Improved support for item selector expressions (fix for #124)

plugins/org.eclipse.epsilon.eol.engine/src/org/eclipse/epsilon/eol/dom/AssignmentStatement.java

@@ -9,6 +9,9 @@
 **********************************************************************/
 package org.eclipse.epsilon.eol.dom;
 
+import java.util.List;
+import java.util.Map;
+
 import org.eclipse.epsilon.common.module.IModule;
 import org.eclipse.epsilon.common.parse.AST;
 import org.eclipse.epsilon.eol.exceptions.EolRuntimeException;
@@ -82,6 +85,25 @@ public Object execute(IEolContext context) throws EolRuntimeException {
 				throw eox;
 			}
 		}
+		else if (targetExpression instanceof ItemSelectorExpression) {
+			ItemSelectorExpression ise = (ItemSelectorExpression) targetExpression;
+			Object source = executorFactory.execute(ise.getTargetExpression(), context);
+			Object index = executorFactory.execute(ise.getIndexExpression(), context);
+			valueExpressionResult = executorFactory.execute(valueExpression, context);
+			Object value = getValueEquivalent(source, valueExpressionResult, context);
+
+			if (source instanceof List) {
+				if (!(index instanceof Integer)) 
+					throw new EolRuntimeException("Collection index must be an integer but " + index + " was provided instead.", ise.getIndexExpression());
+				else ((List) source).set((Integer) index, value);
+			}
+			else if (source instanceof Map) {
+				((Map) source).put(index, value);
+			}
+			else {
+				throw new EolRuntimeException(source + " is not a list or a map.", ise.getTargetExpression());
+			}
+		}
 		else {
 			Object targetExpressionResult;
 			if (targetExpression instanceof NameExpression) {

plugins/org.eclipse.epsilon.eol.engine/src/org/eclipse/epsilon/eol/dom/ItemSelectorExpression.java

@@ -10,6 +10,7 @@
 package org.eclipse.epsilon.eol.dom;
 
 import java.util.Collection;
+import java.util.Map;
 
 import org.eclipse.epsilon.common.module.IModule;
 import org.eclipse.epsilon.common.parse.AST;
@@ -40,9 +41,9 @@ public Object execute(IEolContext context) throws EolRuntimeException {
 				throw new EolRuntimeException("Collection index must be an integer but " + index + " was provided instead.", indexExpression);
 			else return CollectionUtil.asList(expression).get((Integer)index);
 		}
-		//else if (expression instanceof EolMap){
-		//	return ((EolMap) expression).get(index);
-		//}
+		else if (expression instanceof Map){
+			return ((Map) expression).get(index);
+		}
 
 		throw new EolRuntimeException(expression + " is not a collection or a map.", targetExpression);
 

tests/org.eclipse.epsilon.eol.engine.test.acceptance/src/org/eclipse/epsilon/eol/engine/test/acceptance/EolAcceptanceTestSuite.java

@@ -88,7 +88,8 @@
 	BreakAndContinueTests.class,
 	EnumResolutionTests.class,
 	CircularImportTests.class,
-	ImportCachingTests.class
+	ImportCachingTests.class,
+	ItemSelectorTests.class
 })
 public class EolAcceptanceTestSuite {
 

tests/org.eclipse.epsilon.eol.engine.test.acceptance/src/org/eclipse/epsilon/eol/engine/test/acceptance/ItemSelectorTests.eol

@@ -0,0 +1,74 @@
+@test
+operation testExistingIndexInSet() {
+	assertEquals(1, Set{1, 2}[0]);
+}
+
+@test
+operation testExistingIndexInSequence() {
+	assertEquals(1, Sequence{1, 2}[0]);
+}
+
+@test
+operation testIndexOutOfBoundsInCollection() {
+	assertError(Sequence{1, 2}[2]);
+}
+
+@test
+operation testExistingKeyInMap() {
+	assertEquals(1, Map{"a" = 1}["a"]);
+}
+
+@test
+operation testExistingKeyInNativeMap() {
+	assertEquals(1, createNativeMap()["a"]);
+}
+
+@test
+operation testUnknownKeyInMap() {
+	assertEquals(null, Map{"a" = 1}["b"]);
+}
+
+@test
+operation testAssignToListIndex() {
+	var s = Sequence{1, 2};
+	s[0] = 3;
+	assertEquals(3, s[0]);
+}
+
+@test
+operation testAssignToExistingMapKey() {
+	var m = Map{"a" = 1};
+	m["a"] = 2;
+	assertEquals(2, m["a"]);
+}
+
+@test
+operation testAssignToExistingNativeMapKey() {
+	var m = createNativeMap();
+	m["a"] = 2;
+	assertEquals(2, m["a"]);
+}
+
+@test
+operation testAssignToNewMapKey() {
+	var m = Map{"a" = 1};
+	m["b"] = 2;
+	assertEquals(2, m["b"]);
+}
+
+@test
+operation testAssignToSetIndex() {
+	assertError(assignToSetIndex());
+}
+
+operation assignToSetIndex() {
+	var s = Set{1, 2};
+	// This is not allowed as Set is not a java.util.List
+	s[0] = 3;
+}
+
+operation createNativeMap() {
+	var m = new Native("java.util.HashMap");
+	m.put("a", 1);
+	return m;
+}

tests/org.eclipse.epsilon.eol.engine.test.acceptance/src/org/eclipse/epsilon/eol/engine/test/acceptance/ItemSelectorTests.java

@@ -0,0 +1,19 @@
+/*******************************************************************************
+ * Copyright (c) 2008 The University of York.
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which is available at https://www.eclipse.org/legal/epl-2.0/
+ *
+ * Contributors:
+ *     Dimitrios Kolovos - initial API and implementation
+******************************************************************************/
+package org.eclipse.epsilon.eol.engine.test.acceptance;
+
+import org.eclipse.epsilon.eol.engine.test.acceptance.eunit.EUnitRunner;
+import org.junit.runner.RunWith;
+
+@RunWith(EUnitRunner.class)
+public class ItemSelectorTests {
+
+}
+