JS inline: added invocation utils

js/js.inliner/src/org/jetbrains/k2js/inline/InvocationUtil.java

@@ -0,0 +1,75 @@
+/*
+ * Copyright 2010-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.k2js.inline;
+
+import com.google.dart.compiler.backend.js.ast.*;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+
+import java.util.List;
+
+class InvocationUtil {
+
+    /**
+     * Tests if result of call is being used in containing statement
+     */
+    public static boolean isResultUsed(JsStatement containingStatement, JsInvocation call) {
+        return !(containingStatement instanceof JsExpressionStatement)
+               || call != ((JsExpressionStatement) containingStatement).getExpression();
+    }
+
+    @Nullable
+    public static JsName getName(@NotNull JsInvocation call) {
+        JsExpression qualifier = call.getQualifier();
+        if (qualifier instanceof JsNameRef) {
+            return ((JsNameRef) qualifier).getName();
+        }
+
+        return null;
+    }
+
+    /**
+     * Gets inner function from function, that creates closure
+     *
+     * For example:
+     * function(a) {
+     *   return function() { return a; }
+     * }
+     *
+     * Inner functions can only be generated when lambda
+     * with closure is created
+     */
+    @Nullable
+    public static JsFunction getInnerFunction(@NotNull JsFunction outer) {
+        List<JsStatement> statements = outer.getBody().getStatements();
+        if (statements.size() != 1) {
+            return null;
+        }
+
+        JsStatement statement = statements.get(0);
+        if (!(statement instanceof JsReturn)) {
+            return null;
+        }
+
+        JsExpression returnExpr = ((JsReturn) statement).getExpression();
+        if (!(returnExpr instanceof JsFunction)) {
+            return null;
+        }
+
+        return (JsFunction) returnExpr;
+    }
+}