Implement "Alias" to support feature request

#16

Author: yanntm

Diff for: fr.lip6.move.gal/src/fr/lip6/move/Gal.xtext

@@ -59,6 +59,7 @@ GALTypeDeclaration:
 	(typedefs+=TypedefDeclaration)
 	|(variables+=VariableDeclaration) 
 	|(arrays+=ArrayDeclaration) 
+	|(alias+=AliasDeclaration)
 //	|(lists+=ListDeclaration)
 	)*
 	(transitions+=Transition 
@@ -93,7 +94,7 @@ TemplateTypeDeclaration  :
 
 /* ============ GAL System Content ================== */
 
-NamedDeclaration : VarDecl | InstanceDecl ;
+NamedDeclaration : VarDecl | InstanceDecl | AliasDeclaration;
 
 VarDecl :
 	VariableDeclaration | ArrayDeclaration
@@ -103,6 +104,10 @@ InstanceDecl :
 	InstanceDeclaration | ArrayInstanceDeclaration
 ;
 
+AliasDeclaration :
+	'alias' name=FullyQualifiedName '=' expr=BitOr 
+;
+
 //Ex: int abc = 10 ; 
 VariableDeclaration returns Variable:
 	(comment=COMMENT)?

Diff for: fr.lip6.move.gal/src/fr/lip6/move/gal/instantiate/Instantiator.java

@@ -22,6 +22,7 @@
 import org.eclipse.emf.ecore.util.EcoreUtil;
 
 import fr.lip6.move.gal.AbstractParameter;
+import fr.lip6.move.gal.AliasDeclaration;
 import fr.lip6.move.gal.ArrayInstanceDeclaration;
 import fr.lip6.move.gal.Assignment;
 import fr.lip6.move.gal.Event;
@@ -409,6 +410,7 @@ private static void initializeParametersAndVariables(TypeDeclaration type) {
 		//first substitute const param by value
 		// replace all parameters by values
 		int nbsub = replaceConstParam(type);
+		nbsub += replaceAlias(type);
 		if (nbsub > 0) {
 			Simplifier.simplifyAllExpressions(type);
 		}
@@ -441,6 +443,29 @@ private static void initializeParametersAndVariables(TypeDeclaration type) {
 
 	}
 
+	private static int replaceAlias(TypeDeclaration type) {
+		int nbsub = 0;
+		if (type instanceof GALTypeDeclaration) {
+			GALTypeDeclaration gal = (GALTypeDeclaration) type;			
+			if (! gal.getAlias().isEmpty()) {				
+				for (TreeIterator<EObject> it = gal.eAllContents() ; it.hasNext() ; ) {
+					EObject obj = it.next();
+					if (obj instanceof VariableReference) {
+						VariableReference ref = (VariableReference) obj;
+						if (ref.getRef() instanceof AliasDeclaration) {
+							AliasDeclaration alias = (AliasDeclaration) ref.getRef();
+							EcoreUtil.replace(obj, EcoreUtil.copy(alias.getExpr()));
+							it.prune();
+							nbsub++;
+						}
+					}
+				}
+				gal.getAlias().clear();
+			}			
+		}
+		return nbsub;
+	}
+
 	private static int replaceConstParam(EObject parent) {
 		int nbsub = 0;
 		for (TreeIterator<EObject> it = parent.eAllContents() ; it.hasNext() ; ) {

Diff for: fr.lip6.move.gal/src/fr/lip6/move/scoping/GalScopeProvider.java

@@ -482,6 +482,7 @@ private static IScope getVars(TypeDeclaration type) {
 			List<EObject> res = new ArrayList<EObject>();
 			res.addAll(gal.getVariables());
 			res.addAll(gal.getArrays());
+			res.addAll(gal.getAlias());
 			return Scopes.scopeFor(res);
 		}
 		if (type instanceof CompositeTypeDeclaration) {