.sirius.common.tools.api.interpreter.IInterpreterContextUtils;
+import org.eclipse.sirius.common.tools.api.interpreter.TypedValidation;
+import org.eclipse.sirius.common.tools.api.interpreter.ValidationResult;
+
+/**
+ * A common entry point to get validation for all the {@link IInterpreter}. The
+ * actual {@link IInterpreter} implementation which is going to be call depends
+ * on the given expression. This class guarantees that when the context changes,
+ * the IInterpreter's configuration regarding available metamodels or imported
+ * classes will be adapted.
+ * 
+ * @author <a href="mailto:cedric.brun@obeo.fr">Cedric Brun</a>
+ *
+ */
+public final class MultiLanguagesValidator {
+
+    private IInterpreter currentInterpreter;
+
+    private IInterpreterContext currentContext;
+
+    /**
+     * Analyze the expression and provide a validation result. This method will
+     * dynamically re-configure the required interpreter based on the given
+     * context.
+     * 
+     * @param context
+     *            the {@link IInterpreterContext} to use for validating this
+     *            expression
+     * @param expression
+     *            the expression to analyze
+     * @return the validation result.
+     */
+    public ValidationResult validateExpression(IInterpreterContext context, String expression) {
+        IInterpreter interpreter = provide(context, expression);
+        ValidationResult result = new ValidationResult();
+        if (interpreter instanceof TypedValidation) {
+            result = ((TypedValidation) interpreter).analyzeExpression(context, expression);
+        } else if (interpreter != null && interpreter.supportsValidation()) {
+            result.addAllStatus(interpreter.validateExpression(context, expression));
+        }
+        return result;
+    }
+
+    private IInterpreter provide(IInterpreterContext context, String expression) {
+        if (currentContext == null) {
+            createNewInterpreter(context, expression);
+        } else {
+            if (!IInterpreterContextUtils.haveSameScopeDefinition(context, currentContext)) {
+                if (currentInterpreter != null) {
+                    currentInterpreter.dispose();
+                }
+                createNewInterpreter(context, expression);
+            }
+        }
+
+        return currentInterpreter;
+    }
+
+    void createNewInterpreter(IInterpreterContext context, String expression) {
+        currentContext = context;
+        currentInterpreter = CompoundInterpreter.createGenericInterpreter();
+        IInterpreterContextUtils.configureInterpreter(currentInterpreter, context);
+    }
+
+    /**
+     * Clear any internal state which would have been kept.
+     */
+    public void dispose() {
+        if (this.currentInterpreter != null) {
+            this.currentInterpreter.dispose();
+            this.currentInterpreter = null;
+        }
+        if (this.currentContext != null) {
+            this.currentContext = null;
+        }
+    }
+
+    /**
+     * Returns the shared instance.
+     * 
+     * @return the global viewpoints registry.
+     */
+    public static MultiLanguagesValidator getInstance() {
+        return MultiLanguagesValidatorHolder.instance;
+    }
+
+    private static class MultiLanguagesValidatorHolder {
+        private static MultiLanguagesValidator instance;
+        static {
+            instance = new MultiLanguagesValidator();
+        }
+    }
+
+}
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/tools/internal/validation/description/constraints/ValidInterpretedExpressionConstraint.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/tools/internal/validation/description/constraints/ValidInterpretedExpressionConstraint.java
index 4813a67bdb..d31faf88c1 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/tools/internal/validation/description/constraints/ValidInterpretedExpressionConstraint.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/tools/internal/validation/description/constraints/ValidInterpretedExpressionConstraint.java
@@ -19,10 +19,10 @@ import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EStructuralFeature;
 import org.eclipse.emf.validation.IValidationContext;
 import org.eclipse.emf.validation.model.ConstraintStatus;
-import org.eclipse.sirius.common.tools.api.interpreter.CompoundInterpreter;
-import org.eclipse.sirius.common.tools.api.interpreter.IInterpreter;
+import org.eclipse.sirius.business.api.dialect.description.MultiLanguagesValidator;
 import org.eclipse.sirius.common.tools.api.interpreter.IInterpreterContext;
 import org.eclipse.sirius.common.tools.api.interpreter.IInterpreterStatus;
+import org.eclipse.sirius.common.tools.api.util.StringUtil;
 import org.eclipse.sirius.tools.api.interpreter.context.SiriusInterpreterContextFactory;
 import org.eclipse.sirius.tools.internal.validation.AbstractConstraint;
 import org.eclipse.sirius.viewpoint.description.DescriptionPackage;
@@ -74,13 +74,11 @@ public class ValidInterpretedExpressionConstraint extends AbstractConstraint {
 
     private IStatus checkExpression(IValidationContext ctx, EObject target, EStructuralFeature feature) {
         String expression = (String) target.eGet(feature);
-        IInterpreter interpreterForExpression = CompoundInterpreter.INSTANCE.getInterpreterForExpression(expression);
 
         Collection<IInterpreterStatus> errors = Sets.newLinkedHashSet();
-        if (interpreterForExpression.supportsValidation()) {
+        if (!StringUtil.isEmpty(expression)) {
             IInterpreterContext context = SiriusInterpreterContextFactory.createInterpreterContext(target, feature);
-
-            errors = interpreterForExpression.validateExpression(context, expression);
+            errors = MultiLanguagesValidator.getInstance().validateExpression(context, expression).getStatuses();
         }
 
         if (errors.isEmpty()) {
@@ -101,4 +99,5 @@ public class ValidInterpretedExpressionConstraint extends AbstractConstraint {
         }
         return returnStatus;
     }
+
 }
diff --git a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/viewpoint/SiriusPlugin.java b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/viewpoint/SiriusPlugin.java
index 7a59a36e8c..22a5c551bc 100644
--- a/plugins/org.eclipse.sirius/src/org/eclipse/sirius/viewpoint/SiriusPlugin.java
+++ b/plugins/org.eclipse.sirius/src/org/eclipse/sirius/viewpoint/SiriusPlugin.java
@@ -19,6 +19,7 @@ import org.eclipse.emf.common.util.ResourceLocator;
 import org.eclipse.emf.ecore.EValidator;
 import org.eclipse.emf.ecore.plugin.EcorePlugin;
 import org.eclipse.sirius.business.api.componentization.ViewpointRegistry;
+import org.eclipse.sirius.business.api.dialect.description.MultiLanguagesValidator;
 import org.eclipse.sirius.business.api.helper.SiriusUtil;
 import org.eclipse.sirius.business.internal.helper.delete.DeleteHookDescriptorRegistryListener;
 import org.eclipse.sirius.business.internal.session.factory.SessionFactoryRegistryListener;
@@ -158,7 +159,8 @@ public final class SiriusPlugin extends EMFPlugin {
             javaActionRegistryListener = null;
 
             ViewpointRegistry.getInstance().dispose();
-
+            
+            MultiLanguagesValidator.getInstance().dispose();
             super.stop(context);
         }